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MattiJ
03-08-2017, 02:40 PM
I promised to show some photos trying to illustrate the usage of my cut knurling tool. I don't have any dimensions as I just dig up some good looking pieces of steel and started to machine. I think anyone can figure their own version with possible improvements and I am happy to help if there something mystery.

These are the main parts:

http://i.imgur.com/JF3bQG6.jpg

Knurling tool set to toolpost, mounting shaft angled approx 5-degrees in the tool post to create relief angle for the cutting edge:
(In this picture the Knurling tool set to cut the second cut of the diamond pattern, lathe run in reverse)

http://i.imgur.com/78PvEST.jpg

Centering the knurling tool to workpiece with ruler method:

http://i.imgur.com/V5rCC51.jpg

Position for cutting lathe spinning in normal direction:

http://i.imgur.com/Tqc1CPX.jpg

Rest of the photos are here:
http://imgur.com/a/nzkag

You really need to flush the tool with coolant or use constant air blast to blow of all the chips so that they don't mangle between the tool and workpiece.

MattiJ
03-08-2017, 02:55 PM
The knurling wheel is "normal" Zeus knurling wheel that I sharpened and polished on both sides:
https://www.zeus-tooling.de/de.html

Only critical dimension in my "desing" is that the knurling tool cutting edge is in a same line with the long mounting shaft center axis. This way you don't need to repeat the height adjustment when you flip the tool to cut the second cut of the diamond pattern.

I was also pondering on the possibility to make cutting wheel position adjustable so that If I ever need to sharpen the knurling wheel and it becomes thinner I could still adjust the cutting edge position correctly. Should be reasonably easy modification if need rises.

mars-red
03-08-2017, 03:00 PM
Well done, I like it! I made a simple single wheel knurling tool a while ago, to use in my Rivett lathe, and due to the versatility of the weird-o toolpost on the lathe, it lends itself to cut knurling very well. I have only used it for straight knurls, and for some reason it never occurred to me to angle it and make two different cuts, for diamond knurls! Brilliant. :) I'll have to give that a try the next time I have call for it.

BCRider
03-08-2017, 03:09 PM
I'm a big fan of "coining" or straight knurling for small knobs that only need to be turned and not pushed or pulled. I would imagine that a regular angled knurl sharpened in the same manner would do well for straight knurling?

Paul Alciatore
03-08-2017, 03:11 PM
That's a neat tool. I love it. Not as complicated as the two wheel designs. I will have to save this thread for a later project.

Separate question: In your second photo I see a graduated dial that appears to be part of your QC tool holder: it seems to have 40 divisions. I assume it is for setting the angle of the tool on the post. Can you confirm that. And it has a spring around the top. What is that spring used for?

MattiJ
03-08-2017, 03:27 PM
I'm a big fan of "coining" or straight knurling for small knobs that only need to be turned and not pushed or pulled. I would imagine that a regular angled knurl sharpened in the same manner would do well for straight knurling?
Exactly. I have 30-degree knurling wheel waiting for sharpening so that I can use it to cut straight knurls. Fine adjustment setscrews come handy if I want longer part with straight knurl.

MattiJ
03-08-2017, 04:00 PM
That's a neat tool. I love it. Not as complicated as the two wheel designs. I will have to save this thread for a later project.

Separate question: In your second photo I see a graduated dial that appears to be part of your QC tool holder: it seems to have 40 divisions. I assume it is for setting the angle of the tool on the post. Can you confirm that. And it has a spring around the top. What is that spring used for?
Thanks!
Yes, its a Multifix clone toolpost that can be set to 40 different positions. Probably most common toolpost style here.
The spring is just holding the endplate/swarf cover or whatever that thing is.

Mcgyver
03-08-2017, 07:17 PM
that worked well. John Stevenson posted some time ago a similar idea using the common knurl wheel where the pattern is at 45 degrees....use it in that holder and produce a straight knurl

edit: oops missed the post where you noted that already

pinstripe
03-09-2017, 12:55 AM
Nice. What process did you use to blue/oxidize the part?

MattiJ
03-09-2017, 01:10 AM
Nice. What process did you use to blue/oxidize the part?

Phosphoric acid bath and some parts are blue just because tig welding. Wanted to do parkerizing for the parts but its still cold outside and dont want to "cook" the parkerizing inside.

Forgot to mention the trick to make the split sleeve: its made of two pieces 10x16 key steel stock clamped to 4-jaw chuck, drilled and reamed trough. Key steel stock is a pleasure to machine if yuo dont count the warping habits it has sometimes.

MattiJ
03-09-2017, 03:47 PM
Getting a STRAIGHT knurl turned out to be LOT more difficult than making a diamond knurl. :(
I have now lots of pre-knurled stock for projects ;)

left to right:
6082 Aluminium
Thin wall steel tubing
CR 1018
Another 1018 bar


http://i.imgur.com/7TyuVlX.jpg
http://i.imgur.com/O5QPVZs.jpg

woodenbird
03-09-2017, 03:53 PM
I see mention of sharpening the knurling wheel. Can anyone elaborate on the process/tools used to sharpen one?
Thanks in advance.

MattiJ
03-09-2017, 04:12 PM
This video demostrates the method that I actually use for setting the relief/clearance angle
https://www.youtube.com/watch?v=8FexKdk5pWo

I'll still have to fool around with the starting technique, even that video doesn't show it clearly.

TGTool
03-09-2017, 08:30 PM
I see mention of sharpening the knurling wheel. Can anyone elaborate on the process/tools used to sharpen one?
Thanks in advance.

