Chip Weld

E

EG&M

Guest
I keep getting chip weld on the shoulder of my reamers. Has anyone had this issue and how did you cure it. I am useing Brownells do drill as a cutting oil , 70 RPM , .050 to .100 cutting depth at a time.
Thanks
 
Try some Rigid Black High Sulphur cutting oil, the same kind they use in their threading machines.

Your reamer might not have quite enough clearance ground on the edges of the shoulder, which can cause it to try to rub instead of cut. Or, it could have gotten a little burned at one time.............jackie
 
I was plagued with chip weld on reamer shoulders for years. Tried
oster high sulfer, Ridgid and then Mobilmet omega cutting oil. This
happened with new reamers from Hendrickson, jgs and kiff. It even
happened with new carbide roughing reamers. I stepped up the RPM's
from 60 to 120 and it has been a great improvement.
 
My way is considered "blasphemy"..:eek:...I us a large can of WD-40 with the red spray tube attached..while feeding slowly I put the spray tube into the reamer flute and continue to spray as long as I am feeding in (.050") then I stop remove the reamer spray off all the cuttings and insert reamer then repeat...beautiful chamber finish and no chip welding..my reamers stay very sharp with my preferred method...I use an entire large can of WD-40 to cut one chamber...
Now that I have come out of the closet with my method...I am going to quietly go back in close the door before the "storm" hits..:D:D
 
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Thanks guys I will try your some of your suggestions and see what happens.
I would like to speed the spindle up but my lathe goes from 70 RPM to 220 RPM. Which in my mind is to fast. What do you guys think?
Thanks
 
Slower is better when reaming...don't forget to pre-bore the barrel before reaming...that will reduce the chip load on the reamer cutting edges...chip weld will most likely occur at the shoulder/body juncture of the reamer. ...that is why you should pre-bore to remove the excess metal... give your reamer a smaller amount of metal to remove...
 
FWIW.

I run my spindle speed between 225 and 500 rpm depending on the diameter of the shoulder. I use a "guess ratio" mix of Marvel Mystery Oil and Castol Moly D tapping fluid. My feed rates are an estimated .001-.003 per rev. (I jog the Z axis by hand in .0001" resolution but I'm whizzing the wheel at a pretty good clip) My plunge is usually between .100 and .300. I'll take big cuts in the beginning when the chip doesn't have far to go to evacuate out the back of the tool. As I get further along I shorten it a bit so as not to compact the chip gullets. (don't have my high pressure rig set up yet on this machine)

Point from all this is I'm rather aggressive; to the point of trying to screw something up to see where the threshold is. the surface finishes are great and my runouts are down to almost not worth measuring.

I've not yet experienced chatter, chip weld, galling, any of that using this mix/method so if I may, I'd politely suggest possibly looking at your tooling or your set up.

Take from it what you will. Seems to work for me though.

Good luck.

C
 
In addition to all prior suggestions, you may want to consider your technique in terms of the rate you're feeding the reamer and whether you may be inadvertently allowing it to dwell - that is hold lightly against the work but not cut.
 
I have always used Rigid cutting oil and usually 45 to 60 rpm and have never had a problem with chip weld... about 40 years now.
 
Kodzoff said:
In addition to all prior suggestions, you may want to consider your technique in terms of the rate you're feeding the reamer and whether you may be inadvertently allowing it to dwell - that is hold lightly against the work but not cut.
Click to expand...

I'm with this one :) never stop digging into fresh substrate.

al
 
EG&M said:
Thanks guys I will try your some of your suggestions and see what happens.
I would like to speed the spindle up but my lathe goes from 70 RPM to 220 RPM. Which in my mind is to fast. What do you guys think?
Thanks
Click to expand...
I normally chamber at 260 but I use a barrel flushing set-up from Dave Kiff. I also thread at 260.
 
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