Threading Chatter and ect.

[shoot4fun]

Afternoon guys..

So I finally got my hands on a lathe... super dangerous I know. Before yall roll your eyes to hard I know enough to get myself into trouble. (Continue eye roll) Any how I've been trying to resolve what is left of my lathe chattering issue while threading. Its extremely mild chatter and it a longer pattern rather than short. It's a used enco lathe and I've adjusted spindle bearings, replaced the bearings in the motor which was a major cause of issues. (Installed rubber isolators as well on the motor.) Single phase 220 motor btw. Checked and adjusted ways for play. Machine is anchored to concrete floor and the ways are leveled with a machinist level as well. It may be the nature of the machine that I get chatter at low RPM while threading with HSS and Carbide Threading tools (bought from travers). I can get rid of the chatter at about 400 rpm but I sure as hell ain't got the nades to thread at those speeds. I wouldn't mind some input from some experienced guys on weather I can ever expect a quality thread finish out of this machine or techniques to help a guy that's a jack of all trades and a master of none. Thanks!

FYI you won't easily offend me and I rather hear the God honest truth if you have something worth while to type out.

In my very limited experience The answer is in the part of your original post that I have highlighted in red.
Carbide cutting tools need to run at higher than normal speed to cut out chatter.
I grew up in a family of machinists but it never caught on with me.

 

[lariat]

The DMG’s are sexy. And if you go to Chicago during the Mori DMG Days thst they put on every year you don’t need to bring your wallet. Some of the stuff they have on display is impressive. But even the old ones are quality.

OP, let us know how it turns out. Curious as to how you get it solved.

 

[RanchhandTCR]

So since we're talking shop now.. if you wanted a lathe do barrels and small parts what recommendations you have that does not require a mortgate? Besides grizzle industrial

 

[nikonNUT]

I cut my teeth in Trade School on Nardini and Cluasing Colchester and both were solid lathes. Not sure you can get "small" clausings but a Nardini 16x40 would be one I wouldn't mind having. I've seen 6hp versions in the 8 to 9K range. Other option is to get in good with an old machinist that wants to pass his baby on to the next generation. I know an old cat that has a pristeen LeBlond (1960s vinatge) that I would love to scoop up!

P.S. Surplus Record is your friend!

 

[iceng]

Years ago i was at a place which was spending $150k on custom hydraulic rams, set of 4 at a time. Thet were 6m long from memory. Huge. Needed a tread each end, about 5" diameter. Couldnt be done, thus imported from UK !!

I asked why they didnt make them.. they said impossible.

Grabbed an old one, setup in the lathe through the head stock / spindle. Got 2 of the welders roller steady things and a shitty worn out riggers sling.

Greased the crap of the sling and supported it with the over head crane, and roller frame things. Threaded both ends in half a day. Boss baught the special rod... like 10k each. I threaded them all within a week.

Boss was amazed. I didnt even get a carton of beer of a bottle of wiskey as thank you. I saved him my entire years wage in one job.

I did it again on another job a few months later, boring out some special bushings. I left shortly after that.

Bosses should pay for experience, not all of us are monkey button pushers. And i know dudes WAY better than me. Im not saying psy me $10k cash as a thank you... not at all, but a bit of recognition goes a long way.

 

[MK20]

I am just learning myself but the above advice about finding an old machinist who wants to pass his machines on is often good.

I just got this 20x168 Lodge and Shipley and this J head Bridgeport from an old gentleman with all the tooling and accessories you could ever want for $4800 for the pair.

 

[RanchhandTCR]

Well gents.. between your advice and growing a pair and threading at 240 rpm I'm getting a good finish outta the threads... thank you gents/ladies that all commented.

 

[lariat]

Well gents.. between your advice and growing a pair and threading at 240 rpm I'm getting a good finish outta the threads... thank you gents/ladies that all commented.

The only things left are:

1. Bury the threader into the part.

2. Trash the insert. Don’t do this halfway.

3. Crash the lathe.

4. Cuss, go get a beer and think about what you have done as well as the trajectory of your life. Tomorrow you can use your savings to repair the lathe.

Don’t laugh too hard. It happens to many much better than you or I. I had one of my workers throw a 10” OD part out of the chuck in mid drill cycle. It was a damn mess. Another time I had a dude crash my Okuma so hard the turret’s bolts broke off and the damn thing was almost laying in the chip pan. Neither work for me any longer because of their lack of attention to detail but I have definitely had my own mistakes. This whole thing of yours went way too smoothly. We can’t have that level of success around here.

All kidding aside, good job on getting it done. Major and minor are good I assume?

 

[Makinchips208]

It gets exciting when you crash a big Cnc Grinding machine. Most of them use oil as a coolant. Yeah, big fire ball!

 

[RanchhandTCR]

The only things left are:

1. Bury the threader into the part.

2. Trash the insert. Don’t do this halfway.

3. Crash the lathe.

4. Cuss, go get a beer and think about what you have done as well as the trajectory of your life. Tomorrow you can use your savings to repair the lathe.

Don’t laugh too hard. It happens to many much better than you or I. I had one of my workers throw a 10” OD part out of the chuck in mid drill cycle. It was a damn mess. Another time I had a dude crash my Okuma so hard the turret’s bolts broke off and the damn thing was almost laying in the chip pan. Neither work for me any longer because of their lack of attention to detail but I have definitely had my own mistakes. This whole thing of yours went way too smoothly. We can’t have that level of success around here.

