Thread: Knurler for small hobby lathe

What's a good knurler for a small hobby lathe?

At the moment I'm using (successfully) the knurler below -



But.....someone told me that if I keep using it, I run the risk of stuffing up the bearings in the headstock of the small lathe (AL-60).


What are these knurlers like ???? -



Is it hard to get enough oomph out of them to knurl successfully?? (90% of my knurling is on brass)



P.S. Forgive me as well if I'm annoying anyone with all the threads asking questions all the time. I'm just really enjoying myself with 're-discovering' model engineering and fooling around again with machinery and tools and the like and am keen to learn and hence....ask questions.

Nothing wrong with the sqeeze knurl, and it's recommended for light lathes, and has adequate oomph.
Maximum diameter is limited though.

Jordan

Jim,

On a piddly lathe a clamp(or a sissor)type knurler is in my opinion the way to go especially if you plan to tackle knurling steel. I have a home made clamp knurler and it works well enough on 4140. Good quality wheels help along with the means to provide a fair amount of leverage on the clamp. The knurled handwheel shown in your photo could be removed and replaced with a nut enabling a spanner to be used for additional leverage should you ever desire to knurl tougher stuff.

Bob.

If you are only knurling brass and having problems it sounds like your wheels are getting clogged.
I was taught to use a light oil for knurling but now I use flooding coolant and I blow the crap off the wheels every now and then with a compressor and my simple pressure knurler seems to work OK on brass/

Originally Posted by Anorak Bob

Jim,

On a piddly lathe a clamp(or a sissor)type knurler is in my opinion the way to go especially if you plan to tackle knurling steel. I have a home made clamp knurler and it works well enough on 4140. Good quality wheels help along with the means to provide a fair amount of leverage on the clamp. The knurled handwheel shown in your photo could be removed and replaced with a nut enabling a spanner to be used for additional leverage should you ever desire to knurl tougher stuff.

Bob.

G'day Bob, I was wondering if it was ok to put a nut on that, because I was thinking that its limited as is to how much finger pressure one can apply.

Originally Posted by BobL

If you are only knurling brass and having problems it sounds like your wheels are getting clogged.

No, not having a problem knurling brass. It's actually something that turns out real nice for me

What the worry was, the knurler I'm using. Someone told me that I'm putting a huge amount of stress on the spindle bearing of the lathe because the knurler is trying to push the piece of work away and out of alignment (I 'think' that's pretty close to what he said).

Jim no dumb questions unless its the one not asked and by asking this one you have also helped me out in doing so I also am new to machining with lots to learn from those with more experience.

So Jim Thanks for asking

Jim,

Here is a link to a photo of Bruce's clamp knurler with a nut. http://www.woodworkforums.com/f65/ne...ml#post1497368

And here is a photo of my home made version. The handle length has been adequate for the knurling I've done. http://www.woodworkforums.com/f65/no...ml#post1402076

A cheap ring spanner cut in half would work.

Bob.

Originally Posted by Anorak Bob

Jim,

Here is a link to a photo of Bruce's clamp knurler with a nut. http://www.woodworkforums.com/f65/ne...ml#post1497368


Bob.

There's no need for a nut.

The correct way to use a scissor knurl as I was taught is to tighten it down finger tight, back off the cross slide, tighten the knurl another 1/4 turn, and feed the cross slide /knurl back into the work.

You don't screw the bejezzus out of the knurl bolt.

Rob

Interesting thread I just bought a jones and shipman scissor knurler I haven't had a chance to have a play yet.

Originally Posted by Jim Ferrous

Someone told me that I'm putting a huge amount of stress on the spindle bearing of the lathe because the knurler is trying to push the piece of work away and out of alignment (I 'think' that's pretty close to what he said).

I have been told that, but not sure how true it is. However, thinking about it, lathes used to be plain bearing and I would imagine that if you pushed hard enough you could disrupt the oil film in the bearing and so have metal on metal contact. Wear and sloppy bearings follow. Lathes these days are usually roller bearing so the risk of damaging something in that way would be far less. I suppose on a (really) small lathe there is also a chance of damaging the spindle itself if you pushed too hard on it.
The other thing about a push knurl is support of the work - if you are trying to do a long knurl or a knurl away from the chuck there is a risk of bending the material. A clamp knurl eliminates the risk

Originally Posted by nearnexus

There's no need for a nut.

