Chipmaster Thread Cutting

[Piers037]

I am batching it this weekend (with 3 kids...) so I was able to slip out to the shed once they were all in bed and have another go at thread cutting.

this time I did not disengage the half nuts, used a smaller depth of cut and mixed up some cutting fluid to use.

the results where much better. I still have a bit of work to do to improve the surface finish of the thread (any pointers appreciated)but not to bad for my second attempt.

Thanks to everyone who posted replies and to Phil Steamwhisperer for his assistance.

Cheers

Piers

[Ueee]

Looks good Piers!

It looks like you got a little chatter on the last few cuts. I find once chatter starts when threading there is not much you can do, except ensure you cut on on the leading edge only. I'd say you took just a bit too much off with both edges. What speed did you use?

Cheers,
Ew

[achjimmy]

My father used to buy up the threaded dies from the coventry die heads used on automatic lathes. We used to braze them on to bars to make multi point cutting tools. Excellent on fine threads like that.

I always found flooding the job with cutting fluid produced best results with thread cutting too.

[morrisman]

Looking 100% better Piers .

If I stuff up a thread job on the lathe . If I can, I usually turn it down and then shrink a sleeve onto the part, then turn to size and re-cut the thread Mike

[Piers037]

Ew,

Not sure of the speed as I have a DC motor with a variac, but I am pretty sure I was running slower than you where in your video. What is better?

I think you are right about taking too deep a cut on both sides on the last pass. I was only trying to take a thou plunge but it did bog down a bit and not make nice clean spiral chips like it had on all the other passes.

Cheers

Piers

[Ueee]

Ew,

Not sure of the speed as I have a DC motor with a variac, but I am pretty sure I was running slower than you where in your video. What is better?

I think you are right about taking too deep a cut on both sides on the last pass. I was only trying to take a thou plunge but it did bog down a bit and not make nice clean spiral chips like it had on all the other passes.

Cheers

Piers

You need a Tacho! (i'll tac a link on) I take it your machine is variator free?

I generally thread at 250-300 RPM, depends if i'm threading to a shoulder or not. I was threading M18x1.5 tonight at 250, to a shoulder. I think I've pushed it to 400 on small stuff, but the reflexes have to be good, especially since i always leave the nuts engaged. You have a mechanical brake on the Chippie though don't you? Plus your DC should stop pretty quick. Next time i think of it i'll do a vid of threading without moving the compound from 0.

Cheers,
Ew

[morrisman]

I generally thread at 250-300 RPM,

Cheers,
Ew

You must have reflexes like superman

[j.ashburn]

You must have reflexes like superman

Not for the faint hearted my testicles have shrunk with old age.

[Ueee]

You must have reflexes like superman

Not that fast, the lathe stops pretty quick at those speeds. I like my VFD. You get used to how much thread the lathe will cut coasting.

Here is the link to tacho info Piers, there is 11 pages in all, but we got there in the end. https://www.woodworkforums.com/f65/wo...erence-157501/

Cheers,
Ew

[j.ashburn]

You need a Tacho! (i'll tac a link on) I take it your machine is variator free?

I generally thread at 250-300 RPM, depends if i'm threading to a shoulder or not. I was threading M18x1.5 tonight at 250, to a shoulder. I think I've pushed it to 400 on small stuff, but the reflexes have to be good, especially since i always leave the nuts engaged. You have a mechanical brake on the Chippie though don't you? Plus your DC should stop pretty quick. Next time i think of it i'll do a vid of threading without moving the compound from 0.

Cheers,
Ew

Piers might take a trip in in the morning and see how you going. Have you got enough bar stock? GIve us a yell if you need a chunk. Size?