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Brushless Motor Rebuild / Upgrade

Old 11-08-2023, 02:21 PM
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Originally Posted by gigaplex
There's no PWM at full throttle. I've also never seen a meter do an RMS conversion when in DC mode.
No there isn't, but the meter doesn't just magically switch is coupling either. And if you haven't seen it happen, you can find it on Google.

EDIT: I'm not saying that is the issue. I'm only offering something to check.
I work in IT for my real life job. We throw stuff at the wall all day long and see what sticks. In other words, I troubleshoot a lot. And that means there are a lot of wrong answers before I get to the right one sometimes.

But, by all means tell us why it isn't reading correctly.

Last edited by trilerian; 11-08-2023 at 02:39 PM.
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Old 11-08-2023, 04:01 PM
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Originally Posted by gigaplex
It makes no difference which lead it's connected to. Kirchhoff's law, current in is current out.
Originally Posted by DirkW
It does not matter where in the circuit you insert the meter.
This I know. However, some find it less confusing if you give them an exact lead. Trust me. I've been in the automotive electrical industry for a couple decades. Some people get lost with the simplest directions. You should see how frustrating it is trying to tell someone how to trouble shoot electronics in a car, over the phone.

"No, you test the grean wire with white stripes and silver dots. It's to your left. No, your other left... still to your left... yes, with silver dots. Now test it for a ground pulse. No, your set on continuity... no, it's not the same! No, it doesn't matter which lead goes to ground..."

I'm going to have nightmares tonight!
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Old 11-08-2023, 06:37 PM
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Originally Posted by OffRoadJunkie
This I know. However, some find it less confusing if you give them an exact lead. Trust me. I've been in the automotive electrical industry for a couple decades. Some people get lost with the simplest directions. You should see how frustrating it is trying to tell someone how to trouble shoot electronics in a car, over the phone.

"No, you test the grean wire with white stripes and silver dots. It's to your left. No, your other left... still to your left... yes, with silver dots. Now test it for a ground pulse. No, your set on continuity... no, it's not the same! No, it doesn't matter which lead goes to ground..."

I'm going to have nightmares tonight!
Except they didn't get confused, they accurately described in detail how it was connected.
Originally Posted by shortcut3d
Iím used a Klein RMS Multimeter that is 10A current rated. I connected it in series with the ESC / battery using alligator clips. ESC positive lead to the positive 10A port. ESC negative lead to the battery negative. Battery positive to the comm port on the multimeter. Throttle control with the transmitter
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Old 11-08-2023, 06:40 PM
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Originally Posted by shortcut3d
Correct. The ESC positive is going to the meter positive. The ESC negative is going to the battery negative.
I think you might have put reverse polarity on that meter.
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Old 11-12-2023, 06:25 PM
  #20  
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Originally Posted by gigaplex
I think you might have put reverse polarity on that meter.
Changed the order of the meter in series, and built up custom leads for the meter to make it fool proof for connecting to an installed motor.

At the end of the day, the issue was the meter was auto recognizing the current as AC. I manually switched to DC and the readings are now accurate. Hobbywing also seems to set the timing low for the amp draw out of the box.
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Old 11-12-2023, 06:34 PM
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Originally Posted by shortcut3d
Changed the order of the meter in series, and built up custom leads for the meter to make it fool proof for connecting to an installed motor.

At the end of the day, the issue was the meter was auto recognizing the current as AC. I manually switched to DC and the readings are now accurate. Hobbywing also seems to set the timing low for the amp draw out of the box.
The G4 does seem to run a bit on the warm side. It'll probably get pretty hot if you turn it up too much. The no-load current isn't particularly indicative of load current.
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Old 11-13-2023, 08:45 AM
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Originally Posted by shortcut3d
I tried using a multimeter to measure the amps on on of my HW Xerun V10 G4 17.5 motors today. It only pulled just over 1 amp. It peaked at 1.6 amps on trigger pull. Am I doing something wrong?

