CAD Ideas and Inspiration (Serious)

#40

generally these systems tend to be very noisy as the outer ring gear has large exposed surface that can resonate.

2 Likes
#41

the problem is that there are so many different use cases. a 2wd street baord (eg kaly @4:1) needs a different ratio to a 2WD ATB (eg trampa @~6:1) which is different to a 4WD that may only need 3:1

1 Like
#42

Golden gear ratios are really hard because the motor RPM is a range factor of 3 and the target speed output is a range factor of 3 so gear has to pick up that range factor of 9

I mean we can all say we want a 1:4 ratio for everything and pick the motor kv and battery voltage accordingly but even then you’d need every kv from 90 to 270 for people to be happy

3 Likes
#43

I think there are “golden ratios” for a given kv motor.
Personally I think the sweet spot is somewhere around 3.5/1 for 170/190kv. If you go any lower for example 2.5/1 you lose torque big time. If you go any higher than 4/1 you have almost no top end.

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#44

Agreed, I think if a vendor sold this planetary drive set up, you would see 2 or 3 pre-set motor kv ratios to choose between for urethane, street carver, or mtb.

But will we see it in 2020? :thinking:

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#45

Fully possible:

#46

The ultimate solution is a DD for eMTB :wink:

4 Likes
#47

Would it be possible to make a gearbox for emtb with a clutch to switch gears between 2 different ratios?
That would be really dope.

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#48

Yes, but how many pesos do you have to fund it?

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#49

everything costs! actually a CVT clutch may end up meeting your wishes and expectations… readily obtainable, cheep,l been proven

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#50

Do they make them small enough to fit a skateboard truck with 8-9” wheels?

#51

I’d definitely take part in the first batch preorder. But as far as funding stuff I am not really rich even in pesos.

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#52

I have one on my 5hp two-smoke engine that powers my fat-bike… so yeah… and with a little search… i’d say yeah… and if not now… infinely/possible/build-able/likely

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#53

I will look it up

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#54

I mean if you’re feeling kinda risky, you can pull the clutch and gearbox assembly from a drill. If you’ve got a 4045 motor or something small like that it’ll probably run… just get a servo and Arduino with accelerometer to switch it once you reach say 15mph

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#55

gears and such are esoteric and fun… and I may be wrong… but a CVT clutch/transmission is relatively cheap and proven

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#56

Heh?

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#57

I toad ya

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#58

So if anyone wants to PayPal me $100 so I can do some science…:wink:

1 Like
#59

I need to watch an “how this stuff work” video to understand how this stuff work.

2 Likes