Thread Milling

Sorry, I didn't want it to go off on a tangent but WOW, I like the look of that code. I've never hear of the DOS system before, what happened to it?

On the LinuxCNC link I gave earlier, it seems like it too can do a 'one liner', by specifying the number of turns after the 'P' option. Nice, if you can get your CAM system to make the right code.

Martin.

As for the Heidenhain code the only bit I understand, or like, is the IPA

IPA on a Heidehain control = Incremental Polar Angle

Heidenhain plain language dialogue programming is much more user-friendly than ISO for programming at the machine.

Nigel B.

IPA = India Pale Ale

I've done a quick air cut this evening, on an internal thread of 1mm pitch and 100mm diameter. With a feedrate of 100mm/min the cut cut took about 3 minutes. Ergo, the feedrate seems to be applied using the distance around the spiral, not that on the Z axis.

Regards,

Andrew

These are somewhat surprising tools. Is there really no UK source for them?

Regards,

Richard.

Why? Feel free to add a link to a UK source.

Andrew

You can also use a tap with all but one flute ground off.

One pitch cuts all if it fits into the hole.

Got a Cromwell catalogue today that lists Thread Milling cutters, metric and pipe and other British threads. The prices , well, they are special!

Several bargains also appear in the milling cutter part.

I am not associated with Cromwell.

Clive

Hi Clive,

How do you get hold of a paper Cromwell catalogue (I can get one through work if they are trade only).

Neil

>edit< Cancel that I just saw the big picture of a catalogue with 'request a catalogue' written by it!

Edited By Stub Mandrel on 02/07/2013 20:37:01

Neil, you could have had mine before I dumped it.

Never seen anything in there I can't buy cheaper or better from other suppliers.

Just been looking at broaches and they don't do the one I want but take say an 8mm keyway broach.

From Cromwell it's £244.81 and you need to push this thru 4 times with 3 added shims to reach depth.

They do a cheaper on at £119.48 but this one takes 6 passes to do the same job

J&L sell DuMont broaches which only require 3 passes [ big difference if you have a stick of gears to do ] for £79.50

No contest.

To get back to thread milling if you are doing an OD thread or biggish infernal thread you can use a Coventry die insert in a holder.

Same holder can be used to screwcut infernal threads on the lathe.

There's cheap and there's clever.

Luckily I have a Cromwell outlet very near my workplace and call in about once a month just to pick up the monthly cut price catalogue. They are selling 2 flute and 3 flute and 4 flute center cutting Carbide milling cutters in a set of 6 at a time for £29 or so. Rippa cutters also are reasonable in sets of 3. It takes me a couple of hours to read through and digest the contents and find the bargains. Agreed there are some expensive tooling in the catalogue but it is all named tooling like Ghuring and Mitsubishi. Just now and again I catch sight of bargains that are worth looking at further.

Clive

Interesting John. Not good for the tiny sizes I need, but looks good.

Is there any problem with the thread form when using thread milling with rapid helix threads?

The sort of thing I want to try to do is M13.5 x 3, triple start. In theory it's simple on my lathe. In practice, since I'm missing one of the gears for 3mm threading, it's less easy. Warco didn't supply the 63 tooth gear when I got it, and supplied me with a third 27 tooth instead. However, as it was 8 years before I noticed , I can't complain . Also, acrylic seems to be less easy than metals to thread & get a reasonable finish - you seem to have to go at either almost no speed or very, very high speed. I suspect thread milling will be more successful as the cutter speed will be very high on a tiny cutter.

Regards,

Richard

Richard,

Can't see a problem with that but you would need a single point tool as against the multi tools.

Pick up on the second pass will be interesting in that you will need to start 120 degrees away and 1/P down

Dont know what Warco lathe you have but ARC are selling some 63t gears to go with Neil's article in MEW 204

These are 1 Mod and have on OD of 65 mm to give you an idea of size.

Sent from my iPram

Late entry to the discussion I know but...

I've used the cutters shown by the original poster for a few years, they work very well and I've done smallish threads, twin start M6, and large threads, M16 + using two different sizes of cutter. All have been external threads though.

All my threads were coded using the NF wizard available in Mach3.

Steve

Steve: Thanks for the information; it's always useful to know that some-one has successfully used the tools. At least if I foul it up I'll know it's a defective operator, not the tooling. What sort of speeds and feeds did you use? Does the NF wizard come with Mach3 or is it a purchased add-on?

Regards,

Andrew

The NF wizards are included but don't work until you purchase a code. Not sure if there isn't a thread milling wizard in the normal wizards.

Just checked and there is a thread milling option in the normal wizards. I seem to remember that the NF one worked better though.

I think I just used a sensible speed, probably 75 - 100 mm/min but I can't remember. I tend to use slower speeds and work up but as I tend to do one offs I forget for next time

Steve

Careful with the thread milling wizards in mach there are bugs.

I have been repeatedly reporting them for about 5 or 6 years with no success. I'm told they work OK but even when i sent the files they are ignored.

Problem is Ron Ginger who is responsible for the wizards is American and only uses imperial. However like most Americans who think that Neil Armstrong was the first American to go abroad they can't accept that the rest of the world use metric.

Try this in the wizards.

Select metric, conventional, multi pitched cutter, right hand, inside.

Then do preview.

Always wanted to thread mill a D shaped hole

Imperial works fine. However when mach 4 comes out you won't even be able to do this as multi pitched cutters have been left out.

And I though Mach 4 was going to be aimed at industry ??

Edited By John Stevenson on 28/08/2013 21:41:32

Ahh, the mythical self locking thread is finally found!

Can you input the metric measurements, pretending they are in Imperial and use a scaling factor of 25.4 for the output?

Neil