Belt drive Sprockets on the Cheap!

Very interesting. Found this thread while looking for information on "lantern" gears. No modern types available. But a lantern gear might make an interesting approach to an "internal tooth" ring gear sprocket. If it were made chain-pitch a small sprocket could be run inside of it as pinion gear. Very high reduction ratio with much closer shaft to shaft distance than belts or chains. Nice and compact. Perfect for bike application. Noisy? I tried looking for anything like this and found nothing via google. I don't know how successfully any conventional/standard internal tooth ring gear or sprocket might be run with a gear pinion without adequate protection and lubrication. Probably a non starter there. But a "lantern" gear pitched appropriately for a chain sprocket tooth so that a sprocket could run inside as a pinion gear? Might be interesting.
 
Yes. Interesting ideas there.
lanternpinion.png

Here's another closely related drive. I'm sure this one well known here.
panasonicedrive.png

I wonder what the noise and vibration level is with the "lantern", or as the Anytime bike calls it "barrel cog" sprocket? If more (any?) of that style of sprocket, either as a drive sprocket or as larger diameter chainrings that could be welded to an existing sprocket, existed in the market it would be interesting to experiment with.

Picture an internally driven chainring like below, but with lantern gearing. It's what I was thinking of when I went searching for "lantern" gears on google and found this thread in Endless Sphere.
internaltooth.png
It allows closer shaft spacing than belts.
Open "barrel cogs" are relatively immune to contamination, mud, dirt, debris. Better than belts or gears.
Inside drive enables more meshing than externally driven. Quieter and better power handling.
Also it preserves the clockwise/counterclockwise rotation of the driveshaft as a belt would.

Ideally I suppose the chainring would be inside toothed with standard pitch sprocket teeth and the smaller pinion gear would be "barrel cogged" like the one shown in the first image. That would keep the larger ring lightweight. With a really well built "barrel cog sprocket" it might be fairly quiet indeed.

Wish I had a nice lathe with indexing tools.
 
scanner said:
Yes. Interesting ideas there.




Ideally I suppose the chainring would be inside toothed with standard pitch sprocket teeth and the smaller pinion gear would be "barrel cogged" like the one shown in the first image. That would keep the larger ring lightweight. With a really well built "barrel cog sprocket" it might be fairly quiet indeed.

Wish I had a nice lathe with indexing tools.

Yeah, that's a nice idea from a tooth engagement standpoint. However, you would play hell supporting that ring gear. I think the only way to support it would be from the outside. And you would still need a center shaft mounted to the ring gear to trasmit the power to whereever......Great if your going to build 100a of these things and can aford the engineering and manufacturing but not for a one or two peace project.

Bob
 
Actually two equal sized chainrings,

Screenshot-3.png

...and a handful of the right ID drill shaft stock pieces might produce one fairly easily.

Mount up both rings, with spacers between, on a crank. Spacers should set the rings exactly so that they are approx the width of your inner chain links.
Measure the length for the "spokes" or "cogs" and cut as many as needed from the drill shaft stock.
Set these cogs in each tooth valley and then tig weld each side of the cog. Would not need a lot of weldment. There would end up so many small weld joins in the end that it would be quite strong.

When finished, remove from the crank, cut/remove the bolt pattern of one of the rings, and bolt the final assembly back on the crank.
The "lantern" pin spacing is a mirror reproduction of the chain pitch, indexes with a small sprocket run on the inside perfectly, and is very rigid. Not much gap to play with between the faces of the drive and driven sproket faces now, but that could be worked out with a little more thought.

If you're not using this at the crankset it'd be just as easy to use a full sprocket and a chainring with equal teeth and pitch.
 
scanner said:
Ideally I suppose the chainring would be inside toothed with standard pitch sprocket teeth and the smaller pinion gear would be "barrel cogged" like the one shown in the first image. That would keep the larger ring lightweight. With a really well built "barrel cog sprocket" it might be fairly quiet indeed.
 
Miles, did you just cad that? I wish I was that fast. I only know sketchup. If that's sketchup, you're much better than I am at it.
How difficult would it be to draw Anytime Bike's "cogged" sprocket running on the inside?
file.php


My brother has a small machine shop. I might tease him with a drawing and ask if he can make me something.

I've been picturing something in my mind along those lines. It would be an interesting way to build a single stage very compact and lightweight reduction.


...and apologies to the OP. Got off track here since this is not belt drive per se.
 
scanner,

I use Alibre. It's very much better for this kind of modelling than Sketch-Up. I've been using it for six years now so I'm quite quick.

It's no trouble at all to model the lantern pinion. If you specify it all properly, I can do a model.
 
Never doubt Miles' CAD ability, it is fearsome, prodigious, and many other big words.

He can make a cad model of your vague ideas, in the time it took to read this.

