开云体育

ctrl + shift + ? for shortcuts
© 2025 Groups.io
  1. Unimat
  2. Messages
Expanded Topics Messages Polls
Date
Re: Looking for some help.

 

On Fri, Sep 13, 2024 at 12:07 AM, Jim Korman wrote:
I didn't call out the spindle thread as I assumed most would know that.
Most will know, but best not to assume all do.
?
?
Re: Looking for some help.

 

On Tue, Sep 10, 2024 at 10:27 PM, Keith S. Angus wrote:
https://www.doublemountainview.us/shopwork/unimat/eccentric/20240910_170819.jpg
?
Presumably this is a tommy bar hole (so 4 mm diameter) to help in getting it off.
?
Also note that the 12 mm thread is actually M12 × 1, although you may be already tooled up for that. Since the hole does not have the clearance for the plain 12 mm portion of the spindle you may have to watch the depth of the threaded hole to control the position of the eccentric. Or you could add washers or other packing to make sure it lines up with the connecting link. Just something to keep an eye on.
Yes, it appears that the hole is for a tommy bar so that the eccentric can be tightened on the spindle.
I didn't call out the spindle thread as I assumed most would know that.
?
--
Jim Korman
Re: Dumb question dept.

 

开云体育

and its kinda fun

Best Regards
John



On Sep 12, 2024, at 1:54?PM, Mehmood via groups.io <mehmood.naqshbandi@...> wrote:

?I don’t know to what accuracy you want to shape your tools, but the old hands here (not me, im an old beginner) often sound off about lesson number 1, or close to 1, is ‘learn to grind your own tools’, and that invariably assumes using just a regular bench grinder 20 <insert preferred unit of currency> or so.?

The learning process involves holding the tool at the correct angles and watching the sparks fly. ?Plus a finishing sharpening again by hand. ?Plenty of videos online, and while the cutting and rake angles are important, they don’t need a high degree of precision to be good enough for most things that a hobby lathe is intended for. ?I’m sure wiser heads will chip in with details.



On 12 Sep 2024, at 02:02, John Hutnick <johnhutnick@...> wrote:

?
For any grinding on the Unimat lathe, I usually just cover the rods and bed with plastic wrap.
Re: 795, 895 (etc) DC motors

 

RPM isn't the only factor, feedrate is also part of the calculation. And taking shallow cuts are going to show less of a difference than deeper passes.

Paul

On Thu, Sep 12, 2024, 2:17?PM John Hutnick via <johnhutnick=[email protected]> wrote:
Further about cutting speeds.? Here is a block of aluminum, with 1/4" wide grooves that I cut.? ?The 2 grooves to the right are at the Cowells highest speed, maybe 5000.? The left is with the machine turned to a slow rpm that I rarely use.? I notice little difference.
?
Now I see here discussions of alloys and what cuts well.? I just get scrap pieces from Federal Metals(junk yard).? So I do not have alloys, just brass or aluminum.? Now in this case I can see that previous work machined well, but that is rare to see.
Re: 795, 895 (etc) DC motors

 

Further about cutting speeds.? Here is a block of aluminum, with 1/4" wide grooves that I cut.? ?The 2 grooves to the right are at the Cowells highest speed, maybe 5000.? The left is with the machine turned to a slow rpm that I rarely use.? I notice little difference.
?
Now I see here discussions of alloys and what cuts well.? I just get scrap pieces from Federal Metals(junk yard).? So I do not have alloys, just brass or aluminum.? Now in this case I can see that previous work machined well, but that is rare to see.

20240912_160345.jpg

Re: Dumb question dept.

 

Thanks everyone. I’ve ordered a ‘normal’ grit cup wheel to fit on the U3, to go with the diamond wheel.
?
I’ll also make an accurate sliding rest / guide for the non-whetstone end of the bench grinder.
?
And keep a cup of water nearby.
Re: Dumb question dept.

 

开云体育

I don’t know to what accuracy you want to shape your tools, but the old hands here (not me, im an old beginner) often sound off about lesson number 1, or close to 1, is ‘learn to grind your own tools’, and that invariably assumes using just a regular bench grinder 20 <insert preferred unit of currency> or so.?

