Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL
Hello,Carl
Aggreed!
Backlash compensation was the first thing we learned in trade school when learning to operate the lathe. The same principle applies to most any machine tool,
although theses days many machine tools are outfitted with ball screws which pretty much eliminate all backlash. Most of us hobby machinists though, are using plain lead screws equipped machines.
Dick
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Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL
This.
Somebody wiser than I am tought me that me that you can't ever
totally eliminate backlash on a screw and nut setup. You can
lessen it so it is less obnoxious, but you can't eliminate it. So
you will have to live with it. Since you have to live with it
there it doesn't make much sense to jump through major hoops to
get rid of the last little bit.
So you do what Carl said, the last motion is always in the same
direction, and is larger than the backlash. Sometimes that means
you overshoot and come back more than the backlash. Or if you
overshoot you come back more than the backlash and go in again
more carefully.
Ideally that last motion should be in the opposite direction than
cutting forces are going to try to move the cutter. This way the
cutting forces have something to push against instead of pulling
the cutter into the backlash zone where it can float around.
On 4/5/23 15:28, Carl wrote:
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Show quoted text
Hi
Gang:
As a
toolmaker we learned to always turn the cranks the same way,
usually clockwise. This has fallen to the wayside with ball
screws and digital read outs.
Carl.
On 4/5/2023 2:26 PM, Herman de Leeuw
via groups.io wrote:
Hi Jpow,
Having come the same way as you do,
I just would like to toss in here my humble 2 cents of wisdom
without any claim to UNIMAT 3 lathe mastery at all, but here
goes:
In this rather comprehensive (and
recommended) , published by the then importer for Unimat in
the Netherlands, in Utrecht (still in
existence), I stumbled upon the below passage on page 58 (see
scan).?
The main point here is about the "transporteurs"?
- the spindles for the different movement feeders
(longitudinal, cross-slide and tailstock). According to this
manual, the backlash ("speling") on the spindles is on
purpose and one should not try to reduce the backlash. Coming
to the field of metalworking as a woodworker, I was not
surprised: when dealing with cast iron woodplanes, one
encounters the same backlashes when adjusting the cutting
iron.?
What one should do is to 1) either
keep a record when the cross slide spindle starts to engage
and the slide starts to move, or 2) avail oneself of a set of
adjustable handwheels that allow you to set the wheel at zero
the moment the spindle engages.?
As much as I would want to take out
the backlash (I have a history of maintaining motorcycles,
mopeds and bicycles, where it is all about reducing friction
and taking out backlash) I have come to live with it now.?
Now hoping to hear from a few others
whether this makes any sense,
Herman
? 
Hey all,
I'm having this really irritating problem with backlash
coming from the Unimat PC cross-slide handwheel.
My understanding is that backlash (for the Unimat) can come
from two sources
A) Play in the slide lead nut / screw itself; OR
B) Having too much of a gap between the threaded
handlewheel and the cross slide itself.
My main issue is with B)
Following the Unimat instructions, I screw in the threaded
handlewheel all the way, and back it out JUST a bit, before
tightening up the locking nut (on the outside).
For the life of me, I can never get it "just right". If I
tighten enough so everything JUST rotates smoothly, the
backlash is too much (0.07mm). If I tighten anymore, the
backlash is a bit better, but the handwheel starts to bind
and it is difficult to turn freely.
(The binding is strange in the sense that "tightness"
occurs at certains angles of rotation only, rather than a
constant heavy friction).
Could this be some issue with the bushings or something? I
tried putting in small thrust bearing between the
handlewheel and where it is mounted, but it didn't help
much.
Appreciate any advice thanks :)
|
Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL
Hi
Gang:
As a
toolmaker we learned to always turn the cranks the same way,
usually clockwise. This has fallen to the wayside with ball
screws and digital read outs.
Carl.
On 4/5/2023 2:26 PM, Herman de Leeuw
via groups.io wrote:
toggle quoted message
Show quoted text
Hi Jpow,
Having come the same way as you do, I
just would like to toss in here my humble 2 cents of wisdom
without any claim to UNIMAT 3 lathe mastery at all, but here
goes:
In this rather comprehensive (and
recommended) , published by the then importer for Unimat in the
Netherlands, in Utrecht (still in
existence), I stumbled upon the below passage on page 58 (see
scan).?
