OT-how to test and repair DC brushed motors.
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If I talk to anyone in or from Santa Fe Springs I might get homesick! ;) Grew up mostly there, Norwalk, La Mirada, and Whittier. I have been using heck out of my newest DVM from Harbor Freight. Got a nice continuity check function, and if you select any of the Ohms settings except that or diode check, it will auto-range. Getting 20.3ohms even without one of the brush caps in place. Hit the interiors of the brush holders with CRC QD Electronic Cleaner and a Q-tip, just in case it had surface corrosion. Have to properly caffeinate this old body, and then clean and search the floor for the one missing nut and brush cap. Had a catastrophic spill of gatorade last night. Threw towels on everything, and went to bed. This morning I've been picking up what I can, and getting it ready to wash. Sticky from the sugar in the gatorade. Found one nut, and hadn't lost the other brush cap.? I can steal one from the other motor, and ops check, if needed, but I'd rather find the missing bits. I need to clean up this dump anyway.? Bill in OKC William R. Meyers, MSgt, USAF(Ret.) Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY! Physics doesn't care about your schedule. The only reason I know anything is because I've done it wrong enough times to START to know better. Expect in one hand, expectorate in the other. See which one gets full first.
On Friday, August 11, 2023 at 08:34:09 PM CDT, Steven Nederhiser <7101sned@...> wrote:
Hello Bill; Mr. Ohmmeter would be my friend in this application. Check the field windings to see if they are good, not shorted. Check the armature for shorts and continuity. I am sure that there is a tutorial on the internet covering this. 95% of the time the armature goes bad. Try eurton electric out in Santa Fe Springs in California. I have sent many items out to them over the years. They also carry brushes, switches, ect. Check the power, fuses, and switch. On Fri, Aug 11, 2023 at 4:55?PM Bill in OKC too via <wmrmeyers=[email protected]> wrote:
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Yep. PM brushed motor. Ohm meter is still useful for continuity checks through the brushes, brush holders, wire from them to the connectors, etc. Dad taught me how to use an ohm meter back when most of them were vacuum tube operated and all analog displays. Pretty sure I still have a VTVM here someplace... Been a while since I've seen it, though. ;) Been a hobby electronics type most of my life, and 12 years as a Satellite Communications tech for the USAF. Had some spiffy test equipment there, and that was long enough ago that most of it is probably available on the surplus market for prices I could almost afford now. But I already have too many expensive hobbies. ;) William R. Meyers, MSgt, USAF(Ret.) Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY! Physics doesn't care about your schedule. The only reason I know anything is because I've done it wrong enough times to START to know better. Expect in one hand, expectorate in the other. See which one gets full first.
On Friday, August 11, 2023 at 09:43:01 PM CDT, Jon Elson <elson@...> wrote:
On 8/11/23 20:33, Steven Nederhiser wrote: Hello Bill;I'm pretty sure that is a permanent magnet motor, so no field winding. Jon |
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Not where I grew up. We had another phrase for that, and I'm too inhibited to use it anymore. I guess we could call it red-neck engineering. Sort of thing farmers do to get critical equipment to operate when they need it and the only folks that can be hired to fix things have a long wait time and harvest is due RFN.? Not really a redneck, just a wannabe. Though my other grandma was from Beckley, WV. So I have some redneck ancestry! ;) Bill in OKC William R. Meyers, MSgt, USAF(Ret.) Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY! Physics doesn't care about your schedule. The only reason I know anything is because I've done it wrong enough times to START to know better. Expect in one hand, expectorate in the other. See which one gets full first.
On Friday, August 11, 2023 at 09:53:35 PM CDT, mike allen <animal@...> wrote:
??? ??? no " micky mousing " is when you do something halfassed that? you know in the back of your mind can possibly injure someone . ??? ??? animal On 8/11/23 5:31 PM, Bill in OKC too via
groups.io wrote:
Yep. That's what we call
"micky-mousing" something. I grew up not too far from
Disneyland! Dad and Grandpa were great at it!
