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Knurling Tool

naijin

Active Member
Active Member
#1
I am thinking of making a knurling tool for my lathe..... any one out there who made one, or have any ideas or plans, and wishing to share them I would greatly appreciate it, thanking all in advance....:))
 

basalt

Active Member
Active Member
#4
I am thinking of making a knurling tool for my lathe..... any one out there who made one, or have any ideas or plans, and wishing to share them I would greatly appreciate it, thanking all in advance....:))[/QUOTE

I made this one, I milled a hex on the knurled part so I could apply extra pressure.

KNURLING.jpg
 

GadgetBuilder

Active User
Active Member
#7
I recently made a cut knurler; used to make diamond knurls rather than straight knurls. It takes a little more fiddling to set up than a pressure knurler but puts less strain on the lathe and makes a nice knurl in one pass. It uses straight knurl wheels with a sharp (not chamfered) edge to produce diamond knurling. It cuts the knurl so the diameter of the work doesn't increase - if you need to expand the diameter, as I sometimes do with a fine straight knurl for a press fit, use a pressure (aka bump or clamp) knurler. So, straight knurl wheels can produce diamond or straight knurling, depending on the type of knurler used.
Cut_Knurler_0S.jpg

I made a clamp knurler previously and this cut knurler was easier to make. Cut knurlers are generally more expensive than pressure knurlers so they're not as common in home shops.
More info here: http://www.gadgetbuilder.com/Cut_Knurler.html

John

Cut_Knurler_0S.jpg
 

MikeWi

Active User
Active Member
#8
I read your web article and the attached links. Looks really interesting, but I can't understand why it needs less pressure. Can you elaborate there? Does this also mean that you would not need a follower rest when using this?
 

GadgetBuilder

Active User
Active Member
#9
Pressure knurling exerts enormous pressure to extrude the material, that's why clamp knurlers are favored on small lathes. A cut knurler cuts the material, a little on each revolution, so there is relatively little pressure involved - just enough to keep the knurl fully engaged so it cuts. I run the work at low RPM and feed slowly slowly; it is possible to knurl at several hundred RPM and feed much faster but this would likely need flood coolant. A cut knurler can knurl a fairly thin tube, one which would be crushed by a pressure knurler.

There is some pressure involved so on thin work you might need something to keep it from deflecting. I knurled some 0.300 steel extended a couple inches from the chuck without difficulty, something that couldn't be done with a bump knurler but could be done with a clamp knurler.
 

naijin

Active Member
Active Member
#11
Thanks to everyone, there a lot of good ideas and photos out there, I am sure I will be able to use some of them to build my project, when completed I will post a photo.
Regards
Nick
 

Frank Ford

Active User
Active Member
#12
I use the scissor style knurling tool and I find that it takes a lot of pressure on the screw to make a good impression. To avoid that issue, I simply set the tool up so that it bears nicely top and bottom of the work, then retract the cross slide, tighten the tool and run the cross slide in to do my knurling. Then, I get tremendous pressure as the knurls approach center. The knurls don't actually have to reach the center line, and they work perfectly with very little strain on the lathe headstock or any other part of the lathe.
 

Tony Wells

Former Vice President
Staff member
Administrator
#13
That's the proper way to use a scissor tool, Frank. The knurling pressure is on the scissor and very little on the cross slide screw. Otherwise it's the same as a bump knurler.
 

clevinski

Active User
Active Member
#14
I use the scissor style knurling tool and I find that it takes a lot of pressure on the screw to make a good impression. To avoid that issue, I simply set the tool up so that it bears nicely top and bottom of the work, then retract the cross slide, tighten the tool and run the cross slide in to do my knurling. Then, I get tremendous pressure as the knurls approach center. The knurls don't actually have to reach the center line, and they work perfectly with very little strain on the lathe headstock or any other part of the lathe.
I guess I don't understand. This sounds like it's being used as a bump knurling tool, which does put tremendous load on the cross-slide screw. What am I missing?
 

