[Closed] Engineering / tinkerer types - how hard would this be to build

Looks good. In the "history" section of that site is a photo of the original wooden prototype.

The £300 will be lighter, more durable and has been properly tested. Perhaps start with your wooden design and if it works buy the £300 one? It's not that much cash in MTB terms - you can't even get a carbon wheelset for that (or perhaps you [url= http://www.ebay.co.uk/itm/26er-Mountain-Bike-Carbon-Clincher-Wheelset-Hub-Shimano-MTB-26-Carbon-Wheels-/221106604963?_trksid=p3284.m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA%252BIEW%252BFICS%252BUFI%26otn%3D21%26pmod%3D221084192804%26ps%3D54 ]can[/url])!

I'm not so sure that it'd be a good idea. You'd maybe be better off getting a below knee prosthesis and modifying the cup on it to fit a bent knee which still had a leg attached. That make sense to you?

Or modify an axillary crutch.

Glutton - the challenge with that is the fixings. False legs have a deep cup for the stump to fit in.

My original ideas were something hinged or fixed below the knee so I could walk but unless I wore built up soles on the other foot I wouldn't get the ground clearance on the cast.

They do have deep cups to hold the stump, but they use the epicondyles of the femur to hold the thing on. You could cut the back of the cup away and it would still have an interference type fit on the epicondyles - you could use a velcro strap arrangement to help keep it in place if needed.

I reckon you could knock that up easily enough, but don't forget a parrot for your shoulder!

You did notice they will hire you one for £25/wk didn't you?

I'd be taking to your Consultant first, you don't want to even more more damage.

It looks a brilliant bit of kit, shame no-one had thought of it years ago. Get the money spent and get a proper one.

However I also realise you're bored and haven't done yourself any more damage in weeks, so yeah, go for it and lash something up.

Since you want a wide platform for the knee and shin, and need to keep it all snug to the front of the thigh, how about rigging up the basic frame and padding, clingfilm the leg and set up temporary boxing around the frame. Fill the gap with expanding foam for a proper custom fit. When the foam goes off you can trim back the excess to just the contact area. The commercial crutch would benefit from this too, but it needs to be adjustable out of the box, yours only needs to fit you.

Obviously video the process so we can see you entomb your lower leg in foam then slice yourself to ribbons as you try to cut yourself free. 🙂

I'd spend the £300 and then stick it on Ebay when I'd finished with it!

used medical stuff is big business. we ve done a lot of work with a company that buys and resells stairlifts.. they guarentee to buy yours off you when grandma doesnt need it any more. the average use is about 18 months they reckon.

get normal crutch saw off to desired length, couple of cable ties jobs a good`un, spend the remainder of £300 on alcohol to take away pain

I reckon a pogo stick would be a better starting place.

Do you know anyone flying over from North America? They're (apparently) $249 (£155) on the US site at the moment...

http://iwalk-free.com/sale/

Reading various reviews it appears they are awkward to fit and remove. Also you can't sit while wearing one. This makes them noticeably less useful for day to day use. Okay if you spend your day standing but imagine my working day

Leg on, go to taxi
Leg off to sit in taxi
Leg on, go to train
Leg off to sit on train
Leg on, walk to tube and negotiate rush hour standing with your foot stuck out behind
Or
Leg on, walk to taxi
Leg off to sit in train
Leg on, walk to office desk
Leg off to sit down
Leg on to go to meeting upstairs
Leg off to sit in two hour meeting
Leg on to return to desk
Leg off to sit at desk
.,..

You get the picture. It either needs a hinge to get the bottom half out the way when sitting or better straps to make fit and release easier.

Yes, I had spotted the rental option and will be talking to them on Monday about a four week trial once they have clarified the leg on/off and sitting issues.

I will post pictures of the prototype I have built when I can. Even I think my version look funny

As this is a bike forum, it has to be made in carbon. Should be fairly easy, just a PU foam model, used to make a glass fibre mold, then make 100's in carbon.
I'll take 10%.
All the best

As this is a bike forum, it has to be made in carbon[b][i] and cutlery[/i][/b]

You missed a bit!

I wonder whether you could add the lock from a kids scooter? The sort that fold flat have quite neat and secure fixings. Hinge would only lock at 90 degrees and would convert to swinging when you pulled a knurled knob. PS should be made from Ti in a Jones stylee (prototype could be steel for ease of fabrication)

Kids scooter, remove wheels, stick the bottom of the normal crutch at the front below the platform...

The wooden one I have built is quite heavy and needs a better strap to the thigh but it works.

It may not be suitable for a foot like yours, but when I was recovering from fracture of the lower tibia I had a patellar tendon bearing cast ('Sarmiento') which I could walk on. I could sit in a car or at a meeting, although (even before I had the cast) I often had to elevate the leg when sitting. It's a long shot but it might be worth asking your consultant if there's anything similar for your case.

WCA could you use an aero roof bar rather than your bit of 2x4? It will at least have the tracks for mounting stuff too like your bit to rest you knee on and the support straps.

Hi there! I was astonished to see a huge surge of hits on the website from here so I thought I'd pop in and say hello.

A couple of things that came out of your discussion:

I was a user myself when I broke my ankle slipping on ice in France and ended up with a plate in it - that's why I became the UK distributor. I found that after a bit of practice I could get it down to about 10 seconds to get the thing on and off but I agree, for moving around the house from one sitting place to another, or out to the car crutches were much more convenient. Where it scored for me was when I needed the use of my hands - I was in the middle of refurbishing a house at the time and it meant I could get around a building site easily and still do things to help. It also made shopping in the supermarket possible.

The price issue: Would you believe that after shipping to the UK in boxes of 6 and paying import VAT and all the other charges I make well under £100 profit on each unit - I couldn't see how I could reasonably charge more, though.

If you did buy one, you don't need to bother with eBaying it afterwards - I have a buyback scheme where I pay £100 for used units to add to the rental fleet for time to time.

I'd far rather rent you one, frankly, as I then get it back to let it earn its keep again.

surely this is the solution?

[img] [/img]

Foam, composite kit (glass fibre or carbon) and a hard shell kneepad. Not impossible to do a hinged version using spring loaded pins.