Open Hand Project


Shipping Complete

The last few months have been very exciting for the Open Hand Project. We've been working extremely hard to deliver all of the hands out to our generous backers and we're happy to announce that this has now been completed. All of the hands have now been sent out and the open source files have been released on our website, which is the final milestone for the Open Hand Project Indiegogo campaign.

We were lucky enough to meet one of our backers, Nicolas Hutchet, in person and get some feedback from him on using his hand. He picked up the muscle control very quickly and was soon picking up cups and shaking hands.

We were also fortunate to catch up with Liam on the phone after he received his Dextrus hand and he had wonderful things to say about it. He was able to get it working very quickly and had a lot of fun showing off his new hand to his children. If you're an Open Hand Project backer that received a robotic hand, let us know how you get on with it!

Over the last two years the Open Hand Project has evolved dramatically. It started with me slaving away on my own at my desk making cool robotic hands but without totally understanding the needs of the amputees that would use them. Since then I've joined together with a team of great people and we've spent a lot of time co-designing hands and functions with amputees. Co-design and collaboration is a far better problem-solving practice!

This will be the last post on the Open Hand Project website but please keep following us! Open Bionics will carry the torch forward and continue developing robotic hands for amputees. You can follow the blog here, or keep up-to-date on Twitter or Facebook. These prosthetic designs will still be open source and designs will be shared online as new developments are made.

Thanks for being a part of this fantastic journey and please keep in touch as we push this technology forward. The Open Hand Project was the catalyst to a huge movement in the prosthetics industry. The Dextrus hand has already enabled biomedical engineers around the world to contribute some award-winning research on EMG control to the medical industry. The Dextrus has also enabled students to develop academic robotics projects both in the US and UK. Over the next few years we'll see the ideas and developments put into practice with amputees in the real world. The Dextrus hand has also been printed in the US for a wounded marine and an amputee in Ecuador. Makers are using the work you funded to have a real impact on people's lives! Thank you for enabling this.

E-Nable Conference

Check out our awesome latest robotic hand design! We've been working really hard lately trying to iron out the last few creases in the design. Things like making sure the tendons don't come off the spools when the fingers are moving and ensuring the connection to the motor shaft won't weaken after heavy use. The hand is working really nicely now, all of the electronics are working on our custom circuit board and everything looks a lot neater. Final tweaks will be to do with how the parts fit together, ensuring the screws don't get in the way of the internal mechanisms and putting a cover on the back of the hand! These should be completed in the next couple of weeks and then We'll be making up the hands ready to send them out. I ordered the motors weeks ago, which have the longest lead time of all the components and these should arrive just as we finish printing the first batch of 5 hands.

We've also been working very hard on the Intel Make It Wearable competition. We're a finalist now and the workload this brings with it is quite substantial. As part of the finals, we've been enrolled in an intense accelerator program with the UC Berkely Haas School of Business. It's been quite heartbreaking to put some of our developments on hold to make sure we're completing all that's required of us but in the long term this will certainly help us with our ultimate goal of providing low-cost prosthetic hands. Part of the program involves us speaking to as many amputees as possible and getting their views and insights into how they wear and use prosthetics. This has been invaluable in making sure we meet their needs. What's more, we have the opportunity to win a further $500,000 in funding to push these devices out to amputees, so I do hope our very kind and patient backers understand why it's necessary for us to do this.

This weekend Lulzbot, who make my awesome TAZ 3D printer, sponsored me to fly to the e-Nable conference in Baltimore in Maryland, USA. If you're not familiar with e-Nable, check out their website here. The organisation is a network of passionate volunteers that 3D print body powered prosthetic hands for children with upper limb differences. The really cool thing about the model behind their idea is that everything is free and voluntary, it relies on makers making hands, families travelling to have them fitted and several committed volunteers organising everything and making sure the kids end up with a smile on their faces! I had the honour of meeting the folks behind this organisation and many of the children that have been fitted with e-Nable hands. Of course I took our hand designs over to show off and the kids absolutely loved them, I was asked if I could make robotic hands for them and one young lad called Luke even requested a robotic tentacle! We should be testing our hands with amputees over the next few weeks and as we do I hope everyone that has supported us so far will feel as much pride and accomplishment as I do.

We're working with some designers to make some really cool looking hand designs for children, when it comes round to selling the devices in the near future, we plan to start with a hand for kids. Children are particularly under-served by the prosthetics industry because since they grow so fast, the have to have replacement prosthetics made very frequently and the cost of this becomes overwhelming. We think this is an area where we can make a particularly powerful change and help many families that have been saving for years to try and buy a hand for their child. In the mean time, we point them to e-Nable, and if there's anyone in the UK that needs one of these hands printed, let us know and we will be more than happy to do it.

Posted by Joel on 07/10/2014

Make It Wearable Finals!

We've made it the finals of the Intel Make It Wearable competition! This means $50k prize money and the chance to win the $500k grand prize! I entered the competition as Open Bionics, however, since it relates only to the wearable side of the robotic hands, all of this money will go towards prosthetic development (i.e. the Open Hand Project). As well as the money, the prize also includes an incubation program with UC Berkley. It's going to be a lot of work over the next few weeks, but it should pay off even if we don't eventually win the competition as there will be loads of teaching on product design and business!

As for the Dextrus hand, we've made some great progress in the last few weeks. We've got the circuit boards working and controlling the motors, all that needs to be done now is a few more tweaks on the hand design and for the code to be written. I've enlisted the help of an embedded software developer that I work with at the Bristol Robotics Lab so we'll be working on this over the next few weeks. The aim is to get the Dextrus hands sent out before the end of the Make It Wearable competition and have some useful feedback about how they're working!

