Re: Unimat black crackle jig-saw

开云体育

Some of the early DBs – at least here in Switzerland - definitely came original with gray enamel, including several I’ve seen plus one Mk2 that I personally have.

?

Also, I’ve separately acquired gray enamel DB accessories from different sources throughout the country, all of which visibly still had their original paint.

?

Friendly regards,

Alan

?

Show quoted text

From: [email protected] <[email protected]> On Behalf Of g steinback via groups.io
Sent: Thursday, April 6, 2023 6:33 AM
To: John Hutnick <johnhutnick@...>; [email protected]
Subject: Re: [Unimat] Unimat black crackle jig-saw

?

John,

I've never seen a Unimat DB/SL without a crackle or hammertone finish. That eBay photo looks like a pretty standard machine gray enamel.

Re: Unimat black crackle jig-saw

#59755

John,

I've never seen a Unimat DB/SL without a crackle or hammertone finish. That eBay photo looks like a pretty standard machine gray enamel.

Re: Unimat black crackle jig-saw

#59754

This looks to be about correct for the green unimats. Not easily available in the US, but you might have some luck in Europe.?

Re: T-slot adapter screw

#59753

Thanks all, it looks like I will be making a few different ones, the dimensions of the slot on the cross slide would help

Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL

#59752

I have the same backlash on the cross slide of my U3.? I placed a thin,? small diameter brass washer between the knob and the lathe.? This reduced the diameter of the contact circle between the knob and the lathe and so reduced the change in backlash caused by the back of the knob not being exactly perpendicular to the lead screw axis.? There was still a bit of backlash, but still a definite improvement.

Re: T-slot adapter screw

#59751

12mm. Not 1mm, not 112mm.?

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, April 5, 2023 at 08:41:12 PM CDT, Bill in OKC too via groups.io <wmrmeyers@...> wrote:

We have blueprints for the regular t-nuts, and all you need to get the length of the thread is count the number of threads. That's a 1mm pitch. You get 12 threads? it's 112mm plus 1 or 2 for the chamfer. Ten threads? 10+1 or 2, then add the height of the regular t-nut.? If you use a pair of dividers, you can set them to the corners of the front flat, which is 12mm, IIRC, and then walk the dividers up the photo to measure the height.? There are parts that would be a great deal more difficult to scale from a photo, like the bases for the threading attachment, but this particular part should be dead easy.?

Got busy with other stuff, or would have done exactly that for the pile of parts I've been building for mine.?

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, April 5, 2023 at 08:29:07 PM CDT, Charles Kinzer <ckinzer@...> wrote:

This eBay item has two of different lengths.? I don't know what the longer one is all about.

And this is one of a different design that looks a little interesting.? Perhaps a stronger scheme.

I tried to find an existing drawing for the original part online but had no luck.

Charles E "Chuck" Kinzer

On Wednesday, April 5, 2023 at 06:14:12 PM PDT, David James via groups.io <davebjames@...> wrote:

Hi all,
With a long weekend coming up I need a project. I want to make a T-slot adapter screw. My lathe has not arrived yet so I have no idea of the dimensions of T-slots ect.
Does any one possibly have the dimensions of this item like
1. Total length
2. Size of T- nut (base)
3. T-nut shaft diameter
4. Length of T-nut shaft

5. The M12 x 1 thread length, the thread looks like it is about 6-7mm long, counting the threads.
Would be much appreciated if someone could supply these dimensions and it will keep me busy over this long weekend. Thanks

Re: T-slot adapter screw

#59750

We have blueprints for the regular t-nuts, and all you need to get the length of the thread is count the number of threads. That's a 1mm pitch. You get 12 threads? it's 112mm plus 1 or 2 for the chamfer. Ten threads? 10+1 or 2, then add the height of the regular t-nut.? If you use a pair of dividers, you can set them to the corners of the front flat, which is 12mm, IIRC, and then walk the dividers up the photo to measure the height.? There are parts that would be a great deal more difficult to scale from a photo, like the bases for the threading attachment, but this particular part should be dead easy.?

