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Canopy chamfer paranoia - Please help me interpret the plans

bertschb

Where's my engine????
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So I'm on page 38-21 step 9. I know I need to chamfer the underside of the canopy. I'm 99% sure I'm being asked to chamfer the entire leading edge from points on either side that start 3" from "point Oscar". But, the plans don't clearly state that. At least it's not clear to me. See step 9 below.

Can somebody verify I need to chamfer the entire leading edge and not the inboard edge "on both sides of the canopy". I follow a builder online and his photos just showed chamfering around the sides, not the entire leading edge. But, I'm not sure if he had fished that step when he took the picture. If you have pictures of how your chamfering looks, that would really help!!!


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Brian, I think you’re interpreting the instructions correctly. If you look forward in the plans to where your fiberglassing the canopy to the skin, the drawings show the chamfer. This is the way I did it.
IMG_3507.jpeg
 
I only chamfered 3" forward starting at point 'Oscar' per Step 9 in the plans. Basically, just chamfered the curved area. Canopy fits great.
 
I only chamfered 3" forward starting at point 'Oscar' per Step 9 in the plans. Basically, just chamfered the curved area. Canopy fits great.
OK, I just re-read the plans for the 10th time and this time I can see where they might be asking us to chamfer just that 3" section. But, page 38-30 shows a chamfered edge and it kind of implies it's the entire leading edge of the canopy. I know I'm over thinking this but the canopy is right up there with fuel tanks for new builder anxiety. I don't want to screw it up.
 
I'm working the canopy fit as well, as we speak! To me, the goal is to minimize the gap between the canopy and the skin to the extent possible. I think if you chamfer more than the 3", the gap in the middle will get worse.

My canopy fit looks pretty close unchamfered, and with the riveted brackets, I think the canopy will fit as close as anyone could expect. I may not touch it at all. Maybe just a bit of trimming the aft edge, but not much.
 
The area where the plans call for chamfering doesn't touch the skin in my situation. My canopy touches the skin about 6" further towards the center. It seems like this is where I should be chamfering. Hung up again not understanding the purpose for what I'm being asked to do :-(
 
Just checked mine based on your comment. It's pretty close to what you are saying. Maybe a bit of chamfering there? Still seems to me that a couple of properly placed riveted brackets will tie the canopy down pretty close. Plus one in the middle.

Yes, I don't see how chamfering along the 1st 3" would help at all.
 
I also thought the instructions were a bit confusing at this point. I ended up chamfering the entire forward inside edge, but I now believe this was incorrect. You don't really need to do the entire front edge as the fillet will level the forward edge anyway so as long as the inside edge of the canopy makes contact with the skin, you should be fine.
 
... You don't really need to do the entire front edge as the fillet will level the forward edge anyway so as long as the inside edge of the canopy makes contact with the skin, you should be fine.
That's my thinking as well. It seems like the instructions should recommend that we basically remove material wherever there are "high points" so the canopy basically makes contact along the entire leading edge uniformly (more or less). I removed some material yesterday per the plans (that 3" section) but after setting the canopy back on the fuselage, those areas had large gaps and removing that material just made it worse.
 
That's my thinking as well. It seems like the instructions should recommend that we basically remove material wherever there are "high points" so the canopy basically makes contact along the entire leading edge uniformly (more or less). I removed some material yesterday per the plans (that 3" section) but after setting the canopy back on the fuselage, those areas had large gaps and removing that material just made it worse.
Yeah, that's been my experience as well. It really only fits well once you put weight on the canopy to hold it down.
 
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