The main point here is about the "transporteurs"?
- the spindles for the different movement feeders (longitudinal,
cross-slide and tailstock). According to this manual, the backlash
("speling") on the spindles is on purpose and one should not
try to reduce the backlash. Coming to the field of
metalworking as a woodworker, I was not surprised: when dealing
with cast iron woodplanes, one encounters the same backlashes
when adjusting the cutting iron.?
What one should do is to 1) either
keep a record when the cross slide spindle starts to engage and
the slide starts to move, or 2) avail oneself of a set of
adjustable handwheels that allow you to set the wheel at zero
the moment the spindle engages.?
As much as I would want to take out
the backlash (I have a history of maintaining motorcycles,
mopeds and bicycles, where it is all about reducing friction and
taking out backlash) I have come to live with it now.?
Now hoping to hear from a few others
whether this makes any sense,
Herman
? 
Hey all,
I'm having this really irritating problem with backlash
coming from the Unimat PC cross-slide handwheel.
My understanding is that backlash (for the Unimat) can come
from two sources
A) Play in the slide lead nut / screw itself; OR
B) Having too much of a gap between the threaded handlewheel
and the cross slide itself.
My main issue is with B)
Following the Unimat instructions, I screw in the threaded
handlewheel all the way, and back it out JUST a bit, before
tightening up the locking nut (on the outside).
For the life of me, I can never get it "just right". If I
tighten enough so everything JUST rotates smoothly, the
backlash is too much (0.07mm). If I tighten anymore, the
backlash is a bit better, but the handwheel starts to bind and
it is difficult to turn freely.
(The binding is strange in the sense that "tightness" occurs
at certains angles of rotation only, rather than a constant
heavy friction).
Could this be some issue with the bushings or something? I
tried putting in small thrust bearing between the handlewheel
and where it is mounted, but it didn't help much.
Appreciate any advice thanks :)
|
Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL
Hi Jpow,
Having come the same way as you do, I just would like to toss in here my humble 2 cents of wisdom without any claim to UNIMAT 3 lathe mastery at all, but here goes:
In this rather comprehensive (and recommended) , published by the then importer for Unimat in the Netherlands, in Utrecht (still in existence), I stumbled upon the below passage on page 58 (see scan).?
The main point here is about the "transporteurs"? - the spindles for the different movement feeders (longitudinal, cross-slide and tailstock). According to this manual, the backlash ("speling") on the spindles is on purpose and one should not try to reduce the backlash. Coming to the field of metalworking as a woodworker, I was not surprised: when dealing with cast iron woodplanes, one encounters the same backlashes when adjusting the cutting iron.?
What one should do is to 1) either keep a record when the cross slide spindle starts to engage and the slide starts to move, or 2) avail oneself of a set of adjustable handwheels that allow you to set the wheel at zero the moment the spindle engages.?
As much as I would want to take out the backlash (I have a history of maintaining motorcycles, mopeds and bicycles, where it is all about reducing friction and taking out backlash) I have come to live with it now.?
Now hoping to hear from a few others whether this makes any sense,
Herman
?
Op 05-04-2023 09:11 schreef jpow <powster@...>:
Hey all,
I'm having this really irritating problem with backlash coming from the Unimat PC cross-slide handwheel.
My understanding is that backlash (for the Unimat) can come from two sources
A) Play in the slide lead nut / screw itself; OR
B) Having too much of a gap between the threaded handlewheel and the cross slide itself.
My main issue is with B)
Following the Unimat instructions, I screw in the threaded handlewheel all the way, and back it out JUST a bit, before tightening up the locking nut (on the outside).
For the life of me, I can never get it "just right". If I tighten enough so everything JUST rotates smoothly, the backlash is too much (0.07mm). If I tighten anymore, the backlash is a bit better, but the handwheel starts to bind and it is difficult to turn freely.
(The binding is strange in the sense that "tightness" occurs at certains angles of rotation only, rather than a constant heavy friction).
Could this be some issue with the bushings or something? I tried putting in small thrust bearing between the handlewheel and where it is mounted, but it didn't help much.
Appreciate any advice thanks :)
|
Re: Unimat black crackle jig-saw
Re the comments from Mr. Jaynes, here is a piece from Ebay showing Unimat gray.
