At the bottom of page 14, Bulletin
33-j, it says you can order RED
or Grey as
your color....
On 1/27/2024 2:16 PM, mike allen wrote:
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Craftsman sold a Lathe setup fro doing armatures , hey come up
every once in a while on ebay . Had a jacobs chuck that screwed
on the spindle , a Jacobs chuck live center I believe , a Mica
undercutter & sopme misc parts .
I found 2 South Bend Lathe co publications on Armature work
its interesting that they made the lathe
look
red on one of the SB
publications
, my TruCut armature lathe is red .
animal
On 1/27/24 7:53 AM, Charles Kinzer
wrote:
There were special lathes
made for this that were very appropriately called "armature
lathes."? The lathes were small and didn't have much power
(didn't need much) but the swing was big enough to clear the
armature.? Otherwise, they only needed to be substantial
enough to turn the smaller diameter of the commutator which
was only brass and you were only taking off maybe 0.010"
anyway.? Some also had an "undercutter" feature which was
like a little tiny saw blade to cut away some of the mica
insulator to make sure it was below the surface of the
brass.? My first lathe (way back when) was an armature lathe
a friend had made from a kit in a high school shop class.?
He had also designed and made a compound for it.? Powered
with a washing machine motor.
Charles E. "Chuck" Kinzer
On Saturday, January 27, 2024 at 02:34:42 AM PST,
davesmith1800 <davesmith1@...>
wrote:
DAVID WILLIAMS
12:11am? ?
Restoring the commutators on vehicle
dynamos.
(British cars probably from the
1940¡¯s/50¡¯s/60¡¯s)
I have books from 1941 that cover cars from 1930s and
had same in book.
I repair my father's drill motors in 1960's? used in
construction.? They used 8 hours 5 days drilling
steel. I use book on redoing the comutators on a South
Bend 9A. Learn lot on DC motors and generators.?
What you said was cover in book which had forgotten.??
Dave?
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Re: Direct Reading cross feed dial.
If there's a great concern regarding the correct depth of threads there's another way to do it.? The motion of the compound when it's set over to 29.5 degrees can be approximated by two separate motions on Z and Y (the compound and cross slides respectively).? The compound is accurately set to zero degrees, parallel to the bed.? Using this approach, the cross slide is the only thing that determines the depth of the cut so that's why it makes it easier to determine your depth of cut.
A little trigonometry is needed.? Motion at 29.5 degrees simultaneously produces motion on the Z and Y, but that same motion is replicated if you move the compound and cross slide.? The ratio of motions on those axes (Y/Z) is equal to the tangent of 29.5 degrees, which is .566.? In other words, Y/Z = .566.? Let's make Z (the compound) the dependent variable, so Z = Y/.566 = 1.768*Y.? You will get some oddball values you need to set, but calculating this on the fly can be done with a 4-banger calculator or ahead of time by using a spreadsheet.
Using a spreadsheet and making a table of cross slide positions in .005" increments, I got:
Y? ? ? ? ? ? ? ? ? ? ? ? Z(compound)? Rounded to nearest .001"
.005? ? ? ? ? ? ? ? ? ?.009
.010? ? ? ? ? ? ? ? ? ?.018
.015? ? ? ? ? ? ? ? ? ?.027
.020? ? ? ? ? ? ? ? ? ?.034
.025? ? ? ? ? ? ? ? ? ?.044
.030? ? ? ? ? ? ? ? ? ?.053 (1 turn + .003)
.035? ? ? ? ? ? ? ? ? ?.062 ( 1 + .012)
.040? ? ? ? ? ? ? ? ? ?.071 (etc.....? ?)
.045? ? ? ? ? ? ? ? ? ?.080
.050? ? ? ? ? ? ? ? ? ?.088
.055? ? ? ? ? ? ? ? ? ?.097
.060? ? ? ? ? ? ? ? ? ?.106
I did not come up with this scheme, other folks on this forum have mentioned it in previous discussions of single-point threading.
