MadModder
The Shop => Tools => Topic started by: awemawson on September 30, 2013, 09:12:55 AM
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Knurling tools come in various flavours. There are the single and double wheel types that are just pressed hard into the work and load the lathe bearings and cross feed screw horribly. There are the clamp types that squash the two knurls into the work so that the force is taken by the tool and not the lathe. Then apparently there is the 'cutting knurling tool'
Seems that this variety tilts the knurl axis so that the leading edge is ahead of the trailing edge as far as penetration into the work is concerned, and rather than plasticaly (sp.) deforming the work it actually cuts it. Several Youtube advertising videos but very light on technical details.
Anyone familiar with these knurling tools and can enlighten me ?
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The cut knurling tool is far superior to any of the 'force in' knurling. Tends to produce excellent knurls but it does have one draw back they are oh' so expensive.
It is probably the cost that tends to put it out of reach for the home workshop.
:beer:
DaveH
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Dave yes - that's why I'm trying to get as much gen as possible and make one :ddb: After all the actual knurls themselves are available as spares so it's only the body at issue. I'm sure the big makers won't mind little old me copying their tooling, after all imitation is the best form of flattery :clap:
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I have never made one, only used and abused them :lol:
They also take a bit of setting up so for 1 off's can be a bit off putting. Your lathe needs to be rigid and I have only used them with flood coolant, may be they can be used with out flood coolant that I don't know.
:beer:
DaveH
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This'll be for the Traub, so with an 18 kW main spindle and weighing over 4 tons with 320 litres of flood cooling when full I don't expect those to be issues :lol:
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Nope, that will not be an issue :lol:
:beer:
DaveH
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I also think it would be a very nice tool to make, certainty a lot of fun and satisfaction in making one :thumbup:
:beer:
DaveH
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Hello, There was an excellent series of build articles in Home Shop Machinist magazine some time ago on a cut knurling tool. Got started on it, but not finished. Regards, Earl
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Thanks Earl - are they available on line as I haven't seen a copy in many a year this side of the pond
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Anyone familiar with these knurling tools and can enlighten me ?
Yes..........
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I have a copy of a hardinge one - it works very well when it works but, is it a real PITA to set up.
Getting to two wheels to bite exactly the right amount requires several adjustments - angle, centring , etc.
There are expensive versions that speed the adjustments but all require rehearsal passes so are better suited to production then the homeworkshop. IMHO.
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Anyone familiar with these knurling tools and can enlighten me ?
Yes..........
Is that once you have read Daves article in MEW? :D
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Dave based it on one I have, many emails fasted both ways before that article was written.
I have a Quick model and they are, used to do 2" stainless bar 700 rpm, 1500mm long at ****thatwasfast mm/min
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Will see what i can find, will take a few days. Regards, Earl
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I found these by accident and remembered this thread..
Sorry for cross posting forums and sites..
http://www.practicalmachinist.com/vb/general/cut-knurling-how-done-138092/index2.html
http://www.gadgetbuilder.com/Cut_Knurler.html
But he shows a tool that can be made using straight knurling wheels to produce a diamond pattern by cutting with them instead of shoving the material around.
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Thanks Neo, I'll follow that up
Cheers
Andrew
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Thanks for the links Neo. I wonder how much those straight knurl wheels cost?
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I picked up a pir from rdgtools for like 15£ a while back.. been laying in a drawer since.
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If you'd like to turn them into negotiable currency say the word :ddb:
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ooh im gonna use em someday.. i have like 4 large projects ongoing though.
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Seems like all the replies refer to knurling as in straight knurls on lengths of round. Above tools are limited to just that.
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My understanding is that the two knurls are 'straight' ones, but they are angled to cut a helix which if set up right meet at 90 degrees forming a diamond knurl.
To cut a 'straight' knurl, an angled cut wheel is used in a single wheel holder, again set at an angle to the holder.
..... but what do I know .... I was the one asking questions originally, it's only what I've learnt in the last few days :wave:
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Correct.
The angle of the twist also determines the diameter that is cut.
If you don't get it right they don't cross at 45 degrees but in many cases it's not noticable.
The knurls wheel really need to be recessed with top hatted axles so you can get as close as possible to shoulders.
looking for a link to the wheels but gotta post this as need to shut down, relad the latest flash and reboot.
