DIY 10awg phase leads through axle in 9C hubmotor.

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Oct 28, 2008
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Manhattan Beach, CA, USA
I'm making a pair of E-bike for my parents as Christmas gifts.

Methy shipped me a couple 9C hubs. I took a look inside, and I liked everything I saw, except the phase leads. They were not too far off of the hall sensor wire size. lol

I decided 10awg would be a much better suited wire size for the amount of current the motor can be getting.

But, 3x 10awg wires doesn't come close to fitting down the axle, even 2 doesn't fit with the hall sensor wires. So, I stripped off the bulky insulation on the 10awg wires, and slipped over some heat-shrink. This is the same heatshrink used on outrunner motor leads, and it's pretty darn good stuff. You can see how much more thin the wire becomes once it's got shrink wrap for insulation.

2wireinsulationshrink.jpg


I was able to stuff them all through. It took some effort, but I got all 3 pieces of 10awg through with the hall wires.

3testfit.jpg


Two soldered up, one to go.

4connectedleads.jpg



Cover back in place, and you can see the size difference between the new leads vs the factor wire phase lead I'm holding in my hand in the picture.

5phaseleadsout.jpg


Here are more detailed pics of this phase wire upgrade:

"The helpful 9C wire upgrade thread, explicit DIY pictures" (liveforphysics, 3 pages)
https://endless-sphere.com/forums/viewtopic.php?f=2&t=24547

[moderator edit to add link at the bottom]
 
Zoot Katz said:
Bend over.
I wanna kiss your ass.

Thnaks heaps!


No man lips on my O-ring ;) :p :shock: 8) :lol:

You're welcome for the mini-guide my friend. Methy convinced me to share some pics, as the 9C has such a small channel through the axle to work with for wire stuffing, it makes things tricky to get decent sized phase leads via normal means.
 
Tiberius said:
Do they have to come out through the axle?
Can't you bring them out next to it, Crystalyte style, or some other route?

Nick


The axle is bored rather than slotted, and the bearing size, both ID and OD is very small. I initially thought I would machine the cover to accept a larger bearing, and find something with the largest ID I could fit, then slip a spacer with a notches for large wire clearence around the axle. However, the cover uses perhaps a 1/8" of material around the bearing, with minimal webbing, so I didn't feel it would be safe to turn it and open it up any more without something like making a whole end plate from scratch designed to fit a larger bearing.

This method only took about 45mins of my time to complete from start to finish, and 10awg should be adquate for bikes my mom and dad will be to toodleing around town. These leads have 8mm gold bullet connectors on them now with 8awg phase leads to the controller, which is a 12-fet infinion modded with IRF4110's. Battery leads are 4awg, and I've not decided entirely on the packs yet, but I'm thinking perhaps 1Kwhr of 25c LiPo at 72v should be adquate for little trips around town. It's not anything fancy, just something to try and get the parents to perhaps make 1-2 less trips a week via-car. They might never use them, but whatever, that's kinda the nature of a gift.
 
Zoot Katz said:
fuk man!
Can I adopt you?


Likely, but an E-bike or two would never be worth the sleepless nights. lol :p
 
Very cool, Luke!

I was planning on doing this after seeing how fast Justin managed to start melting the phase wires during his saturation tests. I was going to try and find some big teflon-coated wires to do it (hard to find?), but your heatshrink idea sounds good... what temperature is that stuff good for, and where do you get it?

I once used some large magnet wire to do this to a golden motor hub, and although this solution is great for it's heat resistance, it was a real pain getting such rigid wire through the axle bend.

Pat
 
The shrink says 165C on the outside. I figured the idea was to stop the source of the heat in the phase wires rather than to increase the heat limits. :)

The wire is fine stranded cheap car audio 10awg. I carefully slit it up the side to strip off 10" sections of bare wire, then twisted the end a bit to get it to all slide into the heat shrink tube, shrunk it down, and cut it off the mother wire. It goes pretty quickly. I also found that leaving some excess heat shrink shrunk down smaller than the wire hanging off the tip made a pretty easy point to grab with the needle nose pliars to pull through the hole at the bottom.

To avoid potential abrasion issues with the thin heatshrink, I think I will mix up a syringe of epoxy and shoot it down the axle tube to lock all the wires in place and prevent possible chaffing. I want the bikes to be ultra-reliable for my parents. My dad is tough as nails, and I know he could push the back home 10 miles up hills, but I would never want to put my mom through the same burden, so I'm seeking reliability as my #1 objective with their gift-bike builds.
 