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The motor controller may not be adjusted correctly:? or the controller is a POS.? A good motor controller uses feedback to maintain the RPMs under load.
Or perhaps you don't know your own strength?? You should put it all back together again and see how your lathe works to actually cut metal.? Do you know for a fact that it's a problem?
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Paul, the power is very low when the speed is turned low. You may want to try and hold it while someone slowly increase the speed. These motors have poor torque at low end.
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Re: Direct Reading cross feed dial.
Take a sharpie and cross out the numbers on your dial, then double them and write the new numbers in.
?
Brian?
Sharpie may last 30 seconds. I like the look of manufacture type dial. My second lathe had most of marks worn off and I used a center punch to fix it look tacky Dave?? Dave?
|
Craftsman sold a Lathe setup fro doing armatures , hey come up
every once in a while on ebay . Had a jacobs chuck that screwed on
the spindle , a Jacobs chuck live center I believe , a Mica
undercutter & sopme misc parts .
I found 2 South Bend Lathe co publications on Armature work
its interesting that they made the lathe look red on one of the
SB publications , my TruCut armature lathe is red .
animal
On 1/27/24 7:53 AM, Charles Kinzer
wrote:
toggle quoted message
Show quoted text
There were special lathes
made for this that were very appropriately called "armature
lathes."? The lathes were small and didn't have much power
(didn't need much) but the swing was big enough to clear the
armature.? Otherwise, they only needed to be substantial
enough to turn the smaller diameter of the commutator which
was only brass and you were only taking off maybe 0.010"
anyway.? Some also had an "undercutter" feature which was like
a little tiny saw blade to cut away some of the mica insulator
to make sure it was below the surface of the brass.? My first
lathe (way back when) was an armature lathe a friend had made
from a kit in a high school shop class.? He had also designed
and made a compound for it.? Powered with a washing machine
motor.
Charles E. "Chuck" Kinzer
On Saturday, January 27, 2024 at 02:34:42 AM PST,
davesmith1800 <davesmith1@...> wrote:
DAVID WILLIAMS
12:11am? ?
Restoring the commutators on vehicle
dynamos.
(British cars probably from the
1940¡¯s/50¡¯s/60¡¯s)
I have books from 1941 that cover cars from 1930s and
had same in book.
I repair my father's drill motors in 1960's? used in
construction.? They used 8 hours 5 days drilling steel.
I use book on redoing the comutators on a South Bend 9A.
Learn lot on DC motors and generators.?
What you said was cover in book which had forgotten.??
Dave?
|
Re: Direct Reading cross feed dial.
Take a sharpie and cross out the numbers on your dial, then double them and write the new numbers in.
Brian?
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Show quoted text
-------- Original message -------- From: Paul Fox <pgf@...> Date: 1/27/24 1:07 PM (GMT-05:00) Subject: Re: [7x12MiniLathe] Direct Reading cross feed dial.
I for one would be happy to purchase replacement dials that measure the diameter change, rather than the radius.? One less thing to remember as a novice.
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Rather than building a thread dial for metric threading (needs multiple gears) you might consider building a dog clutch - it works for imperial and metric, eliminating the thread dial.? You can manually operate the dog clutch or build an auto-stop for it.
I have look dog clutch but I have never seen any manufacture use a dog clutch. Even the automatic type still used a gear on the screw for engagement of haft nut. Dave
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Re: Direct Reading cross feed dial.
I for one would be happy to purchase replacement dials that measure the diameter change, rather than the radius.? One less thing to remember as a novice.
I like direct dreading / diameter reading dials
What is your cross feed screw TPI or mm?
Can be simple to do?
Dave
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Re: Direct Reading cross feed dial.
I for one would be happy to purchase replacement dials that measure the diameter change, rather than the radius.? One less thing to remember as a novice.
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Re: Direct Reading cross feed dial.
mario mohl
6:16am? ?
Or maybe you could get really bold, join the rest of the world and stop mucking around by reading the dial as intended.