The learning process involves holding the tool at the correct angles and watching the sparks fly. ?Plus a finishing sharpening again by hand. ?Plenty of videos online, and while the cutting and rake angles are important, they don’t need a high degree of precision to be good enough for most things that a hobby lathe is intended for. ?I’m sure wiser heads will chip in with details.



On 12 Sep 2024, at 02:02, John Hutnick <johnhutnick@...> wrote:

?
For any grinding on the Unimat lathe, I usually just cover the rods and bed with plastic wrap.
Re: Looking for some help.

 

Jim,
I am in Minnesota also.
Just curious, what part of Minnesota do you live?
I am in Buffalo, Mn
Dick




On Wednesday, September 11, 2024, 2:05 PM, Jim Korman <jimkorman@...> wrote:

On Tue, Sep 10, 2024 at 07:56 PM, James Quick wrote:
Jim,
Thank you for these.? Exactly what I was looking for.
?
Jim, I updated the drawing to show the correct position of the eccentric. You may have
to refresh your browser to get the new photo.
?
--
Jim Korman

--
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: Dumb question dept.

 

For any grinding on the Unimat lathe, I usually just cover the rods and bed with plastic wrap.
Re: Dumb question dept.

 

You will, even if you take great pains to shield and protect everything you can. If you only do it once in a great while, and are anal about protecting the machine, you may never notice the degradation. If you planned on doing it every day, you need machinery dedicated to that purpose, and do the work well away from everything else.?

SHOULD you do it's another question. ;)

Which wheel is coarser depends on the actual wheel. Grit size should be stenciled on the wheel, or the protective washers. Diamond wheels are, AFAIK, usually made in finer grits, but who knows what you have. Low numbers are usually larger sized grits. 36-3000 are fairly common for non-diamond wheels. I've seen 30,000 for a diamond polishing compound for use on tin laps, but have never looked closely at anything else in the diamond world. And diamond is ofter sold in micron sizes.
?Last I played with anything like that was nearly 50 years ago, and was intended for lapidary work.?

Bill in OKC

As for "can you do it?"?

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, September 11, 2024 at 09:09:35 AM CDT, Peter Brooks <peter@...> wrote:


A U3 is all I have...?? good job I waited before rushing into the workshop and trashing things!
?
I have two grinding wheels.
One is a flaring cup aluminum oxide wheel 4” diameter. The other is a flaring cup diamond wheel. Each
has it’s purpose. I can use them on the Unimat.
Ah, presumably the aluminium oxide cutter is courser (what grit is it?) and more rapid cutting than the diamond.? That sounds like a good idea.
?
Do you have any issue with grit getting into places it shouldn't (on the lathe I mean, ha ha :-) ?
?
Re: Looking for some help.

 

On Tue, Sep 10, 2024 at 07:56 PM, James Quick wrote:
Jim,
Thank you for these.? Exactly what I was looking for.
?
Jim, I updated the drawing to show the correct position of the eccentric. You may have
to refresh your browser to get the new photo.
?
--
Jim Korman
Re: Dumb question dept.

 

You can machine HSS. You need something harder than the HSS to machine it. Carbide & diamond come to mind. Some nitrides, too.

Grinding is a machining process. Grab one of your HSS blanks, and look at it under magnification. It will show signs of one or more machining processes. Also, HSS was and is formulated to cut while red hot. It does wear faster when doing so, but so do the various carbides.?

High-carbon tool steels are the materials HSS was intended to replace, because when they get hot, and long before they get red hot, they lose their temper and their sharpness. With adequate cooling HCTS can be sharper than HSS,? but it's not nearly as durable. You can cut aluminum with mild steel. Brass, too, probably, but I haven't done much work in brass. :(??

The sharpest tools ever made are glass. Obsidian, to be more precise. But it's terribly brittle, and not suited to machining. So you need stuff that holds an edge, and is heat tolerant. It needs to be harder that what you're cutting, or you need something hard enough to cut embedded in a softer material. That's how lapping is done, and lapidaries have used various kinds of grit embedded in wire to cut hard stone for centuries. Bits of specially shaped carbides or diamond are pretty commonly used now. Crushed abrasive can be held in shaped masses of softer metals or even shellac. And rubber. Crates points, for example. But the Chinese were doing grinding, Shaping, polishing, and cutting with abrasives embedded in bits of bamboo a few thousand years ago.

