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Re: Honing turning tools

 

In Trade School I learned how to grind a lathe tool free hand on a pedestal grinder. I still use this skill today. We learned to hand grind to within one degree of angle and maintain a single facet. Practice is all it takes. I also was taught how to grind twist drill bits by hand. Learn this skill and you will never need a cutter grinder.
All things are possible!!
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
Re: Mistery Unimat 3 with interesting modifications

 

Hello:
?
On Fri, Nov 22, 2024 at 08:19 AM, Clive wrote:
... converting it to rack and pinion drive for the carriage ...
It seesm to have been done by a chap called Maurice Rhodes.
Published in Model Engineer Workshop magazine #107 and #112.
The only available source and rather expensive proposition just to have a look and see what it is all about.
?
... that twirling of the leadscrew? handwheel is a nuisance.
To - say - the - least.? 8^¡ã
?
Best,
?
JHM

mew_rhodes.jpg

Re: Mystery Unimat 3 with interesting modifications

 

Hello:
?
On Fri, Nov 22, 2024 at 03:30 AM, Peter Brooks wrote:
... an ¡®improved¡¯ version of a cross slide
A closer look does not improve things much. (see attached blow-up)
?
But yes, it would seem (?) that it is just a motorised carriage leadscrew.
I was hoping that someone had devised a relatively easy/practical way of disengaging the leadscrew but it seems it is not the case.
Not being an ACME thread (with all that it implies) does make it a rather difficult thing to implement.
?
Still, the motorised leadscrew is not a bad idea.
One of the things I really dislike about the U3 is that moving the carriage out of the way is so cumbersome.
?
What seems to be mounted on the carriage is part # 150.190 (top/compound slide holder).
One of the most expensive* U3 accesories, probably designed by a beancounter in a hurry to go to lunch.
ie: a bad design and even worse choice of material.
?
Blue Ridge Machinery and Tools sold it for US$49.00 back when there was no email and traded through a 0800 + a PO Box (pre 1980?).
* Roughly the same price as the power feed #150.300 (US$51.00) and vice #150.310 (US$48.00) ?
?
To get a relative idea of the amount: a loaded hot dog+small Coke in NYC (~ 35th and 3rd.) in 04/1980 cost me $1.00.
?
But I digress ...
?
Can anyone make out what has been done to the cross slide?
I see that a slide stop has been added, surgery done where the screw fits and a new handwheel installed.
Any ideas as to the handwheel?
?
Best,
?
JHM

u3_rare_detail.jpg
u3_slide.jpg

Re: Mistery Unimat 3 with interesting modifications

 

I have a Hector lathe which is based on the Unimat 3 and have thought about converting it to rack and pinion drive for the carriage as all that twirling of the leadscrew? handwheel is a nuisance.

Wouldn't take much to do it - I have an Atlas shaper with which I could cut the teeth for the rack and a new pinion could either be a re-purposed one or custom-made to suit the rack. Of course the carriage apron would need re-making to accommodate the handwheel drive for the pinion and for half-nuts to engage the leadscrew.?

Still thinking about it after 12 years' ownership . . . ;-)

On Thursday 21 November 2024 at 22:21:16 GMT, Julius Henry Marx via groups.io <sawbona@...> wrote:


Hello:
?
Long time no see. 8^)?
?
Absence due to having been busy with a number of things, quite a few of them directly related to putting my U3 in order.
Others less so, but such is life.
?
In the course of what I have been doing with my U3 and while going over my stash of photographs, I came across the one I attached to this post.
Unfortunately, I only recall having it come up while trolling the web for anything with 'unimat 3' in the text file.
Maybe in a 'for sale' ad in Craig's? No idea, I had forgotten all about it till today.
?
But I do recall a couple of things immediately called my attention which is why I saved it:
?
1.
A small motor (w/gear reduction?) and fwd/rev control box for driving the carriage feed screw.
?
2.
An nicely oversized handwheel right in front of the carriage which would indicate (?) it is used to move the carriage left/right without the use of the carriage feed screw which would (obviously) be somehow disengaged.
?
It would be really great to be able to move the carriage left/right with a handwheel and skip the arduous carriage feed screw.
?
So ...
Anyone here seen this machine, reference to it or anything similar?
?
I'd appreciate your views/comments on this.
?
---
?
Something else:
?
As I may have mentioned, I purchased my ca. 1980 U3 used, 2nd. 4rd or Xth hand, no idea.
No history, maintenance log or provenance.
?
Preliminary testing revealed OEM bearings sounding like a muted blender crushing ice.
Further inspection showed the rest of the machine from the 3-jaw onwards having suffered the same lack of care.
A real pity and quite a bit of work to make good, a *still* on-going endeavour.
?
First thing was to swap out the bearings for a new set but did not replace the disk springs.
Besides not being available locally in that (DIN) size, it was not part of the many instruction sets I read on how to carry out the bearing replacement operation.
?
That was 18 months ago and after getting a great many (!) things straightened out, the lack of properly functioning disk springs shows in every turning operation. Obvious reasons being chuck abused -> bearings abused/shot -> disk springs/shot.?
?
A lesson learned:
Change bearings? -> change disk springs.
Just like when you drop the gearbox on your Chevy to do the clutch: replace everything.
?
I am presently awating for the arrival if a set of disk springs for my U3's headstock which I was able to source from an OEM factory in China.
I attempted other sources but they would:
?
1. not sell to me | 2. have a minimum order of US$100+SH | 3. only ship via courier (US$40 / US$60) | 4. only sell to certain countries in the EU.
?
Once we understood our mutual needs, things with China were rapidly ironed out and I was able to purchase a set 8 disk springs for ~ US$5.00 + US$10.00 shipping. A stark contrast with the three or four outfits which directly ignored my query.
?
Needless to say, the jury will be out till I can install and test them.
These chaps export their various models of disk springs worldwide, no reason they will not be just as good as the original ones.
?
Once installed, the level of deflection I now see when taking a cut will hopefully be reduced to a minimum expression.
?
I'll report back on all that once I have something.
?
Best,
?
JHM
Re: Mistery Unimat 3 with interesting modifications

