|
Emery, the rock, is aluminum oxide, and several kinds of iron oxides, plus other odds and ends. . Just looked it up. Corundum is the major ingredient, which is aluminum oxide.?? I remember reading about it being crushed and graded, decades ago, but that was about the time aluminum oxide as a synthetic became really common. IIRC, Corundum is ruby in it's purest natural form, and sapphire is the same thing with chromium instead of iron... Or maybe I misremember. I've been looking forward to synthetic aluminum oxide (more or less sapphire) that is colorless and transparent for use in space ships since I was a wee tot. Too much science fiction as a kid...?
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!
Expect in one hand, expectorate in the other. See which one gets full first.
On Tuesday, September 5, 2023 at 07:17:43 PM CDT, Dave Matticks <dpm100@...> wrote:
?
On 09/05/2023 12:04 PM CDT Bill in OKC too via groups.io <wmrmeyers@...> wrote:
?
Emery is not the same at all!!
A lot of people say they take some “emery” to it!
Aluminum oxide and sometimes silicon carbide yes but don’t think I’ve even touched a piece of “emery” cloth in decades!
Emery is s specific abrasive just like the others.
For what it’s worth.
Dave
?
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
|
??? ??? Like Crocus Cloth , I haven 't seen that in years . Fixed
plenty of crankshafts with Crocus Cloth
animal
On 9/5/23 5:17 PM, Dave Matticks wrote:
toggle quoted message
Show quoted text
?
On 09/05/2023 12:04 PM CDT Bill in OKC too via groups.io
<wmrmeyers@...> wrote: ?
Emery is not the same at all!!
A lot of people say they take some “emery” to it!
Aluminum oxide and sometimes silicon
carbide yes but don’t think I’ve even touched a piece of “emery”
cloth in decades!
Emery is s specific abrasive just like
the others.
For what it’s worth.
Dave
?
|
Crocus cloth has jewelers rouge impregnated in it. ?I wouldn’t use it.? I’ve had good success with a fresh pink pearl eraser. It removes the carbon pretty good.?
toggle quoted message
Show quoted text
On Sep 5, 2023, at 7:11 PM, mike allen <animal@...> wrote:
?
??? ??? Like Crocus Cloth , I haven 't seen that in years . Fixed
plenty of crankshafts with Crocus Cloth
animal
On 9/5/23 5:17 PM, Dave Matticks wrote:
?
On 09/05/2023 12:04 PM CDT Bill in OKC too via groups.io
<wmrmeyers@...> wrote: ?
Emery is not the same at all!!
A lot of people say they take some “emery” to it!
Aluminum oxide and sometimes silicon
carbide yes but don’t think I’ve even touched a piece of “emery”
cloth in decades!
Emery is s specific abrasive just like
the others.
For what it’s worth.
Dave
?
|
Yea I wouldn't use it on a armature either . Handy thing to have
a roll of if yer building / rebuilding a engine .
According to Ehow they say it's s like sand paper , I wouldn't go
near a crankshaft or armature with sand paper . I did a google for
Crocus & that's where I found the Ehow line . I don't think I
would buy it on Amazon , but I did see that MSC has a 60' roll for
$27 & some change , That's around what I paid for my last roll
@ 25 years back .
Thanks for making me look again . I asked for it when I was at a
Grainger a few years back & they said never heard of it .
thanks
animal
On 9/5/23 7:20 PM, Jim F wrote:
toggle quoted message
Show quoted text
Crocus cloth has jewelers rouge impregnated in it. ?I wouldn’t use
it.?
I’ve had good success with a fresh pink pearl eraser. It
removes the carbon pretty good.?
?
??? ??? Like Crocus Cloth , I haven 't seen that in years
. Fixed plenty of crankshafts with Crocus Cloth
animal
On 9/5/23 5:17 PM, Dave
Matticks wrote:
?
On 09/05/2023 12:04 PM CDT Bill in OKC too via
groups.io <wmrmeyers@...>
wrote: ?
Emery is not the same at all!!
A lot of people say they take some “emery” to it!
Aluminum oxide and sometimes
silicon carbide yes but don’t think I’ve even touched a
piece of “emery” cloth in decades!
Emery is s specific abrasive
just like the others.
