Day 1 Practice - lessons learned. 12/30 update

[mram10]

The chatter you are getting here is chronic, the problem is it could be coming from a number of different sources.

Play in the ways, either carriage, cross-lide or compound, play on the tool post, the toolkits to holder, the holder to tool or even the headstock bearings to name a few.

Another possibility is as I said earlier your tool grind, poor relief angles or blunt tooling. It will cost you $75 or less to buy an indexable set-up or why not show us your tool grinding?

Im sure someone could send you a nicely ground HSS tool bit if you didn't want to buy carbide?

Your thread form is good now, screw cutting usually isn't that challenging, its a set-up issue of some kind now rather than a technique one.

I’ll check the lathe over again and verify things aren’t moving. I think the hss tools are the issue. They are looking ok, but not sure if they are perfect. I’ll take pics of my setup. They have about 8-10degree rake. I sharpen the top last on my 1” belt sander. I have iscar carbide tooling coming. I’ll do a couple with that and we’ll see if it chatters.

 

[Stan Taylor]

I apologize for backing out of this I am obviously a dumb ass

 

[mram10]

Jess, why keep,silent when I asked for the critiques? All this is being done to learn my machine and to get it setup correctly. I’m new to lathes for the most part so I’ll take all the advice I can get.

 

[akajun]

.005 is way too big for a finish threading cut on a light machine like that. I start with .005 to .004 cuts, fed with the compound, and every three cuts take a spring cut.
Depending on the thread depth I’ll then get down to .004-.003, spring pass, , .003.002, spring pass, etc
Your final passes should be in the .001 advance, especially if your finishing up the thread with the cross feed.

 

[mram10]

I definitely use a fishtail. I will go do another one with even shallower cuts and see how it does. Very interested to see how the carbide inserts do.

 

[mram10]

I apologize for backing out of this I am obviously a dumb ass

No need. It was a train wreck to start

 

[mram10]

Old barrel blanks. Mostly stainless

 

[Stan Taylor]

No need. It was a train wreck to start

I would like to see you pick one contact on here an work with one individual an they whoever it would be I think could get you going smooth as silk there is definitely a lot of knowledge here reap the rewards an pick one to help you definitely got some energy slow down a little lol.

 

[EWaugh]

I am by no means a machinist nor am I a gunsmith. But I do have a machine and I have cut good threads and threads that look like yours. So here are my thoughts. There has been a lot of good info shared here some of my thoughts may be seconds no harm in that. Go back and check the basics.

1- Level the machine

2- Try a tool with HSS inserts

3- Slow the speed down a little

4- Make sure your threading tool height is correct (centered to the stock).

Check the amount of runout in your work while you are turning and/or threading. Can be done by placing a dial indicator on your tennon. This may show if there is excessive wear in your headstock.

 

[carlsbad]

Indeed a lot of advice in this thread. Most of it good or at least not bad. Many of the suggestions are solutions to problems he isn't having or at least aren't obvious yet. But one of the keys to surviving on the internet is sorting through the chaff for the grains of wheat. So long as he stays safe and doesn't get discouraged, he'll get there. Not ready to predict the quality level of his final product but it will be shootable.

First dibs if he decides to sell his lathe cheap.

--Jerry

 

[mram10]

I have a long time friend that has showed me his ways. Mr Wheeler was kind enough to answer many questions also along with many others on here. I feel like I’m at the point I can take in a bunch of info and see what works best. It’s been a week for goodness sake
I like seeing many ways to see what works for me. I like cross slide better than compound for now because my setup seems off. That way I can lock in the compound. One variable out of the way.

 

[mram10]

Sell my lathe!? Did you hit your head Jerry?

