I feel dumb for needing to ask but can I run sHFI on an OG focbox single at 12s?
I think shifi needs the phase filters to work properly and I donāt know if v4 had that
It seems like Iām not the first to ask but I canāt seem to find a clear answer on this, how would one go about figuring out belt length with idlers? Is there a formula?
I imagine Iām not the first person to run boardnamics XL precision mounts (100mm c2c Ā±10mm), dual 636 bearing (6x22x7mm) idlers, and 15/72 gearing, can anybody say from experience what size belts work?
Guess. If your guess is wrong, chop it up and
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Unfortunately thereās no easy formula. If you already have a belt, you can use Brianās method^^.
You can get an approximation by using string or maybe a thin strip of cardboard (you want a bit of thickness, so paper is less preferable) wrapped around the pulleys and idlers, but it wonāt be perfect - might be off a tooth or two.
You can spend a bunch of time and effort in CAD drawing up your pulley arrangement and calculate the path length that way, Iāve done that once or twice.
Or you can take a guess and buy like eight sizes of belts, and pick the one that fits best. Also done that once or twice.
I use this calculator on sdp-siās site
For your setup:
So you need an 88 tooth belt. 88 x 5mm = 440mm belt.
Probably one or two sizes up if using an idler.
You can adjust it to a 90t belt (450mm) and see that the center to center distances is now 106mm, still within the 100mm +/- 10mm.
EDIT:
I have the same mount, using an idler, on 20/36
Calculator shows a 335mm belt at 100mm. Iām using a 345mm and Iām about in the middle of the adjustment, so adding about 10mm to the belt length to accommodate an idler seems about right.
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or this:
or this:
https://boundmotor.com/electric-skateboard-belt-length-calculator/
boundmotor didnāt pay me to say that, just sayinā
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Whatās everyoneās thoughts on TB motors nowadays? These were pretty cheap at $70+ domestic shippingā¦ I donāt mind all the vents since itās going on a street build.
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I used have a set of those motors, they were champs, worked great for a long time
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@b264 @MysticalDork @jaykup @frame youāre all incredibly helpful thank you very much.
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Those motors arenāt bad. Theyāre not the best motors anymore but were at a point in time.
There were also many iterations of those same motors, and the later ones are a lot better than the earlier ones.
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I had a set of the 74s that were brand new and tried to kill me with broken windingsā¦ be careful
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Iāll open them up and inspect before installingā¦ Thanks. When did you buy the 74s?
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2-3 yrs ago now
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Is there any sort of standard when it comes to phase wire length and what is a good length? obviously they will be long enough to connect and allow for as far over as I can get the truck to turn to each side, but how much longer should they be past that minimum length?
I just donāt want to have to make them longer in the future if I am not considering another important factor
Make sure they have enough slack on them so that they arenāt pulled tight when the truck is at full lean.
By full lean, I mean remove the bushings and see how far the hanger will rotate before it comes to a hard stop somewhere. You may never need that slack in day to day riding, but if you have an impact on one of your wheels, you can reach that full lean point pretty easily.
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I thought the focbox had phase filters and thatās why it could run FOC at 12s
I second this. This exactly.
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As usual, tried searching and nothing came up but thereās definitely an answer out there:
Roughly what stator size are common hub motors? Is there an equivalent 4 digit motor number thatās got about as much copper as say meepo or exway hubs? I know itās not exactly the same performance because hubs are insulated by the sleeves