Replace phase wires MAC

jamo96

100 W
Joined
May 19, 2009
Messages
110
Location
Toowoomba, Australia
Is there a way to remove this plate from a MAC motor to make it a little easier to replace the phase wires?

vXh8W.jpg
 
to me at first look (no prior experience with that particular motor) i would say remove the Phillips screws and the snap ring ... it should just slide of at that point

**EDIT**
i would also make sure to keep the new phase wires a little farther away from the side cover
 
This was just a photo I already had on the computer, taken to show the phase wires shorting on the cover.

I have taken the screws off, and the cir-clip off and that really has done anything apart from allow it to rotate. Thinking I might try to dremel or drill out a better angle to the axle opening. I am not trying to fit larger wires through either, just a straight replacement minus the useless soft black insulation.
 
first off all remove the motor section from the wheel/hub, it all comes out as one unit
thats a start
 
Sorry I should probably explain. This photo is just one I had on my computer from a while ago to point out which part I am talking about. It is not a picture of the progress in trying to rewire the hub.

I have taken the motor out of the hub. I have removed the philips head screws and cir-clip. This hasn't really done much except allow it to rotate. Just wondering if is even possible to remove the part I am pointing to in the photo. I don't really want to have to remove the axle or anything to major like that. Otherwise I may just try and dremel or drill out some space to make it easier to pull some wire through.
 
there have been quite a few different discussions on replacing bmc phase wires in the past, might be hard to find them,
also many cases of burned out phase wires, I think there will the info you want on the forum somewhere
I cant remember taking off that part before so I'm not much help
 
These Macs are easy to take apart and replace the phase wires. Just take photos as you go so you know where everything goes.
I have installed a Mac with 12awg phase wires through the standard axle and am running 30amp battery and 70amp phase currents giving a peak wattage of 2300W showing no problems with wire temps.
Just strip the insulation off some 12awg and put fairly snug fit heat shrink on each of the phase wires then have one final layer of heat shrink encasing the three phase and five hall wires.


The ends of the 12awg phase wires can just be seen here in green heat shrink.

ratfink27.jpg



This bundle is fairly easy to push through and will handle plenty of power, well 1500w continuous and 2500w peak.
Cheers,
 
if you strip the isolation and use super thin heat-shrink i hope you don't put too much threw it as the motor will use the phase wires to help dissipate heat from the windings so by compromising the isolating layer of the wire you have effective lowered the amount of heat it can handle (amps = heat)

just saying

and that is imo and you may source others to cross reference
 
I'm pretty sure its better to run a heavier gauge 'wire with thin insulation than a lighter gauge wire with thick insulation.
The heat issue in the standard phase wires is due to them being too thin, ie higher resistance, for the extra amps we wish to push through to the motor.
I fail to see how thick insulation can help with the amp carrying capacity of the wire.
Cheers,
 
I've just got some 14 gauge teflon coated wire to replace the original ones (which i think were 14 gauge as well). I am not too worried about this I am turning the amps back down to a sensible level on my controller. The replacing is due to me testing my 24 Mosfet controller on this motor... bad idea haha.

At the moment I cannot see a way to get them through without drilling or dremeling some more space where the wires exit the axle and come into the motor. Unless some one has done it before a different way.
 
1000w said:
I'm pretty sure its better to run a heavier gauge 'wire with thin insulation than a lighter gauge wire with thick insulation.
The heat issue in the standard phase wires is due to them being too thin, ie higher resistance, for the extra amps we wish to push through to the motor.
I fail to see how thick insulation can help with the amp carrying capacity of the wire.
Cheers,

yes a heaver gauge will not heat as easily
but that being said
the winding gauge is not user adjustable so it will heat up regardless
the larger wire will wick heat of the windings
so the thicker wire becomes heated
heat that a wire can take (not amps specifically) is in many ways directly affected by the isolation
look at different wires of the same gauge but of different coatings .. one thing you will notice is that the failure temp of the isolation is increased by material and thickness of the coating
silicone seems to be one of the best for its ability to handle heat wile maintaining the flexibility required in a ev application due to vibrations being driven
so with a thinner wire and different insulation (though you will be generating more heat due to the thinner wires higher resistance) you will be able in some cases to handle more current b4 the wire will fail(casing melting down)
just for a easy to do quick experiment hold a flame to your shrink tubed wire ... and now to a quality silicone insulated wire
i already have a good idea of what is going to happen

considering the windings are the load
and the most heat will be found closest to the load
and motor manufacturers do not use heat-shrink were the windings make contact to the power leads they instead use a fiberglass sleeve
and considering that thees sleeves are more expensive then a piece of shrink tubing
and many motor manufacturers are trying to safe money on production to maximize profit and minimize consumer cost
they will save a penny anywhere they can were it wont compromise safety
so one can make a logical assumption that the heat-shrink is far too likely to fail in this environment (without any prior information received on the topic in the first place)
 
jamo96 said:
I've just got some 14 gauge teflon coated wire to replace the original ones (which i think were 14 gauge as well). I am not too worried about this I am turning the amps back down to a sensible level on my controller. The replacing is due to me testing my 24 Mosfet controller on this motor... bad idea haha.