William
R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by:
Good judgement comes from experience.
Experience comes from bad judgement.?
SEMPER GUMBY!
Physics doesn't care about your schedule. The only reason I know anything is because I've done it wrong enough times to START to know better. Expect
in one hand, expectorate in the other. See
which one gets full first.
On Friday, August 11, 2023 at 06:49:02 PM CDT, mike
allen <animal@...> wrote:
??? ??? push comes to shove , ya can gut the motor take the armature off the shaft & put the shaft back in & power the shaft from another motor . ??? You'd be surprised at some of the things we've done to keep things workin . Years ago my bud scores a 4 cylinder compressor from his wife's boss , he was a dentist . The motor had burnt up in this compressor so they bought a new one & passed the burnt on over to my bud . Did the same thing here ,? tore the motor apart emptied the armature shaft & then installed a pulley in the shaft & cut a notch in the motor housing . Then I found a nice piece of scrap plate in my
someday pile & mounted a motor on it & bolted
the plate under the old motor , ran a belt from new
motor to new pulley on the shaft from the old motor
& the rest is history . ??? ??? Yer half way there already with the bad motor . ??? anmal On
8/11/23 3:55 PM, Bill in OKC too via groups.io wrote:
Unless I want to completely redesign
it, I need the right-angle gear box. I'm not
qualified for that! I could probably put a
different gear box on it, but none of the ones
I've found are near the right size. Too big, or
too small, nothing in the Goldilocks zone. I do
have a Leeson DC motor and probably some spare
brushes for larger motors from my former work,
that they trashed. All I have to do is find them.
IF I can find something, I can probably cut it
down if it's not the right size already. I am good
at micky-mousing something...?
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by:
Good judgement comes from
experience. Experience comes from bad
judgement.?
SEMPER GUMBY!
Physics doesn't care about your schedule. The only reason I know anything is because I've done it wrong enough times to START to know better. Expect in
one hand, expectorate in the other.
See which one gets full first.
On Friday, August 11, 2023 at 01:39:17 PM CDT,
mike allen <animal@...>
wrote:
??? ??? Just tossin this out there , with
no load on the motor you will not get the
actual amp reading . Also unless? you have a
good DC clamp meter most DVM that do amps
top out at 10 amps . ?? ??? I thought there was a guy in this group that had a motor shop ?? Does the motor absolutely have to have the right angle gear box or can it be a straight gear reduction motor ? ??? ??? animal On
8/11/23 9:02 AM, Bill in OKC too via
groups.io wrote:
SWMBO' s power wheelchair lift crapped out
the other day. New motor is no longer
available since the lift is ancient.
Manufacturer of the lift removed any OEM
markings. It's a right- angle gear motor,
which I'll eventually have some photos and
dimensions for. This is the in-and-out motor
for a Harmar AL-600 lift that fits in the back
of a van. Near as I can remember it was made
about 2007 or so.?
There is no continuity in the motor, but? othinf seems burned. I pulled it apart and fiddled with it, and got continuity back. Hooked it back up to power trying to get a current draw reading and it spun up and? rapped out again. No continuity again. Brushes look good.? I have a megger for testing? insulation, and an assortment of DVMs and at least one analog voltmeter. Somewhere in the library are a couple of older books on motor testing and repair, but haven't found them yet. Any suggestions for resources? I looked at Grainger & McMaster-Carr, also Amazon & Surplus Center. They have similar gear motors but nothing that looks exactly? right. Most are either way too light or way too heavy. This is a 12vdc motor, could draw as much as 20amps, but probably closer to 10, and could less. There is another motor on it with a different gearbox. Looks to be about the same motor. May fiddle with that, and get a current draw. Found one of these motors for sale on the knoppix site for $600, was $400 from Harmar at one time. Seems a bit fishy to me, and can't afford it anyway.? Gotta get ready to take SWMBO to get fitted for a new CPAP mask, and for both of us to get new CPAP machines. Hope someone can point me in a useful direction. Used to be a bunch of folks whe rebuilt motors & alternators/generators around here. Called one and they don't do DC motors at all, and don't think there's anyone left who does., Any help will be appreciated! Bill in OKC? |
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I think I've got it mostly sorted, at the moment, but I've bookmarked your site just in case! Though I admit to being a cheap bastrich, and wanting to save the money by doing it myself. ;) If it turns out that I'm wrong, I'll give you a call! Bill in OKC William R. Meyers, MSgt, USAF(Ret.) Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY! Physics doesn't care about your schedule. The only reason I know anything is because I've done it wrong enough times to START to know better. Expect in one hand, expectorate in the other. See which one gets full first.
