There was (is?) a type of lathe called a "commutator lathe".? Their most typical application was most likely turning the commutators (cleaning them up) on automobile generators.? It was a pretty common item in auto repair garages at one time.? It is sized to swing the large diameter of the armature but with strength more in line with turning the smaller diameter of the commutator.? So, even more so than regular lathes, it was not designed at all to machine anything the size of its full swing.
Charles E. "Chuck" Kinzer
On Friday, June 23, 2023 at 12:20:24 PM PDT, Mehmood via groups.io <mehmood.naqshbandi@...> wrote:
Brilliant idea to turn your lathe into a generator! ?Just apply electricity to the commutator and then harvest power from the plug. ?Handy if you don’t have, errm, electricity.
Begin forwarded message:
?
Here's one I bought some years ago on eBay. I cannot find a
better picture of it.
Peter Brixey in sunny Florida.
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Brilliant idea to turn your lathe into a generator! ?Just apply electricity to the commutator and then harvest power from the plug. ?Handy if you don’t have, errm, electricity.
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?
Here's one I bought some years ago on eBay. I cannot find a
better picture of it.
Peter Brixey in sunny Florida.
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Here's one I bought some years ago on eBay. I cannot find a
better picture of it.
Peter Brixey in sunny Florida.
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Re: Unimat SL1000 adjustments.
You may be able to put some brass shim under the headstock if it is low relative to tailstock centre.?
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On 23 Jun 2023, at 12:23 am, Quinn Golden <quinngolden@...> wrote:
?I am presuming the drill was mounted in the tail stock. If you can duplicate the set up, and the drill wanders downhill, repeat the set up and rotate the drill 90° and see if it wanders in that direction. ? ?I suspect the drill bit is your challenge and not the machine. ?
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Re: Unimat SL1000 adjustments.
Take the way bars off and check them for straightness? ?Maybe try them the other way up? ?Or even turn one around?
I’m not an expert on this, just thinking of easy things to check.
My first thought was maybe the base is bent, and maybe then clamp it down with something thin underneath in the middle, and measure the straightness somehow as you slowly tighten the clamps to straighten the base, but I’m way out of my depth here.
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On 22 Jun 2023, at 15:17, Quinn Golden <quinngolden@...> wrote:
?I am presuming the drill was mounted in the tail stock. If you can duplicate the set up, and the drill wanders downhill, repeat the set up and rotate the drill 90° and see if it wanders in that direction. ? ?I suspect the drill bit is your challenge and not the machine. ?
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Re: Unimat SL1000 adjustments.
Another good point but I can't get over the description of the
hole angling down. If the workpiece is in the headstock chuck
there is no such thing as down. I can see getting a tapered hole
but not an angled down hole. If the piece isn't straight you might
come out off center but that wouldn't be a fault in the lathe.
On 6/22/23 10:35, Jay Perez wrote:
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Good point Quinn,
I've seen a number of new drill bits from Harbor
Freight where the lips are not of equal length. This will
cause a bit to wander.
One visual clue of this condition is different
amounts of chips coming out of the flutes as you're drilling.
Jay
I am
presuming the drill was mounted in the tail stock. If you can
duplicate the set up, and the drill wanders downhill, repeat
the set up and rotate the drill 90° and see if it wanders in
that direction. ? ?I suspect the drill bit is your challenge
and not the machine. ?
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Re: Unimat SL1000 adjustments.
I was thinking the same thing, bum drill-bit.? With a headstock/tailstock miss-alignment he would have always been turning tapers.
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Re: Unimat SL1000 adjustments.
Good point Quinn,
I've seen a number of new drill bits from Harbor Freight where the lips are not of equal length. This will cause a bit to wander.
One visual clue of this condition is different amounts of chips coming out of the flutes as you're drilling.
Jay
I am presuming the drill was mounted in the tail stock. If you can duplicate the set up, and the drill wanders downhill, repeat the set up and rotate the drill 90° and see if it wanders in that direction. ? ?I suspect the drill bit is your challenge and not the machine. ?
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Re: Unimat SL1000 adjustments.
