Teenagers e-skateboard for Christmas - On a budget

markz

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What ESC and RC motor for a skateboard would be good for a 8 to 12 yr old kid around the $20-$40 price point.
Are their cheap skate board wheels I can buy so I dont have to fabricate something.

ESC - HobbyKing™ SS Series 190-200A ESC (Opto only) for $30

KEDA 63-64 190KV Brushless Outrunner 10S 2000W for $44
*Is using one of these motors sufficient? Be nice to buy the motor below, but its like double the price. Is there a difference in bearings or something?

Turnigy Aerodrive SK3 - 6374-168kv Brushless Outrunner Motor for $80

Belts and Pulleys - http://www.beltingonline.com/timing-pulleys-bars-272/?zenid=d5bh87r5s023majo7sdci7ecu3
Longboard - online classifieds ~$50
Wheels - use the wheels that came with the skateboard or go to a skate shop.
 
The difference in motors is most likely a difference in the quality of materials used. I've never really heard of the first motor. I have seen plenty of builds using sk3's though and I myself have had no problems from my sk3's for almost two years now. This is with riding the board almost everyday to and from class. As the old saying goes, you get what you pay for.
 
Well I was thinking of using just one motor.

I just go to the HobbyKing website, and look for BIG Outrunner motors around the 200kv mark, and big Amp numbers. That $40 KEDA motor I linked too is 2000W and 90A with 6 to 10S batteries. While everyone and their dog is using the $80 SK3 is 2400W 70A with 12S. Maybe all the heavier people are using the SK3, perhaps the shaft has better bearings. Better quality no doubt, so yeah you are right. I might gamble with the KEDA for shits'n'giggles.

How much do you weigh?

I would like to try and build my own for the kids, whether it be a skateboard or those standup scooter thingy's.
For heavy adult use (200+ lbs) a dual $80x2=$160 SK3 would be great, but no adult in my family skateboards or scooters, just ebikes. A skinny kid ~100lbs I think 2000W is good isnt it?
 
Just a quick thing I'd like to point out - because I made the same mistake when I built my first e-board. The ESC that you linked is an airplane ESC.They are cheaper and support higher max amps, but they're really not designed for e-boards.

Especially braking and cruising in neutral will be problematic, because with most airplane ESCs you'll have to chose between either of them.
Startup is the other big problem, because airplane ESC's don't have the same smooth startup acceleration that a car ESC has.

So if you get that one, it will work but braking won't be anything like you want it to be and accelerating will only really be possible with pushing quite a bit first. I'd recommend you look into some Hobbyking X-car ESC's. They have everything you need, some even come with an on/off switch (which saves you about 40 bucks for a switch and however much the XT90 anti-spark loop key method would cost you).

I can personally recommend this or this (if you wanna go for the 150A model). I use the latter and it does everything you need. Obvious drawback is that you're limited to 6s LiPo's but that's more than enough to get around. Getting 2x3s for a 6s build is cheaper than going for a 2x5s= 10s battery build anyway and your kid probably won't be driving around tens of miles at a time, so you can buy lower capacity ones that are flat and easier to mount.
However, don't forget to get the programming card with that ESC because you can't set any of the settings without it. It doesn't have a beeper menu or anything like that.

As far as the belt and pulleys go - just get the complete set from enertion or diyelectricskateboard or alienpowersystems. I found that it's so much trouble to find the right ones that work perfectly together. Plus all the milling work you need to do to mount it on your trucks afterwards. It's not worth the hassle. Even if you end up paying 20 bucks more on one of the complete sets. Everything fits great and is minimal in sides. I spent about 40 bucks on pulleys before I just said frock it and went with one of the complete sets. I'm an idiot like that though.

Oh and regarding the motor - I think you can get away with a different motor. Most motors are made by the same manufacturers and just labelled differently anyway. However, make sure you go for a 63mm one. I played around with 50mm motors as well because I thought I could do with lighter motors, but they all burned through eventually. At 6'3/220lb I'm on the heavier side though. With a 63mm one, your son should be able to ride hills as well so better safe than sorry.

Hope that helped a bit, mate.
 
Agreed with the post above. I weigh about 165 and my area is really hilly. I'm running dual 63mm on 6s with no problems. I think for someone in the 100lb area a single 63mm on 6s is plenty. Also like he said you will want to use a car esc around 120 or 150 amp. Also you'll need the programmer for your individual esc so you can change the settings around.
 
Car ESC
Any paticular name?
http://www.hobbyking.com/hobbyking/store/__418__182__Speed_Controllers_ESC_-Car_ESC.html
Or do I just eyeball the Amp rating.
 