Posted by Joel on 29/08/2014

Open Bionics Takes on its First Intern!

Open Bionics (my new company that is now running the Open Hand Project) has taken on its first employee! Jonathan is a graduate mechanical engineer from the University of Bristol and is working with me for the next 4 weeks.

Development projects like this can often be subjects of a phenomena known as "feature creep" where the developer can't stop innovating; adding new features and improving their designs. I'm trying to avoid this by pushing forward with my current design and letting Jonathan explore some of the more experimental ideas for the future. He's only been here for a few days and has already contributed some hugely valuable work to both the current design and future ideas!

The circuit boards have now been printed and are in the process of being assembled by a Bristol-based electronics design company called Cubik innovation.

I first met Cubik at Bristol Venturefest 2013 where I won their £1000 spend voucher with the Open Hand Project! Cubik have been helping by passing their expert eyes over the circuit designs, making invaluable observations and using their experience to make sure the electronics will work well in the hand. I have a personal soft spot for Cubik, since they recruit from the University of Plymouth (of which I'm an alumni). This year I visited the University of Plymouth for their engineering project fair and bumped into Paul Mullen (founder of Cubik) as he was perusing the projects looking for new talent to bring into his company.

Last week Open Bionics was visited by Vince Cable who is the Secretary of State for Business, Innovation and Skills here in the UK on his way around the Bristol Robotics Laboratory. I told him all about the Open Hand Project and at the end of his visit, he announced that the BRL will be getting £4.5 million funding to help turn research into manufacturing. More about that here. This will directly affect the Open Hand Project in the future, as I hope to remain in the BRL as long as possible and will benefit from the facilities that this funding pays for.

Posted by Joel on 10/07/2014

Dextrus 1.2

For the last few weeks I've been finishing up designing the latest hand, the Dextrus 1.2. It has a host of new improvements from the previous one that are mainly centered around improving the gripping performance and making the hand more robust. This should be the penultimate iteration of the design before the indiegogo one is completed and sent out to backers.

Here's what I've changed for this version:

I've started using steel inserts throughout the design. These nifty little components are heat fitted into the plastic. You design your part with a hole in and then press the insert in with a soldeering iron. It conducts the heat to melt the plastic immediately around it and then once it's in place, you leave the plastic to cool and harden and the insert is perfectly fitted. These parts mean I don't need large bolts that go all the way through the hand and make for a neater external finish that doesn't require nuts on the other side.

The spools have been altered to incorperate the inserts. I now use the inserts with a grub screw to fasten the spool onto the motor shaft and this creates an extremely strong connection which seems to hold up well to being back driven (when you force move the fingers). This has also meant I can make the spool diameter smaller, increasing the torque each finger can provide by around 1.4x and giving the hand a stronger grip.

The fingers now have a rubbery coating made from 3D printed Ninjaflex. This replaces the previous method of using plastidip. The problem with the plastidip coating was that it wore off too easily and didn't bond that well to the plastic. Using Ninjaflex means the fingers can be far more precisely covered and they can be created using just one manufacturing process (3D printing) eliminating the need for dipping.

The thumb connection has been completely redesigned to make its movement more anatomically accurate and to make it look a lot neater, this should make the hand better at grasping.

What's Next?
Next I'm going to test the hands more thoroughly. I'll finally be making the video with the hand grasping all sorts of different objects as per the indiegogo £5 pledge level. I'm also planning to test the hand for endurance, strength and performance as well as doing some real world testing with amputees and research robots. After that I'll review the design and make any necessary adjustments, make it look a little cooler and start assembling the hands for the fantastic indiegogo backers!

Posted by Joel on 12/06/2014

OHP Wins £10K!

A few weeks ago I was made aware of a competition being run by Intuit where small businesses could submit a couple of sentences and a photo about their business and the public could then vote and what they thought was the most deserving business. There were 10 prizes of £1000 and a grand prize of £10000. Naturally I entered the competition, which took 5 minutes, and then posted it to Facebook and Twitter appealing for votes and forgot about it, assuming that I wouldn't have a great chance of winning anything.

Low and behold you guys, the followers of my work, came through emphatically garnering me enough votes to come out on top as the grand prize winner of the competition! So the Open Hand Project has won £10k and can (at the very least) last a little longer! With this money I'm hoping to start looking towards selling hands through my newly formed company Open Bionics and give some longevity to this project and it's ambitions. I would therefore like to extend a huge thank you to everyone that voted for the Open Hand Project in the competition and to Intuit, who were kind enough to run it and help so many small business get off the ground. Intuit invited me to their headquaters on London where I proudly received a comically large cheque and delivered an impromptue Q and A around my work. They were very nice people and showed me Quickbooks, their accountancy software for small businesses, which I've since started using and have been very impressed with. You can see their blog post and more photos here.

In other news, you remember that TEDx talk that I was rambling on about a few weeks ago? Well they've uploaded it on YouTube now so if you want to hear me ramble on for another 10 minutes you can take a look here!

Posted by Joel on 06/05/2014

Flexible Filament (Technical)

This is a technical post, technical posts are a little more in depth than regular updates and may require specific technical knowledge to understand fully.

The 3D capabilities of desktop 3D printers are increasing all the time, and one of the latest developments is in the materials that they can use. I've been messing around with flexible filaments; these materials print just like normal filament, but they come out rubbery and flexible. They can be extremely strong and open up a huge new range of things that can be made. Now you can make tyres for your toy car, a flexible phone case or even flip flops! I'm going to use this for making grippy and spongy fingertips for the hand.