I am presuming the drill was mounted in the tail stock. If you can duplicate the set up, and the drill wanders downhill, repeat the set up and rotate the drill 90° and see if it wanders in that direction. ? ?I suspect the drill bit is your challenge and not the machine. ?
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Re: Unimat SL1000 adjustments.
Part of the secret of Gun drills is the cooling. Not only does it cool the tool tip, but it aids in the removal of the chips. It is the buildup of chips that contributes to a twist drill wandering. ?
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Re: Threadcutting on a Unimat 3
I have seen references to people adapting the Sherline thread cutting attachment to Taig lathes. Not sure how practical it would be to try and make it work on a Unimat.
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Re: Unimat SL1000 adjustments.
A downward slant suggests a vertical misalignment. That is difficult to
adjust on the Unimat as they are not designed for vertical adjustment.
Also, there are several places that may be causing the misalignment, if
that is the problem.
Elliot
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On 6/21/23 5:39 PM, Richy Russo via groups.io wrote: Thanks!
? My problem is I was drilling thru a brass rod to make it a fuel tube
for an SU carburetor. It was approx 2 inches long. I started with a
small pilot, but as I moved up in size I noticed it was drilling into
the workpiece on a downward slant. I was able to complete the process
and make it work. But I asked here because I would like to correct it. I
did manage to get it a little closer messing with the headstock.
? Regards Richy
--
Elliot Nesterman
elliot@...
www.ajoure.net
"The finest jewel cannot disguise a flawed character."
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Re: Unimat SL1000 adjustments.
Hello Dick:
?
As a tool maker I bought two Brown & Sharpe Best Test indicators, the first is 0.0005" and cost me $35 in 1973. The 0.00005 cost me $100 in 1977. They both still work great.
?
Carl.
On 06/21/2023 9:26 PM EDT OldToolmaker via groups.io <old_toolmaker@...> wrote:
?
?
Hello Carl,
Where did you get the 50 millionths indicator? That is quite a close resolution to be using on a Unimat!
Dick
--
http://www.homemadetools.net/
forum/?OFF-SET-tailstock-center-65965#post105972
?SMALL TURRET TOOL POST PLANS?
?LARGE TURRET TOOL POST PLANS
?MINI-LATHE CARRIAGE LOCK PLANS
?SMALL QC TOOL POST PLANS?
?QUICK CHANGE LATHE TURRET
?MINI LATHE COMPOUND PIVOT MODIFICATION
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Re: Unimat SL1000 adjustments.
Hello, Keith,
Yes, gun drills can produce a very deep and accurate hole. They have coolant holes in the ends and are usually used with coolant or oil under high pressure. We drilled deep waterline holes in the plates In injection mold plates. The finish left in the resultant holes was very clean and smooth. Of course it required special equipment and guide bushings to produce nice holes and flush swarf out.
Dick
-- http://www.homemadetools.net/ forum/ ?OFF-SET-tailstock-center-65965#post105972?SMALL TURRET TOOL POST PLANS??LARGE TURRET TOOL POST PLANS?MINI-LATHE CARRIAGE LOCK PLANS?SMALL QC TOOL POST PLANS??QUICK CHANGE LATHE TURRET?MINI LATHE COMPOUND PIVOT MODIFICATION
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Re: Unimat SL1000 adjustments.
Hello Carl,
Where did you get the 50 millionths indicator? That is quite a close resolution to be using on a Unimat!
Dick
--
http://www.homemadetools.net/forum/?OFF-SET-tailstock-center-65965#post105972
?SMALL TURRET TOOL POST PLANS?
?LARGE TURRET TOOL POST PLANS
?MINI-LATHE CARRIAGE LOCK PLANS
?SMALL QC TOOL POST PLANS?
?QUICK CHANGE LATHE TURRET
?MINI LATHE COMPOUND PIVOT MODIFICATION
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Re: U90 motor suppression capacitor
For those wondering about the significance of the X and Y capacitors, they are specifically designed for use in safety critical positions. X capacitors can withstand high voltage pulses without failing, and Y type are designed to fail open circuit, since they are connected between live and earth, where a short circuit could lead to electrocution. The numbers work the reverse of what you might expect - lower numbers give more protection. It is not enough to use capacitors with a high enough voltage rating in these positions. They need the safety rating as well.
