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Discussion Starter #1
Hello all! New to EV and about to purchase my first big motor. I have two options same exact motor though, and neither are local so I can’t see them. Based on these brush pics, would you choose one over the other? My eye hasn’t developed yet. Thanks for your time and sorry for the stupid question lol. I’m very indecisive.
 

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Discussion Starter #2
Question has been answered, most people have said the brushes may be better in Motor A but with Motor B being half the price to go with that one.
 

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Careful. How much brush is left in motor B? I can see the top of the brushes is motor A, but not in B. And the braided pigtails appear possibly to be stretched indicating a short length of brush remaining.
Also, make sure all (each) brush(es) slide smoothly in the holder.

Good luck,

major
 

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Discussion Starter #4
Major, you have a great eye and some one on Facebook mentioned this as well. I got a better picture of the comm and it definitely has grooves and pits from either arcing or low brushes. Bummed because it was only $200. Decided to pass though.
 

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Discussion Starter #6
Well I was bamboozled by the seller. Motor A just arrived and it is in horrible condition compared to the photos. Whoever got Motor B congrats.
 

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Well I was bamboozled by the seller. Motor A just arrived and it is in horrible condition compared to the photos. Whoever got Motor B congrats.
Most people would be flabbergasted with the terrible grody disgustingly filthy condition of some of these motors yet they perform perfectly well. I suggest you snap some photos and describe what bothers you. Then develop a plan to do some initial tests, disassemble and clean the sucker. Avoid commutator surface contamination, even fingerprints. Unless it needs reconditioning, leave it as is.

I've seen forklift motors so full of gunk you'd think they could not possibly even rotate, yet still running. Especially air cooled, they sit inches off the factory or warehouse floor and can go decades without service.
Regards,
major
 

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Discussion Starter #8 (Edited)
Major, thanks for the encouragement! Reconditioning is what I was going to come here to seek help with. Seller issued full refund, but allowed me to keep the motor. The comm on this motor is of concern. What is the recondition process? Also what would you recommend for rust removal and freshening up of the internals? Here is a pic of what I essentially got for free. Was considering getting another and keeping this as a back up or for mock ups. Thanks for any input! I have browsed through the sticky.
 

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I can't open your picture but the thumbnail looks OK to me

I suggest taking it apart - mine was very heavy and I think I damaged the rotor so I suggest standing it on it's tail and taking it apart vertically

Rust and gunk does not matter too much - EXCEPT on the brush holders and the comm

New bearings are cheap

Brushes and brush holders - this is where rust and gunk can cause problems

Major has terrified me into keeping ignorant paws off the comm

The brushes need to be able to slide - and to be long enough and in good nick

I suspect that you have probably got a good if scruffy motor for a record low price
 

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Discussion Starter #10
Duncan and Major, I have decided to use this motor if possible. What are the dangers of touching the commutator? I can’t recall if I had gloves on when I was checking everything out at first. The comm is slightly pitted and covered in dust/gunk. I would like to completely refresh it. Is my only option throwing it on a lathe with sand paper? Everything else on the motor is rusted. And I mean everything. What is the safest way to clean everything once taken apart? I’ve read a lot and watched a few videos but would like to know what you guys think directly in regards to this motor. Lastly should I clean first or throw 12v at it first to see if it starts? Thank you and below are better pics.
 

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Loooool.

The seller took the most flattering picture possible of that motor. Move the camera an inch in any direction and the rust that blankets the rest of the motor would've been visible.

At first I thought perhaps they overreacted by refunding you, but, seeing your pic now... they knew what they tried to pull :p
 

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Discussion Starter #12
Loooool.

The seller took the most flattering picture possible of that motor. Move the camera an inch in any direction and the rust that blankets the rest of the motor would've been visible.

At first I thought perhaps they overreacted by refunding you, but, seeing your pic now... they knew what they tried to pull
I know haha. They were completely understanding and actually have another of the same but not rusted motor I could get with the refund and have 2 motors.
 

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Use Google to find articles:
DC motor commutator care and service

Here's a 5 page file particularly relevant:
Proper Maintenance and Upkeep
in DC Motor Units
By Roly Roberge
Design and Application Engineer Manager

Thru Morgan, aka Morganite, a long time carbon company.