At the moment I cannot see a way to get them through without drilling or dremeling some more space where the wires exit the axle and come into the motor. Unless some one has done it before a different way.
what i have done on the phase upgarde i have done for myself and others is tack all 3 phase wires out of the motor one at a time cliping the off the windings with enuff insolation left on to see what colour the phase was
then i pull out the larger insolation
theni take the new phaze wires and tist/ solder the ends together with hall wires(making one solid wire pack to drag through)
wile soldering them to a lead wire to snake throug first like this

hall--------------------------------|\
PHASE------------------------------|\
hall-----------------------------------|\
PHASE--------------------------------|-----------------------------------LEAD
hall-----------------------------------|/
PHASE------------------------------|/
hall--------------------------------|/

**EDIT** +1 hall wire /palm face

take some this heat shrink and laminate them
then drag the new harness throug the hub
(/me slaps forehead realizing i should indeed have documented this process with photos on one of the motors i have already done)
solder it all in keeping the original fiberglass sleeves intact and in their original locations
then for some extra protection i use a split sleeve over the new harness
 
ps if you grease up the new harness it will be easier to feed through and remember to keep that soldered section to the lead wire as short as possible as it will create a hard spot
 
i normally start on the axel side but either way would work i suppose

i use a small mechanics pick to pull up the end of the lead wire as i find often there is a hard 90 deg angle or some other such obstruction

i guess one could try using a hair pin or something of the like bent into a hook to help for the first little bit of lead wire
 
I ended up drilling out a section of the plate to be able to access the hole in the axle better. I have threaded the wires through from the outside to the inside. Just have to finish soldering the hall wires and do some testing. Glad that there is none of that soft, easily melted insulation inside there now.

RAX27.jpg
 
how did you phase wire replacement go?
 
I have replaced all the phase wires and hall wires. Phase wires are 14awg teflon coated and hall are 30awg teflon coated. I have soldered them on the inside of the motor. I have put it back together and now just need to finish off some of the outside wiring and do some testing and it all should be good. Might post some photos when I have the chance.

I fed the wires through from the end of the axle and just bent them up slightly at the end and it was quite easy to pull them through with some needle nose pliers. Had to make sure not to strip the insulation off in the process as there is a sharp bend.
 
jamo96 said:
I fed the wires through from the end of the axle and just bent them up slightly at the end and it was quite easy to pull them through with some needle nose pliers. Had to make sure not to strip the insulation off in the process as there is a sharp bend.

that would be that sharp 90 deg. turn i was talking about

glad to hear that so far your phase upgrade is going well for you and grats on your first hub repair

i might be getting my buddy a 9c motor and i will document the hell out of the phase upgrade that i will have to do to that (he loves amperage and i had to do up his GM hub after he got his new controller)
so that those of us not in the know can be well informed on the work involved so that we may know if it is something in our power to do or to leave it to a pro ;)
 
Just a note to all those budding phase wire replacers out there. Remember to put the washers and nut on the axle before you solder on the phase wires. And also don't forget the shim washer (which goes in between the cover bearing and the motor cir clip) on the disc brake side of the axle. Without this the side cover rubs slightly on the rivets on the motor.

Such a pain to undo everything and resolder twice!!
 
jamo96 said:
I've just got some 14 gauge teflon coated wire to replace the original ones (which i think were 14 gauge as well). I am not too worried about this I am turning the amps back down to a sensible level on my controller. The replacing is due to me testing my 24 Mosfet controller on this motor... bad idea haha.

At the moment I cannot see a way to get them through without drilling or dremeling some more space where the wires exit the axle and come into the motor. Unless some one has done it before a different way.

May I ask where on earth you got those new 14AWG or possibly 13AWG teflon coated wires from??
I cannot seem to find even 1 meter :cry:
I also need some advice on where to get the fiberglass protection pieces, and on where to get the 'epoxy?' to glue it all in place.

Can somebody help me with this?
 
if you are using wiring that has lower thermal limits i would recommend installing a temp sensor to keep those limits in check
other then that just a hand on the side cover should tell you how your motor is heating up
pull over of you start to notice a loss in output power as this is most likely the thermal limit of you motor

as for the wire source you should be able to find it easily from a electronics store
 
Hopefully this will be my final upgrade,
It's not really clear on the photos, but I found some heat shrink tube that's alittle bit more heat resistant called KYNAR, GOOD stuff!

I think my phasewires are upto about 12G now, more than enough.
Had to replace 1 hall sensor too after a very short first run....
.
Put it all togteher with some JB-weld epoxy
Im now running it on 48V 30-40A on my 6T, but I did 60A, the motor was very ok with it! Amped it down because it drained my batteries too fast..

DSC00731.JPG

DSC00732.JPG

DSC00733.JPG

AXLE-WIRES.jpg

:)
 
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