Criterion Boring Head Questions

rronald said:
I have reduced my shank/arbor length by about 50% and I pressed out the old boring bar. The problem with getting it out is that there was a cover (perhaps a dust cap) in the head bar holder on top of the hole for the bar. Seemed like the cover was pressed sheet metal. I mangled that cover, but I'm pretty sure it's not a problem to leave it out. And the boring bar slides in and out nicely now.

I'm trying to pick an indexable boring bar, perhaps based on the recommendations in this thread. But, I've been looking at pictures and I'm pretty sure that the original bar I got with the head is Right Handed. And, the 1/2" one linked to is Left Handed.

Do I have the "hand" correct? And, if I do...are you running your boring head using a left hand bar? Do you need to run the spindle with the opposite rotation from normal milling cutters and such?
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I have both left hand and right hand boring bars, for me to use left hand bar in my mill was a matter of preference , I think you should invest in a decent quality boring bar that you are most comfortable to set up/use with the boring head.
 
Ken from ontario said:
I have both left hand and right hand boring bars, for me to use left hand bar in my mill was a matter of preference , I think you should invest in a decent quality boring bar that you are most comfortable to set up/use with the boring head.
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Does your boring head have an integral shank? or threaded?
 
rronald said:
4) One of the threads on Criterion boring heads mentioned BBs on the tip of the set screws. Mine has no BBs, but the set screw for the boring bar is clearly made for one. Any ideas on how to size the proper BB? The screws for the ways also don't have BBs and it doesn't necessarily look like they should be there.
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I have a Criterion boring head and it uses 9/64" diameter BB's. I got them at McMaster-Carr, but you have to buy a whole bunch. I have some extra you can have for the price of shipping. PM me if you're interested and these are the right size.
 
BB's where??? My 202 has 3 cup point set screws to hold boring bars. Why would you want a BB and how would it stay in place when you remove the boring bar? Unless you are taking about the smaller screws on the dovetail?

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rwm said:
BB's where??? My 202 has 3 cup point set screws to hold boring bars. Why would you want a BB and how would it stay in place when you remove the boring bar? Unless you are taking about the smaller screws on the dovetail?

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At the tip of each set screw (3 set screws total) there should be a small SS bearing ball that put pressure on the dovetail, that's how my Criterion (Criterion Model 1-1/2) boring head came with, when each set screw is tightened it pushes on the ball bearing which allows the dovetail to slide easier.



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Thanks Ken. That makes more sense. I have never disassembled mine to see those. This is good to know.

Edit: I checked the DBL 202 it also has a BB under each set screw for the dovetail!
 
My pleasure Robert, Mikey was the one who told me all about these BBs and what they are designed to do, I'm just passing on what I learned from that remarkable man.
 
ARC-170 said:
I have a Criterion boring head and it uses 9/64" diameter BB's. I got them at McMaster-Carr, but you have to buy a whole bunch. I have some extra you can have for the price of shipping. PM me if you're interested and these are the right size.
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I appreciate the generous offer. It's taken me a whole day to follow up...but it appears that I have some of the proper sized BB's already.

I do a lot of bike riding and my bottom bracket (holds the axle for the pedals) got a bit rough. When I removed the bearing seal, it was contaminated by water. I wanted to clean and relube, but there was a bearing holder in place impeding access. So I removed the bearing carrier. Which was a terrible idea! Not only was I unable to align the balls sufficiently to reinsert the carrier....but the inner race and all the balls came off and fell on the floor of my garage.

I was starting to think I'd need to mount my bike on the mill to use the boring head to remove the remaining outer bearing race, but I finally got it out with a custom ground drift.

A day of so later, I saw your email about the ball size. And tonight, I went out hunting and found four of the suckers still on the garage floor. They are 9/64ths, so I think I'm set. What are the odds? Free ball bearings on the ground for the picking. :)

It occurs to me that only the outer two screws on the boring head should be optimized for sliding since the center screw is used to lock the ways Te center one should always be loose when the head is adjusted. Making the center screw easier to slide seems like a bad idea. So I may try installing two rather than three.
 
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