Yeah I mean hanger width. I have to disagree with you, because a) longboard trucks are different than car axles, and b) check out what ronin (one of the best truck makers on the planet says about this) says regarding this topic:
“Despite popular belief, narrower is not less stable. What you get is a quicker turning truck that allows you to better apply your weight on the wheels. The cleaner you are through the turn, the faster you go, and narrower setups provide this.”
Alright guys, I just wanted to give y’all an update on where I’m at. I decided to go with Caliber II pivot cup and bushing seats, because a) they are some of the most common and b) they take some of the biggest pivot cups, which gives me more confidence about the longevity and durability. I have designed the baseplate with the pivot cup seat, but I haven’t designed the kingpin holder because I wanted to do the hanger first.
Now, the hanger is where things are getting really interesting. I used this website https://celsiainc.com/heat-sink-size-calculator/ to roughly estimate how much heat sink volume I need. I plugged in 1,512 Watts, or 50.4 Volts (a fully charged 12S battery) x 30 amps. Then I plugged in 60 degrees Celsius as the maximum temperature for the motors (obviously motors can get much hotter and still be okay but 60 degrees is about the temperature where they start to temporarily demagnetize, which quickly reduces efficiency) and 25 degrees as the maximum ambient temperature. I got 3456 cm3! And that’s for one side (aka one motor)! For two sides it would be 3456 x 2 = 6912 cm3. So obviously I can’t meet that number. But I can try. I’ve been designing the hanger with as much heat sink as possible. And the result is… 118.7 cm3 in volume! Lol. But some is better than none.
Here’s a picture of my current design:
Okay, a little update. I decided to go with Carvon style motors in the end. I think they just have so many advantages to Hummie style motors (not that Hummie style motors are at all bad). I am currently redesigning a lot of stuff, but I will post a picture once I have made some progress.
I think if the motor was totally inefficient and turned everything to heat that would be appropriate but much of that energy is turned to motion. maybe could assume 85% efficiency and cut 85% off that number
bigger and bigger hanger with lots of fins but how about a better conduit for the heat. will the motor just be sitting against the hanger aluminum because even with thermal paste that area is sure to be the bottleneck. it needs more contact either by being a continuous metal all the way under the stator or much more surface area in contact.
maybe forget that approach of trying to transfer from the motor’s metal case transfering to the hanger and instead have the phase wires or magnet wires going through the hanger. they’d have to be electrically isolated somehow but if that can be done and still with a good thermal pathway then you could free the rest of the design up for other goals. also those wires coming out could be made much more robust and that’s where a lot of hubs break.
to make the wires insulated electrically but with a good thermal pathway is a challenge. the best i came up with was some thermally conductive silicone and was planning to make wires with it but it’s not nearly as strong as typical silicone for wires and dont think it will work that way. thermal and electrical conductivity seem to go hand in hand.
you can get magnets that have different much higher currie temp (demagnetize) and the lead up to that temp and subsequent temporary loss of magnetism is also moved to higher temps.
That’s super interesting Hummie! Thanks for giving your input on this thread, I was hoping some of the big guys would chime in 
no problem this is fun for me i like design challenges. I only have big interest. …and hopefully you see things my way and further develop it. gotta find that conductive insulator/ insulating conductor and figure a way to do it practically. another option which would be easier would be flattening the motor leads or better yet the magnet wire as it comes out of the motor and epoxying it to the hanger outside. could look really nice or could like like a kindergarten art project but a lot easier. a thin coat of epoxy on the wires after banging them flat and then just glue them on, maybe route them up to some imbedded bullet plugs or something would be slick
Quick update. I’m super torn between Hummie style hubs and Carvon style hubs still. Earlier I said I was going to go with Carvon style, but now I’m not so sure. Deciding what to design is almost harder than designing!
how bout you do an inrunner motor in the hanger.
Interesting. Can you elaborate?
I vouch for carvon, as you get a full amount of urethane to dampen the ride, with in-wheel hubs you will only get about 10-20mm of urethane
True, but with Hummie style hubs you have waaay more protection for the motor.
This is my latest design. I think it looks a lot better than the hexagonal one.
Just add a urethane sleeve…second wheel?
I like the idea but it doesn’t look to be a simple CNC job. Also, some of the shown geometries are nearly impossible to machine. Curious what the outcome is! A few people have tried making CNC trucks but never really marketed the thing. Making trucks is pretty expensive. My own set (just the hangers) cost me $270 per piece machined out of AL7075 and abut $240 out of AL6082. Adding things like a queenpin is a nice idea but is going to be expensive at the end of the day. Not sure if you find a lot of people who are willing to buy a CNC truck for their cheap Chinese hubs
Yeah, this is a passion project and I don’t really give a fuck about whether or not it’s too expensive to sell 
Good points. I would also suggest that once the design is finalized it’s a good idea to speak to the one that’s going to machine it and see if there is changes that can be made to simplify machining without sacrificing to much on the design. Small simple things can make a huuuuge difference in cost/time.
There is always the possibility to upload the 3D file to xometry or 3D hubs to get an instant quote. They also show the price reduction for multiple copies. When tighter tolerances come into the game e.g. axle concentricity or pivot seat, the price changes pretty quick.
Cough A layer of Gelid Extreme or Shin Etsu compound trapped around your cables and hanger, then epoxy armor lacquered on top of it Cough
There goes your insulated thermal conductor for your wires 
Yes with planetary gears in the wheel!
I dont know what shin etsu product you were thinking but the gelid extreme stuff looks awesome, but im still not sure what you meant to do with it. If gluing flattened motor wires to the hanger id think it wouldnt be worth using a paste and just the thinnest insulator between the wire and hanger…a painting of epoxy. But if you mean a hole in the hanger…then yea maybe just a thin painting of epoxy in the hole and insert the tight fitting wire with the gelid stuff to fill any gaps. seems risky though and fear the wire would be not secured and eventually if it rubs the epoxy off against the inside of the hanger. just gluing the flattened motor wires to the outside of the hanger with a very thin heat resistant epoxy is seeming the more reliable and doable. I dont think a conductive epoxy would be as good and instead a pure resin unfilled and the thinnest coat possible. if the wire cant move it seems safe. so i think. or maybe the wires in the holes if they were the original motor leads with their insulation and then fill the hole with a harder resin like a highly filled epoxy so the wires were fully secured. @Luvafreeride planetary gears maybe are an unnecessary complication if you can make the motor big and strong enough. they make noise and need maintenance and will be the first to break. try to make it all as simple as possible and more likely to actually make it to reality.