spade drill flute question

[subi4ester]

Looking for experience / recommendation on using a straight flute spade drill holder (series 1 w/ 49/64 insert) in a vmc (VF3 with TSC). Wondering if any one has done this successfully using TCS to help clear chips. I have broken a straight flute holder in the past, but manually drilling with a bridgeport, and just before discovering spiral flute holders for vertical use. Now considering trying the straight flute again, but on the cnc with the added dimension of TSC?

[Donkey Hotey]

Your cutter vendor should be answering these questions for you but, since we all know that saleseman vary in both experience and honesty...

Yes, I believe it should work fine. Haas runs demos all the time cutting 2.5-3.5" holes into steel, with no pilot hole. They do this on CAT40 machines--though they do have the gearbox option. Do you have a gearbox?

[subi4ester]

Cat50, gearbox yes, my question isn't if the machine can do it, I already drill larger holes using spiral flute spade drill holders. I am concerned about using a straight flute spade drill holder in vertical drilling.

[WOLOG]

I have a VF-5/50 with 1000 psi TSC. A straight flute holder will work, but.... That depends on the depth , diameter and material. I find that when I use a larger insert size for the series of spade bar, I have more problems with drilling 17-4 PH and some 4140. The 17-4 will pack up tightly once the TSC can't overcome the weight of chips stacked up. i try to avoid that situation whenever I can. I think it is a trial and error thing until you can find the right feed/speed/diameter/depth for your app. I also tend to make the drill string on deep holes rather than chip just to avoid locking up a drill in a part. I will bump feed hold whenever I need to.