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Bt30 Experts - enlighten me with BT30/BBT30 tooling advice

Joined
Mar 9, 2021
I will soon have a number of BBT30 (dual contact) mill-turn machines, similar in form and function to a Mazak Integrex or DMG Mori CLX/CTX. They have 10kw, 24,000 RPM BBT30 spindles.

While I have used CAT40 dual contact and BT40 non-dual contact before on VMCs I owned in the past, I would like to know everyone's best practice tips for 30 taper machines, as well as specific tools and holder types that people have had good results with.

My biggest concern for any 30 taper machines is how to make features that require long tool gauge lengths, such as big and deep holes, very tall sidewalls, or deep pockets with small radii in the bottom. These are the types of parts and features that I struggled with in the past due to chatter, chip evacuation, tolerances, etc. I have seen some impressive demo cuts with Brother machines, and I want people who have experience doing heavy of difficult cuts with BT30/BBT30 machines to tell me how I can safely pull off these types of cuts without bustin pull studs and sending holders through the safety glass at 20k rpm.
 

finix

Plastic
Joined
Jan 31, 2021
Is it a brother m200 or m300? If it is, then it’s nothing like a Mazak intergrex/or mori ntx(ctx). Are you located in Taiwan?
 

DavidScott

Titanium
Joined
Jul 11, 2012
Location
Washington
So much depends on how much drawbar pressure you have, so how much in your machines? The more you have the more projection you can get away with. The trick to not bustin pull studs is to not overpower the drawbar pulling the tool holder out of the spindle while in the cut.
 

LOTT

Hot Rolled
Joined
Nov 28, 2016
I figured it out, he has a SwissMak. Has a 30 taper, sort of a mill/turn-ish setup.

Just a joke, I hope....
 
Joined
Mar 9, 2021
Are you intentionally posing this question as a riddle?

Is the name of your machines top secret?
The Taiwanese machine builder mostly does OEM work for Japanese and Korean CNC brands, a lot of pallet changing HMCs and automated cell type production lines, this machine has a Mitsubishi controller on it. The OEM does build much larger mill-turn machines with HSK spindles, but doesn't want this new one to be revealed until a trade show next year.
The BBT30 spindle has 300kg of drawbar force.

I am just asking for what types of tools and holders are good to use with a BBT30. I have read on this forum that 10mm endmills and under are best for BT30 because they break before the pull stud does. But I have seen some demos of much larger tools being used on BT30s.
 

DavidScott

Titanium
Joined
Jul 11, 2012
Location
Washington
300kgs is good but not great. 12mm is the common largest size end mill you should use to protect the spindle should you have a mishap. Most mishaps that break the pull stud involve pulling the tool holder out of the spindle some, which then puts a side load on the pull stud, which is what breaks it. BT30 pull studs are good for around 11,000 lbs tensile so you are not going to break one without the side loads. The overriding rule of thumb for 30 tapers is to minimize the tool projection to an absolute minimum. The less side force on the tool the more projection you can have. If you have too much you will get chatter and if bad enough you will get fretting between the tool holder and spindle taper. If you slowly increase how hard you push the cut you will get plenty of warning signs before anything real bad happens so don't be shy about it, just do it in controlled increases. Of course there is way more to how robust the 30 taper holders are than just the holder, there is the spindle and the rest of the machine. Kitamura does some pretty impressive cuts with a 30 taper in their little horizontals on Youtube that you wouldn't imagine doing on any 30 taper verticals being made now.
 

gkoenig

Titanium
Joined
Mar 31, 2013
Location
Portland, OR
I am just asking for what types of tools and holders are good to use with a BBT30. I have read on this forum that 10mm endmills and under are best for BT30 because they break before the pull stud does. But I have seen some demos of much larger tools being used on BT30s.

10mm or 3/8" is the rule of thumb I tell folks for job shop work where you're getting setups on-off, programing quickly, often have a lot of different things going on at once, might not have the best dimensional control on your stock, etc etc. It is the safe default.

I've run 16mm tools at very aggressive feed rates on scaled production jobs with absolutely no problem. This is an environment where we are 100% confident in the work holding (Schunk KSP vises with part presence detection), 100% confident in the stock thanks to gauging on the automated band saw, and we took our time incrementing up to some relatively aggressive feed rates (50mm DOC, 1.5mm WOC, 12k, 3000mm feed)
 

Orange Vise

Titanium
Joined
Feb 10, 2012
Location
California
I've run 16mm tools at very aggressive feed rates on scaled production jobs with absolutely no problem. This is an environment where we are 100% confident in the work holding (Schunk KSP vises with part presence detection), 100% confident in the stock thanks to gauging on the automated band saw, and we took our time incrementing up to some relatively aggressive feed rates (50mm DOC, 1.5mm WOC, 12k, 3000mm feed)
Not bad.

I usually run 17mm tools at 51mm DOC, 1.6mm WOC, 13k, 3100mm feed.
 
Joined
Mar 9, 2021
Not bad.

I usually run 17mm tools at 51mm DOC, 1.6mm WOC, 13k, 3100mm feed.
The legendary, ultra-rare 17mm endmill.

I think I remember seeing a forum poster here showing an extended, reduced shank carbide endmill in a hydraulic holder cutting a titanium plate. I wonder if this would work with a stubby sidelock for minimal gauge length. I have used a 16mm endmill at a gauge length of 5.5 inches recently, but I'm always afraid it will get kicked out of the spindle and trash everything. It looks cool when its running though.
 








 
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