Tony Wells

Former Vice President
Staff member
Administrator
#15
You're missing that the adjustment it just smaller than the OD of the part being knurled. The pressure is through the pins the knurls ride on and the scissor pivots on. The rolls actually contact the work almost directly on center. The pressure is more like clamping the part than pushing into it.
 

clevinski

Active User
Active Member
#16
You're missing that the adjustment it just smaller than the OD of the part being knurled. The pressure is through the pins the knurls ride on and the scissor pivots on. The rolls actually contact the work almost directly on center. The pressure is more like clamping the part than pushing into it.
Hi, Tony,

I understood what you've described; what I didn't understand was the "then, I get tremendous pressure as the knurls approach center". I guess my confusion was that I thought that he meant tremendous pressure on the cross-slide lead screw. Rereading it, I now realize he probably means the tremendous pressure between the knurls.

Thanks for the explanation...
 

clevinski

Active User
Active Member
#17
Hi,

Since I just received my scissor-type knurling tool via UPS today, I wanted to make up a convenient spreadsheet of exact diameters for various nominal (starting) material diameters for various knurl pitches. I've attached it below; maybe it will be of help to someone. You should be able to copy the formulas to add other nominal material diameters and knurl pitches. Just be sure to place the knurl pitch in row 8 of any new columns, with the two-digit number of knurls per inch as the first two characters. The spreadsheet looks up the pitch from that row and uses it to make the calculations.

Here is the file: View attachment Knurl Diameters.xls
 

mikey

Active User
H-M Supporter-Premium
#20
Here is my rendition of Chris Heapy's Clamp/straddle Knurler:

straddle knurler.jpg

They are not difficult to build but does require some thought and careful work. You can find the basic drawing here: http://www.astronomiainumbria.org/a...anica/easyweb.easynet.co.uk/_chrish/plans.htm Just adapt the size of the tool to your lathe and choose a mounting method. I suggest mounting directly to your carriage if you can. Knurling is a high-torque operation and all that torque is taken up by the tool; if it can move, it will. Mine is made to lock onto the Sherline carriage with a fairly large block; it is absolutely solid. Capacity is 0-2-1/2" so it works for me. This one is made from mild steel and uses 3/16" drill rod for the knurl axles so the cost, aside from the knurls themselves, was almost nothing but time.

One benefit of this design is that the arms are backed by a solid plate so there is very little deflection of the arms when axial running, which makes for a very consistent knurl.

If you haven't perused Chris' site before I suggest you take a look. It should be required reading for us hobby guys.

straddle knurler.jpg
 

WallyM3

Active Member
Active Member
#22
One more design idea. Once I got used to it, I could do fine and medium knurls in less than 5/8" stock in one pass. DSC_25760001.JPG DSC_25770001.JPG

Knurls are easily interchangeable.

DSC_25760001.JPG DSC_25770001.JPG
 

Splat

Active User
H-M Supporter-Premium
#23
Made from a Kant Twist clamp:

Kant-TwistKnurler_2.jpg
Necroposting this because I was just searching for DIY knurling tools and this is right along with what I was thinking about! Gerry, are you still using this and how's it working? Thanks.
 

4gsr

Global Moderator
Staff member
H-M Supporter-Premium
#24
Gerry R hasn't been seen since July 2014.

Maybe send him a PM and see if he answers..
 

Cadillac STS

Active User
H-M Supporter-Premium
#25
Knurlers can put significant pressure on the cross lead screw. I think a design that would place the knurler directly on the cross slide and jack up from there to the workpiece would solve that. Base with a screw mechanism keyed to a slot on the cross. Align the part, put a turn on the screw for pressure and switch on the power feed.
 

Okapi

Iron
Registered Member
#27
Hi, I'm only a small new member working alone in my rabbit burrow, but I make a lot of knurling and sometimes constructing specific tools fot the Tripan system as on this page : http://www.lecollectionneur.ch/po-tripan/
On a website page I've put some documentation about the Quick system : http://www.lecollectionneur.ch/documentation-pdf/
My knurling wheels used in the compression system are coming from a closed production enterprise but with standard metric measures as 6mm. axis for example, if you want i can make a picture of the various profile and dimensions wheels I conserved in a small collection
 

Uglydog

Active User
H-M Supporter-Premium
#29
...I make a lot of knurling and sometimes constructing specific tools fot the Tripan system as on this page : http://www.lecollectionneur.ch/po-tripan/
Okapi,
You made the knurls wheels?
Your work exceeds the O-Cool threshold!
Are you willing to tell us anything about how you make these?
If so, please do!
Wish I could afford to pay what you'd appropriately charge for those gorgeous knurls.

Daryl
MN