1340gt surface finish problem

[rherrell]

I figured out how to get into Super Macro mode, these aren't very good but they're closer

 

[davidpbest]

Looks to me like the material is being forced off CL as it's being cut - like the tool is deflecting the stock as it rotates. That could mean bad or loose spindle bearings. Try putting a DTI against stock in the chuck and pushing on the chuck horizontally with the weight of your body to see if you get deflection on the DTI.

 

[qualitymachinetools]

Any way you can post a video of the cut? Or of the settings? Does it do it on the cross feed too? Im running alum. in a 1340GT this morning, single phase machine. Its not the single phase doing that much. Those feed rates do look like what jbowlin said, that looks like a much more coarse feed than .002 or .005 Double check the settings here: http://www.machinetoolonline.com/files/PM-1340GT_v1_6-2016_indd.pdf

The patterns also look to be going the opposite way of each other, were they cut in different directions?

I get this question about 10 times a week, normally its a setting, tool, feed or speed, etc.

 

[rherrell]

I put a piece of 1" stock in the chuck and put the DTI 1" from the jaws. When I push on the chuck with my hand it moves .0005" with just moderate pressure. When I push as hard as I can it moves .0015".

 

[qualitymachinetools]

You mean .0005 right? Thats normal. Its going to move a little. Please try to post that video, and even a picture of the settings. Dont even look at the bearings until you check that all out. Im not saying that they might not need adjusted after some time, they are tapered rollers. But what I am seeing there is not anything to do with bearings. Please post that video if you can of it taking a cut, from as far back as you can so I can see the whole carriage and cutting tool.

 

[rherrell]

Matt, can I post videos here or do you want me to put it on You Tube?

 

[qualitymachinetools]

I think if you put it on youtube and then post the link here is the easiest.

 

[rherrell]

Here's a photo of the piece that's in the video...

It's got the same pattern to it. Here's a link to the video...

WARNING!..I'm not any good at videos so don't laugh too hard. I hand held the camera, I can use a tripod if you want a steadier shot.

 

[qualitymachinetools]

In that picture above, it just looks like a machined finish with a sharp tool to me. Try the setting on E and 8, also whats the radius on the insert? The tool also looks high to me, but that might just be the camera angle.

 

[rherrell]

The insert is a CCGT 32.51 but I have the same problem when I use a HSS tool with a large radius. The HSS tool I use for brass has about a 3/16" radius and it does the same thing.

My carbide inserts are all either 32.51 or 32.52 and they do the same thing.

I forgot to mention that I have the same problem with hand feeding as I do with power feeding so I doubt if the problem is with the power feed.

The power feed for facing gives a better finish but it's still has some fine ridges in it.

I have to leave now but I'll be back tomorrow to check on the thread.

THANKS for all the input, keep it coming if you have any ideas.