Deathly Hallows - FW - Alligrater

[Deathly Hallows]

any reason why you can't use a dead shaft ? that way you can attach the sprockets directly to the wheels?

Or if you want a live shaft why not a plate which is attached to the shaft and bolt the wheel to that?

I am learning stuff every day! I love this hobby.

So a 'dead shaft' would mean the shaft is fixed (not rotating) the sprocket is fixed to the wheel so when the sprocket turns the wheel does too. At these low speeds for short duration then no bearings needed I would assume, just a dab of grease or PTFE. Though I could insert something to reduce the bore to allow a narrower gauge of rod/axle.

Did I understand correctly? I don't have an engineering background so I could be totally off mark

Thanks for your input - very much appreciated.

[Maxamuslead]

Bang on, I dont have a engineering background either but have always had a health interest.

I would look into using some bronze bushings at the very lease as it would help reduce friction prevent as much wear on the wheel hub.

[Deathly Hallows]

Since the last post I have been trying to source parts and get the layout sorted in my head. Unfortunately my son is revising for his exams and he is hogging the laptop, so not had the time I need to work in CAD.

Oilite bushes purchased they will work fine.
I bought a 25H chain seems a perfect fit for the existing MY1016 sprockets. But I am out of my depth when it comes to the names and codes for sprockets and chains. I was looking on Gears and Sprockets for a suitable one to mount on my wheels. I thought I may find a cheap one on eBay but the mini dirt bike and mini atv ones look too big. The outer diameter of the wheel is around 150mm and I would like something nearer 90mm. This may limit the ratio I can achieve without more complexity than I want, >5:1 would be nice. 2750 -> 550 would still be very fast. Would need to configure the controller for logarithmic to make it controllable at low speed.

Is 04B compatible with 25H or do I need to look elsewhere? Suggestions appreciated
I'll need an idler sprocket on a slide too, or at least i think i will so I can adjust the tension/allow easy removal replacement.

Cheers

[Maxamuslead]

04b IIRC is a 6mm chain and 25h works with fine (i can vouch for t8f and 05b 8mm chain). i take it a 13 tooth sprocket ( think that what stock on those motors) so that will require a 65 tooth sprocket (if your going for single stage) which will require a 126mm platewheel. https://www.gearsandsprockets.co.uk/...lex-sprockets/

or you could use a two stage system which will make it more compact

I fine THIS website helps with designing a gear ratio

[Deathly Hallows]

Took some pictures of the sprocket.

IMG_20180501_195327.jpgIMG_20180501_195347.jpg

So it's a 10T and as you see from the chain picture it fits nicely no issues despite low diameter.

I will need to order the wheel sprocket soon as it is key to the layout. Once I know how it will fit together, I can work out the lowest angle for the wedge that I can get away with.