Canopy install

[Gripdana]

I'm getting the frame assembled. Since the canopy is sort of a bubble I can't quite figure out how to set the bows in relation to rest of the airframe. Should the bows be 1/8" inch below or flush with the airframe and windshield. Or is there another way to set this so that the faces are flush?

[Gripdana]

I finished the canopy. 100 degree heat while cutting and drilling. Here is a link to the photos on flicker.
https://www.flickr.com/photos/90889513@ ... 1591930853
https://www.flickr.com/photos/90889513@N04/

[rizzz]

Ok,
I’ve just started fitting my canopy, haven’t started cutting yet, only laid it in place for the first time last night. As pere the instructions I will start by cutting to the factory placed tape first and then go from there.
I’m still debating if I will cut using the factory band saw method or with the Dremel tool with cutting wheel, the latter I can do by myself which is an advantage.

Now for the (scary) drilling part, I will just make drill bits as per the Sonex method, i.e. dull the edges and flutes, most people seem to have success with these.
To do the actual drilling though, is it best to use high speed and low pressure? My intuition is yes but would like to hear from people who have done it.
Also, to you drill a very small pilot hole first and very gradually up-drill? Do you maybe up-drill in only a few steps? Or; Do you drill as close to the final size as possible from the start?

Thanks.

[falvarez]

I did my canopy install completely by myself using the advice of another Sonex builder...no cracks and it was fairly easy to do...

What he had advised me to do when cutting the canopy is to set it on an elevated padded surface with the sides draping down (like a square card table with a couple pillows on top). This way you have easy access to all the edges. I used the Dremel cuttoff wheel method and it worked great for the rough cuts. I found that a belt sander with 120 grit worked great for removing the last 1/16 to 1/8 inch up to the line. Then I just used a sanding block to smooth the edges before moving the canopy...of course I repeated this process numerous times throughout the fitting.

Regarding the bits, I rounded off an my old bits...and I mean almost a completely rounded tip. It took about 10 to 20 seconds to drill each 3/32 hole and it was clear that the bit was melting the plastic rather than cutting into it. I think the key thing on the bits is to make sure you are melting the plastic. I then updrilled the holes with rounded off 1/8 and 5/32 bits.

[rizzz]

I think the key thing on the bits is to make sure you are melting the plastic.

That’s what I hear.
You’ve got to wonder though, If we’re really melting our way through the canopy rather than drilling, wouldn't it be easier to make a pointy piece of 3/32 rod (or whatever gauge required), heat it with a propane torch until glowing red and then just “push” it through the plexiglass?

[fastj22]

drilling is easy. Just take your super sharp, brand new, fancy bit, put it in the chuck and drill a shallow hole in concrete. At that point, its perfect for drilling the canopy. It will melt through and leave you a perfect, crack free hole. Practice on scrap and you will agree. I've done two canopies. Trust me.

[sonex892]

Hi Michael

I totally fitted my canopy by myself. I don't recommend it but my helper wasn't in town the weekend I got keen to fit it.

My choice of cutting tool is a small angle grinder with standard metal cutting wheels. Not the ultra thin blades! The plastic goes semi liquid and bubbles up a bit from the heat when cut, and the narrower gap of the thinner blades seems to allow the perspex to touch and stick back together before it cools. Whereas the wider blades and cut gap don't seem to have that problem.

For trimming I also used the angle grinder with a flap disc. With a coarse flap disc a lot of material sands off real quick. So can get it down to near where it needs to be, then go to a finer flap disc for final shaping. I didn't sand anything by hand until it was basically to the finished size. The canopy being a 3 dimensional shape is a lot like trimming the cowling.

I know we can grind our own drill bits, but for the price of a few dollars each I bought perspex drills from spruce. They work great. They are also very cheap compared to the cost of freighting a canopy to Aus.

My canopy has been on the plane and in use for over 4 years. So far no cracks. It was also the old material which had been sitting in the box for over 4 years. I still have a brand new, now 9 year old spare canopy in the box as insurance.

However you do it good luck

Cheers
Steve
Sonex 892

[DCASonex]

Best tool I have found for cutting canopy is the half moon wood/plastic/soft metal saw blades for oscillating multi-tools such as the cheap ones from HF. Trick is to drag the blade along the cut line, cutting deeper with each pass, and not cut all the way through in one pass. While blade is cutting the surface, vibrations are in same plane as the material and do not cause the material to vibrate. If saw plunges deep into the materiel, the vibrations become more in an up and down plane like a saber saw. It is very easy to cut a nice straight line with this, and progressive trimming is easy with minimal handling of the canopy.

Same tool also works great for trimming the cowl. However count on wearing out one blade on this. (Blade for cutting canopy should be new and sharp.)

David A.

[Gripdana]

I did it exactly the way Sonex recommends. Everything worked out great. My brother came over and assisted with cutting.

[rizzz]

So far it’s been going well, cutting using the Dremel tooll with cut off wheel, initial sanding using a small palm belt sander, finishing off with a bit of block sanding.
I have been able to do it all myself, I know it’s not advised but I feel being very careful it’s doable.
Some pictures:

The tools Dremel tool, palm sander and sanding block:


Cutting setup:


After 2 Initial cuts a slight overlap remains on the aft side:


Another cut, good fit between the turtledeck and windscreen now, will need more material removed to achieve the 1/16 gap but I’ll do that later:




Now I need to start cutting the sides.

I’ve done some drill tests on a bit of the scrap pieces I’ve been cutting off and I must say, this “Sonplex” material is much harder to crack than I initially thought.
Even using sharp new drill bits and high pressure I’ve not been able to crack it with the 3/32” or 1/8” drill bits, only when using the real thick drill bits without pilot drilling I’ve been able to crack the material.
That’s encouraging but I’ll need to make sure I don’t get overconfident and remain cautious.