Angled holes through tube

[bobp]

I am prototyping and need to drill? 3/16" and 5/16" holes at 30 to 40 degrees through thin walled aluminum and steel tubing .50 to 2.0" d.

I have the fixtures to clamp the tube in place - the problem is the deflection of the hole, particularly on the bottom of the tube as the bits skate down the inside of the tube.

As I am doing a number of test holes at various angles and through different diameter tubing any suggestions on performing this operation without making elaborate guides?

Should I be using a mill bit instead of a drill bit?

Thanx, Bob

 

[jcrowe]

Bob,
Using an end mill will help a lot, the edge cuts into the tube wall and helps prevent sliding. The more fool-proof way is to make a "drill guide" and harden it after you have the guide hole, then use an end mill in the drill guide, as even the mill will deflect as it reaches across the tube trying to do both walls in one pass you may have to do the hole(s) in two passes of the drill guide so each pass only does the one wall.

JSC

 

[umamagesh]

Try designing and using two hardened guides one on the inside of tube and one on outside of the tube. Why dont u try laser drilling or wire cutting if you are so particular and you need hole on either wall of tube. End mill will help you if you are still wanting to go for drilling process.

 

[coachjoker]

You don't mention volumes, but you could pilot from both sides then finish straight thou.
Also solid carbide mills will deflect less.
We index the parts in these operations.
Joker