Impressive as usual,

Katou
 
scanner said:
Yes. Interesting ideas there.
file.php

.
As i mentioned on the other thread..
.. this is just not a practical drive mechanism. The chainring teeth are too narrow to withstand the drive loads imposed by the single tooth to tooth gear drive. they will wear rapidly and most likely simply strip off if any significant loads are applied.
Chain sprockets are designed to transmit power through multi tooth contact with the chain.
Gear drives which operate with only one or two teeth in contact have much wider contact faces to resist the loading.
You would also benefit by studying the theory behind the different teeth profiles used on chain sprockets and gear sprockets
 
Maybe a laser cut custom stainless chainring is part of the parts list. It would be kind of funny if hillhater is right and this kit shears off teeth. That's a lot of R&D down the gurgs. I guess the 500w limitation is what keeps the kit from disintegrating
 
Hillhater said:
As i mentioned on the other thread..
.. this is just not a practical drive mechanism. The chainring teeth are too narrow to withstand the drive loads imposed by the single tooth to tooth gear drive. they will wear rapidly and most likely simply strip off if any significant loads are applied.
I didn't think the proposal was to use a standard chainring? It would certainly need to be hardened steel.

I think it's doable. Whether it's a worthwhile direction to take, I'm not sure...
 
I had always assumed chainrings ( quality) were hardened anyway ?
The problem is the limited width of the teeth (3mm ?), and even if using something like 219 chain that only becomes 5mm at best. The tooth profile is also not optimised for tooth to tooth drive.
Just a very poor idea from an engineering power transmission viewpoint !
 
Hillhater said:
I had always assumed chainrings ( quality) were hardened anyway ?
They aren't even steel. Most chainrings are 6061 alloy, I think. Some are 7075. They are rarely hard-anodised. Of course, they are heat treated to T6....

Hillhater said:
The problem is the limited width of the teeth (3mm ?), and even if using something like 219 chain that only becomes 5mm at best.
Scanner's idea is for internal teeth - greater/smoother engagement. On my model, I increased the width of the internal teeth to 6mm, could be more...

Sure, it's a compromise but I think it's worth an experiment.....
 
Hillhater said:
The problem is the limited width of the teeth (3mm ?), and even if using something like 219 chain that only becomes 5mm at best.
Scanner's idea is for internal teeth - greater/smoother engagement. On my model, I increased the width of the internal teeth to 6mm, could be more...

Sure, it's a compromise but I think it's worth an experiment.....[/quote]

it i definately worth an experiment!! 7:1 reduction with sweet FA parts count would be exciting to see!!
 
damonjackson_spl said:
Scanner's idea is for internal teeth - greater/smoother engagement. On my model, I increased the width of the internal teeth to 6mm, could be more...

The internal teeth version could be made with any normal gear profile & width, as compared to the original idea that had to use the external chain drive teeth which are constrained by the chain design.
 
Hillhater said:
The internal teeth version could be made with any normal gear profile & width,
Of course, but only the lantern gear version can be milled...

Hillhater said:
as compared to the original idea that had to use the external chain drive teeth which are constrained by the chain design.
You have to follow the sequence of this thread! :roll: :)

scanner said:
Very interesting. Found this thread while looking for information on "lantern" gears. No modern types available. But a lantern gear might make an interesting approach to an "internal tooth" ring gear sprocket.
 
so, blatantly taking advantage of the fact that the belt know hows are all here, I have a question:

What is the best belt size to use for a medium powered (5 ish hp, turnigy 63-74 motor) reduction? and where could i get it from that will post to australia?

ok, so back to topic, im no machining guru, but the laser cutters dont cut perfectly vertical cuts do they? i know on plastic parts they taper noticeably on thicker stuff, does it still do this with stainless? i dont imagine it would be very good for the tooth mesh and alignment.
 
bandaro said:
so, blatantly taking advantage of the fact that the belt know hows are all here, I have a question:

What is the best belt size to use for a medium powered (5 ish hp, turnigy 63-74 motor) reduction? and where could i get it from that will post to australia?

5mm pitch 15mm wide HTD profile. :D

Matt
 
recumpence said:
bandaro said:
so, blatantly taking advantage of the fact that the belt know hows are all here, I have a question:

What is the best belt size to use for a medium powered (5 ish hp, turnigy 63-74 motor) reduction? and where could i get it from that will post to australia?

5mm pitch 15mm wide HTD profile. :D

Matt


Unsure where Matt buys his belts, i have purchased a few and pulleys from

https://sdp-si.com/eStore/

They delivered very promptly to OZ..Best of luck

KiM
 
sweet, shall look into them then, would they be stronger than the syncroflex 16mm t5 that pies sell here in oz? http://www.piesau.com.au/shop/index1.html
 
bandaro said:
sweet, shall look into them then, would they be stronger than the syncroflex 16mm t5 that pies sell here in oz? http://www.piesau.com.au/shop/index1.html
bandaro, follow your link and search for "260503303" (without the quotes). You should then have a list of 5mm pitch 15mm wide HTD profile belts
 
wow, why i did not find those htd before and get them instead of the t5, i do not know...

So i shall get an extra belt of the 5m (they dont mesh onto t5 right) so we get another reference as to the method that 1000w has posted, so any ideas on a good epoxy/glue to use? what is the reflector glue he was recommended? not sure what my stock will be made from, but most likely aluminium. The workshop manager at uni is a mad keen composites designer (been designing and making carbon bikes for about 17 years now - made a composite trike as his major project back in 93) so i will definitely be able to get any resin and apply it properly for a good test, will take pics and post results somewhere when proper testing has occurred, within a few a few weeks.

edit: oh yeah, a heavy duty #25 chain from electricscooterparts.com work with 5ish hp? or do #35/8mm?
 
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