First Boring Head.

[Ken from ontario]

Yes, just a ball between the screw and gib.

Mike would you know if the Criterion s-2 boring head also has a bearing ball between each screw and gib? I looked at the pics closely and it looks like there's no moveable /sliding gib on this model and the set screws force the "fixed" gib to clamp against the boring head body, also there's not enough space in there to fit a bearing ball. :

 

[4GSR]

Mike would you know if the Criterion s-2 boring head also has a bearing ball between each screw and gib? I looked at the pics closely and it looks like there's no moveable /sliding gib on this model and the set screws force the "fixed" gib to clamp against the boring head body, also there's not enough space in there to fit a bearing ball. :
View attachment 227390 View attachment 227389 View attachment 227392

Looks like that model head does not have the ball installed. Pull one of the set screws or gib screw and see what kind of end configuration is on the screw. You also have to remember the S-2 head is the older design model of the later head mentioned above. still being built and more rigid than the 202 or 203 model in my opinion. Just doesn't have the multiple hole arrangement for boring bars. Ken

 

[Ken from ontario]

Looks like that model head does not have the ball installed. Pull one of the set screws or gib screw and see what kind of end configuration is on the screw. You also have to remember the S-2 head is the older design model of the later head mentioned above. still being built and more rigid than the 202 or 203 model in my opinion. Just doesn't have the multiple hole arrangement for boring bars. Ken

Thanks Ken, I haven't received mine yet ,it's just the curiosity is killing me, I'm sure the first thing I'd do is to check under the set screws , I bought this older model mainly for it's size so it would be a good fit for a mini mill and of course the quality in general is supposedly better than the equally priced but imported boring heads.

 

[mikey]

Mike would you know if the Criterion s-2 boring head also has a bearing ball between each screw and gib? I looked at the pics closely and it looks like there's no moveable /sliding gib on this model and the set screws force the "fixed" gib to clamp against the boring head body, also there's not enough space in there to fit a bearing ball. :
View attachment 227390 View attachment 227389 View attachment 227392

Ken, the gib does not slide. If you look at your pics, you can see a small vertical slice to the side of the dovetail on the right; the part between the dovetail and the slice is the gib. You can see that only a very small area of metal supports that gib and this is fine in normal use. Just don't go cranking down on the gib screws without the main bar holding section in place.

Yes, there is a small ball bearing under each gib screw. It allows the moving part of the head to slide smoothly in use. There are three gib screws. The center one is to lock the head prior to using the head; it is not a gib adjustment screw. You are supposed to unlock the center screw, move the head to the new position, then snug the center screw to hold it at that setting. You only need to snug this center screw; do not crank down on it. The outer two screws are the gib adjusters; you snug one up until slight resistance to movement is felt and then you do the same to the other. Many guys adjust all three the same way and use the head without locking anything down. This works but is not the way Criterion intended the head to be used.

The S-series heads have a relatively large dovetail contact area for its size, which adds to their stability as Ken said. I have a S 1-1/2 and it is very precise, very smooth and very accurate. Because the bar hole is centrally located the hole size it can bore is limited but it is an excellent head within this range. Although my DBL-202 can do it, when I need to bore a smallish hole I reach for the S 1-1/2. Unlike the 202, my 1-1/2 can extend to the limits of travel without vibrating unless I get stupid with speed.

Don't worry, Ken. You will love this head.

 

[Ken from ontario]

Ken, the gib does not slide. If you look at your pics, you can see a small vertical slice to the side of the dovetail on the right; the part between the dovetail and the slice is the gib. You can see that only a very small area of metal supports that gib and this is fine in normal use. Just don't go cranking down on the gib screws without the main bar holding section in place.

Yes, there is a small ball bearing under each gib screw. It allows the moving part of the head to slide smoothly in use.

Don't worry, Ken. You will love this head.

Now it makes so much sense to me, this square shaped boring head shares the same basic design as the bigger round shaped ones as far as the gib/dovetail configuration goes, and both types (round and square) have a fixed body part that resembles a Gib,the set screws pushes on the ball and the ball focuses the force to a single point on the fixed gib and makes it lock against the bar holding section.Thank you Mike .
By George, I think I've got it.

 

[FanMan]

boring/facing head for future use. Use mine for more facing than I thought I would,no need to tear down and reset on the lathe. Mill becomes more useful.

Stupid question then, are boring heads and boring/facing heads two different things?

 

[mikey]

Now it makes so much sense to me, this square shaped boring head shares the same basic design as the bigger round shaped ones as far as the gib/dovetail configuration goes, and both types (round and square) have a fixed body part that resembles a Gib,the set screws pushes on the ball and the ball focuses the force to a single point on the fixed gib and makes it lock against the bar holding section.Thank you Mike .
By George, I think I've got it.

Yup, you have it exactly right. Funny thing happened today - a good friend came over for a visit and he brought me a mint condition S 1-1/2 head with a 1/2" Criterion shank in it. Now I have two S 1-1/2 heads.

 

[Ken from ontario]

Yup, you have it exactly right. Funny thing happened today - a good friend came over for a visit and he brought me a mint condition S 1-1/2 head with a 1/2" Criterion shank in it. Now I have two S 1-1/2 heads.

That's great, you can never have too many boring heads

 

[4GSR]

That's great, you can never have too many boring heads

Yeah, you telling me! I only have one mill to use them on. Last count around 10 boring heads, including two I rebuilt. I only use a couple of them, too.