There are two main flexible filaments, Filaflex, made by Recreus and Ninjaflex (I'm not sure who makes this). I've tried them both out to see what they're like but before starting, I had to make some adjustments to my 3D printer. When the filament can flex, you can run into problems trying to push the filament down into the extruder. Where a solid plastic filament can just be pushed down into the hot end, a flexible filament is prone to folding and buckling when being pushed. To rectify this, the hot end entrance hole needs to be right up against the extruder drive gear so there is no room for buckling. This is problem is summed up well here. I solved the problem by drilling out my extruder hole and inserting a PTFE tube that I shaped to be really close to the drive gear of the extruder and allow no room for buckling. You can see this in the first photo. This alteration has no affect on the ability to print plastics, so is a nice little upgrade to increase the printer's capabilites.

Having tried the two filaments I conclude that Ninjaflex will suit my needs better than Filaflex. Here's are some more details.


Filaflex is very rubbery and flexible and has a slightly grippier texture then ninjaflex. I tested it printing at 190, 205 and 220 degrees and found 205 to be the best temperature. For this filament to work with a conventional extruder (like mine) it needs to be printed extremely slowly at around 5mm/s. I expect you can print faster if you follow the advice on the Recreus website and get a hot end with a better flow. The material comes out nice and grippy and it seems it's slightly grippier went printed at lower temperatures. This filament is extremely oozey and is constantly falling out of the hot end. In consequence you need to print it with a skirt of around 6 loops to normalise the pressure in the hot end. Once you've got it extruding reliably it prints very well and creates very nice looking parts with superb layer adhesion.


Ninjaflex is a little less rubbery than filaflex and extrudes much nicer, it's less oozey and I was able to print it faster at around 20mm/s (although it worked best at 10mm/s). It won't extrude at 190 degrees and works best at about 210 degrees. The surface finish seems to be just as grippy regardless of the temperature and is slightly less grippy than filaflex. At lower temperatures (205 degrees) it has a matt surface finish and it's glossy at 210 degrees or more. I think it's the better material of the two because it is so much easier to work with. It Extrudes very nicely and reliably and prints more quickly than Filaflex.

I found the best way for me to print the fingertips was to use the flat first layer as the pad of the fingertip as this gave the grippiest surface. The layers then give it a cool fingerprint effect which should look nice. I used a "concentric" fill pattern for the top and bottom layers to exagerate this effect. I always used a heated bed at 60 degrees and printed onto PET tape. First layer adhesion was never an issue.

Both of these materials offer huge benefits and really open up the possiblities of desktop 3D printing, the more materials we have, the more things can be 100% 3D printed. This is a big deal because we move closer and closer to a future where you can just print stuff off and use it. Imagine you have a machine that is loaded with raw materials that can make anything; your phone, your TV, your cutlery, your clothing... I'll post again once I've designed some fingertips and put them onto the fingers.

Posted by Joel on 01/04/2014


Back in October I was invited to come along and speak at the 2014 TEDxExeter conference. For those of you that are unfamiliar with TED (Technology, Entertainment and Design), it's a nonprofit organisation that shares "Ideas worth Spreading" through talks from innovative people. I highly recommend exploring their site if you haven't before, there's something for everyone. A TEDx event is an independantly organised event that licenses the TED brand and speaking framework and TEDx talks can be selected to go on the highly viewed homepage of the TED website.

I met some really cool people there, including slam poet Harry Baker, who gave a funny performance of some of his award winning poems, and Ann Daniels, house-wife turned record-breaking polar explorer! I gave a talk about my story so far, how I got into robotics and what I plan to do through the Open Hand Project, I'll let you know once my talk goes online so you can have a watch. What's more, I unveiled my latest hand (pictured right), which I've been developing over the last few weeks. It has a few improvements on the "Indiegogo" version, the fingers are much more robust and easy to assemble and I've redesigned the tensioner system with new components to make it work considerably more reliably.

The next step is to get all of the electronics working and give the thumb and hand a bit of a re-vamp to make them look and work better.

Posted by Joel on 31/03/2014

3D Printing Essentials

Several weeks ago I was given "Blender 3D Printing Essentials" by the kind folks at Packt Publishing to read and offer my opinions on. So here they are, along with a few tips of my own on how to apply blender modelling to 3D printing!

When using a 3D printer you can print any 3D object that has been designed in Computer Aided Design (CAD) software. Websites like Thingiverse offer an extensive resource of 3D objects that you can print, but often you'll want to design your own objects and you'll have to use some CAD software to do so. My software of choice is Blender, which is a cutting edge, free and open source CAD software. It's completely flexible and you can make literally anything with it once you know how to use it (which takes some time).

Once you're a proficient computer modeller you may still have problems with designing for 3D printing. There are certain things that you need to consider when designing an object that will actually be made, compared with designing an object that will only ever appear on a computer screen. Blender 3D printing essentials is a guide that shows you exactly what you need to do to design objects for the real world. As well is introducing the problems and restraints that you will face, it also gives many valuable tips and tricks to make design in Blender smoother and more efficient.

As with all practical material when reading this book it's important to make sure you follow all of the tutorials at the same time on your computer to make sure you retain the information. It's a good idea to follow them a couple of times to get used to the processes that are introduced. I found the tutorials highly relevant and for me the instructions were in just the right amount of detail. You should have basic blender modelling skills to use this book and if you do, I'm sure you will find the tutorials just the right level of depth.

