Gear Friction Comparison - what's the best?

[TechnicBrickPower]

The relative friction of four different solutions for transferring motion from one axle to a far away axle are compared. The friction load differences are compared using a differential to measure the speed difference of the load on two medium motors. The four motion transfer solutions that are compared are a series of nine 16 teeth gears, three 40 teeth gears, a chain, and bevel gears driving a perpendicular axle.

 

 

[keymaker]

Great video! But I have one suggestion, you should check every pair in every two configuration to exclude influence of friction of the part behind the lever and to confirm the winner of every round. I left this comment also in comments section of the video.

[jorgeopesi]

Nice video.

[howitzer]

Very interesting!

I was surprised to see 40T gears losing to 16T gears, as the latter has many more moving and sliding parts so intuitively it ought to have higher friction, I wonder what's the explanation here? I wonder what the effect of significant load would be on the results? Distance also matters, as with chain and bevel gears you don't really need to add any moving parts with increasing distance (unless you count the supporting bearings of the driveshaft) but with the spur gears even a small increase in distance immediately adds moving parts.

[Parazels]

Can you in your next video 

compare loudness of different combinations of gears?

For example, which combination of gears 16+16+16 or 20+12+20 

makes more noise?

[arieben]

Excellent video.

4 hours ago, howitzer said:

Very interesting!

I was surprised to see 40T gears losing to 16T gears, as the latter has many more moving and sliding parts so intuitively it ought to have higher friction, I wonder what's the explanation here? I wonder what the effect of significant load would be on the results? Distance also matters, as with chain and bevel gears you don't really need to add any moving parts with increasing distance (unless you count the supporting bearings of the driveshaft) but with the spur gears even a small increase in distance immediately adds moving parts.

I'm guessing that the 40T gears would perform much better under load. The trade-off for less friction with the 16t gears is much greater backlash - the teeth on 40T gears mesh much more frequently per rotation, which introduces more friction, but keeps them in better sync.

[aeh5040]

That's very interesting. It would be good to see the comparison under load too.

I do wonder how big a role the choice of bracing plays. E.g. with the 40t gears, some of the axles go though multiple stacked liftarms, which can add a lot of friction.

[TechnicBrickPower]

On 8/9/2020 at 9:13 AM, aeh5040 said:

That's very interesting. It would be good to see the comparison under load too.

I do wonder how big a role the choice of bracing plays. E.g. with the 40t gears, some of the axles go though multiple stacked liftarms, which can add a lot of friction.

 

Yes I agree - a load comparison would be most important as most models are run under at least some loading. Maybe I will look at that sometime.

 

On 8/9/2020 at 4:33 AM, Parazels said:

Can you in your next video 

compare loudness of different combinations of gears?

For example, which combination of gears 16+16+16 or 20+12+20 

makes more noise?

I don't have anything to measure noise with. They are all loud!

 

Edited August 12, 2020 by TechnicBrickPower