Chatter so bad it looks like knurl

O

outsider347

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Been fighting with this, on and off for 4 weeks now. Held off asking for help , it s my nature to try to figure things out for myself. If I don t get this soon I ll have to read the instructions here as to how to post pics

Info:
Cman 101.28940

Had this lathe for 5 yrs now and it has been great. I understand the limits of the Cman/Atlas. Cut every thing from mystery metal to 4130 easy cutting with great finish & control. Cut tapers, fine, and easily set back to almost perfect. Overall, really satisfied with its performance, fit and finish. Parted mild steel with no probs once I learned how to properly set it up.
Lathe worked great for my hobbyist needs.

Had to take the lathe apart to move. after re assemble, is when the chatter started. I leveled(Machinist level) the bench close first. Put the bed in the table& re leveled. Assembled all the components and re-leveled, again with the Starett level

In the last 4 weeks, re ground at least 12 HSS tool bits...Tubalcain style, Barry Young style, Tom Griffin style, all pretty much the same, with subtle differences, for RH tool. Chatter pattern looked the SAME for all

Using a QCTP from Tools for Cheep. I even put the old lantern back to see if any change....SAME

Gibbs. re adjusted, to the kinda tight side, The saddle, cross slide, compound ... SAME

Checked, re checked to to be on center. Tried a little low & high....SAME

Used my new 4 jaw, old 3 jaw, collets. SAME

Took lite cuts for below steps

Turned & faced 1 in mild steel, 2in stick out .. SAME

Set up a 1in x 18 in mild steel on centers.
Reset the tail stock gib to the tight side
Turned near the chuck, & near the tail Bad at both ends, but a bit worse at tail. Really bad at center, Don t have a follow rest, never really needed one...again SAME

I put a indicator on the operator side of the spindle, and had .004 out when I pushed the belt engage lever. Thought that I found it.

So,,, Took the spindle shaft out yesterday (BTW using the green HF link belts) Have a pal that builds racing rear ends for the last 40 yrs, He's the best bearing and race reader I know, come over to help. He sez brgs, & races look fine! Re assembled And HE set the spindle nut to the tight side. Indicating a half thou now. ..SAME

Re checked the bed level again

After all this cuts look as bad now as it did when I started. Like NO change!

I think it might have something to do the re install.
Going to take every thing apart on the left/head side and hopefully find something

Anyone have the ordering phone number at Precision Matthews:thinking:

I ll try for pics later

Tks for any suggestions
ed

I use the the
Speed x 4 / dia = cutting speed
I have tried all the lower end feeds as well.:thinking:
 
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I don't know how an atlas compound is secured but check for raised metal or a crack under it allowing the tool to move up and down. I had an old Logan the used setscrews into a taper under the compound and the metal was raised around the hole, creating a see-saw point. Tightening it harder just raised more metal. Good luck.
Ed P
 
Grab the spindle nose and wiggle it all around looking for movement, or play. Do the same for the carriage. Don't know anything about the 101 series, but could the headstock/bed bolts be loose?

.0005" seems a little loose for a bearing spindle in good shape, but maybe that's the specs for your machine. Have you tried taking a deep cut? My 109 can't take a very light cut, or the tool just pushes away and chatters. Does it chatter using a shear tool? Hmm :thinking:
 
Andre said:
Grab the spindle nose and wiggle it all around looking for movement, or play. Do the same for the carriage. Don't know anything about the 101 series, but could the headstock/bed bolts be loose?

.0005" seems a little loose for a bearing spindle in good shape, but maybe that's the specs for your machine. Have you tried taking a deep cut? My 109 can't take a very light cut, or the tool just pushes away and chatters. Does it chatter using a shear tool? Hmm :thinking:
Click to expand...

Might try/check the saddle to see if it is tight. There may have been a shim that wasn't re-installed.
 
outsider347 said:
Been fighting with this, on and off for 4 weeks now. Held off asking for help , it s my nature to try to figure things out for myself. If I don t get this soon I ll have to read the instructions here as to how to post pics

Info:
Cman 101.28940

Had this lathe for 5 yrs now and it has been great. I understand the limits of the Cman/Atlas. Cut every thing from mystery metal to 4130 easy cutting with great finish & control. Cut tapers, fine, and easily set back to almost perfect. Overall, really satisfied with its performance, fit and finish. Parted mild steel with no probs once I learned how to properly set it up.
Lathe worked great for my hobbyist needs.

