The Heavyweight (Hub Motor Build)

Freshair

100 W
Joined
Mar 12, 2014
Messages
122
Location
British Columbia
Made a bunch of changes recently which freed up a lot of time and a little bit of money, and since my job entails running cnc's figure it was about time to build me an electric longboard. The heavyweight is quite a suitable name since without batteries it weighs 15 lbs.



First was to take apart the sk6374's and figure out how I was going to mount these stators onto my roja hybrid hangers. Did not foresee a problem though since the hangers are cylindrical.



Ended up making an axle extension that screws onto the hanger and slides into this recess in the stator



And as you can see, decided to put thermally conductive potting epoxy on my windings

The other side conveniently had three screws that I could use to fully secure the stator from movement, and ended up making a flange welded to the hanger to support everything



Made a plug for the can so that I could get the potting epoxy in between the magnets as well.



Decided that the original flange for the larger bearing was too flimsy, and it also needed to be a little wider so I could tap larger screws thru it to later on secure the liner which slides over the can and bonds the urethane. Also the tiny little bearing on the other side just would not do, so made a new flange which fits regular 608 bearings, and beefed it up a good deal.




Everything went together just as imagined


Had some urethane cored out for me by pediglide, and made some liners to bond them to. Ended up making the liners out of steel, it is a little heavier but far stronger and from what I understand thru asking about on the sphere, steel on the outside of the can helps keep the magnetism where it belongs which couldn't hurt


And with everything put together, it is looking pretty stealthy!!



Also decided to 3D print badwolfs enclosure for the gt2b



And that is where it rests for now. Am making a big move out to Australia come sept 20, and will be taking this with me and getting in touch with onloop about putting a space cell underneath the deck, as well as getting jacob to set me up with a couple of vesc's. Will keep updating this thread as everything comes together, and will take video of her maiden voyage!

:mrgreen:
 
Oh no worries, but I think we really need to thank Stielz for being the first. And maybe even adrian_sm and Kepler for showing the possibility of using the SK3 motors with the skirt bearing.
 
True enough, stielz was the first I saw to do something along these lines, not sure who those other guys are though, but many thanks for all!

On a side note, it is incredible how little resistance there is just pushing around on the board with the motors in the wheels, with the momentum these big wheels generate you would think there is no motor at all causing resistance!
 
beautiful setup Freshair!

I thought i was the first e-GBomb, but you've really built a custom board here. Love what you are doing with a truly custom build. My whole setup was just about 20lbs with batteries (8s 8Ah). I'd just built a 12s setup and unfortunately was dumb and left it in my car at work (stolen). I'm planning to rebuild now and hope scott/subsonic can help me redo this board. Mine was the previous generation of the adjustable drop brackets and the lighter mahogany deck.

my setup before the 12s batteries:
20150721_224609.jpg


With the new brackets likely much ligher i think i can rebuild and save a bunch of weight!

nice build and will follow!!
 
Thanks guys :mrgreen:

Sheeeeeit! Man that is no fun, sucks to hear that your wheels were stolen...
Other than the time and money that you lost, at least you'll get to take that experience and build something even better, and will be watching for the build when you do!
Pretty sure you are the first e-gbomber, my setup is not even electric yet, just home to a couple electric motors at the moment. Getting there though!
Yep, the new brackets and mounting system are quite a bit more refined, you will definitely enjoy them! Can't imagine ever going back to a normal set up, it is far too convenient to be able to fit massive wheels and to adjust the dynamics of the board at will, all in a nicely dropped set up! You outta try out some of the roja hybrid trucks...a little pricey but if you like adjustability, they are the bees knees! Can turn my trucks from a pumping/carving set up, to a speed machine setup in about 2 minutes, and the hanger is not likely to bend after even the toughest abuse!

Cheers!
 
To ask about the endcap of the sk3 motor with the notches that help space the magnets. How is that part removed from the sk3 motor before you rebuild it? From the pictures, I'm thinking it was press fitted in.
 
