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Knurling HLV-H

majohnson

Cast Iron
Joined
Jan 3, 2013
Location
Erie, CO
Just wondering if others have been knurling on their lathe. I tried it once and didn’t like the idea of putting that much pressure on the crossslide and carriage.
 
Just wondering if others have been knurling on their lathe. I tried it once and didn’t like the idea of putting that much pressure on the crossslide and carriage.

Just switch-over to "cut" knurls instead of "pressure" or roll knurls and THAT part of the problem goes away.

Or seek an old (maybe even still in production?) Eagle-Rock or clone "scissors" type roll knurl holder that applies pressure from itself to itself, only needs the TP for torque reaction control, not for applying pressure.

Even the most modest of SB 9's can knurl all day with either of those, not stress the structure. MOTOR, maybe. Depends on yer level of patience and whether knurling shiney-wood, brass, ordinary steels, Inconel or ... Mangalloy, if yah dare?

:D
 
What’s a “Cut” Knurl?

I knurled on an HLV-H at work, the first
time it turned out perfect, the second
not as good. I was using a knurling
tool similar to a scissor type. It seems
like the set-up has to be damn near
perfect for the knurl to be be perfect
also.
 
What’s a “Cut” Knurl?

I knurled on an HLV-H at work, the first
time it turned out perfect, the second
not as good. I was using a knurling
tool similar to a scissor type. It seems
like the set-up has to be damn near
perfect for the knurl to be be perfect
also.

"Cut" knurls are the ones that do most of the world's knurling. Turret lathes to CNC.

Professionally/industrially. By the multiple tens of thousands of parts.

Not the odd by-hand one-off and few-of's for hobby, repair, or VERY small batch.

Look 'em up. Not as if there was any mystery.

And OF COURSE "the set-up has to be damn near perfect for the knurl to be perfect also"

Why would that be any different than any other op that has to hit a spec more detailed than "kinda round", "nice and shiney", or "metallic-looking"?.
 
Hardinge makes a very nice quick change tool post for their manual lathes. The L20 2-wheel knurling tools for it are the cut type. I find them tricky to adjust.

DSC00561.jpg DSC00560.jpg

I prefer my Miller Quick (Innsbruck, Austria) brand 3-wheel cut knurling tools with Morse taper or straight round shanks that are held in the tailstock or turret. They are pretty easy to set up and adjust for cutting depth. The adjustment mechanism is a scroll, like on a universal chuck. Once set, they repeatedly cut perfect knurling. Here are pictures of an old Hardinge turret with new knurled parts I made with a Miller tool, a Miller tool and some different size Miller tools.

Cat 7 in turret 4.jpg DSC02179.jpg DSC02180.jpg

Decades ago, I drooled over stuff in the SPI catalogs. The Miller knurling tools cost thousands, even back then. Then along came eBay and I was able to afford several different sizes when one sold for a relatively low price. Accu Trak Tool Corp. (USA) makes very nice cutting knurl wheels in the metric sizes that fit the Miller tools, and many other knurling tool items. I think Miller is no longer in business. A German company still makes the Quick knurling tools.

Randelfrasen Archive - Hommel+Keller

Larry
 
Hardinge makes a very nice quick change tool post for their manual lathes. The L20 2-wheel knurling tools for it are the cut type. I find them tricky to adjust.

View attachment 271915 View attachment 271916

Larry

I have a little experience with the L20. The diameter of the cylinder to be knurled cannot be any dimension I wanted. The circumference of the piece has to be
a multiple of a tooth width on the wheels. And quite a bit of force is needed when doing tough material.
 
I have a little experience with the L20. The diameter of the cylinder to be knurled cannot be any dimension I wanted. The circumference of the piece has to be
a multiple of a tooth width on the wheels. And quite a bit of force is needed when doing tough material.

Not sure what ELSE you would expect, given knurled forms and gear-teeth do share a tad of commonality in that their shape has to "map" to a pitch-line they FIT into on a "regular" cyclic - not take a different track, every successive revolution.

Perhaps you missed it on softer metals, but if that match isn't "there" they ultimately must FORCE it onto a diameter they alter by raising metal as well as depressing it, to where the peaks and roots produced line up nice and well-formed "pretty" rather than just as a randomized chewing-up of the surface?