Re. Touching the comm. Wear clean white cotton gloves. No reason to contact it with bare skin. Nothing good happens. And you can't avoid leaving fingerprints (oil) and other crap. A proper comm film is worth its weight in gold. Actually a very good reason to buy a used motor. Only remove it if absolutely necessary. In an EVcar, it'll take years to re-establish. Even with a 100 hour break-in. Without a proper film, there will be high friction, high voltage drop, rapid brush wear, possible dusting, thermal trouble, copper drag, comm distortion, etc.
Regards,
major
 

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Discussion Starter #14
Use Google to find articles:
DC motor commutator care and service

Here's a 5 page file particularly relevant:
Proper Maintenance and Upkeep
in DC Motor Units
By Roly Roberge
Design and Application Engineer Manager

Thru Morgan, aka Morganite, a long time carbon company.

Re. Touching the comm. Wear clean white cotton gloves. No reason to contact it with bare skin. Nothing good happens. And you can't avoid leaving fingerprints (oil) and other crap. A proper comm film is worth its weight in gold. Actually a very good reason to buy a used motor. Only remove it if absolutely necessary. In an EVcar, it'll take years to re-establish. Even with a 100 hour break-in. Without a proper film, there will be high friction, high voltage drop, rapid brush wear, possible dusting, thermal trouble, copper drag, comm distortion, etc.
Regards,
major
Major thanks for the article just read it and saved to my phone notes. So even thought it’s pitted, gunked up, and perhaps has a finger print or two, my best bet is to just vacuum/dust removal and leave it at that because of the film it’s built up? I plan on replacing the brushes because of a few being frayed. Is this okay without messing with the comm? A YouTube video said to clean the comm with terminal/contact cleaner. Lastly is 75% Isopropyl ok for cleaning everything else?
 

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Just seen your later pictures - still can't open the other one

To be honest it looks pretty damn good to me! - it looks a lot better than the one that is in my car just now

One question I would ask - are you sure it's a series motor? - have a look at the field coils should see what is effectively copper bars as the windings - if it looks like copper wire it will be a SepEx - not as easy to get a controller

I would be very tempted to do the 12v battery test - you will feel much happier about it after you have given it a spin
Do this on the floor - and be prepared for it to kick - don't let it bite you or jump off the bench
 

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Discussion Starter #16 (Edited)
Just seen your later pictures - still can't open the other one

To be honest it looks pretty damn good to me! - it looks a lot better than the one that is in my car just now

One question I would ask - are you sure it's a series motor? - have a look at the field coils should see what is effectively copper bars as the windings - if it looks like copper wire it will be a SepEx - not as easy to get a controller

I would be very tempted to do the 12v battery test - you will feel much happier about it after you have given it a spin
Do this on the floor - and be prepared for it to kick - don't let it bite you or jump off the bench
I am 99.9% sure it is a series motor. Only doubt .1% because you asked haha. It has been used in two other builds and jefsmk who has been posting in the motor stickie has the same motor. Terminal lugs all the same size, labeled A1-2 S1-2, big bars coming from the S1 and S2 terminals. Part number is Clark #2774337/5BT1362B144.

As for applying 12v, it is safe to do so even with the motor being caked with grime on the inside? I am eager to test it, but don’t want to deep clean it quite yet. Want replacement parts/bolts available when I do that.

For the comm, can I at least wipe it down?

Also already have the controller for this motor. Using a EVnetics Soliton Jr. that I purchased super cheap with billet throttle and 2/0 AWG hydraulic crimpers.

Thanks!
 

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Major is the expert and he normally say leave it alone!
Use your head. If there's a glob of bird sh!t on the comm, wipe it off with a dry rag. If there's something crusty which would make the brush bounce, scrape it off using a hardwood stick like a tounge depresser. If it's worse, buy a seating stone. But try to let the brushes do their job of wiping the comm.

major
 

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Discussion Starter #19
Major is the expert and he normally say leave it alone!
Use your head. If there's a glob of bird sh!t on the comm, wipe it off with a dry rag. If there's something crusty which would make the brush bounce, scrape it off using a hardwood stick like a tounge depresser. If it's worse, buy a seating stone. But try to let the brushes do their job of wiping the comm.

major
Thank you! This is what I thought, but wanted to make sure. Everyone seems to have a different practice on YouTube/Google but with the same general out come if they need to clean and resurface. I will update this thread with pics and videos of the motors progress before starting a build thread.
 

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Discussion Starter #20 (Edited)
Quick question about reverse contactor wiring. I would like to use a SW202 with my EVnetics controller. Below are two diagrams. The EVnetics controller has the two terminals for motor. I know I would run S1/S2 as pictured in the SW202 diagram and A1 as pictured in the EVnetics diagram, but would A2 run to the SW202 as I have marked in red and then from the circled terminal back to the other EVnetics post? Sorry if this is a dumb question. 218A700E-23AA-4141-9028-78FEDE237277_1582919797337.jpeg CB88356C-BE48-4E8C-A47D-4BFD6E30DD43_1582919783683.jpeg
 
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