Yep it is just a press fit with some epoxy, a few love taps with a rubber punch will remove it from its home.
 
Very nice, any chance you could upload the dimensions for the teeth mounting you used if they are accurate? Also, how hard was it to remove the end bell? I am trying to find the best way to modify one as manufacturers aren't being helpful.

Cheers
 
Not hard at all, like mentioned above your comment, all it takes is a couple love taps with a rubber punch.
Once you have the bell off it is pretty simple to measure and duplicate. Will see what I can do this week at work to get those dimensions for yea.
 
Hey Freshair - can you walk me through your badwolf v2 GT2b? I have a new v2 being printed and want to install the electronics into the smaller BW enclosure. He doesn't show the steps all that well and not sure about the resistors you need to install? Do you still have throttle trim?

Where in Australia are you locating to? We did a 2 week trip (too short) in 2014 and loved it! Melbourne, Sydney, Adelaide, Darwin - hurricane re-route instead of Cannes for barrier reef diving :( . Absolutely amazing trip and the coolest folks to hang out with!!!

Beautiful build so far and will follow your progression.
 
The instructions are pretty straight forward once you start taking everything apart and looking at it, but like you was also confused about the resistors and had to send badwolf a message to straighten it out. Basically you take the leg of one resistor and solder it to the outside left pin (of the three highlight pins) than take the leg of the second resistor and solder it to the outside right pin, and than solder the two remaining resistor legs together to the middle pin. There is not much room for both legs on the middle pin so used a separate wire to connect to the two joined legs.
Not sure what you mean by throttle trim?
The battery and usb wiring is very straight forward and if you look closely at badwolfs pictures you can see where they were placed. When you take apart the battery keep the plastic part on the top that shows the -/+ , so you know what to solder to.

Am headed to Bowral NSW, and really looking forwards to a change!!
 
Thanks Freshair. That does make sense. Do you remember which 680 Ohm resistors you used? I'm guessing the smaller 1/4w vs larger 1/2watt, but want to confirm.
I hope to have my v2 enclosure in hand this week and will try this out. A trip to the local hardware store for the extra screws/nuts and hope to have it ready for the new board!

Bowral - i've been there! I was mistaken as we didn't get quite to Adelaide (did see 12 apostles which was amazingly picturesque). I meant Canberra - which was beautiful.

Two friends live there and we drove from Sydney to Canberra, stopping in Bowral at Milton Garden - Gorgeous! I took some pregnancy pictures for them in the gardens as a thank you for spending a week w/ us and showing us around. If you haven't gone there (Milton Gardens), definitely check it out! Bowral was great, i think my favorite was Gumnut Patisserie down in the shopping district (delicious afternoon treat)!

Looked like a great place and congrats on your relocation! Best of luck!!
 
Yep just the small 1/4w is fine. Good luck with the project! Let me know if you have any questions thru the process.

Thanks man, have heard loads of good stuff about Australia...my family is worried I may not come back. LOL
 
This is my understanding of the assembly: Please help if something is incorrect
1. Cut a bit of the left of the PCB off
2. Solder wires from the battery gold plates to the 3 pins on the PCB where channel 3 connected (I might just use the cable from the pcb to channel 3 except not use the channel 3 connector and instead just solder that to the battery)
3. De-solder usb port (What to do with this I have no idea) I think I might just leave it there and then dremel a hole in the case for it to stick out of. I dont mind if the PCB of the usb is sticking out a bit because I don't think I will be putting it in my pocket. I definitely wont go fast and crash either.
4. My antenna fell off so I will re-solder that on
5. Then I will use the steps you gave to Sl33py for the resistors.