Does anyone have this color???
|
Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL
Hello Jpow:? I have just used some thrust bearings on my unimat when I fitted stepper motors they are working very good here is the info: 4 pieces AXK0515/AS0515 Budget Needle Roller Cage with 2 AS Washers 5x15x4mm
Phill 
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Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL
Hello
Jpow:
They
also sell plastic washers to put behind the hand wheel. Allows
you to reduce the clearance with less friction.
Ball
thrust bearings might be nice if you can find any. ( I might
have some from old phonographs, etc. )
Carl.
On 4/5/2023 3:11 AM, jpow wrote:
toggle quoted message
Show quoted text
Hey all,
I'm having this really irritating problem with backlash coming
from the Unimat PC cross-slide handwheel.
My understanding is that backlash (for the Unimat) can come
from two sources
A) Play in the slide lead nut / screw itself; OR
B) Having too much of a gap between the threaded handlewheel
and the cross slide itself.
?
My main issue is with B)
?
Following the Unimat instructions, I screw in the threaded
handlewheel all the way, and back it out JUST a bit, before
tightening up the locking nut (on the outside).
For the life of me, I can never get it "just right". If I
tighten enough so everything JUST rotates smoothly, the backlash
is too much (0.07mm). If I tighten anymore, the backlash is a
bit better, but the handwheel starts to bind and it is difficult
to turn freely.
(The binding is strange in the sense that "tightness" occurs at
certains angles of rotation only, rather than a constant heavy
friction).
Could this be some issue with the bushings or something? I
tried putting in small thrust bearing between the handlewheel
and where it is mounted, but it didn't help much.
?
Appreciate any advice thanks :)
|
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Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL
It's possible your lead screw is bent, if it is, the bearing surfaces will touch at some points and not at others, that could be the cause of the tightness.
|
Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL
Hey all,
I'm having this really irritating problem with backlash coming from the Unimat PC cross-slide handwheel.
My understanding is that backlash (for the Unimat) can come from two sources
A) Play in the slide lead nut / screw itself; OR
B) Having too much of a gap between the threaded handlewheel and the cross slide itself.
?
My main issue is with B)
?
Following the Unimat instructions, I screw in the threaded handlewheel all the way, and back it out JUST a bit, before tightening up the locking nut (on the outside).
For the life of me, I can never get it "just right". If I tighten enough so everything JUST rotates smoothly, the backlash is too much (0.07mm). If I tighten anymore, the backlash is a bit better, but the handwheel starts to bind and it is difficult to turn freely.
(The binding is strange in the sense that "tightness" occurs at certains angles of rotation only, rather than a constant heavy friction).
Could this be some issue with the bushings or something? I tried putting in small thrust bearing between the handlewheel and where it is mounted, but it didn't help much.
?
Appreciate any advice thanks :)
|
Re: Unimat black crackle jig-saw
This what I can find in SE Asia where I live, I've chosen the silver for my old model. Tbe pale green looks ok, maybe too green.
On Wed, 5 Apr 2023 at 8:14, Steve Johnson <steve@...> wrote: This looks to be about correct for the green unimats. Not easily available in the US, but you might have some luck in Europe.? 
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Re: Unimat black crackle jig-saw
Mine is a horrid colour and I will repaint it, I have managed to find silver hammered. What colour logo did the original cast iron models have?
I dont have a logo on mine hopefully I can have a sticker printed, it will at least make me feel better
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Re: 4 jaw chuck M12 x 1 thread
Get the Sherline chuck. They are better quality than the emco ones.
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Re: Unimat black crackle jig-saw
I also have a red badged SL that has the Gray Hammered finish. And it is not uncommon for the motors to be a shade lighter then the lathe.
?Jeff
-----Original Message-----
From: Steve Jaynes <srjaynes@...>
To: Ruben <groen.drenthe@...>; [email protected]
Sent: Mon, Apr 3, 2023 9:52 pm
Subject: Re: [Unimat] Unimat black crackle jig-saw
I found the text from my discussion of Unimat Colors, circa 1999. ?Sorry, I haven't resurrected the photos, but will keep trying: ?
