Parts for hand ergometer (exercise bike)

[irving2008]

@chopper. Thanks for offer, tho if JazzCNC can do it sooner I might take him up on it. While adding additional dimensions I realised I'd made a slight boo boo in the design which needs correcting. I'm updating drawings and will post updates and some new drawings for other parts tomorrow.

@JazzCNC thanks, sooner is better. As I said above there's a few other parts drawings to come.

With regard to current drawing for handle, is depth of boss (10mm) into tube enough or should I increase to 20mm?

The axial slot on the larger side of the boss is to allow the cross screws to clamp the outer shells of two 10x22x6 bearings. I copied this from an existing assembly which I couldn't dismantle. Will this work or does it need a slot radially where the clamp section meets the 64mm dia, 3mm thick hand guard section to allow the clamp to, well, clamp?

[JAZZCNC]

With regard to current drawing for handle, is depth of boss (10mm) into tube enough or should I increase to 20mm?

Yes more the merrier I think considering the handle is 150mm long thats not much holding it.

The axial slot on the larger side of the boss is to allow the cross screws to clamp the outer shells of two 10x22x6 bearings. I copied this from an existing assembly which I couldn't dismantle. Will this work or does it need a slot radially where the clamp section meets the 64mm dia, 3mm thick hand guard section to allow the clamp to, well, clamp?

Know what you mean and yes it would clamp better if this was slotted.

I'll PM you Email address.

[mekanik]

Hi irving
If i was making the handle assembly i would manufacture from one piece of ally with an interference fit for your two bearings. also make the 150mm length 22mm Dia & then you can fit some proper cycle handlebar covers.I bought that ring gear just to see if i could work out the gear form(probable modular) don't know if the required wheel size will mesh though as the mating components from the hub it came from are rather small.
Take care M8

[irving2008]

Hi irving
If i was making the handle assembly i would manufacture from one piece of ally with an interference fit for your two bearings. also make the 150mm length 22mm Dia & then you can fit some proper cycle handlebar covers.I bought that ring gear just to see if i could work out the gear form(probable modular) don't know if the required wheel size will mesh though as the mating components from the hub it came from are rather small.
Take care M8

Thanks for your input.

I had considered machining it from the solid but thats a huge amount of wastage of a 65 or 70mm bar x ~350mm. Thats over £50 +p&p on ebay to throw 50% away! However if someone wants to provide the stock for free then I'm not proud

Not sure a pure interference fit would be stable enough and all the designs i looked at use a clamp arrangement with either one or two clamp bolts. Two bolts might be overkill tho.

The diameter of the grip needs to be much bigger than a normal cycle handle bar as I cant wrap my fingers that tightly. The 32mm dia is the same size as the one I use at the rehab unit and will be wrapped in bar tape or sleeved with rubber tube heatshrunk on.

[JAZZCNC]

Thanks for your input.

I had considered machining it from the solid but thats a huge amount of wastage of a 65 or 70mm bar x ~350mm. Thats over £50 +p&p on ebay to throw 50% away! However if someone wants to provide the stock for free then I'm not proud

No problem if you want it from Solid Irving I can sort that, thou it will mean a slight delay has I have to get from a mate.

[irving2008]

No problem if you want it from Solid Irving I can sort that, thou it will mean a slight delay has I have to get from a mate.

Prefer the tube approach as less inertia as well.

Whats your view on 1 v 2 clamp bolts?

Updated drawings attached. I've only taken the radial slot down to the top of the bearing, think that'l give enough movement?

[mekanik]

If made from solid you could place one bearing in the centre of the handle and one @ the end

[JAZZCNC]

Prefer the tube approach as less inertia as well.

Whats your view on 1 v 2 clamp bolts?

Personally I'd have gone for solid and let me take the weight out of it by boring.!

Regards clamps bolts then probably 2 has it will clamp more even. How many bearings are you planning on using.?
Also the specs for 6900zz are 22x10x6 and if this is being assembled like I think (see pics) then you have allowed for 2 bearings @8mm is this correct.?
See pic6 and you'll see what I mean with 6mm bearing and 4mm spacer between, it leaves shaft sticking out.!

Let me know if I'm wrong and if this is the final drawing.

cheers
Dean.