airguy

airguy

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I'm only a few days away from tackling my canopy - where are you guys finding the special plexiglass drillbits for use on the canopy?
 
Plexiglas drill bits

Avery
http://www.averytools.com/pc-716-27-plas-drill-plastic-drills.aspx

Cleaveland
http://www.cleavelandtoolstore.com/products.asp?dept=22

Craftics
http://www.craftics.net/ShowItems.aspx?Category=132&ParentCategory=87
Plas-drill bits have 90 degree included angle and zero rake angle, only 8 sizes
http://www.craftics.net/ShowItems.aspx?Category=133&ParentCategory=87
Plexipoint bits have 80 degree included angle and zero rake angle, available from 1/16" up in increments of 1/64"

I noticed my local plastics supplier had some as well.

AC43.13 shows a 150 degree included angle and zero rake angle for acrylic plastics and also recommends an Unibit
 
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don't bother

I used plexi bits and still got cracks. Later, I was advised by one of the gurus on this site to simply to further dull a used #30 bit by drilling it into cement for a few bursts. I did just that and it worked well on the canopy.
 
...and a Unibit...

...in a slow cordless drill will work well to make small holes larger - but not for that initial hole.

I too drilled with a used #40 drill bit and had no trouble even in cool temperatures.
 
I've had good success with simply reversing the drill and using standard (not too sharp) bits. It simply melts its way through without any grabbing at all.
 
Glue the blimin thing with sikaflex and save your fears of cracking for something else...

Seriously I bolted on the outriggers of my 9 tonne steel trimaran and used sikaflex just to seal the plates. When I came to unbolt them years later I had to jump up and down, prise with bars and all kinds of things before the sika gave way. Sika is **** strong, flexible and UV resistant and probably a bit quicker too...
 
TAP Plastics has several outlets here in the Northwest which several different sizes of plastic drill bits. Much cheaper than the aviation tool stores and of high quality. I've got a few sizes and have been impressed thus far.
 
I bought the plexibits from averys....zero problems...and saved a few hundred over buying sika stuff.
 
Plexiglass Bits

Buy your bits from Avery. He has quality tools. Be sure to have the Canopy very warm before you start drilling, I put a Ceramic
heater inside and brought the temperature up to about a 100 degrees and did not have any problems or cracks. The canopy temperature can not be too hot. If it is chilled you will have a good chance of cracks.
 
warm canopy

I tried it at 75 degrees and cracked the #%&! canopy. 2nd time, I bypassed my garage heater till it was about 85, then I heated the area where I was drilling with a heat gun to about 100, checking with an infrared temp sensor.

Be VERY careful to sand the edges smooth before you handle the canopy after cutting. I found the Harbour freight oscillating multifunction tool worked good for cutting. It does not tend to take off on you. It takes about 4 passes to get through.

try bending a scrap piece that you trimmed off. with the edges rough, it shatters with just a little bending. smoothing the edges makes it much less susceptable to crack from stress.
 
Try tapered drill reamer

See http://www.vansairforce.com/community/showthread.php?t=48367&highlight=tapered+reamer&page=2

I drilled scraps just out of the freezer, while pushing hard with no backup and could not crack the plexiglass.

Drilled the entire canopy with these bits and not a single chip on any hole exit. I did pilot the holes with a standard #40 drill first. That did create small ships on the exit side, but the tapered drill reamer removed all of that and left a clean, smooth hole.

Plus I never did work on my canopy in temperatures above 65F.
 
who makes the canopy???

Since we are going to live with these canopies from now until...well, forever,
It would be nice to have the real goods on how to care for them.
Who is the manufacturer of most? Has anyone seen a tech sheet on the material?
Even some of the manufacturers tech info isn't necessarily applicable to aviation uses of blown acrylic. This info at least gives specs on drill bits.
I've had good luck making my own with a dremel.

http://aristechacrylics.com/sites/default/files/tb134_0.pdf

In the sign & display business it was common practice to use a flame to melt the cut edge and leave a beautiful clear wet look....but this only works with non structural flat stock; it seems any further stresses, bending etc. can cause cracks!
Sanding and then machine polishing seems to be the best way to relieve edge stress from cutting. I always found the vertical edge cutting action of a router preferable to a circular saw or recip saw.
 
Wet and dry paper...

flyboy1963 said:
...
Sanding and then machine polishing seems to be the best way to relieve edge stress from cutting.
.....
Click to expand...

....used wet does a very good job of polishing the edges. If used dry, it clogs quickly.

Sanding by hand with a rubber block works fine - no power needed...:)

The material is relatively soft, so it doesn't take long to use each successive finer paper down to 1500 grit or smoother.
 
Sikaflex is not that expensive - just glue the blimin thing. My canopy was drilled and when I got her flying, a bit cracked and fell off. Now I am constantly worried it is going to crack again, so I am drilling out the pop rivets and squeezing in sikaflex and then using small bolts in the holes with stiffnuts that are just snug not even pinched. My other RV is going to be all sikaflex.
 
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