UNiMAT Colors
I have identified four distinct UNiMAT colors in my personal collection. ?I believe I have decoded how they relate to the different models of Unimats preceding the UNiMAT 3. I hope to have comparative pictures on this page by April 1999.
The colors I've identified as "factory finishes" are:
DB200 Hammer-finish Silver. Found on the original cast iron DB200's, this color often fades or stains to a "Champagne" color sometimes with a vague green tint.
UNiMAT DB200?Crinkle?Black?I detrmined the surface finish of this color is a "controlled" crinkling effect. ?In spite of fragile appearance, seems to be quite robust.?
UNiMAT SL - Model DB200 Hammer-finish Green?. Found on the early SL-DB200's this green has a pronounced blue cast contrasted with the SL1000 Hammer Finish Green which has a pronounced yellow cast. I have only seen one UNiMAT SL - Model DB200 painted entirely this color. This color is reserved for the U90 motors on many UNiMAT SL - Model DB200 's and UNiMAT SL1000's.
UNiMAT SL1000 Hammer-finish Green?As mentioned above, UNiMAT SL1000's have a hammer finished green which has a pronounced yellow cast or pea-Green appearance.
-- Steve Jaynes Unimat owner/collector since 1995, all generations.
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Re: Unimat black crackle jig-saw
Thanks very much Pat for the information. Looks like those eccentrics more often are missing now than present ? ? Was making the cam for mine out of brass and, like you, the shaft in steel. I’m still on my first attempt and being lazy I designed the piece empirically. Would be grateful to receive your pictures and instructions... ? Friendly regards, Alan ?
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From: [email protected] < [email protected]> On Behalf Of pat goodyear Sent: Tuesday, April 4, 2023 2:53 AM To: Alan Ehrlich <alan.ehrlich@...>; [email protected]Subject: Re: [Unimat] Unimat black crackle jig-saw ? Alan,?
I too received a fret saw without the eccentric and without the drive cam, I made both on my Unimat.? ?It is documented on this site, If you can't find it let me know and i will send you pictures and instructions.? ? I used a chunk of Grade 5 ASE bolt as the base.? And a block of aluminium for the drive cam.? ??
pat?
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Re: Unimat black crackle jig-saw
I found the text from my discussion of Unimat Colors, circa 1999. ?Sorry, I haven't resurrected the photos, but will keep trying: ?
UNiMAT Colors
I have identified four distinct UNiMAT colors in my personal collection. ?I believe I have decoded how they relate to the different models of Unimats preceding the UNiMAT 3. I hope to have comparative pictures on this page by April 1999.
The colors I've identified as "factory finishes" are:
DB200 Hammer-finish Silver. Found on the original cast iron DB200's, this color often fades or stains to a "Champagne" color sometimes with a vague green tint.
UNiMAT DB200?Crinkle?Black?I detrmined the surface finish of this color is a "controlled" crinkling effect. ?In spite of fragile appearance, seems to be quite robust.?
UNiMAT SL - Model DB200 Hammer-finish Green?. Found on the early SL-DB200's this green has a pronounced blue cast contrasted with the SL1000 Hammer Finish Green which has a pronounced yellow cast. I have only seen one UNiMAT SL - Model DB200 painted entirely this color. This color is reserved for the U90 motors on many UNiMAT SL - Model DB200 's and UNiMAT SL1000's.
UNiMAT SL1000 Hammer-finish Green?As mentioned above, UNiMAT SL1000's have a hammer finished green which has a pronounced yellow cast or pea-Green appearance.
-- Steve Jaynes Unimat owner/collector since 1995, all generations.
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Re: Unimat black crackle jig-saw
EARLY in my Unimat collecting days, I read that the "Sears Roebuck" Unimats and accessories were, for some period of time, shipped in the Black Crackle finish. ?That said, "mixed" sets may or may not had some pieces purchased from Sears and other pieces purchased from other dealers. ?Hobby Shops, Edmund Scientific, and least Sears, sold the Unimat product line in the various shades of Hammered Green. ?The Crackle and Hammered finishes are quite different. ?At one time, In my old web site, I had different factory finishes photographed. ?I'm committed to other projects right now, but I'll try to resurrect those photos and post them here.
?
--
Steve Jaynes ?AKA "Tiny Lathe Man" which is a mysterious moniker considering I'm 6' and 270lbs...
