Threads were made today

[Kevin T]

Alrighty, I was going pretty hard at trying to make thread a couple months back but then I realized that I had a ton of slop in my compound screw assy. I ended up getting a new screw and nut and then realized I also had wear at the handle end and the collar. I thought if i could only find some precision washers I could take out the play. I came across "arbor shims" that gave me hope but then I found "ring shims" at good ole McMaster Carr!

I needed about .012 to make it work but I stuffed 2 .010 thickness ones in there and snugged it down and I am in business.

Here you can see where I put them. Hard to notice but between the handle and the graduated dial.



So my thread progression had me pretty angry because I was sure I was doing everything right but terrible results as the compound would jump or bounce back from all the slop but with new tolerance it's good.

My plan was to try a 3/4-10 thread since I had some threaded rod and a couple nuts to refer to.

I used the Aloris CXA8 and provided cutter



There was a bit of tearing if I took too big of a cut. Truth be told I have no idea what the metal is that I am using either. I grabbed a stack of smooth dowell rebars for concrete slabs that are .75 dia by 18" long to practice on. So I am hoping that with better material I can control the surface a little better.



Heres a good shot of the attempts (Right to Left) and the goal and good one I made with the silver nut on it. Blue nut on far left is standard threaded rod

[Kevin T]

This thing is you friend if you are making threads! It really cuts down on the time needed between passes.



Some better pics of my work piece



Now I can get busy with trying knurling, then I have a bunch of things I want to make.

[texasgunsmith]

Good stuff ! I've been eagerly awaiting this thread.

If I recall, you had an Aloris tool, with the index-able head. Was that not as good for threading ?

How do you like the CXA 8 ? There's different cutting attachments for it too, different degree threading blades and insert type too I believe.

I have not bought one yet. But have been considering the No 8 tool, or using a threading tool in a No 1 holder.

[Kevin T]

Good stuff ! I've been eagerly awaiting this thread.

If I recall, you had an Aloris tool, with the index-able head. Was that not as good for threading ?

How do you like the CXA 8 ? There's different cutting attachments for it too, different degree threading blades and insert type too I believe.

I have not bought one yet. But have been considering the No 8 tool, or using a threading tool in a No 1 holder.

I don't really have enough time with that #8 tool to make an opinion. It is kinda chunky. I do have the CXA-20 but only one holder that holds the triangle shaped bits. I need to look at the catalog.

[animal12]

good deal on the shims ! thanks I have just the project that needs some . that tool holder looks interesting , but their pretty proud of them . well when I win the lottery
animal

[texasgunsmith]

I don't really have enough time with that #8 tool to make an opinion. It is kinda chunky. I do have the CXA-20 but only one holder that holds the triangle shaped bits. I need to look at the catalog.

One thing with that thread cutter, you keep grinding the cutting edge it as it dulls, then adjust holder up. I would guess it could last a good while. Then it can be flipped the other way too.

[JohnEvans]

Were you using a good cutting oil? If not get some Ridig dark pipe threading oil at Home Depot -ACE etc.

[Phil in Montana]

You need to get your spindle speed up a lot, just takes time...Phil

[Kevin T]

Were you using a good cutting oil? If not get some Ridig dark pipe threading oil at Home Depot -ACE etc.

I did use some Tap Magic toward the end and it definitely helped. I'll check that one out you mentioned. Thank You.

[Kevin T]

You need to get your spindle speed up a lot, just takes time...Phil

Yeah so I was cutting pretty slow because I wanted to make sure I could engage the thread dial right on the mark.

How critical is that? For early passes can I be a little off?

Then the other thing is that cutting a course thread like this 10 the stop zone comes up pretty fast! LOL

[pavt]

Yeah so I was cutting pretty slow because I wanted to make sure I could engage the thread dial right on the mark.

How critical is that? For early passes can I be a little off?

Then the other thing is that cutting a course thread like this 10 the stop zone comes up pretty fast! LOL

Can't be off with anything -- either threads line up, or they don't.

Trick is to be completely awake and alert *without* coffee. You don't want to be wired up, you want to be calm and alert. Kinda like how musicians seem to hit the exact right note at the right time.

[SLK001]

I did use some Tap Magic toward the end and it definitely helped. I'll check that one out you mentioned. Thank You.

The Rigid stuff isn't any good any more. Pick up the OAKLEY dark cutting oil. It has both the SULPHUR and the CHLORINE that limits chip welding to the cutting tool (and thus crappy threads).

As for the cutting tool, I would use carbide (this is one operation where I use carbide almost exclusively). Also, limit your DOCs to 0.010" or less.

[texasgunsmith]

I can't vouch for it personally. But doing some reading in other sections, some experienced guys I'd respect recommend Mobilmet 766. Anyone here use it ? From what I read, it seemed like some might be using it as a sort of coolant as well, not just cutting fluid.

https://www.mscdirect.com/product/details/93057511

[Kevin T]

Can't be off with anything -- either threads line up, or they don't.

Trick is to be completely awake and alert *without* coffee. You don't want to be wired up, you want to be calm and alert. Kinda like how musicians seem to hit the exact right note at the right time.

OK good, kinda backs up how I approach it. You're really using the machine and mind, or at least I was, when doing the threading! Couple of times I thought my tailstock was sliding away from the work when I got disoriented watching the turning! I quickly grabbed the wrench to tighten tailstock before I realized it was an optical illusion! LOL

[pavt]

OK good, kinda backs up how I approach it. You're really using the machine and mind, or at least I was, when doing the threading! Couple of times I thought my tailstock was sliding away from the work when I got disoriented watching the turning! I quickly grabbed the wrench to tighten tailstock before I realized it was an optical illusion! LOL

Yeah, I do that every time... looks like I coulda had a v8

X2 on the cutting oil, I use the Oatey stuff. I always take a few "spring" passes without advancing the compound when I get to the end of the job. This gives the smoothest finish of all, you'd be surprised how much spring there is in these. I've had better luck with HSS for threading, and carbide for everything else -- but to each their own, do whatever works best for you.

[SLK001]

I do spring passes until nothing more comes off the part. HSS is great for threads, but the profile has to be fairly exact (and you have to grind it by hand) - carbide eliminates the manual profile forming and only has to properly lined up on the lathe.

[Kevin T]

The spring passes is a great tip thanks guys. I did not do this but definitely next time and for sure with smaller diameter jobs.

[pavt]

The spring passes is a great tip thanks guys. I did not do this but definitely next time and for sure with smaller diameter jobs.

I thought it was common knowledge -- OK but like the slick one says -- I do spring passes till nothing more comes off. You'd be amazed at the difference.

After that's done, I take a fine file and go lightly over the tops of the threads at high RPM to get the small burr there, and a final clean-up with a small wire brush also at high RPM.

Even cheap hardware store steel comes out nice and smooth.

[SLK001]

I thought it was common knowledge -- OK but like the slick one says -- I do spring passes till nothing more comes off. You'd be amazed at the difference.

After that's done, I take a fine file and go lightly over the tops of the threads at high RPM to get the small burr there, and a final clean-up with a small wire brush also at high RPM.

Even cheap hardware store steel comes out nice and smooth.

I do the same for the threads with a triangle file, then hit the tops with a mill smooth file, then wire brush. You can do this at high speed, too. The threads come out so smooth, I think I'm cheating!

[Kevin T]

So cleaning up the threads with a file was something I did. I am fortunate to own a 8" pippin file that I see are very rare in a smooth pattern. If you guys ever see them there is nothing better for kissing the sharp edge off of a narrow groove like a course thread. The cross section of one is like a tear drop. In fact if you guys ever see any please let me know.