I AM ONLY 12 SO SORRY IF I AM A BIT OF A NOOB
 
You can solder two wires directly from the battery to 2 of the 3 original pins. If you look closely at badwolfs picture you can faintly see which pins he used, and from what I remember they are also marked -/+. No idea what the third pin is for, am a newb when it comes to electrical, but gauging from badwolfs set up he did not seem to care to use the third pin either.
I ended up manually filing most of the usb off of the pcb, am impatient and was waiting for a friend who has a solder gun to come down a couple days afterwards to help me out. Would not recommend doing this since it would be easy to mess something up, though filing the sides of the usb where the solder is used to simply attached the two pieces together makes it easier when you want to de-solder the three pins. The usb only needs two wires as well; based on the pictures in badwolfs instructions, and once the usb is off it is easy to relocate, and was able to use all wire that came with the original transmitter.

Clear as mud?

Good luck, let me know if you have any other questions

Oh, and an easy way to cut off the small section of the pcb is to get a straight edge and an exacto knife, put a deep score in the pcb where you want to trim and then simple snap it off with some pliers.
 
Freshair said:
You can solder two wires directly from the battery to 2 of the 3 original pins. If you look closely at badwolfs picture you can faintly see which pins he used, and from what I remember they are also marked -/+. No idea what the third pin is for, am a newb when it comes to electrical, but gauging from badwolfs set up he did not seem to care to use the third pin either.
I ended up manually filing most of the usb off of the pcb, am impatient and was waiting for a friend who has a solder gun to come down a couple days afterwards to help me out. Would not recommend doing this since it would be easy to mess something up, though filing the sides of the usb where the solder is used to simply attached the two pieces together makes it easier when you want to de-solder the three pins. The usb only needs two wires as well; based on the pictures in badwolfs instructions, and once the usb is off it is easy to relocate, and was able to use all wire that came with the original transmitter.

Clear as mud?

Good luck, let me know if you have any other questions

Oh, and an easy way to cut off the small section of the pcb is to get a straight edge and an exacto knife, put a deep score in the pcb where you want to trim and then simple snap it off with some pliers.

Ok, I got most of that. I really don't want to move the USB so I am just going to dremel a hole in the enclosure. Can I re-solder the antenna onto the board where it was? Thanks!
 
Freshair said:
You can solder two wires directly from the battery to 2 of the 3 original pins. If you look closely at badwolfs picture you can faintly see which pins he used, and from what I remember they are also marked -/+. No idea what the third pin is for, am a newb when it comes to electrical, but gauging from badwolfs set up he did not seem to care to use the third pin either.
I ended up manually filing most of the usb off of the pcb, am impatient and was waiting for a friend who has a solder gun to come down a couple days afterwards to help me out. Would not recommend doing this since it would be easy to mess something up, though filing the sides of the usb where the solder is used to simply attached the two pieces together makes it easier when you want to de-solder the three pins. The usb only needs two wires as well; based on the pictures in badwolfs instructions, and once the usb is off it is easy to relocate, and was able to use all wire that came with the original transmitter.

Clear as mud?

Good luck, let me know if you have any other questions

Oh, and an easy way to cut off the small section of the pcb is to get a straight edge and an exacto knife, put a deep score in the pcb where you want to trim and then simple snap it off with some pliers.

Also, did you solder the wires onto the 2 gold battery plates on the pcb of the battery?
 
So decided the make a nice flat little nook for the battery and vesc's to fit into.



Ordered a vacuum bag kit from roarockit as well as some carbon fiber to add some strength back into the deck, the material wont be in tell next week, but thought I would upload a picture of what I did on the cnc at work today. Will add some more pictures of the layup within a couple weeks.
 
I'm doing similar with mine. Which epoxy did you locate and plan to use?

What bagging kit did you get? Surprisingly I found that I could get some CF pretty quickly from ebay (store). Finding the epoxy is a PITA and expensive. You are just N of me in BC so if it's relatively local that would be good to know. I have ordered stuff from some FL surf companies and Fiberglast - all pretty slow.

Look forward to seeing your setup and how you do it? I'm waiting on something to arrive before i can bag mine...

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