The epoxy is an excellent idea. For ultimate reliability though one might use magnet wire with heat shrink and epoxy. You really don't want to scrimp too much on the insulation. Imagine all the pinch flats mom will get hopping curbs at speed to blow past backed up traffic. I know my mom wouldn't use enough body english to get good loft approaching a curb and I don't trust her timing either. Each time she pulls the wheel to swap a tube those wires are likely to get tugged on a bit. Epoxy alone may not protect the shrink wrap as it exits the axle way.
 
SpeedEBikes said:
The epoxy is an excellent idea. For ultimate reliability though one might use magnet wire with heat shrink and epoxy. You really don't want to scrimp too much on the insulation. Imagine all the pinch flats mom will get hopping curbs at speed to blow past backed up traffic. I know my mom wouldn't use enough body english to get good loft approaching a curb and I don't trust her timing either. Each time she pulls the wheel to swap a tube those wires are likely to get tugged on a bit. Epoxy alone may not protect the shrink wrap as it exits the axle way.


Yes, the flats concern is certianly valid, and I hadn't even thought about that. I don't see my mom doing much curb jumping, but I could see her nailing potholes by mistake. :) Has a proper non-pnumatic foam injection or something option been made for bikes yet? Perhaps that long snake-like tube that doesn't require ever removing the wheel to replace? Any tires with functional pinch-flat protection? I don't care what it costs or weighs if it means no flat tires for my Mom to have to deal with. She is an awesome lady, but a terrible mechanic. lol

Also, as far as additional insulation options go, the outside 3/4" of the axle is actually bored to a signifigantly larger ID than the rest of the axle. I suspect this is because the outside of the axle carries minimal to zero stress for most applications. This would mean the wires could have 2-3 extra passes of shrink wrap shrunk down on them at the vonerable area where they exit the axle and make the corner to meet the controller phase leads.
 
That’s great and generous idea from you making ebike for your parents!.. Luke!

Another great way to increase phase wire size was to use the original phase wire but to cut their length in half and to double the wire qty.. I mean passing 6 original wires.

I did that to when I tried my first Delta WYE setup and that worked well, but if you want to keep the WYE configuration, using these 6 wires is great for high current!

It’s equivalent of 12 gauge per phase.

By this way, everybody can do that mod without the need of buying extra heavy wires.

And… a pair of these original Teflon wires is still able to take 260 celsius before to melt and also just fit perfect in the 30 or 45A Powerpole connectors!

Buy I admit the idea of shrinked car audio 10 gauge strand is flexible and may be help to pass them thru the small axel hole.

Doc
 
I think that the mere mortal folks around here could do well by running 12AWG through the axle using your methods - that can even be found teflon coated fairly easily on ebay.

Good job Luke

Of course... there is always the option of removing a few strands of the 10AWG to make 11AWG or some compromise as well.

-methods
 
Nice work!

Just a little info - If you attempt to remove a few strands from 10g for fit... just be sure to remove exactly the same amount from a length 3x the length and then cut it down into the phase wires... If you removed different number of wires you will change the electrical properties of each wire and the phase lines should be the same diameter and length.

I had this issue trying to go up in guage from stock while keeping 6 phase lines for wye/delta mode operation.

Hope it helps,
Mike
 
Great suggestion, Luke, and also great pics.

I think the DIY motor thread will result in design guides that allow the garage builder to make a motor just the size he wants, with the features he wants too. Axel did a great job producing a one-phase motor building guide, and is working on a scaleable 3-phase motor prototype and guide.

On the thread talking about opto sensors (instead of using halls) there was a pic of a TidalForce hub showing the white/black stripes that triggered the reflected light sensor, but the other thing that caught my eye is the routing for the power wires. The axle is solid, and it has a fat bushing between the axle and sideplate bearing. The bushing (not expensive or hard to make) allows fat power wires, and enough of them for delta/wye switching.

Has anyone tried running two very fat leads out the hollow axle, and then using the axle itself as the third lead? I have no idea if it would work, just a thought...
 

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spinningmagnets said:
Great suggestion, Luke, and also great pics.

I think the DIY motor thread will result in design guides that allow the garage builder to make a motor just the size he wants, with the features he wants too. Axel did a great job producing a one-phase motor building guide, and is working on a scaleable 3-phase motor prototype and guide.

On the thread talking about opto sensors (instead of using halls) there was a pic of a TidalForce hub showing the white/black stripes that triggered the reflected light sensor, but the other thing that caught my eye is the routing for the power wires. The axle is solid, and it has a fat bushing between the axle and sideplate bearing. The bushing (not expensive or hard to make) allows fat power wires, and enough of them for delta/wye switching.

