knurling

[firebird]

Hi

I haven't done a lot of knurling but what bit I have done seems to put quite a strain on the lathe when pushing the knurl into the work piece. The knurling tool I have is the two wheel sort which has a self aligning swivel head. Firstly would a clamp type knurl be better. Secondly if one wanted to knurl say 75mm to make a handle grip do you wind the saddle up and down the workpiece or do you withdraw the knurl, wind the saddle down then push the knurl in again.

Cheers

Rich

 

[Jasonb]

The clamp type puts less strain on the lathe.

Use power feed to run the tool along the work, slow speed on the spindle and don't expect to do it in one pass.

Jason

 

[Tin Falcon]

do you wind the saddle up and down the workpiece or do you withdraw the knurl, wind the saddle down then push the knurl in again.

Once the knurl is engaged keep it engaged. If you withdraw it it will be difficult at best to get it back on track kind of like threading. Use lots of cutting oil and stiff stainless steel brush to keep things clean you are actually swaging the metal rather than cutting but little chips are formed that you want out of the way.
And to reiterate a clamp or scissor style is better.
Tin

 

[firebird]

Hi

With the clamp type of knurl do you tighten the clamp onto the workpiece while it is turning. Am i right in assuming you run the lathe at a slow speed.

Cheers

Rich

 

[Tin Falcon]

yes that is how the knurling tool is advanced into the work. and yes slow speed.

I have done plunge knurling with a scissor type as well where the knurl is pre-set and the knurl is fed into the work with the cross slide then retracted. the knurling is done in one shot. This was on a large industrial machine not a small hobby lathe. and the knurl was not fed longitudinally.
Tin

 

[itowbig]

i bought one of those but then i did not like it so i made a scisor type and i love it but next time ill make it smaller

thisn one works real good

 

[tmuir]

i bought one of those but then i did not like it so i made a scisor type and i love it but next time ill

I bought one of those scissor types but it has a lot of slop left to right, so much so that the knurling wheels end up on an angle to the bar being knurled.
After a bit of effort I got ok results but would I get better results ditching this badly made one and buying or making a better quality one?

Nice job there too.

 

[kvom]

What I was taught at school:

1) Adjust the height by advancing the bit slowly and ensuring that both wheels start turning at the same time.

2) Try to start the knurl in a portion that will be cut or turned off later.

3) Cut the first part of the knurl with no carriage feed to verify the pattern.

4) Then slow RPM and slow feed with lots of cutting oil.

5) For a sharper knurl do a spring cut in reverse (without retracting the tool).

 

[GrahamC]

I struggled for the longest time getting my knurling to the point that I was happy with it.

I had first tried plunge knurling with a tool like you describe with very poor results. I then bought one the scissor types and started to get good results. However, the fit of the tools bits and pieces was not that great and I spent more time rebuilding the tool than using it.

I did some research and since I had an Aloris type AXA QCTP I took the plunge and bought an Aloris AXA no 19 knurling tool holder. You can see a picture here:

http://www.toolguys.com/product/aloris-no-19-adjustable-knurling-tool-holder-series-cxa-cx

This is a scissor type knurling tool in the form of an Aloris tool holder. Yes it is pricey (check eBay you can find reasonably priced ones there) but it works better than anything else I tried, it is of exceptional quality and I know will last my life time.

One tip that someone passed on to me many years ago that you might find helps - start the knurl with only about 1/4 or the knurling wheel on the part, once you have it tracking and producing the knurl you want then start moving it further down the part.

cheers, Graham in Ottawa Canada

 

[Maryak]

Hi All,

My take on knurling.

Since my apprenticeship I have always knurled with the knurling tool at a slight angle to the job, definitely not plunged in parallel. Slow speed and feed. This method allows the depth to be finely controlled and the starting load is small being increased gradually by the taper given to the rollers. The tailstock should be used wherever possible to support the free end of the part.

It has worked well for me with both single and diamond pattern knurls although I have never used a scissor type knurl, 2 roller diamond pattern knurls were of the pivot type.

I hope this helps. ??? ??? ???

Best Regards
Bob

 

[firebird]

Hi

Thanks to all who replied.

Cheers

Rich