For what it’s worth.
Dave
?
|
I use Crocus Cloth when I want to polish but not remove material.??
An old mechanic I worked with polished hydraulic valve spools with it and claimed it didn't remove any material.? Not sure that's true, I figure optics with ball milled rouge, very slow but does remove a little.
Greg
Sent from my T-Mobile 4G LTE Device
|
Crocus cloth is like really fine sand paper. Like 3000 grit. As Mike said, it's jeweler's rouge, or very finely divided iron oxide with a bit of a carrier, likely grease or wax. Or you can get sticks of the jeweler's rouge, and use them on buffs. IIRC, my dad recharged his razor strop with jeweler's rough. It will give a very fine polish on steel, iron, and silver, that I've used it on. You do have to wash it off, afterwards though.?
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!
Expect in one hand, expectorate in the other. See which one gets full first.
On Tuesday, September 5, 2023 at 09:58:16 PM CDT, mike allen <animal@...> wrote:
Yea I wouldn't use it on a armature either . Handy thing to have
a roll of if yer building / rebuilding a engine .
According to Ehow they say it's s like sand paper , I wouldn't go
near a crankshaft or armature with sand paper . I did a google for
Crocus & that's where I found the Ehow line . I don't think I
would buy it on Amazon , but I did see that MSC has a 60' roll for
$27 & some change , That's around what I paid for my last roll
@ 25 years back .
Thanks for making me look again . I asked for it when I was at a
Grainger a few years back & they said never heard of it .
thanks
animal
On 9/5/23 7:20 PM, Jim F wrote:
Crocus cloth has jewelers rouge impregnated in it. ?I wouldn’t use
it.?
I’ve had good success with a fresh pink pearl eraser. It
removes the carbon pretty good.?
?
??? ??? Like Crocus Cloth , I haven 't seen that in years
. Fixed plenty of crankshafts with Crocus Cloth
animal
On 9/5/23 5:17 PM, Dave
Matticks wrote:
?
On 09/05/2023 12:04 PM CDT Bill in OKC too via
groups.io <wmrmeyers@...>
wrote: ?
Emery is not the same at all!!
A lot of people say they take some “emery” to it!
Aluminum oxide and sometimes
silicon carbide yes but don’t think I’ve even touched a
piece of “emery” cloth in decades!
Emery is s specific abrasive
just like the others.
For what it’s worth.
Dave
?
|
Folks have been usin Crocus Cloth for polishing crank shafts
& such for many many years . That's why I bought it a long
time back .
animal
On 9/5/23 8:19 PM, Greg via groups.io
wrote:
toggle quoted message
Show quoted text
I use Crocus Cloth when I want to polish but not
remove material.??
An old mechanic I worked with polished hydraulic
valve spools with it and claimed it didn't remove any material.?
Not sure that's true, I figure optics with ball milled rouge,
very slow but does remove a little.
Greg
Sent from my T-Mobile 4G LTE Device
|
Why not a strip of wet or dry sand paper it doesn't shed as much
abrasive as the open coat rolls. Ive used it on armatures for 54
years.
Dusty
On 9/5/2023 9:28 PM, Bill in OKC too
via groups.io wrote:
Crocus cloth is like really
fine sand paper. Like 3000 grit. As Mike said, it's
jeweler's rouge, or very finely divided iron oxide with a
bit of a carrier, likely grease or wax. Or you can get
sticks of the jeweler's rouge, and use them on buffs. IIRC,
my dad recharged his razor strop with jeweler's rough. It
will give a very fine polish on steel, iron, and silver,
that I've used it on. You do have to wash it off, afterwards
though.?
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!
Improvise, Adapt, and Overcome.
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 Tuesday, September 5, 2023 at 09:58:16 PM CDT, mike
allen <animal@...> wrote:
Yea I wouldn't use it on a armature either . Handy
thing to have a roll of if yer building / rebuilding a
engine .
According to Ehow they say it's s like sand paper , I
wouldn't go near a crankshaft or armature with sand
paper . I did a google for Crocus & that's where I
found the Ehow line . I don't think I would buy it on
Amazon , but I did see that MSC has a 60' roll for $27
& some change , That's around what I paid for my
last roll @ 25 years back .
