Indexable carbide boring bar advice?

[Mirage_Man]

I'm in the market for a new indexable carbide shank boring bar. I have a 3/8" Kennametal that uses CPMT 21.51 inserts already. I need something that is a bit thicker that will allow me to get deeper into a larger hole without chattering. I've been looking at a 1/2" "W" or "Trigon" style holder for awhile but wonder if it's all it's cracked up to be? The one positive to them is they have the smallest min. bore/ shank diameter that I have seen. Since I work mostly with smaller lights in the 123A to 18650 range the shank really can't be any bigger than 1/2"-5/8". I would prefer that the bar have a flat to help locate the right angle.

What are you guys using with good results? BTW I work mostly in 6Al-4V ti.

 

[Mirage_Man]

Nobody has any thoughts or experience?

 

[precisionworks]

they have the smallest min. bore/ shank diameter that I have seen

Sometimes that works well, but it can also cause problems because chip clearance is so limited. In any boring op there's a good chance that the insert is getting serious abuse because some chips are passing back between the insert and the wall of the bore ... and the stronger the corner the better the insert will handle that. Hard to beat an 80° diamond (CNMG -3xx or CNMG-4xx) when that happens, although the 60° edge of the trigon is next in line for strength.

I imagine you probably bore to the same dimension each time, depending on battery size. Have you considered drilling to just under bore size, using an indexable drill bit with coolant through, and reaming the final amount? Finish & hole straightness will both be nicer than boring, but you'll need carbide tipped reamers for each battery size.

 

[mansell2]

IMHO Here is my 2 cents on boring tooling. At work we use kenametal, seco, and sanvik inserts. We also use tooling from each co. Here is my opinnion.

Sanvik - Excellant tooling with high price tags. Their anti vib boring bars can not be beat. If you need to go deep - they are the best. But it may be hard to justify the price tags for hobby work.

Seco - Excellant insertable drills. The do not have anti vib boring bars. But there insertable drills are amazing. Again price tags may surprise you.

Kenametal - Good, but lags behind Sandvik and Seco in many areas. But the pricing is much better. If the Kenametal will perform the task you can save on tooling $$.

What diameter and depth are you attempting to bore? mansell2

 

[Mirage_Man]

I imagine you probably bore to the same dimension each time, depending on battery size. Have you considered drilling to just under bore size, using an indexable drill bit with coolant through, and reaming the final amount? Finish & hole straightness will both be nicer than boring, but you'll need carbide tipped reamers for each battery size.

Barry, because I work to tolerances to within .001" on the depth of the hole I have never thought about going any other route than a boring bar. I always touch off the edge of the outside and zero my DRO so I can get the exact final depth I want. I of course drill to as close the final diameter that I can before boring it the rest of the way. Problem is if I get too close there's always the change the drill will wander ever so slightly and then the finished ID will be screwed up. So I don't get too close to the final ID with the drill. Did that make sense?

My ID's are around .670" and .750" Depths vary by battery length or quantity.

 

[cmacclel]

Barry, because I work to tolerances to within .001" on the depth of the hole I have never thought about going any other route than a boring bar. I always touch off the edge of the outside and zero my DRO so I can get the exact final depth I want. I of course drill to as close the final diameter that I can before boring it the rest of the way. Problem is if I get too close there's always the change the drill will wander ever so slightly and then the finished ID will be screwed up. So I don't get too close to the final ID with the drill. Did that make sense?

My ID's are around .670" and .750" Depths vary by battery length or quantity.

Dude the holes are for battery's.....and your talking +/- .001 give me a break

Just kidding
Mac

 

[Mirage_Man]

Dude the holes are for battery's.....and your talking +/- .001 give me a break

Just kidding
Mac

I know, call me crazy :huh:.

 

[Mirage_Man]

Well I ended up getting another CPMT style bar in 1/2". Just used it and it works perfectly. Got the Ultradex brand from a local tooling supplier. I just couldn't find a Sandvik on ebay and wasn't going to spend $400 or more on one.

 

[cmacclel]

Well I ended up getting another CPMT style bar in 1/2". Just used it and it works perfectly. Got the Ultradex brand from a local tooling supplier. I just couldn't find a Sandvik on ebay and wasn't going to spend $400 or more on one.

I bought all of my carbide boring bars on Ebay. The most expensive was a 5/8 10" bar with 25 inserts for $110.

Mac