On Saturday, August 12, 2023 at 09:01:30 AM CDT, rockindubya via groups.io <jeffwoods95@...> wrote:
Late to the thread.DC motor guy here - 50 years. I can repair and or rewind. Still quite involved in my "golden years" Please post 2 pics of the armature, one each side. Odds are I can evaluate by viewing. Be happy to assist you. Here's my Hemmings ad. |
 wannabeGP
On Saturday, August 12, 2023 at 01:30:12 PM EDT, Bill in OKC too via groups.io <wmrmeyers@...> wrote:
Not where I grew up. We had another phrase for that, and I'm too inhibited to use it anymore. I guess we could call it red-neck engineering. Sort of thing farmers do to get critical equipment to operate when they need it and the only folks that can be hired to fix things have a long wait time and harvest is due RFN.? Not really a redneck, just a wannabe. Though my other grandma was from Beckley, WV. So I have some redneck ancestry! ;) Bill in OKC William R. Meyers, MSgt, USAF(Ret.) Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY! Physics doesn't care about your schedule. The only reason I know anything is because I've done it wrong enough times to START to know better. Expect in one hand, expectorate in the other. See which one gets full first.
On Friday, August 11, 2023 at 09:53:35 PM CDT, mike allen <animal@...> wrote:
??? ??? no " micky mousing " is when you do something halfassed that? you know in the back of your mind can possibly injure someone . ??? ??? animal On 8/11/23 5:31 PM, Bill in OKC too via
groups.io wrote:
Yep. That's what we call
"micky-mousing" something. I grew up not too far from
Disneyland! Dad and Grandpa were great at it!
William
R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by:
Good judgement comes from experience.
Experience comes from bad judgement.?
SEMPER GUMBY!
Physics doesn't care about your schedule. The only reason I know anything is because I've done it wrong enough times to START to know better. Expect
in one hand, expectorate in the other. See
which one gets full first.
On Friday, August 11, 2023 at 06:49:02 PM CDT, mike
allen <animal@...> wrote:
??? ??? push comes to shove , ya can gut the motor take the armature off the shaft & put the shaft back in & power the shaft from another motor . ??? You'd be surprised at some of the things we've done to keep things workin . Years ago my bud scores a 4 cylinder compressor from his wife's boss , he was a dentist . The motor had burnt up in this compressor so they bought a new one & passed the burnt on over to my bud . Did the same thing here ,? tore the motor apart emptied the armature shaft & then installed a pulley in the shaft & cut a notch in the motor housing . Then I found a nice piece of scrap plate in my
someday pile & mounted a motor on it & bolted
the plate under the old motor , ran a belt from new
motor to new pulley on the shaft from the old motor
& the rest is history . ??? ??? Yer half way there already with the bad motor . ??? anmal On
8/11/23 3:55 PM, Bill in OKC too via groups.io wrote:
Unless I want to completely redesign
it, I need the right-angle gear box. I'm not
qualified for that! I could probably put a
different gear box on it, but none of the ones
I've found are near the right size. Too big, or
too small, nothing in the Goldilocks zone. I do
have a Leeson DC motor and probably some spare
brushes for larger motors from my former work,
that they trashed. All I have to do is find them.