Thanks for making me look again . I asked for it when
I was at a Grainger a few years back & they said
never heard of it .
thanks
animal
On
9/5/23 7:20 PM, Jim F wrote:
Crocus cloth has jewelers rouge impregnated in it.
?I wouldn’t use it.?
I’ve had good success with a fresh pink pearl
eraser. It removes the carbon pretty good.?
?
??? ??? Like Crocus Cloth , I haven 't seen that in
years . Fixed plenty of crankshafts with Crocus Cloth
animal
On
9/5/23 5:17 PM, Dave Matticks wrote:
?
On 09/05/2023 12:04 PM CDT Bill in OKC too via
groups.io <wmrmeyers@...>
wrote: ?
Emery is not the same at all!!
A lot of people say they take some “emery” to it!
Aluminum oxide and sometimes silicon carbide yes but
don’t think I’ve even touched a piece of “emery” cloth
in decades!
Emery is s specific abrasive just like the others.
For
what it’s worth.
Dave
?
|
My recollection is that emery grit is conductive and you don't want any missed particles shorting out commutator segments.? Just my memory from working on old DC motors, wind turbines, and electric vehicles decades ago.
|
If you look at the various abrasives under a microscope (electron) you can determine the shape. Silicon carbide is sharp for instance.? Rouge is almost round at least is when milled, about 250 nanometers in diameter and very consistant in size.
If interested I can post the scans in a few days.? I have several optical polishing g compounds and may have AlO.
Greg
Sent from my T-Mobile 4G LTE Device
|
I was figuring that was probably the problem. It's been most of 50 years since I last played with the stuff. Been buying silicon carbide as much as possible since the 80's. Polished the commutators last night, and they look good. Now I need to find out how to check the armature without a growler. Going to try one of my DVM's on the high ohms scales. After I take a dive into the book I bought on fixing motors. Was published in 1920, so may have info on making a growler, or other methods of testing.?
Took me about 4 hours yesterday to find the Morse taper wedge I knew I had, and take the MT3 to MT2 sleeve off my MT2 ball bearing center, then about another hour to do the polishing. Just canceled my wife's dental appointment, as she woke up with a fever and sore throat, so may get to work on the brush holder caps today after all. And do the wiring checks and such, as well. I should manage to stay busy and productive all day. Maybe. ;)
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!
Expect in one hand, expectorate in the other. See which one gets full first.
On Wednesday, September 6, 2023 at 09:14:14 AM CDT, Jim Erdman via groups.io <jiminwis@...> wrote:
My recollection is that emery grit is conductive and you don't want any missed particles shorting out commutator segments.? Just my memory from working on old DC motors, wond turbines, and electric vehicles decades ago.?
|
I can't swear anyone else will be interested, but I will be! Somewhere around here I have a couple of digital microscopes, one kid's toy, and one "real" scientific tool from the 90's or maybe a bit later. In the drawer next to me is a student's optical that I bought as pieces and am slowly putting back together. Whoever took it apart in the first place lost all the screws, or used them to fix the other identical microscope in the bag. Also a small tub of cerium oxide I bought when I was a teen for lapidary work. How I've managed to hang on to it for all these years, I couldn't tell you...
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!
Expect in one hand, expectorate in the other. See which one gets full first.
On Wednesday, September 6, 2023 at 09:18:31 AM CDT, Greg via groups.io <gregj@...> wrote:
If you look at the various abrasives under a microscope (electron) you can determine the shape. Silicon carbide is sharp for instance.? Rouge is almost round at least is when milled, about 250 nanometers in diameter and very consistant in size.
If interested I can post the scans in a few days.? I have several optical polishing g compounds and may have AlO.
Greg
Sent from my T-Mobile 4G LTE Device
|
Bill, they both look serviceable, as is.
Really no need to polish, as there is minimal grooving.
That said, I have seen some emery paper that is actually electrically conductive. Crocus cloth has a biding agent for the rouge that will attract carbon dust as the brushes wear.
Both are bad news, creating possibilities of a short bar-to-bar. (That's what the brush does momentarily, until they contact the next segment, and so on...)
Aluminum oxide is non-conductive electrically.