You would prefer 6s or better. for a conventional belted geared setup.

http://www.banggood.com/Racerstar-4076-Brushless-Waterproof-Sensorless-Motor-2000KV-120A-ESC-18-Cars-RC-Car-Parts-p-1080781.html?rmmds=search

This would be run as a direct drive, no belts, the motor shaft simply presses on the wheel, to turn it.

The shaft comes out 20mm, the motor is attached to angle aluminum, instead of flat aluminum. This gives a stiffer assembly and more area to wells to the trruck.

If you really wanted to you could up the power to 6S, It makes sense to keep the power limited to 3s.

The whole thing is a bargain, because the ESC is 120 A 6S, and suitable for a high-powered skateboard in the future.

This powertrain should have plenty of grunt for a light kid, but The more you ask, The faster the wheels will wear. The nice thing is you have four of them and you could rotate the wheels, with no extra cost.
 

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http://www.banggood.com/Racerstar-F540-Waterproof-Brushless-Motor-45A-ESC-For-110-Buggy-Racing-Cars-p-1056319.html?rmmds=detail-left-viewhistory

This would work as well for a super budget build.

You don't have a lot of friction area, so it can (and should) slip under severe use, however that is OK because you are a trying to keep the speed low and not break anything.

A penny board at 10 mph is scary fast anyways.

Obviously if your eight-year-old is 160 pounds, this might not be the best.
 

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What do you do with 2000 or 3000kv motors? Isn't that trying to spin waaaaaay to fast for longboard use? I know you could gear it down, but I'm not sure you could achieve that ratio in one step?
 
Wow yeah I didnt see the KV on those. Thats too high.
Might be doable to gear it down, but gear it down in a 10:1 ratio, all underneath the skate board deck. :shock:

Yeah its gunna look like a hack job with $50 worth of sprockets, so its gunna be a offroad skateboard for the cabin and not school. If I do it that way. 3.5" is a mile for a skateboard.

Im just gunna buy a ~200KV motor. And buy them gears and pulleys in the first link and figure out how to drive the wheel(s).
 
MagiicHat said:
What do you do with 2000 or 3000kv motors? Isn't that trying to spin waaaaaay to fast for longboard use? I know you could gear it down, but I'm not sure you could achieve that ratio in one step?


Does nobody ever read anything? Or am I really sucky at communicating?


I'm pretty sure there's no ambiguity in "direct Drive, the shaft presses against the wheel."

Also, I provided the calculations for you in graphic form. 1:1 drive use any wheel size the speed is the same.

The engineering is solid, even though it's not a lot of surface area for the friction, the small shaft is not trying to move that much per revolution, so the force transferred works out well. If you keep it down below 3-600 W per motor, that's a fun vehicle.

I wouldn't think an eight-year-old Should go more than 8-10 mph, maybe slower if they can't run it out.

So it's possible that it still overpowered, even in the super cheap build, depending on how heavy the person is.

The build with 120A Esc has a big motor, but if you try and take advantage of all of that power on 6s single drive you'll run into mechanical issues with heating up the wheel, and slippage.

On 6s it's a top speed 26MPH, 2800w rated 400g motor, which is actually pretty big even For a full size adult. I forget what size the boosted motor is but probably a similar weight and power handling.
 
Hi
My 2 Cents - take it or leave it, just my opinion.
I would advise pretty strongly against those two Banggood options. A direct drive, with the shaft pressing on the wheel, is IMHO a bad idea.
First off you would have to have some form of cohesion between shaft and wheel. A nice polished shaft on Urethane is not going to give any traction. It will, I imagine as I have obviously never tried this, spin (very high KV motor) like crazy, get warm and melt the urethane. (I know there are direct drive, basically clip-on modules out there - if you are going this route get them rather)
I am thinking the bloke wants something decent for his kid, even if on a budget. I would still suggest a low KV motor (5065 would do for a small kid) with pulley and wheel gear together with a 6S battery and ESC.
Gear it real low for slower speed and you can always change the gearing easily to suit if needed.
 
dannydoyle2 said:
Just a quick thing I'd like to point out - because I made the same mistake when I built my first e-board. The ESC that you linked is an airplane ESC.They are cheaper and support higher max amps, but they're really not designed for e-boards.

Especially braking and cruising in neutral will be problematic, because with most airplane ESCs you'll have to chose between either of them.
Startup is the other big problem, because airplane ESC's don't have the same smooth startup acceleration that a car ESC has.

