RV-8A Canopy Frame

[pvalovich]

I've started work on the canopy and have found a ton of material regarding fitting and gluing the plexiglass. However, I'm stumped regarding instructions concerning the slide block and anchor block. A hole has to be drilled in the slider block to permit a pin to engage the pivot arms of the canopy frame. However, no dimensions for placement of the hole are given. Rather, the instructions refer to proper clearance within 1/32 inch. The design of the slider block - with "ears" covering the pivot arm holes make precise measuring of the hole location improbable. My initial inclination is to center the hole on the ears and take whatever clearance it gives. However, I'm not sure if that won't set me up for obstruction issues later in the process. What am I missing?

[Craig23]

I am working on my canopy now and had the same questions. When I drilled the slider block I put the hole a little low, which caused the protrusion that acts as the the stop for the forward canopy position to drag along the center canopy rail. I ordered a new block and drilled a little higher only to have the same problem. I ended up by putting some UHMW tape in the slot that slides along the center rail to get the aft part of my canopy frame high enough so the protrusion doesn't drag.

Contact me in a PM or by e-mail if the explanation above is too confusing.

Good luck,

[Craig]

I just ruined my slide block, so I have some insight into this.

I made a strap duplicator to transfer the hole from the frame to the delrin block. It ended up quite a bit too low. $13 for a new block.

I have the misdrilled block to play with now. Here is how to set it up:

1. Put something that is the correct thickness (I think the manual says about 3/32) on the slider rail. I found that the blade of my square is just right.

2. Put the slider block on the center rail, and put the canopy on the slider block.
Here's a picture - click on it to make it big:

3. You can see that I have the hole in the delrin offset from the hole in the canopy frame. This is so you can mark the center of the hole on the plastic. Measure from the top, transfer the measurement to the outside, center it fore and aft, then drill the hole. Do the same to the other side.

4. The manual says to counterbore the plastic for the head of the clevis pin. I tried it with a regular twist drill and a plexiglass drill. Both of them grabbed the plastic and made a mess. I would suggest just countersinking as much as you need.