The book introduces new tools that the average blender user won't be familiar with, and applies them in a way that is specifically aimed at 3D printing. I've found since reading Blender 3D Printing Essentials that I have been using many of the tips regularly, such as making use of the 3D printing add-on to check the integrity of objects before sending them to the printer. This can save hours because you can often know before printing whether or not an object is likely to fail. Another asset was learning how to apply real world measurements to your blender models. For me this helps to make sure parts will fit together properly with real world components.

This book would certainly provide value for anyone using Blender for 3D printing design, even if they are already a highly proficient modeller.

Posted by Joel on 01/03/2014

New Home

The Open Hand Project has found a new home! I'm now working out of the Bristol Robotics Laboratory (BRL) in their business incubator. It's a fantastic opportunity since I'll be working alongside other start-up businesses, roboticists and innovators.

The BRL is the leading and largest academic centre for multi-disciplinary robotics research in the UK. It has produced some fantastic projects such as the Shrewbot robotic shrew and the TACTIP tactile fingertip for robotic hands. I'm confident that this environment will help to accelerate and diversify the development of the Open Hand Project and lead to a better product.

Posted by Joel on 18/02/2014

New Website

The new website is up and running. I hope you like it. It has been developed from scratch which makes it more flexible and easier to edit. I've now finished packaging all of the lower level perks and the last ones are being sent out today.

The mechanical design of the hand is moving forward, I'm going back to using ball bearings for a smoother and more robust joint mechanism. I have worked out a way of using just one bearing per joint and doing away with nuts and bolts in favour of metal dowels to maintain the smoother aesthetic and save on weight and cost. Next I'm going to try creating some mechanical compliance in the "splay" plane of the fingers so that if they are bashed on something they won't break.

Posted by Joel on 21/01/2014

Perks in Progress

It’s been too long since I’ve posted an update, for which I apologize. These last few weeks I have been dealing with a lot of admin related things in preparation for beginning the next stage of development of the hand. The Perks are gradually being fulfilled. All of the gloves have been sent out now and I have had most of the responses I need to begin sending out the other perks. This evening I’m going to start a small 3D printing production line to print out all of the 3D printed rewards. None of the items are particularly large so should only take around 10 minutes to print each and I should be able to do everything in a few days.

I’ve been making contacts around Bristol to try and make sure the project has a future and all of the wonderful contributions haven’t gone to waste! The ultimate plan is to create a company and sell the hands. While forming a charity and subsidizing the distribution of the hands sounds like an attractive option, my personal opinion is that it’s better to operate as a company if at all possible. Turning over a small profit rather than relying on donations all of the time. This is how I plan to advance the Open Hand Project in the future.

I have added a “donate” button to the homepage of this website at the request of a few people that have heard about the Open Hand Project since the end of the crowd-funding campaign.

The next stage of development will be to make the first version of the electronics for the hand, which will enable it to work independently from the computer. Another challenge is going to be making the hand robust enough for every day use, not only must its components not wear out too quickly through normal usage, but it must be resilient to bashing against surfaces during day-to-day use.

IndieGoGo Funding

The indiegogo campaign has finished and we made it! Everyone that has followed along the way knows how exciting, stressful and draining this has been but it’s all been worth while and it feels incredible to have the validation that this level of public support brings, as well as the money. I’ve been told by several people that this was a particularly exciting and nail biting campaign so I wanted to share how I succeeded and the triumphs and mistakes that I made along the way. If you’re just stopping by, just take a glance at this graph of the funding being raised.


At the beginning I tried to post my campaign on Kickstarter (yes you read that right). Kickstarter is the most successful crowd-funding website and Indiegogo’s main competitor. I had spent a long time investigating crowd-funding and how to approach it. I decided the best platform was Kickstarter (based on the funding statistics) and then created and submitted my campaign. Unlike Indiegogo, Kickstarter has a rigorous moderation process and a lot of terms and conditions that you have to meet in order to get onto the site. I already knew of this term:

No bath, beauty, and cosmetic products; electronic surveillance equipment; eyewear (sunglasses, prescription glasses, and others); firearms, weapons, knives, weapon accessories, and replicas of weapons; medical, health, safety, and personal care products; or infomercial-type products.

I naively thought that they might bypass this. The Dextrus hand is a medical/health product but I suppose it is arguable in some ways. I thought if they saw potential in the project they would be more relaxed about the guidelines. This was not the case. They rejected the submission, which probably turned out to be a good thing.

Since it took over a week to get rejected by Kickstarter, I was very anxious to get my project out on Indiegogo. By this point I had no money left and still had to last another month and that was assuming I was going to succeed. Luckily there is no moderation on indiegogo, once you’re ready, you just begin your campaign. I started mine on September 4th with a duration of 35 days.

Week 1

The first couple of days went quite well and were primarily friends and family, it’s these folks that you should be relying on at the start of the campaign to help get things moving. It became obvious very quickly that I was never going to get the £1114 every day to progress linearly towards the target. About 5 days in I started to get some media recognition from technology blogs like Wired and Techcrunch. I expected this to snowball rapidly and that it would be easy from then on. I have personally read most of these blogs for the last 5 years or so and when a story gets out at one location, it usually filters through many other websites quite quickly. This didn’t seem to happen as smoothly as I wanted. I kept at it and continued to e-mail everyone I could possibly think of.

Week 2

After about 10 days of the campaign, around September 13th, I had my first mental setback. Looking at my backers I realized that no-one was really going for the hand perks. This makes perfect sense in hindsight; I’m an unknown developer making promises about what will be created in the next year. It’s a huge risk to pledge so much money for a product that is still in development and many people would want to wait until after the development to make their decision. The reason I had set the goal quite high in the first place was to make up for the very low profit margins on the hand perks. I realized that this was the wrong way to approach the fund-raising, I should have gone for a lower target, kept the higher profit margins on the smaller perks and not offered any hands.

