Heya guys! I’m here on behalf of a friend, she is trying to make an electric penny board for $250. This type of build is not what I’m used to so I need help finding better options. Currently it’s looking like $310 which is too much
Hi, it certainly is possible to build such a cheap board that works.
If it can be a bit more work then plug and play, you could use an small brushless outrunner with a belt or a chain. The belt probably would have to be HTD3 due to the wheel size, so Id recommend the chain, as my HTD3 belt was skipping a lot.
You can buy a whole penny board with trucks and wheels off of eBay for around 25Dollar (or at least in Germany you can, I don’t know how it is in the US, as I guess that’s where you’re coming from). The board won’t be good for that prize, but it will be working.
You could make the motor mount yourself pretty easily if you can work with aluminum or know someone who can.
Doing it the way of building most of it yourself will be the cheapest, but also the hardest. If you want I can share a few pictures of how I made my mount.
I think I can get a board for $25ish off eBay, mount with pulleys and belts for $40, a motor for $30, and clone wheels for $20 but I’m not sure if the mounts will even fit
The problem I had with the mount is that the axle doesn’t have the length for standard motor mounts. What I came up with is basically a block that gets screwed and glued onto the truck. The plate which holds the motor gets screwed on to that block with two countersunk screws.
Yep, it is. I just turned it down to make room for the pulley and drilled the hole(s) into. If done right only one hole needs to be drilled into the truck, but I don’t think you can get away without turning (or filing) at all. The benefit of working on a cheap truck is that the aluminium is pretty soft, so it wont take that long to get the truck ready to accept the mount and pulley.
I bored it to the right diameter on the lathe, and then drilled the holes for the screws on the drill press. You can maybe get around this step by printing a pulley. You would only need to drill holes into the wheel then, which is pretty easy with a drill press. There are some topics about 3d printed pulleys you could have a look into then.
If you meant the motor pulley, that is just bored to the shafts diameter and then glued onto the motor shaft with Loctite 648. If you glue it right and give it enough time to cure it will hold up just fine.
Speed?
Depends on who you ask, I won’t go above 45kmh for now.
If you meant kV its not that easy. You should take the max speed, voltage, wheel size, and gear ratio into consideration. When using a belt with normal wheels, the gear ratio shouldn’t be more than about 1:3 (just a guess, I’d rather stay underneath). If the ratio is too high, there won’t be enough teeth engaged to transmit the power and the belt will skip.
If you use a chain I’d say you can have slightly higher gear ratios, as skipping teeth won’t really happen here.
Here is a calculator where you can enter all your variables and see which speed you will achieve:
Oh I can get the specs, I’ve got some motors in a cart and a custom calculator, I just wanted to know what nominal speed I’m aiming for, I’m guessing 17mph is the highest you can reasonably go? I got to 22 on a cheap nickle board with RKP trucks and it nearly killed me
On my current board I drive around at around 27mph pretty often if the road is in good condition. The board has RKP trucks whitch are 180mm wide, but the board isn’t that much longer then a penny board.
On my penny board I had a max speed of around 20mph. I had gone that speed occasionally, but I wouldn’t go any faster on an penny board myself.
I haven’t tried it myself, but i have seen some pictures of penny boards with 80mm or bigger wheels, i don’t know if they were with or without risers anymore tho. It could get pretty tight with 80mm wheels, but you can still use risers, and bigger wheels mean more comfort and a smoother ride.