Measure it AFTER as well as before. It didn't take your sub-optimal choice as sacred. The process changed it for you.

That "raising", obviously a useful associated product long valued for its side-effect. The ability to tighten fits in the long eons before Loctite. No surprises a general "chewing up" is easily as good for that purpose - often BETTER - than neatly formed patterns.

The spacing ain't otherwise a pressure form-roll vs cut-knurl thing. Basic Geometry, rather.
 
Just a couple of notes on knurls. I used a Somma straddle knurl on my turret lathe and set up was quite involved. I made a chart with the correct blank size for each diameter part as well as the setting size for each. Each set of dimensions was found by a lot of trial and error. If the dimensions were not set correctly we would have tracking problems.
Since then I have only done a few sizes using a modified Zeus cut knurl on my Omniturns. So far the cut knurl does not seem to be fussy about the blank diameter prior to knurling, just .001 smaller than the finished size. So far I have not had one tracking issue. The Zeus has worm gearing for setting the angles of the cutters to the size in millimeters on the blank size, lock it down when set, then adjust the height so both rollers cut equally as deep. The original Zeus holder took up too much real estate on the gang tool machines so I made a new shank to hold the head from 1 inch square A6 steel.

CutKnurl.jpg
 
I do a lot of knurling on an Hardinge AHC and HC. I use a scissor style set up with AccuTrak convex knurls. The o.d. before knurling is crucial to get a clean track. The scissors type holder puts very little pressure on the cross slide or spindle.
 
I prefer my Miller Quick (Innsbruck, Austria) brand 3-wheel cut knurling tools with Morse taper or straight round shanks that are held in the tailstock or turret...
Larry

I have one of the "chuck style" Miller-Innsbruck knurling tools like the one in your photo. Got it ages ago during the "good 'ol days" of eBay and it came without the back plate/shaft. Still have not used it but will need to do some knurling soon.

I thought about making a MT2 shank for it but thought it might rotate in the tailstock bore. Is that not a problem for you?
 
I have one of the "chuck style" Miller-Innsbruck knurling tools like the one in your photo. Got it ages ago during the "good 'ol days" of eBay and it came without the back plate/shaft. Still have not used it but will need to do some knurling soon.

I thought about making a MT2 shank for it but thought it might rotate in the tailstock bore. Is that not a problem for you?

I have a 3MT tanged shank on one of my big Miller heads. I hold the straight shank Millers with 2 MT and 3 MT shank end mill holders or Morse taper shank ER collet holders. My Clausing lathe has a tanged ejector slot in the 3 MT tailstock, a nice, but uncommon feature. My Hardinge tailstock has a normal 2 MT bore. The Miller heads do not need a lot of torque to cut a knurl, so I have never had a slipping issue.

If you got a Miller head that is missing the shank, you will also be missing the three hardened steel adjusting pads. These are for making a slight alinement adjustment and also allow rotational adjustment of the shank in case of having a tang or milled flats.

Larry

DSC02235.jpg
 
Larry,
Thanks for the offer, however I have no Miller parts. The only tool for knurling I have is from Dorian that has the flex head. It takes a load of pressure to make it work.
 
Larry,
Thanks for the offer, however I have no Miller parts. The only tool for knurling I have is from Dorian that has the flex head. It takes a load of pressure to make it work.

My "offer" was advice that the tailstock-mounted knurling tools by Miller (there are other brands) put zero load on your carriage and compound. And they put darn little load on the tailstock feed screw. Plus, they can do a great job of knurling. Feel free to refuse my offer, but know that there are some really good knurling tools out there, probably many that are better than what you have used and found wanting.

Larry
 
If you got a Miller head that is missing the shank, you will also be missing the three hardened steel adjusting pads. These are for making a slight alinement adjustment and also allow rotational adjustment of the shank in case of having a tang or milled flats.

Larry

View attachment 274388

Thanks Larry. I don't have the pads you show in the photo and wouldn't have know about them without your post.

Once concern is that the HLV-H tailstocks do not have the "tang holder/ejector". I guess Hardinge didn't want operators putting big MT2 tang drill bits in the tailstock and subjecting them to twisting stress. Seems strange to me since my Schaublin MT2 tailstock had a tang ejector that worked well and was adjustable.

