CharlieWaffles

CharlieWaffles

Well Known Member
So I realized I should have enlarged the tooling/conduit holes in my right wing so I can run my AOA tubing through some bushings rather than take up room in my flex conduit. But the ribs are already riveted to the main spar, so I can't drill the hole larger (7/16") with a normal unibit. I have a 90 degree drill adapter, but it wont chuck the large unibit, and I dont see any threaded base 7/16" drill bits available for it either. So other than finding a REALLY long drill bit at home depot that I could plunge all the way through all the ribs from one side, any ideas?

Basically, you can see in this picture, the bushings I want to be able to install in my other wing as well as the un-enlarged tooling hole.

http://myrv10factory.files.wordpress.com/2011/05/img_0901.jpg
 
Unibit

Suggest a smaller Unibit. The 1/2" size should fit. I've used this size in a 3/8" right angle cordless drill (Milwaukee or Bosch 12V) in some real tight spots.

Good luck,
Mike
 
extensions available

Check at the tool dept. in your local lumber yards, home depot etc. you can find drill extensions in many different lengths. They work like this, one end has a hole for your unibit and two allens that secure it and the other end chucks up to your drill. Maybe you can give that a try. I would think that you would need and extension just long enough to get through the root where the doublers are and after that an air drill and unibit should get the rest. Just a thought.

good luck,

bird
 
That'l work

bird said:
Check at the tool dept. in your local lumber yards, home depot etc. you can find drill extensions in many different lengths. They work like this, one end has a hole for your unibit and two allens that secure it and the other end chucks up to your drill. Maybe you can give that a try. I would think that you would need and extension just long enough to get through the root where the doublers are and after that an air drill and unibit should get the rest. Just a thought.

good luck,

bird
Click to expand...

I used exactly such a setup to drill the conduit holes in my quickbuild wings. Kind of scary looking in progress, but it worked just fine.
 
I've seen those extensions at Home Depot in the electrical department; they're for drilling in walls and ceilings for conduit. They are also flexible, so they're useful for drilling bulkheads along, say, fuselage skins. Takes two to use; one to run the drill and the other to guide the bit.
 
I bought a cheap unibit from Harbor Freight that had a narrow hex drive shaft. I ground off the corners of the hex drive shaft until I could get it to fit into the small chuck of the angle adapter. Worked good enough, and not expensive.

Be sure to open up the tooling holes on the center section seat ribs of the fuselage before you rivet on the floor skin. :D
 
bruceh said:
I bought a cheap unibit from Harbor Freight that had a narrow hex drive shaft. I ground off the corners of the hex drive shaft until I could get it to fit into the small chuck of the angle adapter. Worked good enough, and not expensive.

Be sure to open up the tooling holes on the center section seat ribs of the fuselage before you rivet on the floor skin. :D
Click to expand...

Also, if you grind it so it is around 1/4 inch diameter it will fit in a cheap HF angle grinder... may be a bit more compact than the angle adapter -

unibit-angle.jpg
 
Like Gil shows there

I chucked up the opposite end of my unibit in a bat powered drill. Put some tape around it to keep from dulling cutting edges. Dress your grinding wheel true/smooth. Run the unibit shank up against the fine grit grinding wheel while spinning. Wear your safety gear while doing this.

I also used my 90 degree with a 1/4" burr bit from Lowe's. Just mark your hole with a sharpie. Rough cut with the burr. Then take some 120-240 grit sandpaper rolled around a 1/4" to 1/2" dowel to smooth out rough edges.
 
Get an appropriate diameter rod or tube that is as long as you want that you can chuck in a motor. With the tube or a drilled hole in the rod, pound the OD down so the hole grips the unibit. (It's called hammer forged rifling in the gun business.:p) Worked for me.

John Siebold
 
I did a 3/4" hole all the way through on my QB wings with a unibit and extension, pics in build log.
 
I have the cheap harbor freight unibits with the hex shanks. Also went to my local home improvement store that begins with "L" and bought a right angle drill adapter that accepts hex shanks. I think it was around $20 for the right angle drill adapter, Milescraft is the brand. It's cheap and makes a lot of noise but so far is still kickin'. Also good for deburring holes in tight spots.
 
img_2044-M.jpg

Here is a picture of my HF unibit in the angle adapter chuck.

Very easy to get in those tight spaces.
 
Socket Extension

I had to open some holes up after the skins were on. I found an idea on this forum using a 9mm socket, socket extensions and an adaptor for a drill driver. I filed the stem of the unibit to to create a rough hex pattern, wrapped the stem in masking tape to stick it into the 9mm socket, and added extension as needed.
 
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