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Dual 9mm belt project



Hey guys,

I have been working on this project for a little while now. I have read about people snapping/stripping belts and want to prevent that from happening to me so I decided on a dual 9mm belt setup. My dad is a machinist so I have access to all kinds of machines. I know I am going to have to modify mounts and trucks to make this fit but other than that it should be cake.
Here are the 2 rough cut pulleys as of now.

Both are aluminum. 14 and 36 tooth
Totally overkill but should look pretty sweet and allow plenty of torque transfer.
I’ll update when I get everything finished up (probably after holidays)



The pulleys look awesome, what technique did you use to machine the grooves?

Have you thought about using 15mm belts? 5m HTD is available in 15mm as standard. I know that is slightly less than the combined 18mm width from 2*9mm belts but wouldn’t make much of a difference for the added simplicity. I know boosted boards use 15mm belts but they also use 3m pitch.



Yep I thought about going with the 15mm but I thought it would be nice to run 2 belts as to have a backup if one failed (rocks or something poking holes in) Really no other reasons behind it lol.

The pulleys were cut down to width on a lathe and then cut the groves out with a cnc mill. Took a few tries to get the correct size and spacing.


cool they look really nice, I have access to a waterjet cutter at Uni so was thinking of getting some pulleys cut, not sure how the kerf would affect the performance though. I might have a go at making some on my CNC router, its lacking the required stiffness for aluminium although possible its just slooooow.

The only thing I would say about using 2 belts next to each other is they may start to slip over each other during operation. If you made a thin plate that ran between the 2 that might work better.


Thanks for the tip! I will do some testing when it’s done.

Good luck with yours!


sweet be sure to share some photos when your done, if you’ve got any during machining i would like to take a look also :smile:


Got the pulleys on and did a test run, so far so good!

I had to use a few washers on the inside of the axle to give it enough room to fit and line up the pulleys ( without modifying the truck/mount). Have just enough threads to hold the wheel on. Totally overkill but it’s done now :slight_smile:



Whose motor is that?


That’s a Tacon Big Foot 160.


How did you fit the 18mm on the shaft?


That’s a tacon bigfoot


How big is the shaft? I thought it was short like a SK3?



It overhangs a bit. Shouldn’t cause any problems.


Yup! Never had an issue using these motors.


I’m offended you’d ask such a personal question :blush:



All joking aside, this is a great job by you and your dad! @sk8ace did the motor pulley end up with just teeth across it’s face? This really makes single drive setups bullet proof!



Thank you!

Here’s a quick side shot,


You can see that it’s open on one side and raised up on the motor side.