Idiots guide to rewinding Revolt 120 pro

[larsb]

@wheazel: The pliers are from Knipex, they're quite (too) expensive. I guess any smooth jaw parallel pliers would work well, they're available for around 15 USD on the web.

..and you need an angle grinder

 

[Wheazel]

Have done my fair share of angle grinding. I usually buy discs in 25 or 50packs.

Bit the bullet and ordered a 3pack of those knipex wrench pliers. I figure they are good for other stuff as well and I can cut the one that is the best size for the wind job.
You didn't protect the wire from the tips any more than just having the tips smooth without edges?

I am looking forward to the rewind right now, but I think I will have another opinion after the first tooth.
Or maybe even before I am at that stage with all motor disassembly and stator prep.

 

[macribs]

Wheazel are your side gig professional burglar or maybe an illegal chop shop seeing you buy grinder disc in 50 packs? :lol: :wink:
[strike]Got any nice hi class parts for cheap :wink:[/strike]

I think your rewind will be great. Iirc your revolt is sitting on the shelf, it got replaced shortly after you tested the revolt on a build. So obvious you were not pleased with the revolt. Maybe the rewind will meet the expectations you first had when you ordered the revolt, and if added man hours turns into a useful and powerful motor that is not too picky on controllers you will have a great motor for mid drive. Still light weight. Reasonable powerful, and consider the paying price not counting the man hours to redo revolts sloppy work that freshly wound motor will have great values in terms of power to weight ratio.

Protip: Do you know anyone with OCD? They should be perfect hire hands for rewinding. Result will be impeccable.

 

[larsb]

Way to go wheazel! It's time to share the load

I really like the knipex pliers and i sort off wish i had bought the set of three.. I have shrink tube on the jaws for protection, not sure if it's really needed but it doesn't add much thickness.
Having tried the 250 pliers i find them a bit bulky, i would choose a smaller one today. Reason i bought the large one was to get long enough jaws. I will cut the handle of the pliers to make them a bit smaller, with the narrow jaws they can't take a lot of force anyway.

Today I'd try the smaller pliers, cut them down to a minimum and if longer jaws are needed i would epoxy some carbon fibre bars as jaw extensions.

 

[larsb]

It turns out that my dad has an ocilloscope that he got on a sale some years ago. That means i must be finished with the wind in 3 weeks when he is visiting next time so we can try the motor.

Three coils per week will be hard to fit in, i am training to run my first marathon now and i am not exactly in the right shape
I ran 15km distance and 500 meters of hill intervals yesterday, today i am a bit broken.

 

[Wheazel]

Broken, but very fixable I would assume.
Now go and wind some coils!

 

[larsb]

Rested some.. 4 down.

 

[Wheazel]

Have to say that is looking very good!
I got my wrench pliers yday, but the initial feel is that the smaller ones might be too small.
Will of course measure and decide which one to cut when I get far enough to wind my motor.

How much copper was needed according to your winding pattern Larsb?

 

[larsb]

I'm at 39 something meters but that could be increased. I think 28 turns might be possible, that would be around 46m of wire for the whole stator.

I cut the handle shorter on my knipex 250 pliers, now they are a really good size for the job.

 

[Wheazel]

Very nice, have you drawn any further conclusions by winding the teeth so far other than that you could possibly fit some more copper?
Maybe improved your winding method or discovered new tools to use apart from the modified pliers?

Some prep work with the wire prior to putting it on the tooth? Pre-bending or anything of sorts?

 

[Wheazel]

Sorry for all the questions, but what is the final conclusion around the halls?
Why did you make that hack in the stator for only one of the halls?
Wouldn't the actual advance be secondary if you run it with an adaptto?
While the actual spacing between the halls and equal positioning in the magnetic fields will be important?
I am confused.

Or are you planning on another controller?

 

[larsb]

I use wooden wedges cut from paint stirring sticks in three different sizes, these are needed as well as the pliers to flatten the wire.
I have planned to 3D-print one wedge shaped rod for each layer thickness that would flatten the wire completely but haven't gotten round to it. If i do that i'll post the STL files.

No other lessons learned so far. I have the far end of the wire fixed and hold the stator in myhands and wind each turn. That works well but is pretty strainful.
I am not planning for Adaptto, i have had issues with my controller drowning during a rainy ride, got it fixed by Adaptto but now i have issues again. That's a long story for some other thread.. I currently run the Kelly KLS7230.

