I have a stuck arbor.

[Aukai]

I have an Enco boring facing head with an NMTB 40 arbor that is being stubborn about removal for replacement. Before I resort to violence, how much pressure can be put on the dove tails if I make a spanner wrench, and any suggestions about heat?

 

[Cadillac]

I have a similar boring/facing head. Mine has a setscrew that retains the arbor to the head. I’m not by it till Monday to give you a location.

 

[darkzero]

I have no idea about the dovetails but I'd also be concerned about the facing mechanism also. I've never had one of those or taken one apart so no idea if that would be an additional concern.

This is probably of no help but the arbor on my Criterion was a pita to get off. Because the arbor is threaded & the direction they're normally used in, naturally they get really tight. Especially if used for an interrupted bore.

Could have been easier but I wanted to save the arbor that was on it. I tightened the dovetail screws, stuck a bar in the side hole & went at it. Had to resort to impacting/hammering on the bar. Bent the bar pretty good but it was just mild steel. Got it loose with no damage to the head or arbor. That sucker was on tight & the boring head looked like it didn't really have that much use. BTW I'm not suggesting this method if it has a threaded arbor. Don't do what I do.

 

[matthewsx]

Mine came apart without too much effort, I'd suggest patience and penetrating oil.

John

 

[darkzero]

Mine came apart without too much effort, I'd suggest patience and penetrating oil.

John

Show off!

 

[mattthemuppet2]

heat and cold help alot too, especially several cycles of it. Heat the boring head in the toaster oven to 150F, then empty a can of freeze spray or stuff dry ice/ pour liquid nitrogen down the threaded hole of the arbor. Try and get it cold quickly. Then try loosening it. Sometimes that really helps and I've never had it hurt anything even if it didn't help

 

[DavidR8]

Like Will's, the arbor on my Criterion was near impossible to break loose. I resorted to the judicious application of heat on the head around the threaded portion which seemed to break the bond.

 

[darkzero]

Yep, heat & Kroil pretty much always works (well CRC or KW Knock'er Loose now that Kroil costs so damn much). And I don't even have an acetylene torch (not that machine tools need it), I just use a TS8000 with propane or MAP-P. Except I no longer use freeze spray anymore. I just used canned air upside down. Works just as well for me, much cheaper & easier to get locally. Luckily I don't have to deal with real rust when working on cars which doesn't exist here.

 

[mmcmdl]

Hey man ! Don't hurt that thing . Use a spanner wrench on the adaptor . ( remember , presumed innocent until proven otherwise ) . How about an identical head with an R8 adapter ?

 

[mmcmdl]