Following in The Steps of Carvon

[spade]

https://www.bocabearings.com/products/bearing-and-ball-types/balls/ceramic-silicon-nitride-(si3n4)-series?ProductType=0

Welcome to the future of high temperature bearings - basically say goodbye to exploding ceramic bearings

Silicon Nitride (Si3N4) Ceramic Balls are formed from a new material suitable for applications where high loads, high speeds and extreme temperatures are factors. Long life and the need for minimal lubrication make this material appropriate for extreme applications. Silicon Nitride is non-porous, non-magnetic, non corrosive, lighter than steel and, in ball form, is harder than steel. Because ceramic balls are non-porous they are virtually frictionless and are capable of spinning faster than steel balls.

more info :
https://www.ceramtec.com/news/id/1843/silicon-nitride-ceramics-for-roller-bearing-technology/

retail 608s :
https://www.amazon.com/Si3N4-Silicon-Nitride-Bearings-8x22x7/dp/B073DP1QY5

[AngryTrucker]

wondering if harder=more brittle for these… probably ok in pneumatics, but I’d be pretty sacred to use them on urethane

[kook]

Back on pseudo-rambling topic…
@moon donated a broke-dick 6374 SK3 to further along with this project, if you can recall there was some conversation early in this thread about whether Jerry used an SK3 motor for his Carvon hubs, and I can confirm that they’re very fuking similar…

Left 6374 SK3, right Carvon V4

!
Jerry apparently used 6364 SK3 motors, sensored, and re-terminated the windings WYE versus stock Delta windings, whether he did this himself or his MOQ was enough to have the factory do this for him is unknown at this time…

In this pik you can see the bearings, screws, everything from the SK3 fits into the Carvon

!
A couple of things to note are that Jerry took out the pathetically small bearings, added a centering sleeve bushing, and mounted larger bearings external to the stator… You can look backward in this thread if you care to compare…

One thing that delayed this was a concern of the broken magnet in the original can…

Upon receipt of the @moon SK3, the magnets are Identical, except for the 10mm length difference, so I went on a magnet harvesting project

Acetone seems to be the solvent of choice for removing the epoxy holding the magnets to the rotor/can, and so I built myself a solar acetone enclosed still, I filled acetone partway up in an old salsa jar, set it out in the sun for a good 24 hours and then went about removing the magnets…

I was able to free 5 of the little bastards with only minimal whining and whinging, now to bring out the diamond dremel cutting wheel and see If I can’t hack off approx. 10mm from the magnet and epoxy it into the Carvon can and battle harden the magnets in…

Battle hardening the magnets in seemed like a fools errand with a broken magnet…

stay tuned…

[kook]

measuring inductance on the SK3 vs Carvon V4

SK3

• A-B .078mH
• A-C .080mH
• B-C ,081mH

Carvon V4

• A-B .190mH
• A-C .188mH
• B-C .192mH

and as an added joke I threw the crappy Skullboard hubs into the mix

Skullboard

• A-B .168mH
• A-C .215mH
• A-B .158mh
  as you can see one phase is completely whack…

[Fosterqc]

I have a pretty rekt but working 6364. Its an SK8 not a SK3 tho

[kook]

thanks for this…

how nice for you!!!

even thou I mention SK3, it would appear that Jerry would have indeed used 6364 sensored SK8 vs. the SK3 mentioned above many times… hahahahahaha

[Fosterqc]

makes sense, it’s a wild 245KV which after WYEifying is still too high at ‭144.11764.

[kook]

these Carvon V4s are “supposedly” 113kV wound WYE, I say supposedly as I have not had a chance yet to run them and check kV… but soon-ish I shall…

113kV wound WYE would yield 192kV when would DELTA, I believe…

[kook]

Curved magnet replacement… Thanks @moon… fitting an SK3 6374 magnet into an SK8 6364 Carvon V4

EDIT: supporting text added

As received motor rotor with the broken magnet, placed in a race glove and mounted in a vice

I got a very small chisel and smacked the chisel with a hammer 1/2 of the magnet came out with minor grief

Same with larger magnet piece, magnets out can is filthy

Broke dick magnet pieces

Cleaned up the rotor a bit, and pressed out the minor dent, as best I could, with a pair of welding clamps

Test fit @moon 6374 magnet into the 6364 Carvon

With a diamond cut off wheel in a dremel, I made quick work of that pesky extra 10mm

super clean the can

marked the proper orientaion of the magnet…

and glued the fucker in with a thin layer of JB-Weld magic ala @b264

now we drink and wait…

[moon]

What did you end up using from my motor?

[kook]

A bit more work on the Carvon motors… Nothing substantial just phase wire replacement…

Phase wires cut and cleaned

The soldering 12ga silicone wires

Finished… And wrapped…

[lazopm]

You inspired me and I just finished servicing my carvon v4s. They had a weird clicking noise on both motors.
The clicking seems to come from the three screws behind the stator. Mine had become loose enough to let the stator rotate on the axel a few mm. Tightened those up and they feel good as new!

From reading other threads it seems like a common issue, make sure you tighten those screws and use some loctite.

Last thing I need is replacement spacers, have you by any chance found where to buy them? Standard skateboard spacers are a tad too big.

[b264]

What size do you need? ID / OD / length

[kook]

I’m super stoked you fixerated your Carvon Drives… Yes the three screws… both of the drives I received had those 3 screws loose, one even had one snapped off…

gawd damned phillips head screws replaced on both with proper loctited hex screws…

I’m getting close to pressing the motors back on the axles and getting these running, life just gets in the way most of the time…

post some pix of your drives and the spacer you require… I have a feeling if you’e looking for the end can motor spacers… they will have to be fabricated…

[lazopm]

It the OD of a 10mm spacer and inner diameter of an 8mm one.

I measured OD 12mm, ID 8mm, length 9mm. But it would be nice to have different lengths for different wheels. Maybe I can buy an aluminium tube with those diemsions if I can find someone with the tools to make a precise cut.

[lazopm]

Just set up the motors for the first time after servicing and they sound so good ! Before they sounded terrible like there was a rock in them.

[kook]

interesting! They do sound smooth…

I haven’t gotten to the point of spinning mine up yet… they don’t seem to have much coast (freespin) to them… Is that typical?

I’m curious as to what is your impression of the drives in action, especially considering the 110kV… It looks like you’ve got 90mm ABEC wheels on yours… that’s what I’m planning, and if they have enough initial torque I may go up to 97mm…

[kook]

d00d… post again… I missed it…

[b264]

Made these on the lathe

[lazopm]

I think I accidentally clicked delete:

I think it’s normal if you mean spinning them on the bench by hand, the magnets slow it down almost instantly. With some momentum when riding them there’s no problem though. I’ve ran out remote battery and had to push for a mile and it’s fine. I love them! To be fair I have nothing else to compare them to but they’ve served me well for hundreds of miles.

I’m running 90mm wheels because I need as much torque as I can get to get over some big hills. I weight 130lb and I ran 107mm and a 12S battery for a while and it worked fine on flattish ground. (braking suffered iirc) So anything in between 90 and 107 is probably good. If I remember correctly Jerry recommended 97mm for 2WD