The correct way to use a scissor knurl as I was taught is to tighten it down finger tight, back off the cross slide, tighten the knurl another 1/4 turn, and feed the cross slide /knurl back into the work.

Haven't heard of doing it that way Rob - have to try it. I always have a have a problem working out how well the knurl has formed while cranking down the knob, so that may help. The 1/4 turn would be related to the pitch of the knurl and the gain of the screw so a bit of experimenting may be required.

Michael

Originally Posted by Michael G

I

Haven't heard of doing it that way Rob - have to try it. I always have a have a problem working out how well the knurl has formed while cranking down the knob, so that may help. The 1/4 turn would be related to the pitch of the knurl and the gain of the screw so a bit of experimenting may be required.

Michael

Ask yourself why they don't fit a nut to begin with.

It's not necessary.

The 1/4 of a turn is only a guide, I've gone 1/2 a turn for really deep impressions.

The stress at that setting on steel is huge. In low range the lathe is absolutely struggling.

There is a very good video on YouTube by a school metal work teacher showing how this method should be used for scissor knurl. Unfortunately I can't find it again.

Rob

Originally Posted by Jim Ferrous

What the worry was, the knurler I'm using. Someone told me that I'm putting a huge amount of stress on the spindle bearing of the lathe because the knurler is trying to push the piece of work away and out of alignment (I 'think' that's pretty close to what he said).

It is most certainly not a problem for the spindle bearings, these can easily handle the stress.

- It is the cross slide leadscrew and its bearings that suffers most, when using a simple "push-in" knurling tool on a light hobbylathe. With a scissor knurling tool, the stress to the cross slide are almost eliminated.

- After the cross slide leadscrew, the next thing to worry about when using a simple "push-in" knurling tool on a light hobbylathe is the headstock-to-bed alignment. With many light hobbylathes, the headstock does NOT sit on the vee of the bedways, but only on the flats. And on such lathes (especially the cheaper ones from Chinese origin), the headstock is rarely precision ground or scraped to the bedways. Paper shims are sometimes used to align horizontally, or small grub screws made from soft iron. With a simple "plunge" knurling tool the forces can be big enough there is a real risk of undoing the headstock alignment.

If doing lots of knurling and money does not matter, the best is not to use knurl forming tools at all, and get a real knurl cutting tool instead. Such as the Austrian "Quick" brand. These present one, or two (or sometimes three in a special TS chuck) swharp toothed knurling wheels at a workpiece diameter dependant angle in a special holder, and actually cut real chips instead of pressing and rolling metal dust. The results are sharp and inbelieveably "crisp" and regular knurling results, achieved with very little tool pressure. The downside is that even well worn used knurl cutting tools regularly fetch prices of $200++ on eBay, as there is a very big demand for these items. Chris

Originally Posted by cba_melbourne

It is most certainly not a problem for the spindle bearings, these can easily handle the stress.

- It is the cross slide leadscrew and its bearings that suffers most, when using a simple "push-in" knurling tool on a light hobbylathe. With a scissor knurling tool, the stress to the cross slide are almost eliminated.

- After the cross slide leadscrew, the next thing to worry about when using a simple "push-in" knurling tool on a light hobbylathe is the headstock-to-bed alignment. With many light hobbylathes, the headstock does NOT sit on the vee of the bedways, but only on the flats. And on such lathes (especially the cheaper ones from Chinese origin), the headstock is rarely precision ground or scraped to the bedways. Paper shims are sometimes used to align horizontally, or small grub screws made from soft iron. With a simple "plunge" knurling tool the forces can be big enough there is a real risk of undoing the headstock alignment.

If doing lots of knurling and money does not matter, the best is not to use knurl forming tools at all, and get a real knurl cutting tool instead. Such as the Austrian "Quick" brand. These present one, or two (or sometimes three in a special TS chuck) swharp toothed knurling wheels at a workpiece diameter dependant angle in a special holder, and actually cut real chips instead of pressing and rolling metal dust. The results are sharp and inbelieveably "crisp" and regular knurling results, achieved with very little tool pressure. The downside is that even well worn used knurl cutting tools regularly fetch prices of $200++ on eBay, as there is a very big demand for these items. Chris

Here you go Chris -

http://www.woodworkforums.com/f65/qu...7/#post1538533

I read in a book. Before applying the power , turn the chuck by hand and feed in the knurler and observe the knurl pattern to see if it is a nice clean pattern , this way you wont bugger up the job by having things out of alignment ......... Mike