OK. I'm putting away my soap box for a while... :)

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, September 11, 2024 at 08:12:04 AM CDT, OldToolmaker via groups.io <old_toolmaker@...> wrote:


Andrei,
The question was can you machine a HSS tool bit with an end mill. Not tool sreel.?
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: Dumb question dept.

 

A U3 is all I have...?? good job I waited before rushing into the workshop and trashing things!
?
I have two grinding wheels.
One is a flaring cup aluminum oxide wheel 4” diameter. The other is a flaring cup diamond wheel. Each
has it’s purpose. I can use them on the Unimat.
Ah, presumably the aluminium oxide cutter is courser (what grit is it?) and more rapid cutting than the diamond.? That sounds like a good idea.
?
Do you have any issue with grit getting into places it shouldn't (on the lathe I mean, ha ha :-) ?
?
Re: Dumb question dept.

Andrei
 

开云体育

Indeed. I did not mean to say it is machinable on a unimat. If that was the intention, then the answer is no way jose.

Get

From: [email protected] <[email protected]> on behalf of Les Orton <lesorton@...>
Sent: Wednesday, September 11, 2024 9:38:20 AM
To: Peter Brooks <peter@...>; [email protected] <[email protected]>
Subject: Re: [Unimat] Dumb question dept.
?
I have machined pre-hardened steel with a carbide cutter on a study CNC machine.
To do anything like this you need something 1000x stronger than a Unimat.
The simple answer is no you can't machine it.
Les
Re: Dumb question dept.

 

I have machined pre-hardened steel with a carbide cutter on a study CNC machine.
To do anything like this you need something 1000x stronger than a Unimat.
The simple answer is no you can't machine it.
Les
Re: Dumb question dept.

 

Andrei,
Have you ever done it?




On Wednesday, September 11, 2024, 8:21 AM, Andrei <calciu1@...> wrote:

You can still do it. I posted a video of a guy using his cnc and a carbide bit to machine an hss bit into a form tool.

Get
From: [email protected] <[email protected]> on behalf of OldToolmaker via groups.io <old_toolmaker@...>
Sent: Wednesday, September 11, 2024 9:12:01 AM
To: Andrei <calciu1@...>; [email protected] <[email protected]>
Subject: Re: [Unimat] Dumb question dept.
?
Andrei,
The question was can you machine a HSS tool bit with an end mill. Not tool sreel.?
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

--
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: Dumb question dept.

Andrei
 

开云体育

You can still do it. I posted a video of a guy using his cnc and a carbide bit to machine an hss bit into a form tool.

Get

From: [email protected] <[email protected]> on behalf of OldToolmaker via groups.io <old_toolmaker@...>
Sent: Wednesday, September 11, 2024 9:12:01 AM
To: Andrei <calciu1@...>; [email protected] <[email protected]>
Subject: Re: [Unimat] Dumb question dept.
?
Andrei,
The question was can you machine a HSS tool bit with an end mill. Not tool sreel.?
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: Dumb question dept.

 

Andrei,
The question was can you machine a HSS tool bit with an end mill. Not tool sreel.?
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: Dumb question dept.

Andrei
 

开云体育

Machining hss video



Get

From: [email protected] <[email protected]> on behalf of OldToolmaker via groups.io <old_toolmaker@...>
Sent: Wednesday, September 11, 2024 8:41:56 AM
To: Peter Brooks <peter@...>; [email protected] <[email protected]>
Subject: Re: [Unimat] Dumb question dept.
?
Peter,
You can’t rough it a HSS tool bit using an end mill.
Your best option is to grind it by hand on a bench grinder.
I have two grinding wheels.
One is a flaring cup aluminum oxide wheel 4” diameter. The other is a flaring cup diamond wheel. Each
has it’s purpose. I can use them on the Unimat.
I also have a bench grinder I wouldn’t be without.
Hope this helps.
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: Dumb question dept.

 

Peter,
You can’t rough it a HSS tool bit using an end mill.
Your best option is to grind it by hand on a bench grinder.
I have two grinding wheels.
One is a flaring cup aluminum oxide wheel 4” diameter. The other is a flaring cup diamond wheel. Each
has it’s purpose. I can use them on the Unimat.
I also have a bench grinder I wouldn’t be without.
Hope this helps.
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
1241 - 1260 of 64853