All kidding aside, good job on getting it done. Major and minor are good I assume?

Well to be honest 1 & 2 have already happened previously and currently I have learned from my past mistakes lol.. major and minor for my 5/8 x24 are good my t bac supressor will thread on nicely. I'm useing junk old barrels for practice glad I kept them. I did kick my buddy outta the shop because he likes to try and chat while I'm trying to not crash the sum bitch..

Just glad my 2k purchase that has cost me 2500 is working decent now.. its been 3 months of me on and off getting it to run good. However learned alot in the process and that's half the fun for me.

 

[LeftyJason]

It gets exciting when you crash a big Cnc Grinding machine. Most of them use oil as a coolant. Yeah, big fire ball!

Ive done it. I use oil. Ilocut 5720. No Fireball. I mostly grind inconel though. I side loaded a 16" wheel taking a part out doing the setup (hand in the machine) and exploded a wheel. Also knocked the bed back off the ways. Forgot a driver on a 26" part between centers and had flats on the part. On a chucked part missed an touch off 1" the wrong way. Machine is a 1987 sheffield crush form grinder last rebuilt in 02 and finally getting replaced in February with a Studer s41 (they have a co2 system).

 

[JoshPutman]

 

[RanchhandTCR]

View attachment 8178279

NM vs ftlbs for us knuckle busters

 

[Makinchips208]

Ive done it. I use oil. Ilocut 5720. No Fireball. I mostly grind inconel though. I side loaded a 16" wheel taking a part out doing the setup (hand in the machine) and exploded a wheel. Also knocked the bed back off the ways. Forgot a driver on a 26" part between centers and had flats on the part. On a chucked part missed an touch off 1" the wrong way. Machine is a 1987 sheffield crush form grinder last rebuilt in 02 and finally getting replaced in February with a Studer s41 (they have a co2 system).

Studer are nice!! I want one! Maybe some day.
Ran lots of Walter, Star, and now have a vollmer 5 axis grinder with wheel changer and fanuc robot. This new one hold all dimensions within .0005 easily.
All have the co2, they discharge pretty rapidly in a fire. So it’s a big flash and fire comes out every crack followed by the co2.
I did it once, seen 3 others. Never seen a guy do it more than once.

Some friends had a Schneeberger burn to a crisp cause the fire suppression system failed. That cost them $300k

 

[nikonNUT]

The only things left are:

1. Bury the threader into the part.

2. Trash the insert. Don’t do this halfway.

3. Crash the lathe.

4. Cuss, go get a beer and think about what you have done as well as the trajectory of your life. Tomorrow you can use your savings to repair the lathe.

Don’t laugh too hard. It happens to many much better than you or I. I had one of my workers throw a 10” OD part out of the chuck in mid drill cycle. It was a damn mess. Another time I had a dude crash my Okuma so hard the turret’s bolts broke off and the damn thing was almost laying in the chip pan. Neither work for me any longer because of their lack of attention to detail but I have definitely had my own mistakes. This whole thing of yours went way too smoothly. We can’t have that level of success around here.

All kidding aside, good job on getting it done. Major and minor are good I assume?

Man, been there with the Okumas! Got to where I could realign a turret in about 20 minutes if it just bent the pins. Worst crash I was ever a part of was an LB15. Bossman was cutting jaws (I was watching) with a program and going fast. He mean to use T111111 in the program but fat fingered T110111 (Or something like that. It's been a minute but If ya know, ya know...). Well T1 was a regular 432 facing tool but T11 was an 1.5" boring bar hanging out about 6". He hit cycle start, chuck goes whirrr, and the boring bar that "idenified" as being a facing tool slamed into the chuck at full rapid. Lights flickered, sparks flew, and I ran! Mainly because I figured he was gonna fire the first person he saw. Next day I got to pull the headstock off that machine.

 

[Tokay444]

Take the pins out, and they won’t bend. Then the holes never mushroom and need to be reamed oversize.

 

[iceng]

I am just learning myself but the above advice about finding an old machinist who wants to pass his machines on is often good.

I just got this 20x168 Lodge and Shipley and this J head Bridgeport from an old gentleman with all the tooling and accessories you could ever want for $4800 for the pair.

Did you get a traveling or fixed steady ? You will need one.

 

[MK20]

Got a fixed, don't know if they ever made a traveling steady but I would like to have one.

 

[Blackcreek]

One more thing to check is chuck up your part then take a .001 feeler gauge or shim stock and check the contact between the jaws and part. I had a lathe I was training a guy on that was driving me nuts trying to figure out why it had a bad surface finish. One of the jaws on the chuck was sprung and was only touching at the very front.

 

[Makinchips208]

I am just learning myself but the above advice about finding an old machinist who wants to pass his machines on is often good.

I just got this 20x168 Lodge and Shipley and this J head Bridgeport from an old gentleman with all the tooling and accessories you could ever want for $4800 for the pair.

View attachment 8178187View attachment 8178188

That lathe is awesome!!!

 

[MK20]

Yes it is. It came with a taper attachment and has a quick change gear box too. Made in 1914 in Cincinatti Ohio.

 

[chutinlead]

Another alternative for a lube especially on your last pass is steal some of your kids sidewalk chalk and run the last pass dry with just the chalk rubbed on it.