Had to take the lathe apart to move. after re assemble, is when the chatter started. I leveled(Machinist level) the bench close first. Put the bed in the table& re leveled. Assembled all the components and re-leveled, again with the Starett level

In the last 4 weeks, re ground at least 12 HSS tool bits...Tubalcain style, Barry Young style, Tom Griffin style, all pretty much the same, with subtle differences, for RH tool. Chatter pattern looked the SAME for all

Using a QCTP from Tools for Cheep. I even put the old lantern back to see if any change....SAME

Gibbs. re adjusted, to the kinda tight side, The saddle, cross slide, compound ... SAME

Checked, re checked to to be on center. Tried a little low & high....SAME

Used my new 4 jaw, old 3 jaw, collets. SAME

Took lite cuts for below steps

Turned & faced 1 in mild steel, 2in stick out .. SAME

Set up a 1in x 18 in mild steel on centers.
Reset the tail stock gib to the tight side
Turned near the chuck, & near the tail Bad at both ends, but a bit worse at tail. Really bad at center, Don t have a follow rest, never really needed one...again SAME

I put a indicator on the operator side of the spindle, and had .004 out when I pushed the belt engage lever. Thought that I found it.

So,,, Took the spindle shaft out yesterday (BTW using the green HF link belts) Have a pal that builds racing rear ends for the last 40 yrs, He's the best bearing and race reader I know, come over to help. He sez brgs, & races look fine! Re assembled And HE set the spindle nut to the tight side. Indicating a half thou now. ..SAME

Re checked the bed level again

After all this cuts look as bad now as it did when I started. Like NO change!

I think it might have something to do the re install.
Going to take every thing apart on the left/head side and hopefully find something

Anyone have the ordering phone number at Precision Matthews:thinking:

I ll try for pics later

Tks for any suggestions
ed

I use the the
Speed x 4 / dia = cutting speed
I have tried all the lower end feeds as well.:thinking:
Click to expand...

I forgot to ask do you get the chatter if you hand feed the compound or if you power feed? Wondering if the power feed could be the problem.

Good luck,
 
Grab the spindle nose and wiggle it all around looking for movement, or play. Do the same for the carriage.
Did that. Seems solid. no movement that I can see
Don't know anything about the 101 series, but could the headstock/bed bolts be loose?
​That occurred to me today. Especially since I had all of it apart when I moved the lathe .I will look for that next time I work on it

.0005" seems a little loose for a bearing spindle in good shape, but maybe that's the specs for your

No idea what the spec should be
Anyone know?
machine. Have you tried taking a deep cut? My 109 can't take a very light cut, or the tool just pushes away and chatters. Does it chatter using a shear tool?
​Yea did that. Looked only slightly ,but chatter still in it
Hm
 
Bill C. said:
Might try/check the saddle to see if it is tight. There may have been a shim that wasn't re-installed.
Click to expand...


Found 3 shims in the saddle. 2 .004 1 .003
I was able to get the saddle back on after removing the .003. Nicely snugger...snugger a word?


Chatter present using power feed & hand feed
 
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Spindle bearing $$$$
Class 3 Industrial bearings

14276B $189. bearing
14125A $138. race
16284B $242. race
16150 $269. bearing
Total $838. from local supplyer

Bearings was more$$ $1314.44

Don t think that I will be changing brgs.
I paid $500. for the Lathe
 
just a thought and maybe a bad one at that , but is the bench or cabinet it is mounted on different then what you used before .
maybe something as simple as some hard rubber pads between it and the floor may help .
 
bosephus said:
just a thought and maybe a bad one at that , but is the bench or cabinet it is mounted on different then what you used before .
maybe something as simple as some hard rubber pads between it and the floor may help .
Click to expand...


nope nothing different
same bench on a new location concrete floor
 
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