When I referred to polishing, I meant chuck it in the lathe, and spin it about 500-700 rpm and polish it while rotating. You want it as round as possible.
Concentric to within .002-.004 T.I.R. is mostly acceptable. One high bar, or two directly opposite each other could mean a stall condition, but I see no evidence of that in your pics.
A low bar, burned and pitted at the slot, possibly less so directly opposite, if at all, indicates an open coil (usually at the coil-to-comm connection, called the riser.)
Any of these conditions will cause arcing when the brush makes and breaks contact with the comm, leading to rapid brush wear and decreased performance.
In other words, if the opposite sides look as good as this side in the pics, you should leave them alone. The brown film you see is a good thing. that actually is a conductive deposit from the old brushes and no real need to disturb,(unless it is OOR)
Did you locate your brush caps? Generally the brass ones are used to create a current path plastic might not provide. In a pinc, one coul use a brass washer between the cap and spring to accomplish the same thing...
Jeff in Lone Star, TX
PS. I'll post a couple pics of what I was referring to later. It's 105 in my shop, and I am DONE for today!
|
Bill, Just about any starter shop can growl them for you. As far as larger facilities go, in OKC, if Ron is still at Capitol Electric, tell him Jeff from Warfield and Chapman in Dallas said hello.
All the guys i knew at Evans Electric and Southwest Electric are retired or ...really retired...
Jeff In Lone Star, TX
|
I already polished them, and had the motors reassembled, minus the brushes. The bigger motor works fine on the bench. Likewise the smaller motor. Maybe I won't worry about the contact cleaner on the commutators after all... Going to see if I can get the lift put back together, and see what happens!?
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!
Expect in one hand, expectorate in the other. See which one gets full first.
On Wednesday, September 6, 2023 at 01:07:21 PM CDT, rockindubya via groups.io <jeffwoods95@...> wrote:
Bill, they both look serviceable, as is.
Really no need to polish, as there is minimal grooving.
That said, I have seen some emery paper that is actually electrically conductive. Crocus cloth has a biding agent for the rouge that will attract carbon dust as the brushes wear.
Both are bad news, creating possibilities of a short bar-to-bar. (That's what the brush does momentarily, until they contact the next segment, and so on...)
Aluminum oxide is non-conductive electrically.
When I referred to polishing, I meant chuck it in the lathe, and spin it about 500-700 rpm and polish it while rotating. You want it as round as possible.
Concentric to within .002-.004 T.I.R. is mostly acceptable. One high bar, or two directly opposite each other could mean a stall condition, but I see no evidence of that in your pics.
A low bar, burned and pitted at the slot, possibly less so directly opposite, if at all, indicates an open coil (usually at the coil-to-comm connection, called the riser.)
Any of these conditions will cause arcing when the brush makes and breaks contact with the comm, leading to rapid brush wear and decreased performance.
In other words, if the opposite sides look as good as this side in the pics, you should leave them alone. The brown film you see is a good thing. that actually is a conductive deposit from the old brushes and no real need to disturb,(unless it is OOR)
Did you locate your brush caps? Generally the brass ones are used to create a current path plastic might not provide. In a pinc, one coul use a brass washer between the cap and spring to accomplish the same thing...
Jeff in Lone Star, TX
PS. I'll post a couple pics of what I was referring to later. It's 105 in my shop, and I am DONE for today!
|
I called Capitol Electric a couple of weeks ago. Talked to Mark. Said they didn't do DC motors anymore, and didn't know anyone in the area who still did. I guess the cheap import motors aren't worth working on...?
My boss at the laundry always bought new motors when one had problems. Was of some benefit to me as a lot of the ones that weren't absolutely fried followed me home so they wouldn't have to pay to have them hauled away. Only exception was the 60HP 3phase motor. They had that overhauled a bit in place, and then replaced it outright when it crapped out again six months or so later. That one had about half a ton of copper wire in it, and the seller of the replacement wanted it back. I'm not sure I could have gotten thing thing in the back of my pick up anyway. 800lb motor, it was.?
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!
Expect in one hand, expectorate in the other. See which one gets full first.