Unimat owner/collector since 1995, all generations.
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Re: Unimat black crackle jig-saw
Alan,?
I too received a fret saw without the eccentric and without the drive cam, I made both on my Unimat.? ?It is documented on this site, If you can't find it let me know and i will send you pictures and instructions.? ? I used a chunk of Grade 5 ASE bolt as the base.? And a block of aluminium for the drive cam.? ??
pat?
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Re: 4 jaw chuck M12 x 1 thread
Thank you Bill for sharing your advice and experience!?
I don't have much equipment so looking to get started first.
I didn't know about emco being Cast iron vs steel for the sherline.?
Once my skill level improves I hope to make a collet holder ;)?
On Sun, Apr 2, 2023, 10:19 AM Bill in OKC too via <wmrmeyers= [email protected]> wrote: Depends very much on condition. A like-new Enco chuck is probably made of cast iron, IIRC. Drop it on a concrete floor just once, and it can turn to crap. Cast iron is a bit brittle, and easily broken.? One of our other members is trying to repair his Enco chuck because he dropped it, and the teeth that guide one of the jaws chipped off.? The Sherline chucks are made from case-hardened 12L14 steel. It's a bit tougher, but the L is a small percentage of lead in the alloy, so it's not as hard and tough as 1214 steel would be. IF you can find one for the same price as the other, either would do just fine unless you're getting clumsy. I am, myself, so a cheaper and easier to replace chuck was one of the considerations when I bought my Indian 4-jaw. I can replace it three more times for the cost of an Enco chuck. I'm also a cheap bastrich! I hate spending a lot of money for stuff that may not be in really good shape. A bunch of the stuff I need/want for my Unimats, I'm making myself. Not sure my skills are up to making a 4-jaw chuck from scratch just yet. :) Did make an ER25 collet chuck, though, adapted from one of the ER25 collet chuck extensions like this one:??Though the one I used came from eBay, and had a 100mm shank length.?
One way for a cheap bastrich like me to deal would be to make your own 4-jaw chuck, and such, to fit the Unimat, but based on David Gingery's Build Your Own Metalworking Shop From Scrap, Volume 6 of? 7, The Dividing Head and Deluxe Accessories.?
Depends on what you know, what you would like to learn, and how much of a hurry you're in to get to where you want to be. Buying everything is faster, making everything is slower, but you learn more. A little of each is probably the best way to go, and only you can figure out which parts work best for you. Also perhaps depends on what equipment you have already, and definitely on what skills you have. I cheated a few years ago, and took a precision manual machining class, since I'd forgotten most everything from the class I took in high school nearly 50 years ago now. Been doing non-machining for a lot of that time, as well as working as several kinds of mechanics over the past five decades, but there were some big holes in my knowledge. Accurate measurement was the biggie for me. But I got better! ;)
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 Saturday, April 1, 2023 at 08:17:59 PM CDT, jpow < powster@...> wrote:
Hi all,?
Assuming I had the choice between an older (but good condition) emco original chuck, or a brand new sherline, for the same price.?
Which should I get??
Thanks!?
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Re: Unimat black crackle jig-saw
Gorgeous! ? Thanks too, VERY much for including the fret saw’s eccentric wheel in your photos. That bit was missing from mine and I never before managed to find a pix of it. Thought the form would be scalloped like for the later versions. Seeing now it was completely cylindrical, I could have saved myself a bunch of ‘trouble’ when I reproduced it ? ? Friendly regards, Alan ? Alan Ehrlich Geneva, Switzerland ?
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From: [email protected] < [email protected]> On Behalf Of Ruben Sent: Sunday, April 2, 2023 10:09 AM To: Ruben <groen.drenthe@...>; [email protected]Subject: Re: [Unimat] Unimat black crackle jig-saw ? Most important for me is the Unimat MK2a with mill collumn and I think original.
The black crackle paint is in perfect condition and the 2 rods (bars) didn't see that much use as the other unimat's I have? seen.
The motor paint looks bad and has no plug on it, so I stil have to find out if it runs.
It is an early 40w model with number: 3798
The motor pully is missing.
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OldToolmaker
Carl
Herman de Leeuw
Unimat Matt
David James
Steve Jaynes