So if you get that one, it will work but braking won't be anything like you want it to be and accelerating will only really be possible with pushing quite a bit first. I'd recommend you look into some Hobbyking X-car ESC's. They have everything you need, some even come with an on/off switch (which saves you about 40 bucks for a switch and however much the XT90 anti-spark loop key method would cost you).

I can personally recommend this or this (if you wanna go for the 150A model). I use the latter and it does everything you need. Obvious drawback is that you're limited to 6s LiPo's but that's more than enough to get around. Getting 2x3s for a 6s build is cheaper than going for a 2x5s= 10s battery build anyway and your kid probably won't be driving around tens of miles at a time, so you can buy lower capacity ones that are flat and easier to mount.
However, don't forget to get the programming card with that ESC because you can't set any of the settings without it. It doesn't have a beeper menu or anything like that.

As far as the belt and pulleys go - just get the complete set from enertion or diyelectricskateboard or alienpowersystems. I found that it's so much trouble to find the right ones that work perfectly together. Plus all the milling work you need to do to mount it on your trucks afterwards. It's not worth the hassle. Even if you end up paying 20 bucks more on one of the complete sets. Everything fits great and is minimal in sides. I spent about 40 bucks on pulleys before I just said frock it and went with one of the complete sets. I'm an idiot like that though.

Oh and regarding the motor - I think you can get away with a different motor. Most motors are made by the same manufacturers and just labelled differently anyway. However, make sure you go for a 63mm one. I played around with 50mm motors as well because I thought I could do with lighter motors, but they all burned through eventually. At 6'3/220lb I'm on the heavier side though. With a 63mm one, your son should be able to ride hills as well so better safe than sorry.

Hope that helped a bit, mate.

I popped into here looking to glean some information and thinking about building my first board. I have a bunch of ebikes and I skate already, so I have no idea why I've been staying away from this side of the game.

This particular post is VERY helpful. I think with my knowledge of ebikes and such, I was just needing some insider knowledge as to where to start and what things to avoid. You laid out a really nice plan and I think I will be building one for myself soon.

Great discussion here guys! Sub'd
 
Give us your thoughts on this cal, what are you thinking?


I popped into here looking to glean some information and thinking about building my first board. I have a bunch of ebikes and I skate already, so I have no idea why I've been staying away from this side of the game.

This particular post is VERY helpful. I think with my knowledge of ebikes and such, I was just needing some insider knowledge as to where to start and what things to avoid. You laid out a really nice plan and I think I will be building one for myself soon.

Great discussion here guys! Sub'd
 
WeeChumlee said:
Hi
My 2 Cents - take it or leave it, just my opinion.
I would advise pretty strongly against those two Banggood options. A direct drive, with the shaft pressing on the wheel, is IMHO a bad idea.
First off you would have to have some form of cohesion between shaft and wheel. A nice polished shaft on Urethane is not going to give any traction. It will, I imagine as I have obviously never tried this, spin (very high KV motor) like crazy, get warm and melt the urethane. (I know there are direct drive, basically clip-on modules out there - if you are going this route get them rather)
I am thinking the bloke wants something decent for his kid, even if on a budget. I would still suggest a low KV motor (5065 would do for a small kid) with pulley and wheel gear together with a 6S battery and ESC.
Gear it real low for slower speed and you can always change the gearing easily to suit if needed.


You're wrong, I have no desire to make something for who's under 80 pounds but, it's definitely workable and you don't seem to understand gearing very well.

Is a great from a dead stop, duh, NO. But much of can be done with only a few tens of watts. It's not spinning at the same place, so the urethane will only melt under the conditions I already stated.

You're pretty much repeating my warning, but saying oh it won't work at all. it will, if you use a tiny bit of forethought and adjustability.

What you suggested would not fit the budget, even a little bit.


As a simple exercise, why don't you just get a 3 mm shaft, and see how much braking/pushing power it has, it's a decent amount for A kid at any safe speed.
 
surface area for the friction, the small shaft is not trying to move that much per revolution, so the force transferred works out well. If you keep it down below 3-600 W per motor, that's a fun vehicle.

Maybe you missed this. The gear ratio is around 30 to 1 If you use an 83 mm wheel, it makes sense for you to understand what's going on before you say something won't work.
 
NyOliver said:
surface area for the friction, the small shaft is not trying to move that much per revolution, so the force transferred works out well. If you keep it down below 3-600 W per motor, that's a fun vehicle.

