Boring Head- Minimum ID

I figured that was the problem as my math said the same thing as yours.
 
Ischgl99 said:
I used the chord length formula to calculate a minimum bore of 1.3” with an insert with a 7 degree clearance angle. If you use the inserts with an 11 degree angle, that will get you into the Mesa stated range. The angle C for the formula partially down the page would be 2x the clearance angle of the insert. The chord length would be the thickness of the insert divided by cosine clearance angle.

mathmonks.com

Chord of a Circle – Definition, Formulas, Examples

What is the chord of a circle – learn how to find its length with equation, theorems, and solved examples. Also learn the longest cord of the circle
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Click to expand...
Thank you for that equation! That also agrees approximately with my Fusion simulation.
It's a shame that the manufacturer has already told me I was wrong.
 
I have a Mesa threading tool and like it a lot, it’s disappointing they are so wrong about this one. I was looking at those recently and wanted to buy it, but glad I held off until I really needed it.
 
Ischgl99 said:
I have a Mesa threading tool and like it a lot, it’s disappointing they are so wrong about this one. I was looking at those recently and wanted to buy it, but glad I held off until I really needed it.
Click to expand...
Its well made and works great. Just don't expect it to bore a .925 circle!
 
I’m wondering if they are basing that number on the size of the tool, and not the clearance of the insert. I took a look at the one for the TPGB inserts, and it is also 0.925”. That is an 11 degree insert compared to the CCMT being 7.
 
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Ischgl99 said:
I’m wondering if they are basing that number on the size of the tool, and not the clearance of the insert. I took a look at the one for the TPGB inserts, and it is also 0.925”. That is an 11 degree insert compared to the CCMT being 7.
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I think so. Maybe they don't realize the insert will interfere first? I was very specific with my question to them.

It looks like I could just switch to a CPMT insert? Would the holder accept this?
 
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Similar comment on Mesa boring bar. Might be that a CPMT will give you more insert clearance but the insert pocket is different so the insert may not be secure. On smaller holes I used brazed carbide.

Question on CCMT inserts for boring bar in boring head

I have been using a Criterion boring head in my Bridgeport. The Criterion bars which came with the head don't handle interrupted cuts well. I have wanted to try using a bar with inserts. After reading past threads on the forum, the consensus seems to be that sclrc boring bars using ccmt...
www.practicalmachinist.com
 
rwm said:
I think so. Maybe they don't realize the insert will interfere first? I was very specific with my question to them.

It looks like I could just switch to a CPMT insert? Would the holder accept this?
Click to expand...

I also have some Mesa tooling that I've been satisfied with, but don't have this particular tool. Maybe you should send them the link to this thread and see if they respond.

Ted
 
mksj said:
Similar comment on Mesa boring bar. Might be that a CPMT will give you more insert clearance but the insert pocket is different so the insert may not be secure. On smaller holes I used brazed carbide.

Question on CCMT inserts for boring bar in boring head

I have been using a Criterion boring head in my Bridgeport. The Criterion bars which came with the head don't handle interrupted cuts well. I have wanted to try using a bar with inserts. After reading past threads on the forum, the consensus seems to be that sclrc boring bars using ccmt...
www.practicalmachinist.com
Click to expand...
Looks like that person got a different response from Mesa (2.0"). I guess it depends on whom you talk to. I cannot seem to find my email from them but their website clearly states .925"
I think I am going to make my own tool. I guess I need to ruin a 1/2" end mill first. That won't take too long...

Yes, I was wondering about the pocket. It might be too loose of a fit with the increased clearance of a CPMT.
 
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