Based on the Otherboard MP1 caster. I intend to make a motor mount and wheel adapter that should allow almost any motor size and a max wheel size of 80x40mm.
The Otherboard MP1 is supposed to be a super durable freebord orientated caster.
I already have the motor mount and idler figured out and 3d printed. even my 3d print is strong enough to stand on since most of the weight it distributed directly to the caster. Eventually I will seek out someone to make this part in aluminum. Still needs a lot of work tho.
I am currently figuring out the adapter.
My currant plan is to use the space for the bearing to house the adapter.
Almost all skateboard wheels have a lip the separates the two bearings on both sides.
The Leif and the SBX slip rings have the same diameters for all the rings, so if you were going to make the same type of slip ring it would be helpful to keep those dimensions for your version. Unless you see a reason not to.
Lastly if you think DIYing the slip rings from scratch is difficult, on the leif the bushes regularly get pushed all the way down and you have to bend them back to their position. Thats like the same process as making from scratch with diy bent brushes and a pcb. If you wanted to make your design very modular the brushes could be on their own mini pcb then they are all held down by a bunch of screws into a printed base, burn a brush somehow you just swap it with 2 screws and and wire.
I believe what causes the sbx slip ring to get compressed is the fact that you are standing on them. I want to mount them in a way where they aren’t supporting any weight. This manufacturer has a one piece slip ring that should be perfect for this.
If I can find a hub motor that is spherical shaped and ~80mm without having a shit wattage then I’d be happy but I don’t think such a thing exist. Electric Skateboard Hub Motors Kit - BOUNDMOTOR is the closest I could find and it is still 105mm far to large for my application.
This comes into play in relation to the slip ring because on the SBX sr360 disk/plate the opening is just wide enough to let the entire caster be removed while the sr360 plate is held in place theoretically.
possibly helpful for service especially if you wanted your slip ring to be constrained separately from the castor.
Part of me bringing this up is I wanted to ask how important you feel the CAM/Caster self-centering is for an electric board with a slip ring? perhaps important enough for me to try making a sbx size/compatible bearing block and cam (including the ability to remove through sr360 center hole as just mentioned)
Which is what it sounds like the deal would be with your slip rings from
grand slip ring co
Slip ring would have a bearing feature standalone is my assumtion from looking at them.
I forgot to mention I have the CAD model for the JMK Freeskates wheels, I also should mention reports of them failing and causing crashes at high speeds due to heat/core failures. Not sure if adding that printed part you showed and a lot of epoxy can help with that.
Update. Redesigned the whole caster bracket to be laser cut and bend into shape. same process as the original. Since everything is now once piece then it should be stronger and easier to assemble then before.
This design uses a wheel adapter that sits in the core of JMK wheel in place of the brearing. This adapter will get epoxied into place. The flanged bearings are mounted inside caster frame. The adapter will be keyd and this will allow the entire axle to spin freely. Spacers sit between the bearing and the wheel adapter.
no I don’t think they said the wheel core failure was due to bearings failing (although possible) I think they said the heat built up from the outside of the wheel traveled in and the core eventually snapped.
Worth opening a chat up with Marco Other although he does not like you posting pics like that last one.
The solution they use now is smaller longboard wheels that are lathed for rounded profiles.
When I heard of this I wondered if encasing the wheel core in epoxy + glass fiber would help or hurt.
Interesting. Well I did intend for the caster to be compatible with other wheels so I’ll check that in the future. Lol what you mean he doesn’t like the pic? Is he mad about a efreebord is that I am using his design to do it?
I saw someone posting about them so I asked for a picture of the cam and I got this msg
btw my thoughts on your interesting choice of bending your castor frame are that its probably cheap compared to buying large alu C channel extrusion and needing multiple CNC operations. My only concern is how accurate the 2 bends will be because that would determine how the drive shaft lines up and if the motor/wheel pulleys are exactly aligned as well. Very interested to see how well your belt survives testing.
Finally got back to working on this ecaster.
the original plan was to use a custom made slipring from moflon.com but after I realized the cost involved in custom making a slipring($150-200) I decided to use some of the old leiftech/sbx sliprings I had lying around. I do still plan to have a custom slipring made in the future once I have verified that all of the caster parts work.
I had a slipring with a broken housing with got me thinking. I could just print a custom housing for it. most of the issues with summeboards sliprings seems to come from when the brushes loose contact and ark/short against the rings. so If I could press the two half’s together in a more reliable way then it should eliminate some of the failures that come from the original design.