Re: Back Gear Pin & Rattle
Two hints on this topic. If you use an abrasive cloth like emery of rouge paper, be sure to thoroughly clean the surface when you’re finished. They contain some kind of binder wax that doesn’t get along well with electric current and heat.
If you do try to turn the armature be aware that turning copper requires a sharp tool and a negative rake. If the tool is not sharp it will mush the copper. If the rake is not negative (about 5 degrees in my experience) it will dig in.
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Re: OT-how to test and repair DC brushed motors.
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
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Re: Back Gear Pin & Rattle
On 9/6/23 08:19, jf08056 via groups.io wrote: Since we’re on this subject, my back gear slips out under
load. What do I adjust to keep the over-center lever in?
Thanks. There may be shims under the bracket that holds the back gear shaft.? Changing these changes the amount of gear engagement of the back gears.? Also, there are supposed to be wave washers on the ends of the eccentric shaft that keeps it from moving under gear vibration. Jon
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Re: Back Gear Pin & Rattle
On 9/6/23 00:55, Jon Helig wrote: I have 101.07301 Atlas / Craftsman lathe from the early
1940's.? I was using the back gear and noticed a rattle.?
I'm uncertain which part of the back gear the noise is
coming from.? Is anyone familiar with this problem?? Also
when I tried to disengage the back gear I couldn't get the
pin to go in.? I can move the pin so it's not seized.? Is
the any trick to get the pin to seat in the front gear or
do I need to take apart the spindle? A common problem is that the bushings in the pulley get worn when run without putting oil in the oil hole buried in the bottom of one of the pulley grooves. Jon
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Re: OT-how to test and repair DC brushed motors.
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.?
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Re: OT-how to test and repair DC brushed motors.
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
|
Re: OT-how to test and repair DC brushed motors.
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.
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Re: Back Gear Pin & Rattle
Since we’re on this subject, my back gear slips out under load. What do I adjust to keep the over-center lever in? Thanks.
Jim
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Re: Back Gear Pin & Rattle
Check for missing shims on the back gear mounting bolts to the headstock.? Atlas has .002 & .003 in parts book.?
toggle quoted message
Show quoted text
On Sep 5, 2023, at 10:55 PM, Jon Helig <jlhmnj@...> wrote:
?I have 101.07301 Atlas / Craftsman lathe from the early 1940's.? I was using the back gear and noticed a rattle.? I'm uncertain which part of the back gear the noise is coming from.? Is anyone familiar with this problem?? Also when I tried to disengage the back gear I couldn't get the pin to go in.? I can move the pin so it's not seized.? Is the any trick to get the pin to seat in the front gear or do I need to take apart the spindle?
Jon
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Re: OT-how to test and repair DC brushed motors.
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
?
|
I have 101.07301 Atlas / Craftsman lathe from the early 1940's.? I was using the back gear and noticed a rattle.? I'm uncertain which part of the back gear the noise is coming from.? Is anyone familiar with this problem?? Also when I tried to disengage the back gear I couldn't get the pin to go in.? I can move the pin so it's not seized.? Is the any trick to get the pin to seat in the front gear or do I need to take apart the spindle?
Jon
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Re: OT-how to test and repair DC brushed motors.
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
|
Re: OT-how to test and repair DC brushed motors.
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
?
|
Re: OT-how to test and repair DC brushed motors.
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
|
Re: OT-how to test and repair DC brushed motors.
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
?
|
Re: OT-how to test and repair DC brushed motors.
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
?
|
Re: OT-how to test and repair DC brushed motors.
??? ??? 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
?
|
Re: OT-how to test and repair DC brushed motors.
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
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Re: OT-how to test and repair DC brushed motors.
?
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
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Re: OT-how to test and repair DC brushed motors.
The commutator should have an even chocolate-brown color with no nicks, gouges, high spots, etc.
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Bill in OKC too
Jim F