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Knife tools

 

I dont know what type Keith has, but I happen to have 2 toolholders with knife tools, both from German manufacturer Komet, also spelled Comet. I took pictures of both and created files for these 2 types - Komet A No. 0 DRGM and Comet A00, complete with rough measurements. Please see here: /g/Unimat/files/Comet%20toolholders%20for%20tool%20knives?
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Komet apparently still is in business and the Comet A00 model can still be ordered (there are actually 4 types there), with a whole range of knives, please see here: ?
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Hope this helps and I too would love to hear a bit more from Keith, time permitting.
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Herman

Op 21-11-2024 07:19 CET schreef james Pineda via groups.io <james_h_pineda@...>:
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HI Keith.
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Could you elaborate on what you mean by the "knife tool"? You might have just cracked the code for many Unimat/very small lathe users.
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Best,
James
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On Wednesday, November 20, 2024 at 08:23:59 PM PST, Keith S. Angus via groups.io <keithsangus@...> wrote:
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On Wed, Nov 20, 2024 at 07:04 PM, Bill in OKC too wrote:
Properly ground and honed HSS (High Speed Steel) is sharper than any carbide tooling. It takes decent cuts, leaves a finer finish on the work piece, and does not lose its temper if it gets overheated. High Carbon tool steel will take a better, sharper edge, but get it hot enough to turn blue and it loses it temper and the edge disintegrates.
Someone here pointed out that you can get a sharper edge on HSS than with carbon steel, and then I was told that grades with cobalt have a sharper edge. I've found lathe bits from ?' on up in M42, which is a cobalt/molybdenum grade. I haven=t tried it yet - I want to design a holder for the small bits, which will then need less work to grind them to shape. For grinding I have experimented with small (50 mm, 2") diamond wheels and got a good sharp edge and polished surfaces in a short time. There was very little grinding dust, not much noise, no sparks and no smell of burning. I now need to mount the motor and wheel into some sort of frame to give me an adjustable tool support.
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I've never used the tool sets often supplied with small lathes as the shapes are not so useful. The one that does most work for me is the knife tool, good for turning and facing. I rarely need anything else, just the same shape with different rakes for brass, steel and aluminium.

 

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
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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
 

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.
 

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.
 

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.
 

¿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.
 

Hello Carl:
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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.
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Best,
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JHM
 

John,
I understand your approach to tooling and that works for you and is great.
I on the other hand enjoy grinding tools and making cutters. Different strokes for different folks. The only cutters I buy are spiral flute end mills and taps& dies.
I also grind my own single flute cutters used for engraving.
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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