I could make a straight shank for the Miller head to fit into a Multifix tool holder (30mm bore) but I have to find someone to do some EDM work on the holder. I've found a Chinese manufacturer of Multifix clones that makes nice holders, but the fit is too tight on an original Swiss Multifix toolpost (I have an original J.F. Minder "A" and a newer Mivesa "E" size toolpost, both made in Geneva).

Also I'd have to make a pinned T-nut for the Multifix and align it accurately with the spindle. Not sure if that much work is justified.

I'm thinking about converting a shop-made MT2 drill pad I have (made from a MT2--7/8-16 holder for a boring head) into a holder for the Miller head. Can you offer any advice for making the shank holder?

-Jorge
 
Slight thread drift, but:-

A number of my original Multifix tool holders are a bit loose on the post (could re-make the cam, but other tool holders seem ok as it is). Are the clones too tight in an 'absolute' sense or just tighter than ones with a bit of life-history? I had been thinking of getting myself/the lathe a birthday present this year...

PS. I don't get problems with the HLV tail stock. I'd rather not have it try to restrain a poorly fitting tool by using the ejection tang.
 
Slight thread drift, but:-

A number of my original Multifix tool holders are a bit loose on the post (could re-make the cam, but other tool holders seem ok as it is). Are the clones too tight in an 'absolute' sense or just tighter than ones with a bit of life-history?

Here is what I have:
J.F. Minder Multifix "A" Toolpost (original Swiss manufacturer)
5 toolholders stamped "Swiss Made" or "Made in Switzerland", all fit perfectly
2 "clone" toolholders (Create Tool CN), fit is too tight to slide them on the center post

Mivesa Geneva Multifix "E" Toolpost (second Swiss manufacturer)
1 EFI toolholder marked "Made in Switzerland", fits perfectly
2 New old stock ED toolholders in SPI boxes, marked "Original Multi Suisse", and a (R) symbol, no country of origin markings on the toolpost or box. Fit tight but able to slide them on after doing some lapping.

I checked the fit of the grooved arc against the center post on all of them. The best fit is the J.F. Minder "A" and the Swiss holders, second best Mivesa "E" and Swiss holder. The SPI holders (probably German) were nearly as good but some air gap on edges. The Create holders on the J.F. Minder showed the most gap on the edges but it was barely more than the German holders on the Mivesa "E".

I still believe that eroding small amount of metal (about 0.003 in) from the inside of the holes in the edges of the holder in the direction that the toolpost straps pull should fix the problem. Just need to find someone with a sinker EDM who's willing to try it.

How were you able to access the cam in the toolpost?

Thanks!
 
I finally got around to making a MT2 shank for my Miller-Innsbruck (QUICK) STR I head. I've owned that thing for at least 15 years and had never had a chance to try it.

I've now done some initial testing. It turned out I only had the right set of knurls for doing 1.0mm pitch straight knurling.

The QUICK head spun the first time I tried it as I had feared. I came up with the idea of making a collar to fix it to the outside of the tailstock ram to prevent spinning.

The QUICK instructions are somewhat confusing and refer to a much newer version of the head that is substantially different from the one I'm using. If anyone has a copy of the manual I would like to see it.
 
I have used a turret form type knurler from Brown and Sharpe in a light import turret lathe. It would have fit in the boring tool adapter for my HLV-H's 4 sided turret. So there are good tools that do not have to fit in the tailstock out there.
https://www.sommatool.com/catalog/pdf/Somma_Catalog-Knurling.pdf
Page 103 has some current turret mount form knurling tools. One could even make a tailstock to 5/8 or 3/4 bore adapter if you wanted to put one in the tailstock. On other pages of that catalog are some seriously strong straddle knurls that would be mounted in whatever lathe tool style holder you are using. The one scissors style I have will do a knurl but it is not very strong and I would not recommend it to anyone. There might be some better styles out there but I doubt any are as good as the production style from Somma or Brown and Sharpe. I did sell my B&S tool to a friend and I do not regret it as the new cut style is so much easier to set up for short runs.
 








 
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