Has anyone tried running two very fat leads out the hollow axle, and then using the axle itself as the third lead? I have no idea if it would work, just a thought...

That was my original plan. Mentioned earlier in the thread, the bearing recess in the side cover didn't have enough meat in it to open it up further and stuff a bigger bearing inside. I could have stepped up 1 size of ID on the bearing and made a custom bushing, but it wouldn't have much more area than the center of the axle hole with the limited ability to increase the ID of the bearing without increaseing the OD.

These options are of course possible, and you could make a custom side plate for the motor and put a huge bearing in there and run as large of phase wires and water cooling lines or whatever the heck you wanted to run through there.

However, this took about 45mins of time, about $3 in materials, and it's got phase leads that will stay as cool as can be and handle all the current they will need, so it's mission accomplished IMO. :) Not everything needs to get complex and expensive with custom machined bits to make it work. :)
 
liveforphysics said:
I also found that leaving some excess heat shrink shrunk down smaller than the wire hanging off the tip made a pretty easy point to grab with the needle nose pliars to pull through the hole at the bottom.

That's a very clever way to help slip the wire through the axel. 8)

Thanks for all of this.
 
recumbent said:
liveforphysics said:
I also found that leaving some excess heat shrink shrunk down smaller than the wire hanging off the tip made a pretty easy point to grab with the needle nose pliars to pull through the hole at the bottom.

That's a very clever way to help slip the wire through the axel. 8)

Thanks for all of this.

Glad I could help a few of you hubmotor folks :)
 
I hope your Folks get some use out of the ebikes mate, especially your dad he sounds like a character, apple didnt fall far from the tree i think... Between you and him hobbycity would be YOURS and the LIPO powered electric rail would become a reality!!!

KiM

p.s I had a 'funny' response involving you and frocks you would of liked Luke but some here would probably have taken me seriously ...
 
liveforphysics said:
Yes, the flats concern is certianly valid, and I hadn't even thought about that.
...
Any tires with functional pinch-flat protection?

The Schwalbe Marathon Plus is a truely excellent puncture resistant and long lasting tyre for the road.

Code:
"For extreme puncture resistance, Schwalbe has their 5mm thick Smartguard layer between the tread and the casing in the Marathon Plus tires. Tires with the Smartguard layer have relatively high rolling resistance and are heavy for their size, so you won't be winning any races with these, unless the race is being held on a road paved with roofing nails, in which case you'll win by a country mile.
...You need a strong grip to mount these tires..But once you get them on, you'll most likely not have to take them off before they have worn through the outer tread." Peter White Cycles

http://www.schwalbetires.com/marathon_plus
 
voicecoils said:
liveforphysics said:
Yes, the flats concern is certianly valid, and I hadn't even thought about that.
...
Any tires with functional pinch-flat protection?

The Schwalbe Marathon Plus is a truely excellent puncture resistant and long lasting tyre for the road.

Code:
"For extreme puncture resistance, Schwalbe has their 5mm thick Smartguard layer between the tread and the casing in the Marathon Plus tires. Tires with the Smartguard layer have relatively high rolling resistance and are heavy for their size, so you won't be winning any races with these, unless the race is being held on a road paved with roofing nails, in which case you'll win by a country mile.
...You need a strong grip to mount these tires..But once you get them on, you'll most likely not have to take them off before they have worn through the outer tread." Peter White Cycles

http://www.schwalbetires.com/marathon_plus


Sounds like a good tires choice. Thanks Mitch, I will pick a few of them up.

Maybe a double thickness slime filled tube with a couple of kevlar tire shields tucked up in the tire before mounting? Is that about as good as it gets?
 
Pinch flats are caused when the tire compresses so much the the inner tube gets pinched by the rim. Usually results in a double puncture.

Most often is caused by seriously under inflated tires, although hitting big obstructions while heavily loaded at a high speed will cause it to happen at higher pressures. The best defense is a wider tire with more air volume capable of high pressures. I know how much you love overkill and this is one area where overkill is useful. It allows for less frequent inflations.

But frames and rim brakes will limit how wide you can go. Typical mtbs will accommodate 2.0" tires, some can handle 2.25" and even 1.75" at 80 to 100 psi will take most anything you can dish out.
 
Yes thanks for sharing. Especially helpful for me is the lack of high strand count wire other than for car audio, but that plastic is just too thick, so I've had to resort to the stiff stuff. Making your own using shrink wrap is great lateral thinking.

John
 
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