I did what I could, I rearranged the perks so that I was offering far fewer hands, and introduced many more perks at the lower values of between £10 and £100. I believe this decision was pivotal to the success of the project. I couldn’t lower the goal, but I improved my chances of making it. I also took some time to improve the design of my campaign page which I think is very important. People will only share something they like themselves. If the campaign doesn’t come across professional, it won’t get shared.

Week 3

The mid section of the campaign went slowly as expected, but the campaign was still well behind the mark. The initial boost from personal contacts should have been higher than it had been. The mistake I made here was focusing on the big media at the start of the campaign. It would have been far more effective to start as small as possible and work outwards. Something like this:

Family Friends Colleagues Social Networks Local News Niche News National News.

My approach was more like the opposite of that. Many of my personal contacts contributed in the final week or two of the campaign, not because they were lazy, but because only then had they seen me on the local news and heard more about the project.

When it came to around half way through the campaign (September 22nd) the project was on just 17% of the target. If people believe it is going to fail, they will not contribute and this was the point when I really felt like the project was in danger. I had even spoken with a friend about the possibility of him “loaning” me a large contribution to boost the total but decided against it at the last minute as I felt it was dishonest.

Luckily on this day I had an extremely generous and important £1k contribution, which elevated the total significantly and helped to raise mine and everyone else’s spirits. It was also at this point that I started identifying the relationship between funders and money raised. It sounds blindingly obvious, but there is a very precise relationship between number of funders and amount raised.

It’s documented that the average pledge for a crowd-funding campaign is around £39. The average for mine was £40.70; all I needed was to get more funders and the money would come. As soon as I realized this I stopped thinking about the money and just tried to get people behind the project. I called friends on the phone, I started posting updates on indiegogo and social media a couple of times a day and I was chatting to everyone I could trying to get people on board. This was hugely effective, saying to people “hey see if you can get a couple of friends involved” is far more achievable than thinking about a £39k goal. That was something people could really get on board with and it was quite touching to see how much people cared about the success of the project and helped to share it around their networks. Some of these were friends but many I had never met before.

From then on it was all about growth. More funders meant more potential referrers and more exposure on indiegogo through the “gogo factor”. I discovered that you can significantly increase your gogo factor by adding people to the team. I promptly multiplied my team from 1 to 11 people. They all had some small involvement but really it is just me doing this project. This jumped me from the 280th most popular project to the 30th or so in a day.

Week 4

The next week went significantly better than the previous two, progression was much better and I had some great media exposure from the BBC, but it was going too slowly to reach the target. To try and encourage more growth, I introduced the referral contest, which indiegogo facilitates very well, but it didn’t really work. I think that’s because I was offering cash prizes and people didn’t want to be seen to be promoting the project to try and win cash. Some people really did pick it up though and the prizes will have been well worth while when I give them out soon!

Another week passed at much the same rate as the previous one, steady progress but still short of the mark. I needed to re-energize everyone that had been frantically sharing and could now see that it was a bit touch and go. I had had an idea to make a hand for kids, but hadn’t wanted to publicize it until I had something working. I realized this was something people would really want to see, and would really help them stay motivated promoting the project so I set to work designing it. I began designing at about 9am and worked for a solid 14 hours to create the Iron man kids hand shown in Figure 2.

After that I just threw a video together and posted it online the next day. This went down extremely well and helped with the media exposure.

Week 5

Going into the final week of the campaign everything was still very uncertain. This turned out to be media week for me, when I had a different interview every day. The two most significant were BBC Bristol/Points West, and ITV West which were both set up through old school friends that I should have nagged more right at the start of the campaign. These helped massively towards the end and on Saturday 5th October we raised nearly £7k. The project was by no means certain at this point and I thought that (like with the previous media appearances) the burst of funds would stop there.

I had been speaking with an indiegogo representative who had said that I could extend the project if I wanted to, and I asked him at this point when my deadline would be for making this difficult decision. He gave me a time and I wanted to leave it as long as possible to see if the project looked like it would make the deadline, I only wanted to extend it if it was absolutely necessary. When the time came we were still around £11k short of the deadline with the clock ticking so I decided to accept his offer and extend the campaign by 5 days. Unfortunately by the time it went through several hours later it was clear that the target was well in sight and the extension seemed misleading to some people. This had never been my intention, it just came together at the wrong time and turned out to be unnecessary.

The project ended up meeting it’s funding goal within the original timeframe after a remarkable final week and I was absolutely overjoyed with the result. I’ve had time to celebrate now and I can say that this has been the most stressful, exciting, nerve racking and fulfilling experience of my life to date. There were times when I couldn’t speak, couldn’t sleep or couldn’t eat due to an inability to think about anything but this project. It probably wasn’t all that healthy and I’m glad it’s now over! Now I get to work on the fun stuff. Here’s that graph again (figure 3), the red marker shows the original deadline.

Always Persevere, Never Lose Faith

Throughout the campaign I must have sent about 1000 e-mails to different media folks. At one point there were two websites I was yet to crack and I e-mailed them both every day (often twice a day) for about a 10 days until they finally got back to me. One said “Please remove me from your mailing list” and the other published an article!

Ironically the media has now snowballed since the campaign has ended and I’ve been getting a number of interview requests, some would be the biggest yet but I’ve had to turn them all down. I don’t need the exposure any more, that was for the campaign not for me. I want to spend my time developing!