I have to do this about 3 times a week Adobe like Norton wants listing as a virus.
Come back to edit in a bit.
Page 388 in the J&L catalogue, bottom of the page are two side knurling tools, these are the wheeels you want.
The wheels are on page 389 down the bottom, type 5.
There are some TiN coated ones for pig farmers with deep pockets on a previous page.
http://www.mscdirect.co.uk/CGI/INPDFF?PMCTLG=00&PMPAGE=387&PMITEM=BMK-42080M
No idea what they are like, us mere mortals can't afford these.
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Andrew ,
There was one described in "The Home Shop Machinist" March/April 2010 edition
cheers
Mark
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See what you mean John from £43 each plus vat.
Fairly local to me I only buy whats on offer from there which often is still dearer than shopping around. Used to have some good sell offs.
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Hi awe, The HSM series was in 4 parts in M/A, M/J, J/A, & S/O 2010 issues. Back issues are available: https://secure.villagepress.com/store/items/list/group/292/page/2 Don't know if digital or reprints are available. Village Press, the publisher can be reached here: service@villagepress.com.
The knurls on this tool are geared together so it should be easier to adjust for differing diameters once set to center height. Regards, Earl
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Earl, many thanks for taking the trouble to find that - much appreciated.
There seem to be all sorts of designs out there, varying considerably in their ease of use and versatility. I certainly take your point John (S) that recessed knurls allowing you to work to a shoulder are probably the best concept. And for ease of adjustment, to have the knurl wheel mountings geared or otherwise linked makes a lot of sense.
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I came across what looks like quite a nice implementation called the Boni cut knurler
http://www.bluechiptooling.co.uk/edit/files/brochures/Knurling.pdf
It gives the possibility of not only moving both wheels at the same time to adjust for stock diameter, it also allows both to be slid up and down together to adjust for centre height.
Pity there are so many zeros following the price :(
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What is the advantage of a cut knurl?
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Doesn't ruin your lathe spindle bearings by using enormous pressure like a push knurler, and cuts a better defined knurl. Mainly used on CNC lathes but equally applicable to manual ones
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I use scissor type knurling tools.
I calculate the correct diameter, most of the time.
Only have manual machines, I can see the
advantage for cnc production.
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Page 388 in the J&L catalogue, bottom of the page are two side knurling tools, these are the wheeels you want.
The wheels are on page 389 down the bottom, type 5.
http://www.mscdirect.co.uk/CGI/INPDFF?PMCTLG=00&PMPAGE=387&PMITEM=BMK-42080M
No idea what they are like, us mere mortals can't afford these.
I think I may have a pair of these. I bought them cheap at a show. They are a pair of plain German made Knurls with no champer on the corners. Now, where did I put them ...
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You can just grind off the chamfer of a cheap knurl wheel.
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Excellent! Guess mine will work fine then.
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How can you tell what wheel is a cut knurler vs as deforming knurler? I looked at the catalogue John linked to, found the right knurl wheels (I think), and they look exactly like every other knurl.... to my eyes anyway?
What am I missing?
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The leading face is ground so that the exposed end of the knurl shape is sharp, whereas most squash type knurls have a bit of a bevel.
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I have ordered a couple of straight cutting knurling wheels from this site: http://www.uxcell.com/search.php?keywords=knurling&sort=&page=1&view= .The prices are included shipping so I will try to make a cutknurler as a future project.
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Here's a thread on the HSM article,
http://bbs.homeshopmachinist.net/threads/39940-Cut-Knurling-tool-in-March-April-issue?highlight=cut+knurl
Jim
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Good link Jim I had a brisk browse to page 3 then noticed this piccy http://i461.photobucket.com/albums/qq336/gr8lifeLV/Cut%20Knurling%20Tool/100_0417.jpg
Is it me or is that knurling very poor.
Not only is the knurl not even, its got a flat and the pattern is irregular.
I can see the point of using these tools for long lengths, suppose it depends what your standards are and what its for, I wouldnt let that go.
Either its turned down after or the cut knurl has dimensionally gained like a conventional tool. I usually get a gain of 0.4 to 0.5mm on a coarse knurl, double that on round.