Fibreglass sleeving for phase wires

[megacycle]

I was considering using fibreglass sleeving over bare phase wires through the axle to replace telflon insulated for a build.
To get a flat sandwiched set up using more of the wiring slot area, no gaps like circular insulation
Could use ptfe shrink but i think, too easily damaged.
Any thoughts, ideas, criticism would be good

 

[heathyoung]

Risky but high temperature.

You would want some that is very close to the size you are aiming for (smaller so it expands over it nicely)

 

[megacycle]

Thanks for the suggestion Heath, yeh thats an issue, the csa of the copper needs to be at least the internal csa of the sleeve or bigger as it can be stretched but doesnt shrink, Thanks.
I was thinking of maybe using solid copper bus strips, sandwiched in the sleeves width of axle groove and bend tight before entering the axle, conforming staggered right angle radii (never used that word before sounds like i know what i'm talking about :lol: ) when it comes out, embedding this in section in epoxy and make a compression type connector.

Have you seen any good power connectors, i havnt found a good power connector yet, Andersons, Deans, HK's :? dont like any of them, want a flat sandwich layered bus connector that is compressed by a screw or camlock, have to make one maybe.

 

[Punx0r]

If it's just coating the wire bundle you may still have problems with the wires inside melting and shorting together?

 

[megacycle]

If it's just coating the wire bundle you may still have problems with the wires inside melting and shorting together?

Were its connected will be structural too, the small copper bars will have phenol spacers between, hold the 3 layers together with raychem.
I'll probably build it today, got everything together.

 

[megacycle]

Got it pre-assembled.

Need to super glue bond the assembly.
I reckon there's about twice as much copper meat as the normal teflon coated setup. it is a bit chunkier ive used 1.3mm(1/16")
No room for my halls, presently, so 1mm might normally be preferable and conform the hall wires on the top of the assembly.

What do you reckon, about 4mm2 compared to 8mm2, as the solid would be 1.3x 6mm
Geez I'll have to get round to cleaning those fingernails :wink:

 

[megacycle]

I ended up leaving the centre sleeve out, in the slot area, gave me a mm or so xtra, somewhat surplus anyhow and resin the exposed sides, sleeved at both ends still and i'll hit the assembly with low voltage megger before and after assembling and also measure microhm of assembly.
Ended up folding a crimp over the wire, i'll use a longer copper strip for the 5404 build and crimp and solder straight on the winds for a better and less resistance.
I know its going to be tricky getting the cover on & off but hopefully once i got the 2 thermistor leads through it wont be apart again, famous last words :wink:

 

[megacycle]

It wasnt as hard as i thought getting the cover back on, as the cable slot extended out of the motor enough and the actual assembly was free moving in the slot, was a little bending soft copper, so on the next one i wont glue the sleeving external to motor, as it could break the sleeving, there's 2 little phenol spacer from axle to connection point, hard to see.
I think i'm going to go sensorless with both builds now i'm over halls some.
Reckon i can still get two wire thin temp cable on top, so no pressure on it.
I can only test it the moment no controller :?

 

[megacycle]

Better mark the connections, i'll probably dye the fibreglass, unless there's a better way.

I've been looking at connectors again, the connections look like faston tabs, all faston's ive seen, are usually for hv-low current or automotive, but did see a 9.8mm wide used for a 150A auto relay and could use a big single housing if i can get it.

They wouldnt be my first choice, there not usually heavy current and can loosen, still might make my own sometime.

Can anyone help me with working out the average current in a winding?
Running at about 3kW+@ 72V to 100V. Getting confused

 

[megacycle]

Can anyone help me with working out the average current in a winding.
Running at about 3kW+@ 72V to 100V. Getting confused

To answer my own question, following 4 hours of trawling, i thought i'd read about it before,
2.5x battery current max, ref Methods, moons ago.
Approx 40x2.5=100A, :? and guys running at 250A phase currents, oh crap no wonder stuff goes pop more often when backed off WOT, 4mm2 @ 100A, next to the hub bearings, starting out on a 35C deg ambient day, mmm toasty.
Just got to make sure the connection can handle the current ok and keep insertion loss low.
Gonna need bigger stuff again on the 5404, 16mm2.

 

[megacycle]

This is a 6.3mm shroud, should be a 9.5mm somewhere.

These 9.5mm lucar fastons are chunky as compared to the 6.3mm shown, even that looks like it would crap all over a cheapo 6.5mm from supocheap, think i could trust these if i took 8mm phase wires and crimp and solder straight up to the mating face, as the neck section is still thin for my liking and thats usually were the fastons can give way, in my past experience, by folding .
Like to find it's resistance spec, looks coated, but these beasts should allow a good throughput.
Where to source them in Australia hmmm.

 

[Punx0r]

Can you not just solder wires straight to the copper bars?

 

[megacycle]

Yep, but for mine i want a plug and play, so if i disconnect the motor ther's just the assembly connector no wires.
It's worked out well, what i was thinking is for this 4060 build, a 6.3mm faston would do, only if i solder the bigger controller cable or a section of copper from the cable, on the reverse side of the faston end, this should effectively boost the faston contact csa, as a good one might be pushed at 50A.

Reasearched and found connectivity of an overlapping joint is a function of the thickness and width and then clamping pressure to a point and little to do with depth of overlap.
So to boost the faston arrangement for now could reverse the crimp run the cable or strip down the back and solder the extra mm gained at the back, man they should have a standard connecter like this with somekind of crimp behind the mating face.