Dextrus Kids

I had always planned for the Open Hand Project to help children as well as adults. The problems you have as an adult amputee are exaggerated for a child. Financially the price of robotic prostheses for children is very high, almost the same as the cost for an adult and there are even fewer options for them. What’s more, they require replacement hands every year or two as they grow, which dramatically increases the financial burden on the parents. Unfortunately it just doesn’t make sense for the NHS to even try to fund these developments because usually the children are very healthy and the money can be better spent saving the lives of people that aren’t.

What’s more, children often have a hard time fitting in at school at the best of times and anything that’s even slightly out of the ordinary about their appearance can often be difficult to come to terms with. I’m sure child amputees ask questions like “why don’t I have two hands like everyone else” and I imagine in the worst cases they might even get bullied for this by other children that don’t really understand amputations.

Having given this a lot of thought I came up with something that will hopefully help to address all of these problems. It’s a version of the Dextrus hand that’s designed for kids, it will have similar functionality and will be upgrade-able over time.

Take an example where a child is 5 years old and has a hand amputation. The parent can purchase a hand for this child. It would be smaller and lighter than the adult hand and would have significantly reduced functionality (maybe just 2 degrees of freedom, rather than 6 like the Dextrus). This would cost perhaps £400. Every year the parent would send the hand back to me and I would upgrade the necessary components to make it the appropriate size and weight for the new age. Every couple of years there will be more space for new components and the hand will increase in functionality. Each time the parent only pays for the upgrades and labour, perhaps £150-£200 a time. This gives the following benefits:

It’s dramatically cheaper than alternative myoelectric prostheses.

The child continues using muscles they wouldn’t otherwise, keeping their arm active and healthy and keeping the muscles strong for use with myoelectric prostheses.

As the designs and technology are improved over time, the experience for the family will only improve.

The hand essentially grows with the child.

Since these hands are 3D printed, we can add an element of customization to the process. One idea I had was to make the hands in the style of a superhero, such as Iron Man. This helps the child relate to the mechanics of it and humanizes the device. They will want to show it off to their friends and most likely kids will be jealous of them having such a cool prosthesis. They can change the design every year and with 3D printing, adaptations can easily be made for any superhero or action figure.

The superhero angle can also help the kids understand what they’re going though if they have to have an amputation. This idea was executed magnificently with a “superformula” for kids with cancer (video below). There would be comics which we would give to kids after they had an amputation. In the comic, the superhero looses their hand and has to go through getting a prosthesis. It shows scientists and roboticists working together to create this amazing super advanced robotic hand that replaces their missing human hand. This is easy for the child to relate to and helps doctors explain what their options are. The child then gets the same hand that the superhero had in the comic.

The Plan

I’ve been doing some statistics to work out exactly how we can make it to the £39000 goal and make this campaign successful. It’s definitely within reach but we’re all going to have to work together, this is not just my campaign, if you’ve pledged, then you’re on the team. And what a fantastic team we have.

As a team member you have a responsibility to share the project and try to get more people on the team! This is how we’re going to succeed and we need to work together on this. Here’s a graph showing the donations to the Open Hand Project so far:

As you can see in the last few days it’s really started to trend upwards and that trend needs to continue if the campaign is to succeed, we need to build on this momentum and make sure there’s not a single day between now and the end of the campaign when it’s not moving upwards.

The average donation from an individual funder on the project so far has been a whopping £39, which shows just how generous everyone has been. If you do the maths, you’ll see that from now, we need about 700 funders and we’ll make the target! We’ve already got nearly 300 funders, so we really can achieve this. It’s not even that difficult all it takes is for everyone on the campaign to get 2 or 3 friends to have a look at the project, watch the video and make a contribution. I’m sure everyone has a few friends that are either very generous, have some personal connection to a project like this or are just interested in emerging technologies, health, robots, 3D printing, engineering, design, underdogs or any of the above! Here’s a graph to show the growth in funders across the duration of the campaign:

This is trending even better than the graph of the funds and you can clearly see the difference all this sharing is making. The funding base has started to grow exponentially and this will continue to happen if everyone gets on board and gets involved. No one person can be exempt from this if it’s to succeed, you just need to find a couple of very close friends and see if you can get them enthusiastic about the project. That’s it. 3 friends. Why not use this as an excuse to catch up with an old friend, grandparent, or a friend in another country or far away.

To thank everyone for all of this I’ve set up the referral contest, which you can view on the indiegogo page. I’m adding a NEW £200 PRIZE. What’s more to win this prize all you need to do is get people to view the page, not even donate! You can now win a whopping £600 if you take all 3 prizes. I’ve been able to add this because all you wonderful funders have been so generous and many people have selflessly donated in exchange for no perks! This means that I can take it out of the fund I was planning to use to pay for all of the perks.

Get involved now, win some cash and make it happen for the Open Hand Project!

Referal Competion

To quote American gangster rapper 2Chainz…

“Let’s Get This Thing in Action!”

The last week has had some fantastic days of donations to the Open Hand Project and I’ve real felt a lift in the momentum of the project, there are now 213 funders and it’s really gaining some traction on the indiegogo website. However, we’re now at 24% funded and there’s still a very long way to go. The next big milestone is 30%. There’s a documented effect that once a campaign reaches 30%, the public confidence in that project grows significantly. People will be more likely to donate because they think it’s going to succeed. We really need to come together to make sure the project makes it to 30% quickly. The aim is to get there by midnight tonight!

To aid in this ambitious target I’ve created a referral competition with which you could win up to £600 Cash. It’s really easy to get involved, just follow these instructions below:

1. Log in

Log in to the indiegogo account that you used to make your donation.

