Custom Piloted, Inserted Drill

[Frank Caudillo]

Hi everyone,

I'm looking for suggestions on custom tooling companies that could produce a piloted/inserted drill for deep holes. We're trying to drill about 16" deep in 7075 aluminum with roughly a 1-9/16" diameter. Tool will need to be for a CAT50 horizontal mill. We're currently talking with Guhring and Allied Machine & Engineering. At first they were positive they could produce this for us, but lately they've been pushing back, either telling us it isn't possible or suggesting other methods. I understand tooling companies have a great deal of experience and may not want to try something in case it doesn't work to cover their bases. 

Are their custom tooling companies anyone has worked with that has been willing to produce some crazy stuff? I appreciate any suggestions. Thanks. 

[mkd]

so you are trying to achieve something that a coolant fed spade drill won't do?

not sure of the pilot you speak of.

BTW, i was just watching the Okuma video on youtube this weekend. Nice!

[Frank Caudillo]

We have coolant fed spade drills but we have issues with them wandering. We had planned to drill a pilot hole with a deep hole carbide drill, then come in with an inserted drill with a pilot that would follow the pilot hole. 

[mkd]

I've tried this method with a non-piloted spade drill and ended up fighting chatter.

maybe the pilot will help.

I might be more inclined to have a conventional spade drill shank modified with a carbide rod shrunk into an ID bore.

 

Edit: what about a gun drill? they have quite a land on the tip for guidance.

[Frank Caudillo]

Not sure I'm tracking on your idea for a modified spade drill shank. 

We considered a gun drill at first but the finished hole diameter will end up as an interrupted hole - a gun drill probably wouldn't do well in that situation. The pilot size (.75") is small enough that it would be solid thru the length of the hole, so no issues there. 

[Guest]

1 minute ago, Frank Caudillo said:

Not sure I'm tracking on your idea for a modified spade drill shank. 

We considered a gun drill at first but the finished hole diameter will end up as an interrupted hole - a gun drill probably wouldn't do well in that situation. The pilot size (.75") is small enough that it would be solid thru the length of the hole, so no issues there. 

I have used a gundrill on uppers and the end of the hole is interrupted....in that application it worked out OK

[jlw™]

i would look at iscar sumocham for first choice or eldorado/dme for a gundrill.

[Frank Caudillo]

43 minutes ago, JParis said:

I have used a gundrill on uppers and the end of the hole is interrupted....in that application it worked out OK

We might give it a try then. We'll talk with various manufacturers and see what they recommend. Thanks!

8 minutes ago, jlw™ said:

i would look at iscar sumocham for first choice or eldorado/dme for a gundrill.

Thanks, Jlw. If we can't find an off-the-shelf solution we'll talk with them about something custom. Thanks!

[Guest]

I use these guys for gundrills.....they've yet to let me down

 

http://dmetool.com/

[jlw™]

That's Eldorado JP, same for me.  Always good, always fast.

[Frank Caudillo]

Excellent. Thanks for the suggestions, guys. 

[mkd]

1 hour ago, JParis said:

I have used a gundrill on uppers and the end of the hole is interrupted....in that application it worked out OK

Wonder how to get that to work from the opposite end. Pilot bored diamter with center drill for tip of gun drill?

[Guest]

1 minute ago, mkd said:

Wonder how to get that to work from the opposite end. Pilot bored diamter with center drill for tip of gun drill?

 

Came in from the barrel extension end