On Wednesday, September 6, 2023 at 01:18:09 PM CDT, rockindubya via groups.io <jeffwoods95@...> wrote:
Bill, Just about any starter shop can growl them for you. As far as larger facilities go,? if Ron is still at Capitol Electric, tell him Jeff from Warfield and Chapman said hello.
All the guys i knew at Evans Electric and Southwest Electric are retired or ...really retired...
Jeff In Lone Star, TX
|
?I used to do a lot of work for the city that I live outside of .
Unfortunately sometimes that meant that I had to work on equipment
at the sewer ponds & such . Onetime they had put in a new
motor tin one of the lift stations hat one of the bosses had
bought years before to have for a rainy day . When I got there the
wires were all exposed & like a dumb sh** I believed them what
I was told it was the exact same motor . Well after some time
trying to figure out why it wouldn't run had them pull it which
they complained & bitched about . Turned out they bought the?
same pump but with a different motor . The voltage was off by @
200 volts .& the motor could not be re-strapped to run at
their lower voltage . They ended up sending the original back for
repair & rented a trailer mount pump to keep things running .
Me being the nice guy I didn't charge them for all my time , I
kinda felt sorry for the guy . M otor shops are gettin to be like
shoe repair shops , their just ain't as many as there used to be .
animal
On 9/6/23 11:43 AM, Bill in OKC too via
groups.io wrote:
toggle quoted message
Show quoted text
My boss at the laundry
always bought new motors when one had problems. Was of some
benefit to me as a lot of the ones that weren't absolutely
fried followed me home so they wouldn't have to pay to have
them hauled away. Only exception was the 60HP 3phase motor.
.?
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!
Improvise, Adapt, and Overcome.
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 Wednesday, September 6, 2023 at 01:18:09 PM CDT,
rockindubya via groups.io
<jeffwoods95@...> wrote:
Bill, Just about any starter shop can growl them for
you. As far as larger facilities go,? if Ron is still at
Capitol Electric, tell him Jeff from Warfield and
Chapman said hello.
All the guys i knew at Evans Electric and Southwest
Electric are retired or ...really retired...
Jeff In Lone Star, TX
|
Bill, it is easy to make a growler. take a standard transformer with a figure 8 core and cut out a "V" at the intersection of one of the uprights and the crossbar. This should turn the figure 8 into a backwards E. The armature should fit the "V" cut to couple the growler to the armature. Any shorted windings will couple strongly to the AC magnetic field. Use a hacksaw blade to find?which of the windings are shorted.? ?Bill in Boulder
On Wed, Sep 6, 2023 at 4:57?PM mike allen < animal@...> wrote:
?I used to do a lot of work for the city that I live outside of .
Unfortunately sometimes that meant that I had to work on equipment
at the sewer ponds & such . Onetime they had put in a new
motor tin one of the lift stations hat one of the bosses had
bought years before to have for a rainy day . When I got there the
wires were all exposed & like a dumb sh** I believed them what
I was told it was the exact same motor . Well after some time
trying to figure out why it wouldn't run had them pull it which
they complained & bitched about . Turned out they bought the?
same pump but with a different motor . The voltage was off by @
200 volts .& the motor could not be re-strapped to run at
their lower voltage . They ended up sending the original back for
repair & rented a trailer mount pump to keep things running .
Me being the nice guy I didn't charge them for all my time , I
kinda felt sorry for the guy . M otor shops are gettin to be like
shoe repair shops , their just ain't as many as there used to be .
animal
On 9/6/23 11:43 AM, Bill in OKC too via
wrote:
My boss at the laundry
always bought new motors when one had problems. Was of some
benefit to me as a lot of the ones that weren't absolutely
fried followed me home so they wouldn't have to pay to have
them hauled away. Only exception was the 60HP 3phase motor.
.?
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!
Improvise, Adapt, and Overcome.
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 Wednesday, September 6, 2023 at 01:18:09 PM CDT,
rockindubya via
<jeffwoods95@...> wrote:
Bill, Just about any starter shop can growl them for
you. As far as larger facilities go,? if Ron is still at
Capitol Electric, tell him Jeff from Warfield and
Chapman said hello.
All the guys i knew at Evans Electric and Southwest
Electric are retired or ...really retired...
Jeff In Lone Star, TX
|
Bill in OKC too
Jim F