I'd strongly suggest you pick up some good power measuring equipment. 21.5's when at full acceleration will peak just under 60 amps and settle down to a steady state after a couple seconds at full throttle.
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Old 11-20-2023, 02:27 PM
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Originally Posted by Sabin
I'd strongly suggest you pick up some good power measuring equipment. 21.5's when at full acceleration will peak just under 60 amps and settle down to a steady state after a couple seconds at full throttle.
I have a Hobbywing Tunalyzer and Loadmaster for tuning out of the buggy.
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Old 11-20-2023, 02:31 PM
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So I’m inclined to pull all my motors, clean, reassemble, etc. then tune. Is there a pro tip for unsoldering and re-soldering motors? The re-soldering just never seems to come out as nice.
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Old 11-20-2023, 08:55 PM
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Originally Posted by shortcut3d
So Iím inclined to pull all my motors, clean, reassemble, etc. then tune. Is there a pro tip for unsoldering and re-soldering motors? The re-soldering just never seems to come out as nice.
Clean the tabs of solder. You can use solder wick, a solder pump, or some braided wire with flux (essentially solder wick). The reason why the solder job doesn't look as good the next time is because all the flux was used up/burnt off. New solder with flux works wonders, but you have to get rid of the old solder or you just have a mess. For cleaning off flux you can use 99% IPA or brake cleaner.
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Old 11-20-2023, 10:36 PM
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Originally Posted by trilerian
Clean the tabs of solder. You can use solder wick, a solder pump, or some braided wire with flux (essentially solder wick). The reason why the solder job doesn't look as good the next time is because all the flux was used up/burnt off. New solder with flux works wonders, but you have to get rid of the old solder or you just have a mess. For cleaning off flux you can use 99% IPA or brake cleaner.
Thanks! Iíve had trouble with the solder wick. Iíll try adding more flux. I also ordered solder pump.

Any experience with rework flux -
Kester Solder RF741 No-Clean Tacky Rework Flux 30cc 57-0000-5025 https://a.co/d/bgDvFew
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Old 11-20-2023, 11:13 PM
  #27  
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Kester stuff is normally very good (but I haven't used that particular one).
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Old 11-21-2023, 07:01 AM
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Kester is good stuff, but you are going overboard here. No need for a good re work flux when a generic 2oz jar of flux will do the job and last forever. I have one still from Radio Shack. I only break out my Kestors when I am actually doing PCB re work.

Take some 12 or 13 guage wire, unbraid it, dip it into the flux and apply it to the motor tabs using a hot iron. It will soak up the solder and smoke a lot. You can scrape it across the tabs and get pretty much all the solder off them. Careful, the tabs will get hot and can desolder from the commutator ring if you leave it on too long, also some commutator rings (R1) are made with epoxy binding them and you can delaminate them from the heat. I also have a fan with a filter on it for the solder smoke, but as long as you are doing a lot you shouldn't set off any smoke alarms. Funny story about that, I was pre tinning an order and had about 60 wires to make. I set off my smoke alarm at 2 in the morning. New fangled design that is wired into my house and every smoke alarm in my house went off. My wife was not too pleased. Finally got them turned off and they came back on 10 minutes later. The next day I ordered the fume extractor.
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Old 11-21-2023, 02:01 PM
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Get Kester solder with silver in it, that'll help it it look shiney and nice. That and techniques on how do it. Its just an experience thing, keep at it and you'll figure it out eventually.
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Old 11-21-2023, 03:37 PM
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A couple issues Iíve identified with my current work:
  1. Not using flux and relying only on the rosin core solder. Iím going to stop being lazy.
  2. The Hudy solder is only 60/40 which is probably why itís been inconsistent. I was using Kester lead free with silver, but the gauge was thin so I put it aside. Kester was the better choice.
  3. I wasnít cleaning up solder between re-soldering. The wick wasnít effect probably because I needed more flux. I also picked up a vampire solder pump.
Need to stop being lazy AND allow enough time to do the job right. Itís tough when this is just a hobby; and my wife is rushing me, while the kiddo is asking good questions.
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