 

Yep, it looks like an ¡®improved¡¯ version of a cross slide - presumably it can be mounted at angles for taper turning¡­

Tool holding looks much more secure than the original U3 offering!
Re: Mistery Unimat 3 with interesting modifications

 

On Thu, Nov 21, 2024 at 02:21 PM, Julius Henry Marx wrote:
But I do recall a couple of things immediately called my attention which is why I saved it:
?
1.
A small motor (w/gear reduction?) and fwd/rev control box for driving the carriage feed screw.
?
2.
An nicely oversized handwheel right in front of the carriage which would indicate (?) it is used to move the carriage left/right without the use of the carriage feed screw which would (obviously) be somehow disengaged.
?
It would be really great to be able to move the carriage left/right with a handwheel and skip the arduous carriage feed screw.
?
So ...
Anyone here seen this machine, reference to it or anything similar?
?
I'd appreciate your views/comments on this.
?

?
?
Isn't the handwheel (item 2) just for moving the cross-slide?
Re: Honing turning tools

 

Herman,
?
The answer to your first question is yes,?
??
Honing a cutting tool with one cutting edge like a traditional metal lathe tool bit, or a wood chisel blade is the same principle / technique. The term usually refers to simply dressing the "backside" or flat side to eliminate any false burs created while grinding the face. ?That same practice can also renew a cutting edge without regrinding the face. As long as you make ?sure that the material you are using to hone is or is on a flat surface, and it is harder than the cutter's ?edge you are dressing you should be good to go. ?
?
I didn't understand your second question.?
?
all the best,?
Nate?
?
?
?
?
?
?
?
?
?
Re: Mistery Unimat 3 with interesting modifications

 

Hello:
?
... who this Chinese supplier is.
I should be receiving the package in a fortnight or less.
I will post the purveyor's data before testing the springs if it is important to you.
?
But first I want to make absolutely sure that what I am presenting is as advertised / expected.
At least with respect to dimensions and *apparent* quality of the goods.
eg: 34.6mmx 20.4mm x 0.4mm - ~1.89grs. / pcs. ie: they fit in properly
?
Hope you don't mind.
?
Best,
?
JHM
Re: Knife tools

 

Hello Carl:
?
On Thu, Nov 21, 2024 at 08:02 PM, Carl wrote:
... cut-off tool from a 1/4" tool bit.
... ground off a 1/2" from the end to 0.04" ...
The original material quality (important aspect) not withstanding, if it has been in use for 50 years it was quite obviously (very) well made.
Given how difficult it is to get such a tool for the U3, I have been thinking about making one myself.
I'd appreciate your posting photos of the tool you made. TIA.
?
Best,
?
JHM
Re: Mistery Unimat 3 with interesting modifications

 

So tell us who this Chinese supplier is.
Re: Knife tools

 

¿ªÔÆÌåÓý

Hi Gang:

I made my own cut-off tool from a 1/4" tool bit. I plunged ground off a 1/2" from the end to 0.04", been using it for 50 years.

Carl.

PS: I use my Unimat to resize my model railroad wheels.
Mistery Unimat 3 with interesting modifications

 