I have cut three slots, one for each hall and yes, i think the phase advance is not as important as the hall spacing between them as long as the advance is not too large.

 

[Wheazel]

I use wooden wedges cut from paint stirring sticks in three different sizes, these are needed as well as the pliers to flatten the wire.
I have planned to 3D-print one wedge shaped rod for each layer thickness that would flatten the wire completely but haven't gotten round to it. If i do that i'll post the STL files.

No other lessons learned so far. I have the far end of the wire fixed and hold the stator in myhands and wind each turn. That works well but is pretty strainful.
I am not planning for Adaptto, i have had issues with my controller drowning during a rainy ride, got it fixed by Adaptto but now i have issues again. That's a long story for some other thread.. I currently run the Kelly KLS7230.

I have cut three slots, one for each hall and yes, i think the phase advance is not as important as the hall spacing between them as long as the advance is not too large.

If you would need such wedged rods out of cf reinforced nylon, I could arrange that free of charge.
But maybe a solid pla or abs print is stiff enough?

 

[larsb]

I made some wedges, if you could print some trial parts then that would be super! These should work - at least in theory


Here are the STLs:
View attachment first layer wedge.txt
View attachment second layer wedge.txt
View attachment third layer wedge.txt
View attachment fourth layer wedge.txt

Files need to be renamed to .stl as ES does not permit this file extension

 

[larsb]

I have to update those, didn't pay attention to the layer direction in printing. They should be printed lying down so they can take some bending forces.

I think PLA will be ok for the job but it sure would be interesting to see the CF filled nylon.
If they work really well then that might be the next step.

 

[Wheazel]

I have not dealt with converting text to stl. Could you save as stl or any universal 3d format as step for example?

Edit. Saw your disclaimer...

 

[larsb]

I updated the wedges.


Zipfile with STLs:
View attachment wedges.zip

 

[Wheazel]

Yep thats a better geometry for printing, but the old one would have worked as well with some support material.
Ill start by making them in PLA over night to see how that looks.

 

[larsb]

Looking forward to the prints! Always interesting to see new stuff emerging!

 

[Wheazel]

If you need pla wedges to try, pm me mail address and ill send some over. Or are you printing them on your own?
I can send you one set with relatively high infill (40-50%ish) and one set completely solid.
The first set is almost printed and look good.

And as I said, can also print some in cf reinforced nylon if the pla is too weak. (You will not be able to break those)
I have this keyring sample print I use to show people that asks about the tech.
https://markforged.com/wp-content/uploads/2017/02/CF-Cutaway-Small.png
The pictured part doesnt use nylon as filler material but the principle is the same.

It is a 14mm wide and 3mm thick cross section nylon part with cf inlay, and I can not bend/break it with my hands.
Nor has anyone I have showed it to been able either. One would think a 3mm thick piece of nylon is cake to break, but oh no.
It is so incredibly stiff. However I assume that when it finally breaks, it will snap like cf does.

I wonder how you are going to use the wedges, do they have enough grip area?
Or would they be better if they were a bit longer at the thick part for more grip and leverage?
Maybe only supposed to be pressed/wedged into the slots?

 

[larsb]

The wedges are meant to be pushed into the slots only, and should give straight enough wire to use the pliers. They can also be used on the empy side to give counterforce when working in an already half filled slot. Some longer shafts and sharp ends might make it possible to use them as levers but i think the wooden lever square shape will be better for that.
If the CF stuff is stiff and strong then maybe some square levers can be printed in addition to these ones later on.

I'll pm adress, PLA of these will be great! Thanks!

 

[larsb]

some evolution done, i added square lever (good idea Wheazel):

View attachment wedges ver2.zip

 

[Wheazel]

The first two sets of wedges are posted. Printed in regular pla.
The pink set is the solid printed, while the purple is with a an infill structure, so more flexible.

Let us know if they are any help

 

[larsb]

Super, looking forward to trying them!

 

[Wheazel]

Super, looking forward to trying them!

Btw, it is also possible to print the wedges in elastic material if they need more of hard rubber properties.
Would mean they can adapt slightly more to the wire and possibly be a bit gentler on the coating when pressed into the slot.

I have two different types of material for that. One named TPE, and one is the Ninjaflex trademark.
If printed solid, they would be very tough, and hard, but not as brittle as pla.
Just to make sure you know those properties are possible as well.