See:?https://www.allaboutcircuits.com/technical-articles/safety-capacitor-class-x-and-class-y-capacitors/
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Re: Unimat SL1000 adjustments.
What diameter hole was it? If it was relatively long you need to make sure you have a good quality drill. For very long holes you might need an unusual drill type - I think worm drills can help, also gun drills of course. I worked with an expert at working with copper alloys, and asked how deep he could drill. He replied a ?" hole four feet deep - he could drill from both sides and know the holes would meet in the middle. He had a set of drills that worked, all in inches - we never asked for any other sizes!
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Re: Unimat SL1000 adjustments.
were you rotating the workpiece against a non-rotating drill? If
not you should try it.
On 6/21/23 17:39, Richy Russo via
groups.io wrote:
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Thanks!
? My problem is I was drilling thru a brass rod to make it a
fuel tube for an SU carburetor. It was approx 2 inches long. I
started with a small pilot, but as I moved up in size I noticed
it was drilling into the workpiece on a downward slant. I was
able to complete the process and make it work. But I asked here
because I would like to correct it. I did manage to get it a
little closer messing with the headstock.?
? Regards Richy?
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Re: Unimat SL1000 adjustments.
Thanks!
? My problem is I was drilling thru a brass rod to make it a fuel tube for an SU carburetor. It was approx 2 inches long. I started with a small pilot, but as I moved up in size I noticed it was drilling into the workpiece on a downward slant. I was able to complete the process and make it work. But I asked here because I would like to correct it. I did manage to get it a little closer messing with the headstock.?
? Regards Richy?
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Re: U90 motor suppression capacitor
Hi there,
The X1Y2 class capacitor in the datasheet can be purchased from this ebay seller:?
The seller is located in Gl?shuette, Germany.? The price is ~US$6. I'm not sure what the shipping charges are from Gl?shuette, or if the seller will ship internationally.?
Something to consider is that this is an integrated package of 3 capacitors. It has a single X1 safety rated capacitor configured with two Y2 safety rated capacitors. You can make this yourself. There should be a brief tutorial or image showing this somewhere in the files, as I remember. I've constructed several of these over the years when rebuilding U90 and other motors. Take care to connect the L/N?
The basic circuit looks like this: ?? 
The application, in our case, is the motor.
One of the group members has installed a package X1Y2 capacitor outside of the case, with the Line and Neutral leads attached to the motor brushes and the ground attached to the motor case. Not optimal for safety reasons, at least what is visible in the photo, but hey, I'm pretty sure the user understands the electrical shock hazard.?
Brian Gates wrote about the suppression capacitor in a 2019 Unimat group post:
| [email protected] | U90 Brush Cap |
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Lathes.UK also covers this topic, showing the X1Y2 capacitor in circuit:
Doug Feistamel covers this topic as well:
Robert Undine has built a DIY X1Y2 package for the U90 as posted in the photos section:
Digikey, Mouser and other US electronic parts vendors can supply you the X1 and Y2 safety rated caps in pretty much any value you need. They'll be cheap...usually less than $1.50-$3.00, but the shipping might seem expensive. The upside to buying from a big US parts supplier is that you'll get it very quickly. Sometimes the same day.
Hope this helps.
Cheers,
James
On Wednesday, June 21, 2023 at 05:44:56 AM PDT, John K5MO <johnk5mo@...> wrote:
I would be sure to replace that cap with one that is specifically rated to be placed across the mains..? The PN below is available from Mouser, etc.
0.01 uf + 2x 2500 pf @ 220V HPF 65.8
I searched again on the part number -?MIFLEX KSPPZ-10-2. That leads to lots of suppliers in many countries, but this site gets you to the data sheet:
The list of component values shows the smallest one will be roughly equivalent - 0.022?μF + 2 × 2700 pF. The exact values are not critical. It looks like 0.047 μF + 2?× 2700 pF might be more readily available.
Hopefully you can find a distributor somewhere near you. Looking again on Ebay UK leads to four from Germany and one from France. Ebay.com gibes three suppliers in Germany.
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Carl
OldToolmaker
Richy Russo N2ZD