IF I can find something, I can probably cut it
down if it's not the right size already. I am good
at micky-mousing something...?
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by:
Good judgement comes from
experience. Experience comes from bad
judgement.?
SEMPER GUMBY!
Physics doesn't care about your schedule. The only reason I know anything is because I've done it wrong enough times to START to know better. Expect in
one hand, expectorate in the other.
See which one gets full first.
On Friday, August 11, 2023 at 01:39:17 PM CDT,
mike allen <animal@...>
wrote:
??? ??? Just tossin this out there , with
no load on the motor you will not get the
actual amp reading . Also unless? you have a
good DC clamp meter most DVM that do amps
top out at 10 amps . ?? ??? I thought there was a guy in this group that had a motor shop ?? Does the motor absolutely have to have the right angle gear box or can it be a straight gear reduction motor ? ??? ??? animal On
8/11/23 9:02 AM, Bill in OKC too via
groups.io wrote:
SWMBO' s power wheelchair lift crapped out
the other day. New motor is no longer
available since the lift is ancient.
Manufacturer of the lift removed any OEM
markings. It's a right- angle gear motor,
which I'll eventually have some photos and
dimensions for. This is the in-and-out motor
for a Harmar AL-600 lift that fits in the back
of a van. Near as I can remember it was made
about 2007 or so.?
There is no continuity in the motor, but? othinf seems burned. I pulled it apart and fiddled with it, and got continuity back. Hooked it back up to power trying to get a current draw reading and it spun up and? rapped out again. No continuity again. Brushes look good.? I have a megger for testing? insulation, and an assortment of DVMs and at least one analog voltmeter. Somewhere in the library are a couple of older books on motor testing and repair, but haven't found them yet. Any suggestions for resources? I looked at Grainger & McMaster-Carr, also Amazon & Surplus Center. They have similar gear motors but nothing that looks exactly? right. Most are either way too light or way too heavy. This is a 12vdc motor, could draw as much as 20amps, but probably closer to 10, and could less. There is another motor on it with a different gearbox. Looks to be about the same motor. May fiddle with that, and get a current draw. Found one of these motors for sale on the knoppix site for $600, was $400 from Harmar at one time. Seems a bit fishy to me, and can't afford it anyway.? Gotta get ready to take SWMBO to get fitted for a new CPAP mask, and for both of us to get new CPAP machines. Hope someone can point me in a useful direction. Used to be a bunch of folks whe rebuilt motors & alternators/generators around here. Called one and they don't do DC motors at all, and don't think there's anyone left who does., Any help will be appreciated! Bill in OKC? |
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Had to order brushes.??in Princeton, WV, is a good place for motor brushes, and you can search by size. Got 4 brushes, shipped, for about $30, and here in three days. Would have been faster if USPS hadn't lost the package for a day. First motor is running. Looks like I need to create a wiring diagram, and make sure the replacement relay I bought for it is the right one, because the controller isn't working, thought the motor spins on the bench.?
