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Small Crash, now chatter

csharp

Stainless
Joined
Sep 24, 2009
Location
PA
I ran a 1/2" in mill straight down on the edge of a part today. After that the mill seem to really hammer when cutting.

What should I be looking for.

It sees like the tool may not be clamping tight, I have tried new holders, different setup, feed speed etc...

If I place a tool holder in the spindle with a indicator under it and pry with a medium screw driver I can get about .002" movement.

Could the belleville washers be bad?
 
Small crash, now tool chatter

CSharp,
Maybe a little more info.
Name of machine, size of taper etc etc.
Then a little more definition of what you mean by small wreck.
Regards Walt...

PS What part of Penna are you from.?.
 
Machine is a TM3,

Small wreck, I ran a 1/2" endmill down on the edge of a part in a vise. the endmill was in an ER32 collet chuck.

Endmill broke, machine was at 50% rapid travel which is 100ipm on this machine.

Cat40 taper.

From Potter County.
 
I have plunge milled aluminum that fast with a 2" face mill...on purpose. I can't imagine you screwed your machine up, but I don't know about those toolroom mills. Mine is a VF-2ss, but it's the same taper.

When you pry on a toolholder, does the indicator return to zero when you let go?
 
Did you check for runout in your tool when you got back to work? backlash, runout, and vibration all induce chatter.
 
Small crash, now chatter

CSharp,
Darn, I just typed about 4 or 5 paragraphs to explain the folllowing.

With an indicator (.0001") and a mag base and a 2 x 4, do the following. Indicate from the rail to the axis slide assembly and pry the slide one way and then the other. See that the gibs are snug.
Then do the same thing with the indicator from the rail to the slide and you can do this with the 2 x 4 or use the incremental mode and jog the slide first one way and then the other checking for back lash.
Back lash, lost motion samo samo..
Then with the same indicator, mount the mmag base to the spindle casting and indicate athe face of the spindle and pry the spindle up and see if you can move it. Movement would indicate loose preload.
Last but not least, get out the non drying bluing and check the contact from the tool holder to the taper in the spindle. Normally you should see contact of 85 to 90% and evenly all around the circumfrance of the spindle. If the tool holder is not contacting on one side and not the other, you might be looking at your problem..Go back to the mag base and indicate inside the spindle taper behind the key slots. I believe the specification on your machine should be under .0003".

That is about what I typed and I poked the wrong button and it went away..... There darn it, I typed it again.
Regards Walt...

PS I hunted in Potter County. I managed to get back....... Walt
I said back not buck....
 
Hello,

Is there a belt in the head connecting the motor to the spindle? Perhaps you smoked the belt or it is loose. If you try to rotate the spindle with your hand is there any play in the spindle before you feel the weight of the motor offer resistance?
If you just buried to cutter in aluminum, that is a pretty soft landing!

Good luck!

LandM-1
 
Sometime when things are slow, put an end mill (the kind you broke in the wreck) (small wreck) in a vise and then break it off with a pipe or pipe wrench and then see if it was a small crash or was it a wreck?
BTW, did you check the taper for contact to a new tool holder?
If it looks like a banana, you know tight on this side in the big end and the small end and tight on the other side in the middle, you need the taper reground.
We can regrind that taper in place but, I would like to do it before snow flies in Potter County....
OTOH, we are on Route 80 across Penna once or twice a month anyway.
This comming week is Franklin, Penna and Meadville. The following week we are scheduled into Tonawanda, NY.
Regards Walt...
 
I feel quit stupid as to what the problem was. After the crash which was very light, some poeple feed harder than i hit the part. I replaced with a new endmill since the other one was broken. Since the endmill was new I never assumed it could be the problem. I finally tried the tool in a different machine with the same noise and finish, and found the endmill had no clearance, as if it were trying to cut on the heel of the flute.

Walt, thanks for all the info. Tonawanda, NY is actually closer to me. My shop is actually in Wellsville NY. I used to work at Alstom, have you ever done work there? I spoke with one of of the millwrights and they said they have someone come in and grind in place and have been very happy.
 
Small crash, now chatter

Csharp,
Lets see Wellsville, NY, Been to ABB Raymond, Been to Dresser Rand Energy Systems o yes, some place called Alstom Power Air Preheater. Looks like we have been there and reground 8 different machines. Lucas, G&L and others. (Can't get my puter to navigate around the date base). I guess I better stick to regrinding spindles and leave this putor stuff to the experts.
Regards, Walt
Spindle Grinding Service Inc.
 
ABB and Alstom Are the same

It was Combustion Engineering (CE) Air Preheater, then ABB Air Preheater, The Alstom Air Preheater. I worked there 7 years, yes mostly G&L, Lucas, Bullard.

I also worked at Dresser Rand Energy systems. The build Steam Turbines.
 
Small Crash etc etc

Csharp,
I got you e mail... don't feel bad, sometimes I only open my mouth to change feet.
The last two years I lived in Penna, I lived in Newport.
Perry County, almost like neighbors.
Regards, Walt
 
The only time I ever bought any Brand X cheap endmills they turned out to be REAL crap: They were not ground to actually have a cutting edge! I showed them to my tool grinder and he said they appeared to have been made by someone who was looking at a photo of an endmill but had never actually seen one or understood why and how they cut.

Since then I only buy good quality cutters from sources I trust.

But look on the bright side: Your machine is OK!
 
The only time I ever bought any Brand X cheap endmills they turned out to be REAL crap: They were not ground to actually have a cutting edge! I showed them to my tool grinder and he said they appeared to have been made by someone who was looking at a photo of an endmill but had never actually seen one or understood why and how they cut.

Since then I only buy good quality cutters from sources I trust.

But look on the bright side: Your machine is OK!

thanks, I consider SGS to be of pretty high quality. I could be wrong though.
 
I don't kow that brand so I can't say. I've had good luck with Gühring / Robert Stock, Ingersoll, Jongen, Kennametal, Hanita and Fraisa. But there are otherr good ones out too.

I meant the cheapo no-name crapo ones...
 








 
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