2. Share

You’ll have a personalized link that you can use to share the campaign, copy and paste this link and share it around your network. You can use social media, e-mail and maybe even your website to get the word out.

3. Track Progress

I can track these referrals to see who’s referred the most people and who’s created the largest amount in donations from their referrals. I’ll update everyone every few days with the progress. You can track your own progress on your profile.

4. Win Prizes

Prizes will be sent out at the end of the successful campaign. If it’s unsuccessful, I can’t afford to give out these prizes, but that won’t happen!

Most Funders Referred: £200 CASH PRIZE.

Runner up: One OHP T-shirt and one pair of gloves.

Highest Amount in Contributions Referred: £200 CASH PRIZE.

Runner up: One OHP T-shirt and one pair of gloves.

Most Number of People Referred: £200 CASH PRIZE.

Runner up: One OHP T-shirt and one pair of gloves.

If you had already pledged for the T-shirt or gloves, then you’ve either got a cool Christmas present for a friend, or, let me know and we can sort something else out.

Have some fun with it and use this as an opportunity to help a great cause and win a bit of cash, if you haven’t donated already, you only have to donate £1($1) to enter!

I would really like to see some people getting heavily involved with this. It could drastically improve the campaign and provide a much needed boost. Here’s an example of a robot dragonfly campaign that did the same thing, can you guess when they launched their referral competition?

Thanks everyone, keep sharing, I promise it’s all going to be worth it in the end!

In the News

Media Exposure

I always knew that to raise £39k, the project would need a lot of media exposure but donations are not the only thing that has come out of it. There have also been a lot of engineers and developers getting in touch, all keen to help out with the project and contribute to the open-source development! So far the Open Hand Project has been featured on numerous websites and news outlets. It’s had articles written about it in at least 7 different languages in at least 10 different countries. The most notable of which have been Wired, Techcrunch, Hackaday and Robohub. It’s also done very well on social sites, reaching the front page of the /r/technology subreddit and the front page of hackernews. Photos of the Dextrus hand from high profile facebook pages have garnered 10s of thousands of views and thousands of shares. This shows that it’s popular with the public as well as journalists. The project also appeared in my local paper with this picture of me with the hand. As well as the number of donations this exposure has brought, I’ve also had a fantastic response from engineers and developers around the world. To accommodate this, I’ve set up a downloads section here on the website which I’m beginning to populate with more technical information. Once the campaign is over, I’ll formalize all of this and upload other useful files like those needed to 3D print the parts of the hand. For the technically minded and the curious, you can read a detailed document about the mechanics of the Dextrus hand here which intends to show the thought behind all of the design decisions as well as how it actually works.

Developer Interest

An important milestone occurred this week with a pledge from contributor and developer Martijn, who’s pledged for a Dextrus research and means that now at least one of each version of the hand has had a pledge. This is significant because it’s always difficult to get that first pledge, and will give other potential backers more confidence in the project. After the campaign Martijn is going to be working with me on the development of the hand and has a lot of expertise to offer. To ensure that they have everything they need, I’m offering developers early delivery of the hand. That means they’ll get an early version of the hand at it’s current stage of completion (in the next few months) and then once the development is complete they’ll receive all of the remaining components to build the final version of it.

Campaign so Far

Despite this fantastic response to the project (and it really is incredible), the crowd-funding campaign is still quite a bit behind the trend. To show where it is, I’ve put together a graph of the money that’s been raised so far, which can be seen below. The Y axis scale seems a little off, that’s because it is set to include the looming £39K goal. Don’t worry though! I still have a few tricks up my sleeve to push this campaign forwards, but I’m also going to need all the help I can get so if you’re reading this stop what you’re doing right now and pledge, share, tweet and shout from the rooftops!

Now that you’re back I wanted to share some more interesting graphs. Here’s one from Ryan Koo’s Kickstarter campaign, in which he raised $125000 for his film “Man-Child”. You’ll notice that it’s far from linear, and at the start he had a nice initial boost in pledges from his popular website and blog, from which many fans donated. One of the key differences between my project and Koo’s is that while my creation is probably more of a niche than his, my potential market of backers is probably larger. It’s more likely to encompass non-English speakers and also has a more poignant cause (in most peoples opinion).

Here’s another graph, this one from Victoria and Jen Westcott, which had a monumental surge at the end of the campaign to raise 65% of it’s funding on the final day. This is extraordinary, but highlights what is possible. Victoria attributes this to twitter and a relentless twitter campaign that she led on the final day of funding. In her article she says:

“I was told to be careful not to tweet more than 350 times in an hour, which I laughed at. How could anyone tweet 5-6 times/minute?”


“In the last few minutes I was eventually kicked out of twitter.”

Her goal was achieved two minutes before the end of her $20000 campaign, you can read about her journey here - it’s an exciting story.

Some people seem to have a nice relaxing campaign that reaches its funding in the first few days but where’s the fun in that? That’s not what crowd-funding is really about. It’s about these underdog indie projects making ambitious goals and changing the way industries work for the better. If you haven’t already, get behind the Open Hand Project and start changing the prosthetics industry!

Make a Pledge

The Open Hand Project has finally launched on indiegogo! The project has been up for two days now and so far the funding is going really well. A huge thank you to everyone that has pledged so far, getting the ball rolling at the start was very important so I really appreciate these early donations!

