Some beginner questions regarding knurling tools

Hi guys, sorry for another thread. There is so much I don't know, yet trying to get my head round, despite searching for the answers myself.

So I am looking for a knurling tool for my Cowells ME90, The manufacturer sells their own single wheel type with 6mm shank that fit their tool holders.

I have also seen these double wheel types on eBay that I thought might be a bit better and cheaper, but they have a 10mm shank which is too big for the tool holders I own.

Do I buy that and try file the shank down a few mm? (if my files can handle that type of steel?)

Buy a tool holder that accepts slightly larger tooling? If I can I even do that, are all the dovetails on those tool posts universal and interchangeable?

Just buy a single wheel type from Cowells?

or something else?

Not really in a position to make my own just yet which I assume will be a good option down the road at some point when I have more experience and tools.

Thanks

Edited By Steve Sherlock on 06/08/2018 15:29:38

Edited By Steve Sherlock on 06/08/2018 15:30:30

You may find that a small lathe with a small tool-holder is not up to the job of knurling steel. Light alloy, yes, brass, yes, but even then only with a narrow knurl and with patience.

Cheers, Tim

Thanks Guys,

I'm only working with brass and ally. I bought the lathe predominantly to make control knobs so would really love a knurling tool of some sort. I should add that I would probably only be using fine straight knurls any way.

With care I think one of the scissor type knurlers may work on your Lathe provided you can get one to fit your tool post. I made one to suit my lathe.

How about this.

**LINK**

It says: “Shank Size is 10 mm x 10 mm x 50 mm Long. This could easily be removed / modified if you needed a smaller shank”

This one claims to fit a Unimat so should work on the Cowells. I would not even try a single wheel knurl on a cowells.

Thanks Vic that's actually the one I linked to initially, but just realised the link wasn't working, Will I be able to bring that down with a hand file?

Thanks John, Seems we are all finding the same one!

You may be able to file it Steve but why not give us your general location, someone on here local to you may be able to mill it down for you.

Thanks Vic, I'm in London.

On my South Bend 10K I can use bump type knurls without damaging the machine. For smaller machines I would definitely choose the clamp (scissor) type knurls as shown in several of the posts.

For a straight "knurl" on brass you don't even need a knurling tool. Just mount a Vee shaped tool on it's side and traverse along the work. Simple gear on the spindle to index. Top of this lubricator was done in a similar way.

That Looks Great Jason I shall definitely like to try that. When you say a simple gear on the spindle to index please would you mind elaborating on that? or if you could link to a picture maybe that would be great so I can visualise it.

Does it go behind the chuck, like a division plate? then something I'm guessing gets fastened somewhere else to index to those teeth?

I went an ordered a scissor type knurled anyway for the sake of £14 and after realising the tool shaft is removable so I can just unscrew and take my angle grinder to it in a pinch.

Edited By Steve Sherlock on 06/08/2018 19:46:18

You should be able to use the large gear on the left of your spindle under the cover, a simple detent of some form to engage between two teeth will allow you to divide work into quite a few numbers

As sujested by Stan Bray in his book "Introducing The Lathe", I made this knurling tool, it's rough, put together in about an hour, it consists of a bit of scrap steel about 3/8"/10 mm square by 3"/75 mm long with a fork in the end, cut wit a hacksaw. The wheel is from a disposable lighter, this is fitted with a bronze bush, the spindle is a needle roller. It produces a fine, straight knurl, not requiring a great amount of pressure.

Ian S C

F W I W, my preference is for the clamp type knurling tool.

If you cannot find a set of drawings, or a tool, to suit your lathe, how about making one at a reduced scale?

Perhaps Hemingway would sell you a set of drawings that you could "downsize" for your needs?

Howard

Ok guys, I went with one of the scissor types. Had a little play with it today....

Now, After everything I have gleamed from the subject of knurling, I wasn't expecting things things to go smoothly and I was correct. Trouble is I seem to get knurls on the edges and not in the middle, like rail tracks.

I know there are other problems on there such as double lines etc, but been trying to save on wasting stock so using the bar more than once to practice on to see if I can get it to cut in the centre to no avail.

I tried changing the wheels from diamond to straight. Tried the bar stock rough, then tried after turning it to size.

tried with and without cutting oil. Clamping directly on centre and a little off centre. clamping down quickly to gain a bite. All to avail.. Any ideas where I might be going wrong, Do a pair of 'rail tracks' with no knurl in the middle suggest I am doing something obviously wrong?

The first thing I would do with a small lathe is to put it into back gear, you will need lots of torque. My usual technique with a scissor knurl is to start with only a third of the tool width clamping on the job. I introduce the tool to the job and adjust the wheels so that they are finger tight on the diameter of the job. I then withdraw the tool and tighten the tool by about a quarter turn. Switch on the lathe and then advance the tool with the cross slide. This should produce a good pattern. Once the pattern is set then the tool can be advanced towards the headstock with the leadscrew.

HTH,

Rod

Start at one end, with the knurls just overlapping the work. Once they've started to form a good depth of knurl you can move the knurling tool along the rest of the knurl. Trying to form the knurl full width will probably require more force than the tool can provide, unless you have a friendly gorilla in residence.

Andrew