Drilling Canopy:

I had no success with the masking tape method of measuring the tangent line of the canopy to the front bow. I ended up running black electrical tape across the bow and using a silver sharpie to make the tick marks every 2". I made them as a little cross. Then, with the canopy on, the canopy contact line made a shiny line on the black tape. On the cowling I marked whether rmy target was right on or whether it needed to be drilled 1/16" forward or back, etc.

Questions:
Is there supposed to be a rivet in the center 2" where the weld is?

We have to redrill every hole , from #40 to #30, or from #30 to #27. Is there a less risky alternative? Burning holes makes stress, and I don't have a #27 unibit.
Why not drill #30 and #27 holes in the first place?

Further on, you are supposed to drill the rollbar, etc #30 and tap for #8 screws. Won't this break the tap?

John

Previous suggestions

No hole in the center of the front bow. Drill -ONCE- with and drill bit only, period. Then use a small uni-bit to enlarge, and use a slow turning drill with light pressure. I would not oversize any hole in plexiglass with another drill bit, even if a plasti-bit. The holes other than the front bow are all going to have screws and nuts, no tapping.

John Bender

JBPILOT said:

No hole in the center of the front bow. Drill -ONCE- with and drill bit only, period. Then use a small uni-bit to enlarge, and use a slow turning drill with light pressure. I would not oversize any hole in plexiglass with another drill bit, even if a plasti-bit. The holes other than the front bow are all going to have screws and nuts, no tapping.

John Bender

Click to expand...

John,

Just wanted to say "thanks". I did exactly as you recommended and everything worked out smoothly. I have worked plexiglass before and had problems doing it the way I was directed. You saved the day.

Pete

John, what did you use under the heads of the rivets? I drilled the holes out with a 5/32nd unibit. When I counter sunk the hole there isn't much left for the rivet to sit on. Is this a point of pressure using rivets that could cause a crack down the road?

I wonder why tapping the holes in the front bar and using counter sunk screws wouldn't be a better way to go. It is covered by fiberglass anyway, and it would be much less less stress on the Plexiglas.

Larry, Pete

Larry, I like your idea. And you are completely correct, it is covered up completely anyway. A CS screw and threads would work as good if not better than the instructions. The CS rivets instructed do not allow any side to side movement, and have to add some stress on the hole. I used a very thin steel washer under the rivets. It makes a little more work when you fiberglass, but I really don't like the stress and no movement with the instructed method. Time will tell, but our ideas will work fine.

Thanks pete. Saves lots of bad words and everything else.

John Bender

JBPILOT said:

Larry, I like your idea. And you are completely correct, it is covered up completely anyway. A CS screw and threads would work as good if not better than the instructions.
John Bender

Click to expand...

The alum tubing is rather thin wall so you would have at the most, two threads of the screw engaged...in aluminum no less. Not a better choice in my opinion.