Belt n pulley strength

What’s most durable? Carbon option?

Anyone use htd 8mm pitch 15mm wide? Wondering how much torque can take with typical skate use.

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To add to your questions, I’m interested in how much more durable kevlar belts are. I know @XTLA uses them.

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@b264 may have some insight into this.

There’s calculations to figure what belt size is appropriate but then they tell you to throw those calculations out the window if in an abusive environment vs a conveyer belt or the like.

Thinner being more efficient and like to strike a balance. Doing two belt mid-drive bike with a jackshaft and 80mm leopard motor

These motors seem kinda crappy with awfully huge airgap and small magnets

And @b264 I know u like the resins…will pot the cells and motor mount plate and jackshaft hole and mounting bolts (m4 fit nicely through)…all in potting. Actually two pottings One the mass of cells and the other the plate that bolts on to the other.

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There is a topic about belt material

I don’t know about HTD8M but have wondered…

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There are belt drive options for manual bikes too. Might get you started

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They aren’t up for the torque. I wish could use them. The center track is nice

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It’s durable so far, i use TWBelt PU with kevlar cord, no idler. Now i’m ordering their PU with steel cord and about to test it.

http://www.twbelt.com.tw/webe/html/products/show.aspx?id=47&kid=40

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Not yet, but planning on using HTD 8m at 15mm wide for a scooter project. Had a look at the power charts for HTD belts and it really seemed like HTD 5m wasn’t going to work (for long).

It’s bigger, more so than I expected. Size makes it hard to get the lower gear ratios. 15t and 49t below.

Some of the other Gates pulley specs have much better power ratings, but their hardware is much harder to find.

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Running through the calculators inputting 4000 watts and getting high rpms on shafts I can use a 8mm pitch and 12mm wide GT tooth profile belt and still have a 1.7 service factor, so nicely overbuilt. HTD isn’t as good for torque as GT. It’s really worth highly gearing the motor if possible and can use a thinner belt. This jack shaft is doing 1:3.1 reduction at each stage for a total of 1:9.6. 7000rpm at the first shaft n about 2333 at the second stage.

Depending on how thin the stator laminations are I bet we’d all be able to get way more than double the power out of the motor per watt lost to heat with some decent gearing. Able to use thin cheaper belt n pulleys and smaller motor

I’m finding getting standard and custom made pulleys in India cost about 1/5th what they cost here.

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From my own research, kevlar probably isnt worth it, and could potentially be worse. Its got worse water resistance, and In some situations, you want the belt to snap. I can imagine steel belts being to strong. A rock in the belt system that would snap glassfibre instead bends the shaft/moyor mount because a steel belt wont snap :japanese_goblin: - not tested but plausible

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carbon seems the best thing going. i didnt even come across kevlar. there are so many different styles and sizes.