It is a discussion on standard and direct reading dials,? and how too.? I started out with standard reading dials and new lathe I purchased in 1976 had direct reading . For it was big change for better. They even manufacture DRO for lathes that is direct reading. On huge lathes that is great but do have to worry about skipping from the scales.? I wish the mini lathes would have the? DRO mill into the cross slide so does take-up capacity.? But screw is still more reliable. Dave?
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Rather than building a thread dial for metric threading (needs multiple gears) you might consider building a dog clutch - it works for imperial and metric, eliminating the thread dial.? You can manually operate the dog clutch or build an auto-stop for it.
A version which includes an auto-stop is described here:
?
Note that the dog clutch (sans auto-stop) is fairly simple and it would be easy to add a handle to operate it manually.? The half nuts remain engaged while threading with the dog clutch so you would need to add a handle to the leadscrew to move the carriage back without opening the half nuts.
John
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There were special lathes made for this that were very appropriately called "armature lathes."? The lathes were small and didn't have much power (didn't need much) but the swing was big enough to clear the armature.? Otherwise, they only needed to be substantial enough to turn the smaller diameter of the commutator which was only brass and you were only taking off maybe 0.010" anyway.? Some also had an "undercutter" feature which was like a little tiny saw blade to cut away some of the mica insulator to make sure it was below the surface of the brass.? My first lathe (way back when) was an armature lathe a friend had made from a kit in a high school shop class.? He had also designed and made a compound for it.? Powered with a washing machine motor.
Charles E. "Chuck" Kinzer
On Saturday, January 27, 2024 at 02:34:42 AM PST, davesmith1800 <davesmith1@...> wrote:
DAVID WILLIAMS
12:11am? ?
Restoring the commutators on vehicle dynamos.
(British cars probably from the 1940¡¯s/50¡¯s/60¡¯s)
I have books from 1941 that cover cars from 1930s and had same in book. I repair my father's drill motors in 1960's? used in construction.? They used 8 hours 5 days drilling steel. I use book on redoing the comutators on a South Bend 9A. Learn lot on DC motors and generators.? What you said was cover in book which had forgotten.?? Dave?
|
Re: Direct Reading cross feed dial.
Or maybe you could get really bold, join the rest of the world and stop mucking around by reading the dial as intended.
No offense to anyone who's considering this, but? Instead of changing the dial, why not just learn the principles involved in the normal dial. Taking a certain amount off the radius of any cylinder causes the diameter to decrease by twice that amount. That's what you're doing with the cross slide, and it's a simple mathematical principle that's true on the minilathe and will be true on probably any lathe you use for the rest of your life. (And if you're just learning how to use a lathe now, your minilathe may not be the only lathe you ultimately own).
Mike Taglieri?
Here is way of way having direct read dials on mini lathe.
?
If have a 20 TPI cross feed screw.
One turn is 0.050" some most lathes have a Graduated Dial, 50 Divisions. For direct reading you need a Graduated Dial, 100 Divisions so each 0.001 on the dial takes off on the diameter 0.001. You 100 Divisions from
The size could a problem it is almost? 2" diameter but easy to read.
?
Now if you the metric feed screw and inch reading.
It 1mm or 0.03937" per turn
The best is Graduated Dial, 78 Divisions . Next best you can buy is Graduated Dial, 75 Divisions or each Divisions is 0.00052 or off diameter is only of by 0.00002 " . Diameter is only off by 0.00004"
The size is only larger by 0.078" easy to fit on old Dial.
?
?
This what looking and next order I will put cart for upgrade no free shipping I wait for till large order.
?
Dave
?
|
Re: Direct Reading cross feed dial.
No offense to anyone who's considering this, but? Instead of changing the dial, why not just learn the principles involved in the normal dial. Taking a certain amount off the radius of any cylinder causes the diameter to decrease by twice that amount. That's what you're doing with the cross slide, and it's a simple mathematical principle that's true on the minilathe and will be true on probably any lathe you use for the rest of your life. (And if you're just learning how to use a lathe now, your minilathe may not be the only lathe you ultimately own).
