My name is Jamie, I’m a mechanical engineering student from the UK. I’m currently in the process of building my first ESK8 which will be a commuter longboard. The project log with regular progress updates can be found here: Building an Electric Longboard | Hackaday.io
During my research and sourcing, I’ve come across a problem. I’m sure I’m not the first to encounter this. In the UK, it is rather difficult to source high quality Caliber motor mounts. Those currently available and in-stock on the market are either unbelievably expensive, have high overseas shipping fees, or are cheap chinesium generic mounts which look like a recipe for a hospital trip.
I have decided to design and manufacture my own motor mount, with a focus on being as feature-rich as possible for maximum adjustability and versatility, whilst being low cost to manufacture. After a few design revisions, and conversations with machinists to assess the producibility, I have this:
That’s my main inspiration for this design. However, at $35 each, with another $35 shipping I figured I’d like to produce my own .
With respect to the corner that angers you, could you explain what is wrong with it? It’s only there due to the way I constructed the slot geometry and is an easy fix.
I’ve personally found that with an idler on only one side I get belt skipping when the other side (without the idler) gets engaged. I suggest modifying your design to accept dual idlers in case you experience the same issue.
The rest looks pretty standard and doable, although those cross braces won’t do much. I’d move them behind the motors, way more effective there, leverage-wise.
I know BN does the same thing, but I’m not a huge fan of this design
There is a lot of force with an 800g motor on a long lever when hitting big bumps on urethanes at speed. Those closely spaced holes don’t leave a lot of material in the soft aluminum to resist movement.
I think some sort of finger locking design that bolts together would be a lot more secure.
Also it is my solemn opinion that idlers are worthless. They add more rolling resistance and force you to make longer motor mounts to accommodate. Better to have shorter plates for forward mounting and just properly set the belt tension. Shorter mounts leave more room for a larger enclosure which means more battery which = more better
Thanks for the advice. Originally I had a square end with the cross braces in each corner but it looked odd so I moved them to the centre without really considering the structural effect. W.r.t closing that up, as I’m planning to use 608 bearings with an m8 screw for the idler I’d need to create a “bulge” to ensure enough variation in the position. Not sure if that makes sense? I’ll explore the design a bit more, cheers
Using a through bolt with a nut on the other side vs being theaded into the aluminum would make it more secure, reduce the risk of stripping the aluminum threads, and would be cheaper to manufacture
An aluminium thread is just a bolt through in the making.
Not fully, idlers allow for variation in belt length and are kinda needed for large wheel pulleys, as otherwise the belt starts slipping on the motor pulley.
I’m not sure how that affects the closing up? Also you don’t really need an idler for your setup, they make more sense for big wheels pulleys, like 60T+.
Check the diameter of the motor shaft opening. Some motors have a somewhat flush circlip that needs a larger diameter not to rub. At least a 15mm opening. BN uses 16mm.
Good work so far though. Hopefully this doesn’t come off as nitpicking. I went through this process with some personal mounts and there are all sorts of things you don’t even know you don’t know until you start abusing them.
The Torque v6 mounts were some of the worst designed mounts I’ve ever had the pleasure of using. Never do this.
Just a little nitpick, the printed parts would have been much stronger if you had instead increased the perimenter count to completely fill in the part.
Check out how it broke though… across the layers. The design isn’t optimized for plastic, as it’s clear that the thin area that it stresses was too much for both, maybe a double clamp like the BN mounts use would be better for plastic.
I also haven’t seen anyone use a pure 3d printed mount, but maybe someone has successfully done it. Most seem to have at least a metal plate for reinforcement or something.
which means more battery which = more better 
threadlocker
