A couple random questions. Motor pulley. Best hub motors. Troubleshooting bad battery.

How-Tos & Esk8 mechanics
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  1. Is there a rule of thumb maximum motor pulley size? They would go on dual 5065, 160KV.
  2. What are some good quality hub motors? I’d like to build a 40" evo hub deck. I’d imagine a 4wd hub deck could be pretty powerful
  3. What are the best docs, tutorials, etc. for building and troubleshooting packs? I’d like to research as much as possible to be safe when troubleshooting a bad pack.

Thanks in advance

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As big as possible so more teeth do engage.
In fact you will have a limited choice anyways.
There is a calculator in the top menu of this page.
Depending on your desired max speed and the pulley size you can get on your wheels with enough clearance you will pretty easy find out what will fit in your situation best.

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I’d post pictures of the battery pack in question with some information in the battery building thread. We have enough knowledge people here who can guide you through the troubleshooting process.
Like always when working on batteries, do it in a place where nothing flammable is around and be prepared for the worst. Fire extinguisher, fire proof blankets and some gallons with salt water nearby are always good to have.
One more important point, never start working on batteries when you not fully focused. If you just have 30min after a 12h shift to work on your battery, better move it to an other day.

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Visual inspection usually tells alot.
If you have a multimeter and a DC load you can diagonose most if not all packs.

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I looked for quite awhile and the largest tooth size motor pulley (8mm bore) I could find was 16T.

Honestly, I’d like to roll with this 36T/16T kegel adapter kit from mboards. You think this could fit my Onsra trucks? I might just roll the dice.

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I’ll start a thread today sometime in regards.

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What size wheels are you using? 36T is fine for 80 or 85mm wheels, but if you have Onsra 115mm wheels that’s too small for good torque.

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Ive got some 85mm caguamas. About to throw them on now with some 45T/14T pulleys. Just want a better ratio for at least a bit more top speed.

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If you can’t get Hummie Hubs then I would opt for satellite motors.

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Both look pretty tough to find. I’ll just snag if I see some. Probably just go belt for a new build for now.

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Satellite motors are extremely easy to find. This would include belt drive, gear drive, and chain drive.

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I’m confused. Can you provide a link or make model of what constitutes a “satellite” motor? I take that’s not a brand which is what I initially thought.

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a 45t HTD5M pulley would be 71.62mm without flange, let’s say 72mm, that leaves u 13mm, divide that by 2, so u get 6.5mm clearance

let’s not forget belt has thickness, a standard HTD belt is at least 1.5mm thick between each “teeth”
image

so with some maths, ur setup would leave u 5mm of clearance at max, some belts are thicker, so u have even less clearance

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A satellite motor is one that’s not inside the wheel.

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Hihi, I’m a bit late but want to feedback a couple of things here. There’s a good bit of connecting the dots in the middle, if you’re not bothered with that just skip to the end.
As @Andy87 said, as big as possible is good for engaging lots of teeth on the motor pulley because this stops the belt from skipping. A small motor pulley makes the belt contact that pulley at a pretty extreme angle and also has fewer teeth in total so it uses significantly fewer teeth to contact the belt. Transmitting the same power through fewer teeth puts a bigger force on each one, and can mess you up on hard acceleration and especially hard braking. If this is unclear please do let us know, I’ll add some diagrams.

As a very rough point of reference; 14T is about as small as most builders here are comfortable. This means low top speed, high torque, and high chance of skipping. I have used 12T but it is a miserable experience and genuinely a bit unsafe. The good news is that at lower motor kv (160 is a little low) and all else being equal you can use bigger pulleys for an equivalent top speed, and get much more belt traction. Which links nicely to:

At this gear ratio of 14/45 you get a top speed of 29km/h at 10S and 33km/h at 12S, which are both considered very low. This depends a lot on the type of board and rider (a shorter board below 850mm is generally less stable and less suitable for higher speed, and a hardcore vs noob rider makes a huge difference), but IMO those are both very slow for top speeds on a DIY board.

Frame is very right, that’s a small small amount of space here and IMO seems likely to chew through both belts and pulleys.

TLDR;

  1. Top speed is hugely subject to taste so we need to know what you’re comfortable with and expecting to give specific advice. You can go as high as 22T or maybe more on the motor pulley but with smaller motors like yours this isn’t a great idea. 14-20T is probably a good range. As mentioned; use the calculator to find a suitable gearing.
  2. Check the trusted aliexpress vendors thread or something similar if you can’t easily find a place to buy them. I think I’ve bought 20T pulleys in Europe from smaller sellers without too much pain.
  3. 36T motor pulleys for kegel pattern (the same as caguamas) is very common. IMO this is very appropriate for your wheels. If you can, buy these and then adjust motor pulley to taste.
  4. Onsra trucks may be (I’m very much not an expert here) a pain in the ass. Search for them and reply in the threads or link relevant posts, the worst that can happen is you don’t get a great answer but we’re all nerds trying to learn
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Thanks for the detailed reply. :pray:

It’s hard to find the particular details you are looking for, but you answered it. 14-20T for my smaller motors, lower voltage helps a bit… now I’ve read people disagreeing on the voltage/torque ratio subject and I have no idea if that’s true… I don’t have the ability to debate that one… lol

I have the 150mm “AT” wheels back on there now. The caguamas just put the board a little too low, but damn they are a lot of fun. I want a 'thane street deck so I’m probably going put the caguamas on a 40" LY Evo single stack deck, but I need to get the rest of the parts together. I’ll probably go for 2.25 ratio, most likely 36/16. A lot of what seem to be experienced builders are saying that’s the sweet spot for the small thane wheels.

Not sure what’s compatible with the Onsra trucks… another reason why I’m leaning toward building a full DIY deck so I at least have a really nice backup board other than my Backfire G2 :joy:

Thanks again o7