 

[TRA]

You fell of the wagon somewhere as your chatter has gotten worse. Something most never consider is your chuck could have issues with it. Chucks, 3 jaw and especially 6 jaw versions are high maintenance. It only takes one small chip to throw the clamping action and run-out, out of wack. New chucks cannot be presumed to be a mount and go. It's common to find a new chuck, even the high dollar Bucks to be full of crap from manufacturing. I bought a new 12" 6 jaw Buck a while back and it was torn down before it was anywhere near the lathe. It was full of garbage and grit. The Jaws are another source of clamping issues. It probably is not an issue in your case but if your going to cut chips, it's something to be aware of.

When you make a spring pass do "NOT" advance the tool. Run it back, even multiple passes, with the last diameter setting. The purpose is to remove the tool marks and any chatter that is somewhat normal with single point threading.

When you cut the thread relief run the tool in and stop momentarily to clean up the surface of the groove.

As far as bolting your lathe down, that's your call. But if you have to bolt it down to cut good threads or machine barrel steel, you have other issues. Bolting down machinery is not considered a must do these days. Part of the reason big or small equipment could only be setup straight was to bolt them down. Newer machines are a bit straighter than they once were. If a lathe has a twist in it sometimes the only way to get it straight is to bolt it down.

Whatever you do, take Stan up on his offer. You only get offers like that a couple of times in your life. Don't pass it up.

Ain't this fun?

 

[Cloudrepair]

One thing I do with every manual lathe I run is find the exact center facing a piece adjusting the hight till I get a perfectly smooth face, then I measure from the ways with my steel starret scale.
With that info I can set the hight quickly and very close.
most turning operations I do just about .005-.010 low for better results and find if I do have any isse I can make quick miner adjustments up or down to get it just right.
Your lathe should be right about 6" off the flat ways and it should also have very good high quality bearings. So that shouldn't be the problem. The gibs may need adjustment.
Another thing you will want is a high quality tenth indicator for dialing in parts you can do with a .001 but you want a .0001 for sure. It looks like your about ready to start indicating stuff on the four jaw. If you haven't already.
Doing good

 

[carlsbad]

Whatever you do, take Stan up on his offer. You only get offers like that a couple of times in your life. Don't pass it up.

Ain't this fun?

So is stan good at grinding HSS? I almost sent him a message asking what he would charge to grind me some. --Jerry

 

[mram10]

Just did yet another one.....
I found the lathe to have a touch of movement, so I pushed on it while adjusting a base bolt. Seemed to have helped. Didn’t have much audible chatter.

 

[carlsbad]

Getting better. Are you plunge boring like shown on page 7? If so, I'd say your rigidity is there as that is a high stress operation to take that big a cut. How are you cutting the relief groove behind the threads? Everything is looking great except for a bit of chatter in the threads. Change to slowest speed and cut a set of threads, chatter is speed dependent and that should solve it.

--Jerry

 

[TRA]

So is stan good at grinding HSS? I almost sent him a message asking what he would charge to grind me some. --Jerry

I have no idea. He has been in the barrel business for a long time and he offered his help. It's a win, win for mram10. I learned a long time ago that those offers got two chances. In most cases it's a good deal for you. If not you are not out much, but you learn. Personally I'd purchase tooling as I do and that's from the big tool manufacturers, like Sandvik and if necessary, Kennametal. I can't afford to sharpen tooling let alone pay my employees to do it.

 

[mram10]

Getting better. Are you plunge boring like shown on page 7? If so, I'd say your rigidity is there as that is a high stress operation to take that big a cut. How are you cutting the relief groove behind the threads? Everything is looking great except for a bit of chatter in the threads. Change to slowest speed and cut a set of threads, chatter is speed dependent and that should solve it.

--Jerry

I didn't bore this one. It was a bar stock with a big hole drilled in the end. I made a hss parting tool this morning. Not a very good one, but it works ok. I am threading on the lowest speed of 90rpm. I used only the cross slide to take the compound out of the equation. Started with .005 then worked my way down to /001 passes with a spring cut at the end. I'll do another with compound only tomorrow.

 

[carlsbad]

TRA,
I agree. And that is why I didn't send him a note. I decided this was an unselfish offer to help a newbie, not a solicitation for (tedious) work.

--Jerry