Hello:
?
Long time no see. 8^)?
?
Absence due to having been busy with a number of things, quite a few of them directly related to putting my U3 in order.
Others less so, but such is life.
?
In the course of what I have been doing with my U3 and while going over my stash of photographs, I came across the one I attached to this post.
Unfortunately, I only recall having it come up while trolling the web for anything with 'unimat 3' in the text file.
Maybe in a 'for sale' ad in Craig's? No idea, I had forgotten all about it till today.
?
But I do recall a couple of things immediately called my attention which is why I saved it:
?
1.
A small motor (w/gear reduction?) and fwd/rev control box for driving the carriage feed screw.
?
2.
An nicely oversized handwheel right in front of the carriage which would indicate (?) it is used to move the carriage left/right without the use of the carriage feed screw which would (obviously) be somehow disengaged.
?
It would be really great to be able to move the carriage left/right with a handwheel and skip the arduous carriage feed screw.
?
So ...
Anyone here seen this machine, reference to it or anything similar?
?
I'd appreciate your views/comments on this.
?
---
?
Something else:
?
As I may have mentioned, I purchased my ca. 1980 U3 used, 2nd. 4rd or Xth hand, no idea.
No history, maintenance log or provenance.
?
Preliminary testing revealed OEM bearings sounding like a muted blender crushing ice.
Further inspection showed the rest of the machine from the 3-jaw onwards having suffered the same lack of care.
A real pity and quite a bit of work to make good, a *still* on-going endeavour.
?
First thing was to swap out the bearings for a new set but did not replace the disk springs.
Besides not being available locally in that (DIN) size, it was not part of the many instruction sets I read on how to carry out the bearing replacement operation.
?
That was 18 months ago and after getting a great many (!) things straightened out, the lack of properly functioning disk springs shows in every turning operation. Obvious reasons being chuck abused -> bearings abused/shot -> disk springs/shot.?
?
A lesson learned:
Change bearings? -> change disk springs.
Just like when you drop the gearbox on your Chevy to do the clutch: replace everything.
?
I am presently awating for the arrival if a set of disk springs for my U3's headstock which I was able to source from an OEM factory in China.
I attempted other sources but they would:
?
1. not sell to me | 2. have a minimum order of US$100+SH | 3. only ship via courier (US$40 / US$60) | 4. only sell to certain countries in the EU.
?
Once we understood our mutual needs, things with China were rapidly ironed out and I was able to purchase a set 8 disk springs for ~ US$5.00 + US$10.00 shipping. A stark contrast with the three or four outfits which directly ignored my query.
?
Needless to say, the jury will be out till I can install and test them.
These chaps export their various models of disk springs worldwide, no reason they will not be just as good as the original ones.
?
Once installed, the level of deflection I now see when taking a cut will hopefully be reduced to a minimum expression.
?
I'll report back on all that once I have something.
?
Best,
?
JHM

unimat_rare.jpg

Re: Knife tools

 

Now for Bill or anyone here, my goal is not to make tools or fail miserably.? I just want to do things for my model trains.
So I follow what I have noted before:? buy what you can, and then make what you cannot buy.
I only have so many hours.
Re: Cast iron Unimat lathe weight?

 

With milling column, chuck and quill lever it is 11.05 kg. This one has original induction motor.
Re: Knife tools

 

Best of all would to be to make our own. :)

Trying to do that, even if you fail miserably and repeatedly, is educational. ;)

Thomas Edison is reported to have said?¡®Results! Why, man, I have gotten a lot of results! I know several thousand things that won¡¯t work.¡¯

Not saying you should learn how to make your own high speed steel, though. Unless that's what you want to do!

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 Thursday, November 21, 2024 at 09:47:04 AM CST, John Hutnick via groups.io <johnhutnick@...> wrote:


I looked at the Komet, 2.3mm wide, 110 euro.
You can buy a Sherline cutoff tool only 1mm wide.? Kaiser Thinbit goes down to .025.? Arthur R. Warner sells 1/32 and 1/64.? All are US made.? So for us here, why bother with Europe?? We are supposed to make America great.
Re: Knife tools

 

I looked at the Komet, 2.3mm wide, 110 euro.
You can buy a Sherline cutoff tool only 1mm wide.? Kaiser Thinbit goes down to .025.? Arthur R. Warner sells 1/32 and 1/64.? All are US made.? So for us here, why bother with Europe?? We are supposed to make America great.
Re: Knife tools

 

I have a veriation of the Knife Tool that I have been using for many years. It is my go to tool for the 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
Re: Vice for my Unimat DB

 

¿ªÔÆÌåÓý

Hello GS:

When you are grinding on a surface grinder, the magnetic chuck can pull a bent plate flat to the chuck. Then when you turn the chuck off the plate will spring back. Most of the time this is very slight. If you are going for very flat you shim the gaps so the top side is ground straight. I would start will brass shims, and then cigarette paper or the cellophane wrappers.

To check the flatness I would support the bar ( 1/2"x2"x12" parallels for the wire EDM) on two 1x2x3 blocks and check the under side with an indicator. This would tell me where to put the shims. When the difference was less than the cellophane I would coat the spot with Magic Marker, it could shim at about 0.000 05", dust grind the top, flip it over and check again.

It was fun, when it worked.

Carl.

On 11/20/2024 11:30 AM, g steinback via groups.io wrote:

On Tue, Nov 19, 2024 at 07:11 PM, Carl wrote:
Learned from the Andrews shop how to use Magic Marker as shim stock for grinding.
??
Re: Power feed for sale

 

SOLD!
Cast iron Unimat lathe weight?

 

Hey there
?
Does anyone know the weight of a cast iron Unimat lathe with the milling attachment included??
i only have a 2kg max scale¡­.
?
thanks,
?
Jeff
901 - 920 of 64881