The campaign is set up so that if the project doesn’t reach it’s target, all of the pledges are refunded. The idea behind this is that you can make a “risk free” pledge, the project needs the full £39000 to go ahead but if this amount is raised then I’ll definitely have enough to fund the project for at least a year. It may seem like a lot but the entire goal for the project is less than the cost of one robotic hand from the market leaders.

So far the video has had around 5000 views on youtube. This is a lot in 2 days but in internet terms isn’t very many. There have been a good number of pledges from people outside my circle of friends and family – around 10. This is a fantastic ratio, it means that 1 in every 500 people who watch the video are making a donation, with the average amount being about £20. Therefore, if you do the maths, you’ll find that if the video has 1000000 views, the project should get funded solely by generous people that think it’s a good cause (rather than people that need the hand).

This gives me a great target to aim for, and highlights the importance of getting the project out there on the news and on the internet. It’s already had a decent amount of coverage from a wonderful post on TechCrunch and I’ve been e-mailing a number of other sites to get more articles written. Once several articles are written then the media exposure should snowball and hopefully I can get the project onto a few big news websites like the BBC. Another useful promotional tool is going to be Twitter, the TechCrunch article has been tweeted nearly 400 times and by some high profile Tweeters (such as IEEE).

I’m thrilled with the response so far and very chuffed with all of the support that I’ve had. Thank you.

Liam's Video

Today I was fortunate enough to be visited by Liam Corbett, an amputee who’s kindly agreed to help me in the early stages of the testing for the Dextrus hand. Liam found the Open Hand Project online and from there was able to get in touch with me via facebook. A huge thank you to everyone who’s been helping to share the project and raise awareness as I’m sure this has led to myself and Liam meeting.

Liam fell ill with meningitis a couple of years ago. Unfortunately, one of the ways in which the disease can affect you is by cutting the blood supply to your outer extremities. In Liam’s case, this eventually meant that he needed to have his right hand amputated. Fortunately since then Liam has been making a fantastic recovery and has been using a prosthesis on his right arm.

Liam was able to give me some very valuable feedback which lays to rest some of the concerns I had about the hand:

Weight – At 450 grams I thought it might have been a little heavy, but this seems very similar to Liams normal, metal hook prosthesis and he said the hand actually felt light to him.

Aesthetics – I think people will be split on this, Liam shares my school of thought which is that if you have a prosthetic hand, you should be proud of it and having a robotic looking hand is better than trying to hide the fact that you have an amputation by trying to make it as realistic as possible. You’ll never get it to look perfect, so might as well embrace your individuality and show it off.

Fitting – It fit onto his prosthesis perfectly with the connector that I’d attached to it, it’ll just pop straight on and off without any problems.

Unfortunately I couldn’t get strong enough signals to have the hand responding to Liams muscles. I believe this problem is partially down to noise and partly down to my programming. Both of these problems are solvable with a bit more work.

It was a real pleasure meeting Liam and his brother Steve, who came along with him. He’s got an extremely positive outlook and was very willing to help in any way he can with the Open Hand Project. If all goes well with the crowd-funding, I’ll be providing Liam with one of the first Dextrus hands to test out day-to-day.

All Singing and Dancing

Watch this video:

That’s where I’ve got to now. I got the finer grip movement by slowing down the thumb and lowering the “stop threshold” of the digits. The digits begin to close when instructed to do so, and then stop when they sense the force of an object impeding their movement. The force required to stop them from moving can be changed; this is the “stop threshold”. When the stop threshold is lowered the digits handle objects more delicately and if the stop threshold is increased you can crush things. Unfortunately I came across a new problem while experimenting with this; to slow down the thumb I use a technique called Pulse Width Modulation. This sends an On/Off pulse to the motors very quickly, so that when the motor moves it does so more slowly than if you had given it a solid On signal. The frequency of this pulsing interferes with the EMG signals from the muscles and causes problems with the interpretation of these signals. This problem should be surpassable when I build the electronics for the hand, as I’ll no longer be using open wires and connectors in the electronics and I can make efforts to shield the noise.

I’ve also fitted a connector to the hand, which you can see in the photo below. This was provided by Liam, who has kindly volunteered to help test the hand and give some feedback as an amputee on what can be improved upon in the future. The connector allows the hand to fit onto his NHS prosthesis and hopefully will give him some extra capabilities compared with the traditional hook attachments that he has already.

The company that makes this adapter decided to use a non-standard screw thread of 9mm in their design. This means that it’s not possible to buy the correct sized bolt to attach the connector to “third-party” devices. However I managed to foil their crafty plans by 3D printing myself a bolt of the correct size. Another win for 3D printing!

Two Steps Forward...

I finished the next version of the hand, check it out!

That’s the palm view of course (this one is a right hand) and it’s sitting proudly on the 3D printer bed. It may not be obvious to the casual observer but quite a lot of the hand has been redesigned since the previous one, with most of the changes centered around optimizing the most important features of the hand which are; weight, cost, size and aesthetics. I managed to improve all of these things but at a cost of the hand actually working. While the first one worked very well, after I finished putting this one together it seems to have some shortcomings in the actuation of the fingers. The problem is that there is too much friction between the motor and the fingertip, which prevents some of the fingers from closing properly. I believe this can be overcome with some tweaking of the components. Here’s another piccy.

This problem presents the “form over function” argument and with this particular project I think it’s best to err on the side of function, although when the project takes off I’ll be doing a lot to improve the aesthetics.

For the next few days I’ll be focusing on getting the hand working well enough to show off in the crowd-funding video, which will be the most important outlet to potential backers of the project. I have a few people on board helping me out with different parts of it so it should look very professional and polished.

UPDATE: Problem solved now, everything’s running a little more smoothly!

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