Knurling

I would like general advice please on how to knurl, having just purchased a caliper type tool with a diamond pattern for my S7. I understand the need to use slow speed and coolant but what I am not sure about is the number of passes to make.

One book talks about not cutting too deeply at the first pass and use a 10 thou cut, but if you want to make a deeper knurl am I correct in thinking the tool must be kept in contact with the work and not wound clear before increasing the cut ? Otherwise I cannot see how the tool engages exactly with the cut made in the first pass. Is it advisable to knurl with only 1 pass all the time ?

For what it's worth, I clamp about half the width of the knurls on the end of the stock, hard enough to make some impression, then start the lathe running and traverse the knurls along and back using the leadscrew handwheel, clamping up a bit more each time I get back to the half-engaged start point. After the first pass, I stop the lathe to see if the pattern looks right. As Gray says, sometimes the diameter of the stock is such that the knurls "double", producing a pattern twice as fine as I want. The only remedy for that seems to be to turm a few thou off the stock and try again.

If the first pass looks OK, I continue to and fro, clamping the knurls a bit deeper each time until the depth looks right. It's as well not to go too deep; this can result in sharp points on the pattern, making the finished job uncomfortable to grip.

Use plenty of lubrication. It does no harm to stop part-way though and brush off some of the debris. On my lathe at least, it seems best to angle the shank of the knurling tool 4 or 5 degrees towards the headstock, rather than having it exactly perpendicular to the work.

Andy

Alternatively you can calculate the required starting diameter, so that the risk of 'doubling' is greatly reduced. The knurled pattern is effectively a very fine gear. Therefore, to fit the 'teeth' neatly around the circumference of the work the circumference needs to be an integral multiple of the tooth pitch on the knurl.

As an example, I've just knurled the caps for some oilers on the connecting rods for my traction engines. The nominal OD of the cap was 11/16", ie, 0.6875". The knurl wheel I used was 1mm pitch. I reduced the starting OD to 0.677", which gives a circumference of 54.02mm. The knurled pattern appeared with no 'doubling' or other problems.

There is plenty of information on the calculations for form knurling in Machinery's Handbook.

Regards,

Andrew

One issue I have experienced with knurling is shifting of the toolpost. Knurling places much greater sideways pressure on the tool, and this can cause a shift unless you are prepared for it and make doubly sure everything is tight. I find a Gibraltar toolpopst is best.

My reading of this thread has been completely spoiled by the b****y adverts down the right hand side. Is anyone at MHS interested in making this s****y web forum software work with any semblance of normality? It's by a country mile the worst I use.

David

David, I never have your problem except where posts have long URLs posted. The right hand side is blank below the MHS ad.

David, I don't often find threads having this problem but this one does. What makes it more infuriating is that there is no way of viewing the hidden text. Zooming text size just zooms adverts as well.

Might be something to do with the pics in Graham's post.

Gary

Gary, see above, still not a problem using Firefox

Forum working fine on Win 7 & IE 9 Thanks for the info. on knurling, it's new to me too.

Regards Bear..

I know several people have said it works OK in Firefox - but I really don't see why I should change my browser (IE8, as it happens) just because some spotty youth doesn't know how to code a website!

David

Edited By David Littlewood on 06/11/2012 14:26:23

David have you tried clicking on Compatability view that solves it for most people,

Along the top of IE browser where you see the url there is what looks like a page ripped in half, click that and see if it helps. If I turn it off then I get the two photos side by side which makes the text frame too wide and it is hidden by adverts.

The problem would be helped if Gray did not insert the two images on the same line, hit return between posting images and they will come out one below the other

J

Edit comp view on

Comp view off

Edited By JasonB on 06/11/2012 14:37:58

David, I use XP and IE. Though hitting the compatibility button usually sorts things out, it didn't here. I think it may be because the two pics in Gray's post are side by side, rather than one above the other. I had to highlight the text in Andrew and Gray's messages, copy it and paste it into the reply box. Happily, I remembered to delete it before making my submission.

I entirely agree that knurling is not a gentle process, as it involves both cutting and displacing metal across the width of each of the wheels.

Andy

Hello everyone.

This is one of the manifestations of a relatively old problem, created by Microsoft (MS) which, with its strategy of market dominance, from inception of Internet Explorer (IE), never accepted subordination to the standards to which all other producers browsers do. The very existence of buttons with features - such as the compatibility button - are only just workarounds to not completely lose the boat (read market) of the WWW.
This workaround was imposed to Microsoft by all the people producing pages that respect the WWW Consortium standards (please refer to: ***LINK*** ) and don't buy the MS strategy.

To say that, in my house, the page in question is interpreted correctly by the browsers Firefox and Chrome on Windows but not by IE 7 (all on Windows XP).

There's also another sign on the quality (or lack of it...) of the IE: the great difference with respect to the elapsed time between the moment when reading of a page is triggered and the moment it is presented to the user.

Best regards
Dias Costa

Edited By dcosta on 06/11/2012 16:40:02

Jason,

Thanks for the suggestion, but I already had compatibility view on and the problem still exists; in fact, turning it off makes it much worse. Does seem though that I owe an apology to spotty youths as the explanation suggests it is Microsoft's fault. I should have known!

David

I have always had fair results knurling with a scissor type tool and all the good advice above is relevant. I must admit to never calculating knurl/work diameter and it always seems to come out ok in the end.

My view is also being covered with adverts using IE8, comp view on or off makes no difference.

Tony

Thanks for all the comments, some good advice, I hadn't thought about looking in Machinery's, I see there is a lot there.

I am applying pressure above and below the stock, my knurling tool does have a graduated adjusting screw so I can set the depth cut, but I think doing by feel and inspection is probably the best way. I will raid the scrap box and start practicing.

For what it's worth I use the same method as Andyf, except I keep going until I get a nice point on the knurls!

I have only had the cursed 'double knurl' when I have started with insufficient pressure - I think that if the knurl is deep enough then on the second time around they are more likely to pick up the pattern.

Neil

My 4yr old desktop Acer uses XP Pro and is showing posts covered by the adverts on this thread. Even using compatability view doesn`t cure the problem. However, if I call up same on my 3G mobile, eveything is displayed correctly. This leads me to believe that the prob. is likely to be connected with running "obsolete" software. The mob. is running a much more up to date software. B4 anyone says they cannot afford a new mob. that is internet-enabled, mine is a fairly new model - Samsung GS11, FREE on contract. Low cost monthly rental but with a low data allowance. Use it sparingly and it lasts the month till a new allowance received. I am using 02 which obligingly sends me a text if I use allowance B4 end of month - not paid huge xtra cost yet! Just recommending this as purely a very satisfied customer. Cost? well how much do you easte on smokes/booze? & nothing to show for it but a good cough/hangover!

A good informative post , Compleatly spoiled ! wadda lash up!,

Viewing problem with IE8, try moving up to IE9, it's free.You can restore back to IE8, if you set a restore date on your PC. IE9 has certainly worked well on XP for me. Now I'm on Win 7.

Regards Bear..