You want a sharp corner as distinct from the chamfered corner you'd use for bump knurling. How you sharpen depends on the equipment at hand. If you have a tool and cutter grinder you probably know how to sharpen jobs that come up and don't need advice. If you have only a lathe and small stuff, hold it in the chuck or a collet, preferably with a copper or aluminum strip between the knurl wheel and the chuck or collet. Get it running true, then go for a tool post grinder or a hand grinder clamped on the compound.

Mr Fixit
03-09-2017, 09:54 PM
MattiJ,

Thanks for posting. Now I have another tool to make! In a box from the lathe I purchased there were cutters for this but I didn't know how they would be used, now I know how and will be doing so as soon as I get the tool made.
One question, how is this different than a 2 wheel pressure cutter in terms of load on the spindle and materials being knurled?
Look forward to any responses.

TX
Mr fixit for the family
Chris :)

BCRider
03-10-2017, 12:21 AM
Getting a STRAIGHT knurl turned out to be LOT more difficult than making a diamond knurl.....

That's because you were trying to make them so long. The only time I want a straight knurl is for short knobs that I turn to tighten where I want the most grip for turning only. Plus short lengths of straight knurl on small knobs just look "right" to me. On anything as long or longer than it is round I'd much rather have diamond knurling.

MattiJ
03-10-2017, 12:52 AM
You want a sharp corner as distinct from the chamfered corner you'd use for bump knurling. How you sharpen depends on the equipment at hand. If you have a tool and cutter grinder you probably know how to sharpen jobs that come up and don't need advice. If you have only a lathe and small stuff, hold it in the chuck or a collet, preferably with a copper or aluminum strip between the knurl wheel and the chuck or collet. Get it running true, then go for a tool post grinder or a hand grinder clamped on the compound.

I turned end of a scraptanium bar to slight press fit for the hole in the wheel, pressed the wheel on the shaft and gave couple of whacks to get the face running true. After that I clamped angle grinder firmly to my hands ;) and proceeded with grinding. Keep the lathe running on maximum speed and you have pretty good changes to get reasonably flat result. slightly concave sharpening is actually advantage at this point, as I finished the sharpening on diamond stone and grinding paste.

After angle grinder and second one after final sharpening: (yes, its a bit overkill)

http://i.imgur.com/zQanJj7.jpg
http://i.imgur.com/459RGdC.jpg

Sharpening setup with solid-state water cooling:

http://i.imgur.com/4Opsnnt.jpg?1

Mcgyver
03-10-2017, 07:18 AM
you can get the wheels with no corner chamfer.....they will pretty much cut right out of the package. Surface grinder is how i've sharpened them.

MattiJ
03-10-2017, 07:50 AM
you can get the wheels with no corner chamfer.....they will pretty much cut right out of the package. Surface grinder is how i've sharpened them.

Yep, Zeus and Quick make actual cutting wheels, but I had these at hand and cutting wheels cost money (40-50 usd per piece) so...

Ian B
03-10-2017, 08:30 AM
Hi Matti,

From the photo of the cutter on the pages of text, that's a very nice Finnish you've got there!

(sorry - couldn't resist - running for cover...)

Ian

Mcgyver
03-10-2017, 09:00 AM
Yep, Zeus and Quick make actual cutting wheels, but I had these at hand and cutting wheels cost money (40-50 usd per piece) so...

always good to use whats on hand. The ones I was thinking of were <$10 from KBC. They had the straight side and chamfer listed in their catalogue.....their new online system is a nightmare, pictures are not accurate and descriptions brief, so its hard to tell if they still carry them. I can't pinpoint why I think this, but they didn't seem like they were presented as cut knurling wheels which iir were separate and expensive....they were just in with the regular wheels but without the chamfer.

pinstripe
03-10-2017, 11:05 AM
One question, how is this different than a 2 wheel pressure cutter in terms of load on the spindle and materials being knurled?

I think MattiJ missed your question. Cut knurls like this one put very little pressure on the spindle and material because they remove (cut) the material. Traditional knurling tools deform the material.

If your "2 wheel pressure cutter" is the straddle/scissor type that has the wheels on opposing sides of the work, then it won't put much pressure on the machine either because the knurling tool takes the pressure. Bump knurls that you have to push hard against the work with the cross slide are the ones that put the most pressure on the spindle.

MattiJ
03-10-2017, 11:40 AM
I think MattiJ missed your question. Cut knurls like this one put very little pressure on the spindle and material because they remove (cut) the material. Traditional knurling tools deform the material.

If your "2 wheel pressure cutter" is the straddle/scissor type that has the wheels on opposing sides of the work, then it won't put much pressure on the machine either because the knurling tool takes the pressure. Bump knurls that you have to push hard against the work with the cross slide are the ones that put the most pressure on the spindle.
Straddle type bump knurler and cut knurler are both easy for the machine.
Cut type knurler probably works with wider range of materials and also on quite thin walled parts.
The knurled tube in my photo has 1.5mm or so wall thickness.
Anyting from aluminium to semi-hard 416R stainless or crmo is workable with cut knurler, Im not so sure about bump knurling tools.

mattthemuppet
03-10-2017, 12:48 PM
I like the solid state cooling :)

Another thing from what I've read about cut vs. bump knurling is that the OD of the piece with cut knurling stays the same (material is removed) whereas with bump knurling it's increased (material being displaced outwards). Both would have their uses.

MattiJ
03-10-2017, 12:53 PM
I like the solid state cooling :)

Another thing from what I've read about cut vs. bump knurling is that the OD of the piece with cut knurling stays the same (material is removed) whereas with bump knurling it's increased (material being displaced outwards). Both would have their uses.

Loose bearing fits and shafts turned under size :rolleyes: is one thing where I still use bump knurling.

MattiJ
03-12-2017, 02:00 PM
Nice. What process did you use to blue/oxidize the part?

Today was nice sunny day so I decided to try homebrew parkerizing:
http://i.imgur.com/kbiE2uJ.jpg