Maybe you missed this. The gear ratio is around 30 to 1 If you use an 83 mm wheel, it makes sense for you to understand what's going on before you say something won't work.


think you need to check your calculations.
 
xadmx said:
NyOliver said:
surface area for the friction, the small shaft is not trying to move that much per revolution, so the force transferred works out well. If you keep it down below 3-600 W per motor, that's a fun vehicle.

Maybe you missed this. The gear ratio is around 30 to 1 If you use an 83 mm wheel, it makes sense for you to understand what's going on before you say something won't work.


think you need to check your calculations.


It's slightly less, but not in any meaningful way, considering it's stated as an approximation. For every single revolution of the motor, The wheel moves 9.4mm, and if you know the circumference of an 83mm wheel, how many times does the motor need to turn to make one revolution of the wheel.
 
My dear chap, I never said it would not work at all. What I said is that I, personally, would not recommend it.
Get down off your horse please.
And yes, I do understand gearing. Pretty well actually.
Would I do what you suggest? Nope, not at all - but that is just me. If the OP wants to go that way then by all means. I would love to see the end result, I am always game for a chuckle.
 
WeeChumlee said:
My dear chap, I never said it would not work at all. What I said is that I, personally, would not recommend it.
Get down off your horse please.
And yes, I do understand gearing. Pretty well actually.
Would I do what you suggest? Nope, not at all - but that is just me. If the OP wants to go that way then by all means. I would love to see the end result, I am always game for a chuckle.


You said "bad idea", "no traction", and "melt the urethane". Despite what you're saying now, clearly you said it would not work. I'm glad you said you had no experience and were imagining it but, your imagination is wrong. Laugh all you want.

Edit: it's just really sad when somebody with zero experience, and a poor critical skills tries to shut down actual workable engineering based ideas.

There are more than a couple direct drive friction builds on here, and they don't melt wheels, despite the fact that they are moving actual adults at speeds where Wind resistance comes into play. The amount of energy applied to the wheel as friction is approximately the same, as long as you're not slipping.

It only takes a few tens of watts to go forward on level ground at slow jogging pace,

At just 1 MPH the motor is already turning at 2000 RPM, so even a the tiniest push off lets the motor get to work.
 
image.jpegFriction Chart.

Urethane, which is what skateboard wheels are made of, is such an appropriate material for friction drive that it is used for friction drive. Pushing around paper, metal rollers, plastic etc. and in case it's not obvious, the duro, we use for longboard wheels is just dandy for polished steel.

I really don't like wasting my time explaining things to people who lack engineering sense or imagination, however I hope if anybody is following this thread, they can see the clear reasons this works fine, as far as friction drive.

I think it's an elegant and very well fitting solution for the price and desired result, moving somebody around and under 10 miles an hour, up to 100 pounds. It will work for heavier and hills, at the cost of increased wheel wear.

View attachment 1
 
I'd like my board to be able to get me to work if I really felt like doing it, so 15 miles of range (work is about 13). There are some minor hills around and I would like to be able to zoom up them. I like to build on the capable side of things and use them well within their design envelope. I'd be building my own battery out of 18650s, not sure about what voltage I would run at, but likely dual motors and a 150A esc.

I have a bunch of carbon fiber laying around from an old project and might even make my own deck (unlikely for 1.0 though)

I like dannydoyle2's suggestions and will source a kit for my cogs and belts from diyelectricskateboard. Now that I do think of it a bit, I will likely go 12S since most of my current gear is set for that. I think I can tune down as needed from there.

Does that sound like a decent plan?

markz said:
Give us your thoughts on this cal, what are you thinking?


I popped into here looking to glean some information and thinking about building my first board. I have a bunch of ebikes and I skate already, so I have no idea why I've been staying away from this side of the game.

This particular post is VERY helpful. I think with my knowledge of ebikes and such, I was just needing some insider knowledge as to where to start and what things to avoid. You laid out a really nice plan and I think I will be building one for myself soon.

Great discussion here guys! Sub'd
 
Hmm, where did I say I had no experience?
Actually I have built a few boards so I would say I do have a bit of experience.
You seem to have anger issues, take a Valium or two.
There are friction drives, I know, and did state that. Just not quite as you are suggesting.
If you could show a working example of the setup you are suggesting I would love to see it.
I have absolutely no problem in being proven wrong but I stick to my opinion that it is, in the setup you describe, a bad idea.
You seem to be very certain of it, and are obviously so experienced, so I presume you have done it before?
Show us this setup, with someone riding it. If it is such a great idea and so easy and cheap I am sure there are many who would love to see it.
 
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