https://www.dcmotorparts.com/ I'm also considering skimming both commutators, though the one I've already seen doesn't look all that bad. Just because I have them apart enough to do it easily. What I don't have is the special tooling to do that. Does not look like there is any mica to undercut. Have seen a ground hacksaw blade used for that purpose, so don't know if I need the specialty tooling. And no idea how many more motors I might need to work on... Somebody stop me before I eBay again! ;P Never found the missing parts, so I'm headed out to the shop to see If I can make a couple of matching brass brush covers. The two Themac J-3 tool post grinders I wound up with both have more complex brush covers: One on the left is the other one of what I lost. The other two will screw down into the brush holders, but are slightly different in size. I'm going to try ordering some that should be the correct one from Grainger, where they're $2.29 each, which isn't bad, and I can pick them up so not pay shipping, but the earliest they could be here now is after 4PM on Friday. $4.98, so I went ahead and ordered them. The brushes, if I got them from Grainger would be $26.76 each. DC Motor sold them to me for $5.13 each. Probably should have asked if they had the brush caps, but didn't think of it then. ;) Got a package of 50 of the 8-32 kep-nuts from amazon for under $8 last weekend. I now have LOTS of spares! :) Bill in OKC |
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MSC is also useless. Don't have brushes that fit at all, and don't seem to have brush covers at all. Don't carry Leeson motors, apparently, which may be why, these were used on Leeson motors.? All the 3D printed caps I saw were metric sizes, and these are old SAE/ANSI sizes. Might also have to do with why they're so hard to find parts for.? Bill in OKC William R. Meyers, MSgt, USAF(Ret.) Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY! Physics doesn't care about your schedule. The only reason I know anything is because I've done it wrong enough times to START to know better. Expect in one hand, expectorate in the other. See which one gets full first.
On Sunday, September 3, 2023 at 02:32:33 PM CDT, mike allen <animal@...> wrote:
I have a armature lathe , a old " Trucut" & on small motors its probably faster to do the hacksaw trick . As far as the brush covers go , if Grainger has them I wonder if MSC does also . If MSC does have them? there may be a CAD drawing that ya can DL & try printing them on the 3d printer . I know they used to have cad drawings for their stuff , don't know about for these days . A quick google shows that folks? have printed covers/caps & put the files online .
animal On 9/3/23 11:59 AM, Bill in OKC too via
groups.io wrote:
H I'm also considering skimming both commutators, Just because I have them apart enough to do it easily. What I don't have is the special tooling to do that. Does not look like there is any mica to undercut. Have seen a ground hacksaw blade used Somebody stop me before I eBay again! ;P Never found the missing parts, so I'm headed out to the shop to see If I can make a couple of matching brass brush covers. The two Themac J-3 tool post grinders I wound up with both have more complex brush covers: One on the left is the other one of what I lost. The other two will screw down into the brush holders, but are slightly different in size. I'm going to try ordering some that should be the correct one from Grainger, where they're $2.29 each, which isn't bad, and I can pick them up so not pay shipping, but the earliest they could be here now is after 4PM on Friday. $4.98, so I went ahead and ordered them. The brushes, if I got them from Grainger would be $26.76 each. DC Motor sold them to me for $5.13 each. Probably should have asked if they had the brush caps, but didn't think of it then. ;) Got a package of 50 of the 8-32 kep-nuts from amazon for under $8 last weekend. I now have LOTS of spares! :) Bill in OKC |
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Thanks Jeff! First photo, last two digits 82 is the motor we've been talking about mostly. #83 is the other motor. They don't look too bad to me. ;) I'm also having a wiring or relay problem... I can hear the relay click. Nothing else happens. There are also a couple of limit switches in there, and a pair of momentary contact switches that are the Up & Down buttons. . Could be wiring, relay (which I have replaced because the original relay has a cracked open case) or switches. Could simply be corrosion, as this thing sat in an unconditioned shed for most of 20 years. I've got some wet or dry silicon carbide paper, and flint paper, not sure I have aluminum oxide paper... Emery is aluminum oxide. Do you know why it shouldn't be used? Too coarse??
Got plenty of X-Acto knife blades, And I'm sure I could find a broken hacksaw blade. I mostly don't throw stuff like that away! I do not own a growler. Currently, doesn't look like I can afford one that I know works, either. ;) Funny thing, found a cheap ladies nail care file/buffer thing in drawer under my desktop. Think I'll be using that to polish the commutator. Just the couple of strokes I took with it made the segment I used it one nice and shiny! Got to drop all that and get us ready for her doctor's appointment this afternoon. More later! Bill in OKC |
Bill in OKC too