plexi-drill bits

gsimatos · Post by **gsimatos** » Tue Nov 18, 2008 12:55 am

Anyone aware of a supplier for a number 27 plexiglass drill bit for drilling the canopy holes?? Thanks Gary

Post by **bullojm1** » Tue Nov 18, 2008 4:07 am

Gary-

Why do you need #27 plexi bits? If you read the instructions carefully, it tells you to enlarge the holes in the plexi to 5/32" (which avery sells a bit for). The reason behind making the hole bigger than a #27 is to allow the canopy to expand and contract with heat. I think Van's thinks theres a possibility for cracks to occur if you don't oversize the hole.

DanH · Post by **DanH** » Tue Nov 18, 2008 11:10 am

Don't need to buy a special drill bit. Grab an old, dull bit you might be ready to throw away. Hold it parallel to the surface of a hone stone and drag down the stone so as to put a flat where there was a cutting edge on each flute. The flats should be about parallel to a plane in the long axis of the bit. The idea is to convert the edge from a cutting wedge to a scraper.

Be sure to mark this bit with some tape before you throw it back in your drill box <g>

Mike Balzer · Post by **Mike Balzer** » Tue Nov 18, 2008 2:29 pm

I have found that an Uni-bit works great when you have a small pilot hole.

I have installed a couple of windows in aircraft by this method

good Luck,

Mike Balzer

Bob Barrett · Post by **Bob Barrett** » Tue Nov 18, 2008 10:00 pm

My friend who I will leave nameless carefully drilled and clecoed his canopy to the slider frame after carefully cutting the canopy. He enlarged the holes to the next size and left it in the unheated EAA Chapter hanger here in Minnesota. One day another member of the Chapter was out looking at things in the hanger and ZING! A cleco sailed over his head from the canopy hit the wall. When my friend returned from Texas in the Spring he found a nice big long crack in the canopy. My friend had the privilage of ordering a new canopy and match drilling it to the holes in the canopy frame. Needless to sat he enlarged the holes in the second canopy considerally! I also made the holes in my canopy extra large.

Mike Balzer · Post by **Mike Balzer** » Tue Nov 18, 2008 11:42 pm

I couldnt agree with you more Bob,
I use to enlarge the holes to 1/4 for a 3/16- 10/32 screw. You defiantly need some clearance.

Mike Balzer

gsimatos · Post by **gsimatos** » Wed Nov 19, 2008 8:26 am

Again, Thanks very much for the info you guys. Gary

gsimatos · Post by **gsimatos** » Wed Nov 19, 2008 8:38 am

While I am thinking about it what sort of drill speed do you think is best. I have a portable drill which turns very slowly and I get pretty nice holes. This is with the regular metal drill in a practice piece of plexi. I do however get chips when the drill emerges on the opposite side. Maybe more RPMs with the air drill would be better. Anyway, ain't going near the canopy til I have a couple of hundred nice holes. I will try modifying a drill but failing that I will give Avery a call. THX Gary

Bob Barrett · Post by **Bob Barrett** » Wed Nov 19, 2008 9:03 pm

I purchased my bits from Avery or Cleveland. I felt that it was cheap compared to the price of a new canopy. I keep them seperate and don't allow anyone besides an airplane builder to use them. I just recently had to use one my self for something. I don't remember where or why but it is nice to have some bits you know will work on Plexi with out harming it.

RivetBangers.com

plexi-drill bits

plexi-drill bits

Enlarge those holes in Plexiglass!!!!!!!!!!!!!!