Got busy with other stuff, or would have done exactly that for the pile of parts I've been building for mine.?

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, April 5, 2023 at 08:29:07 PM CDT, Charles Kinzer <ckinzer@...> wrote:

This eBay item has two of different lengths.? I don't know what the longer one is all about.

And this is one of a different design that looks a little interesting.? Perhaps a stronger scheme.

I tried to find an existing drawing for the original part online but had no luck.

Charles E "Chuck" Kinzer

On Wednesday, April 5, 2023 at 06:14:12 PM PDT, David James via groups.io <davebjames@...> wrote:

Hi all,
With a long weekend coming up I need a project. I want to make a T-slot adapter screw. My lathe has not arrived yet so I have no idea of the dimensions of T-slots ect.
Does any one possibly have the dimensions of this item like
1. Total length
2. Size of T- nut (base)
3. T-nut shaft diameter
4. Length of T-nut shaft

5. The M12 x 1 thread length, the thread looks like it is about 6-7mm long, counting the threads.
Would be much appreciated if someone could supply these dimensions and it will keep me busy over this long weekend. Thanks

Re: T-slot adapter screw

#59749

This eBay item has two of different lengths.? I don't know what the longer one is all about.

And this is one of a different design that looks a little interesting.? Perhaps a stronger scheme.

I tried to find an existing drawing for the original part online but had no luck.

Charles E "Chuck" Kinzer

On Wednesday, April 5, 2023 at 06:14:12 PM PDT, David James via groups.io <davebjames@...> wrote:

Hi all,
With a long weekend coming up I need a project. I want to make a T-slot adapter screw. My lathe has not arrived yet so I have no idea of the dimensions of T-slots ect.
Does any one possibly have the dimensions of this item like
1. Total length
2. Size of T- nut (base)
3. T-nut shaft diameter
4. Length of T-nut shaft

5. The M12 x 1 thread length, the thread looks like it is about 6-7mm long, counting the threads.
Would be much appreciated if someone could supply these dimensions and it will keep me busy over this long weekend. Thanks

T-slot adapter screw

#59748

Hi all,
With a long weekend coming up I need a project. I want to make a T-slot adapter screw. My lathe has not arrived yet so I have no idea of the dimensions of T-slots ect.
Does any one possibly have the dimensions of this item like
1. Total length
2. Size of T- nut (base)
3. T-nut shaft diameter
4. Length of T-nut shaft

5. The M12 x 1 thread length, the thread looks like it is about 6-7mm long, counting the threads.
Would be much appreciated if someone could supply these dimensions and it will keep me busy over this long weekend. Thanks

20230406_085435.jpg

Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL

#59747

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

Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL

#59746

开云体育

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:

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

?

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 3 / PC Cross Slide Backlash from HANDLEWHEEL

#59745

开云体育

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:

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

?

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 3 / PC Cross Slide Backlash from HANDLEWHEEL

#59744

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

?

Show quoted text

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

#59743

Re the comments from Mr. Jaynes, here is a piece from Ebay showing Unimat gray.
Does anyone have this color???

Unimat gray.jpg

Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL

#59742

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

Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL

#59741

开云体育

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:

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 :)

Last Call for cheap books

#59740

It’s been a decade since Lindsay Publications, Inc. officially closed their doors and now the time has come for Your Old Time Bookstore to do the same.?We've begun our final inventory consolidation & are making prepartions to shut down.

?

We recommend ordering as soon as possible for the best selection!?These are the LAST copies remaining from Lindsay Publications. Inc.’s inventory.?Get em’ before they’re gone!!!

?

WEBSITE SALES END

midnight CST

Wednesday, May 31, 2023

?

All items are currently 75% off retail price,

!

http://www.youroldtimebookstore.com/

Re: Unimat 3 / PC Cross Slide Backlash from HANDLEWHEEL

#59739

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

#59738

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

#59737

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.

Show quoted text

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.?