Final drilling the Nose Gear Flange

[FlyingDiver]

Section 46iS-05, Figure 1. Final drill 3/8".

What kind of drill bit should be used? I've tried every 3/8" I had, including getting a cobalt steel bit from Ace that's marked "Hard Metal". I'm making very little progress.

And I did drill it out 5/16" first to get a head start.

 

[Tony_T]

Hardware store bits have never worked well for me, even so-called Cobalt. I order my drills from an aircraft tool supplier. That said, the nose gear metal is very hard. I used a plug in drill motor with lots of torque, the battery powered motors just spin and hardly cut. Use a slow speed and lots pressure and good cutting lube on the bit. When the drill speed, pressure, lube and bit are working right you can feel it cutting. It is still slow going.

Since you are building new at least you don't have to match drill it with 18" bits and bushings from the inside like we had to do to replace the nose gear by the Service Bulletin.

 

[FlyingDiver]

Yeah, I hear ya. Hate to buy yet another drill just for this. I'll ask at the EAA mtg tomorrow if I can borrow a drill and bit.

 

[Bob Y]

You’re going to need it again to drill the mounting hole for the canopy gas struts. Those were tough for me.

 

[12vaitor]

I have used Trefolex Cutting Paste for many years for drilling and tapping with steel and stainless steel. Drilling thick steel and SS is about a sharp drill, slow speed, good pressure and a good lube. Trefolex has the consistency of grease, so you can dab it on the end of the drill bit when starting and in the hole as it progresses. If you try the high-speed approach all you will do is heat the bit and dull it. You can tell a good cut if you are getting long shavings (1/2"-1") and that is just at a few rpm. Cut a little, lube, cut some more, more lube.

It's hard to find, but a little will last a long time and will help keep your drills and taps sharp.

John Salak
RV-12 N896HS

 

[RFSchaller]

I’ve trashed a lot of Harcor Freight bits drilling holes. My MO is start small and gradually increase hole size. The final enlargement is done with the expensive bit that I don’t want to trash.