Mike Taglieri?
Here is way of way having direct read dials on mini lathe.
?
If have a 20 TPI cross feed screw.
One turn is 0.050" some most lathes have a Graduated Dial, 50 Divisions. For direct reading you need a Graduated Dial, 100 Divisions so each 0.001 on the dial takes off on the diameter 0.001. You 100 Divisions from
The size could a problem it is almost? 2" diameter but easy to read.
?
Now if you the metric feed screw and inch reading.
It 1mm or 0.03937" per turn
The best is Graduated Dial, 78 Divisions . Next best you can buy is Graduated Dial, 75 Divisions or each Divisions is 0.00052 or off diameter is only of by 0.00002 " . Diameter is only off by 0.00004"
The size is only larger by 0.078" easy to fit on old Dial.
?
?
This what looking and next order I will put cart for upgrade no free shipping I wait for till large order.
?
Dave
?
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Re: Extension cross slide
I add a few notes to help you if plan on building the exstension.?
It is in a PDF file for clearer printing?
Dave
FYI?
On my searching I found exstension files dating back to 1990's on the internet. It is a question why the manufacturers have changed this in over 25 years of manufacture.
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DAVID WILLIAMS
12:11am? ?
Restoring the commutators on vehicle dynamos.
(British cars probably from the 1940¡¯s/50¡¯s/60¡¯s)
I have books from 1941 that cover cars from 1930s and had same in book. I repair my father's drill motors in 1960's? used in construction.? They used 8 hours 5 days drilling steel. I use book on redoing the comutators on a South Bend 9A. Learn lot on DC motors and generators.? What you said was cover in book which had forgotten.?? Dave?
|
Restoring the commutators on vehicle dynamos. (British cars probably from the 1940¡¯s/50¡¯s/60¡¯s) I recall this is what we did for dynamos on cars. Fellow engineers - Are motors the same? I really don¡¯t know??
Anyway, ¡ª When I was young, we used to ¡®very delicately¡¯ skimmed the commutators on a smallish lathe and finished off with a fine file (one used for brass I expect - Dad had separate files for brass) and finish off with fine emery cloth/paper.? Slow speed and done very delicately. Then we got an old worn out full sized hacksaw blade and ground the end into a fat claw shape. We then carefully used the blade to pull along the black spacer material between the copper commutators to achieve the required undercut on the commutator. (Something like a fraction of a millimetre or 1/32¡±) The black spacing between the copper commutator sections (mica) seemed something like hard pitch. ?It¡¯s 60+ years ago but I am sure that¡¯s what we did. I can¡¯t remember covering the motor to prevent the ingress of particles but it seems a great improvement. JFI, I recall the commutator on the starter motors were not undercut. Sorry I don¡¯t know why, but definitely different.
I hope this is helpful.
Regards,
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On 27 Jan 2024, at 03:27, Roy via groups.io <roylowenthal@...> wrote:
?To avoid leaving abrasive particles in the motor, filing is preferable to sanding. If you must sand, use old style, "flint" sandpaper; the? abrasive is not electrically conductive. The mica (insulation) between commutator segments should be lower than the copper segments. On larger? machines, a hacksaw blade is the appropriate tool; on small motors, an X-acto razor saw blade (without the handle) is the right size. Copious amounts of cheapest brake parts cleaner from an auto supply store help to get rid of debris.
Roy
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Re: Extension cross slide
?T 7:43pm? ?A lathe basically is just a horizontal milling machine and with the right setups and/or attachments it to can be used as a milling machine. Just as you have stated in your post.
Have A Great Day??
Tracy Ranson
I post so any does not mill can make part.? This project can done without a mill.? Almost first 10 years I had no mill and had use the lathe as a mill.? Dave
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Here what looking at can see any mistakes? 
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davesmith1800
?GadgetBuilder?
GadgetBuilder