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Tipup construction sequencing

Greg Arehart

Greg Arehart

Well Known Member
I'm looking for information from those who have already gone through building their tipup. I am at the point in the instructions where I should be cutting the canopy, but its too cold in my shop to do this safely for at least another month or more. I have the tipup frame essentially completed, with the 702 skin clecoed in place. My question is whether I can 1) go ahead and add on the frame stiffeners; 2) rivet on the 702 skin; and 3) add struts etc. before cutting and installing the plexiglas canopy. My concern is that there is some reason for not doing this that I'm not seeing. I would appreciate comments from anyone who has already passed this point as to whether there is a reason to hold off on the aluminum work until the canopy is cut.

thanks,
greg
 
I can’t think of any reason why you couldn’t finish the frame and add the plexi later. I’m not with plans at the moment so I think the skin you’re referring to is the skin attached to the tip up itself. I found it rather important at the point you're at to locate the sub panel in its proper position. You would do that by clecoeing the front top skin on including clecoeing to the firewall then get your panel in position and bracket it and screw it in place. Then fit the 702 skin to the fuse. Once you’re happy with the way the frame fits the fuse you can remove the forward top skin and drill your hinges. The reason I’m saying to do it this way is that if things are left loose the gas struts will push the canopy forward along with everything in front of and behind the sub panel placing all of your otherwise good work out of position, so, have all of the distances set (bench marked) before adding the canopy. I also only left the struts in place long enough to check for proper installation and then removed them until everything comes together in the end.
 
Last edited:
Rivethead,

Thanks. 702 is indeed the tipup skin. I have already drilled the hinges and installed the canopy stops (to keep the canopy from pulling forward - described on this forum a while back). My main concern was if I riveted on the tipup skin, would that cause me grief later when trying to deal with the canopy. In looking through the instructions and plans, it doesn't seem so, but I have been surprised before. Thanks for your input.

cheers,
greg
 
Oh well then to answer the question. Everthing should be together before the canopy is attached otherwise you wont be able to finish some of the riveting. Esp. across the 702 skin.
 
I wouldn't rivet without fitting the glass before hand

I have completed my RV-7A tip-up and I would not recommend riveting the top skin on or putting the skirts on until you fit the glass. When the glass is attached (either clecoed or screwed) in position the weight and shape of the glass causes the frame to move around (flex) at bit. It effects the side skirt fit (don't ask me how I know) and other areas as well. It may also tend to widen the frame (if I recall correctly). If you rivet the top skin in place before fitting the glass you may have some troubles "tweaking" the frame to get the best skin fits later once the glass is installed.
 
Wow! I'm not saying you're wrong. As the saying goes "your results may vary" but I can't even imagine a close fitting canopy causing problems like you discribe.
 
The canopy is ......

Rivethead said:
Wow! I'm not saying you're wrong. As the saying goes "your results may vary" but I can't even imagine a close fitting canopy causing problems like you discribe.
Click to expand...

The canopy is the most tricky part of the whole project. Whether it is the an RV-4/6/7/8/9 (don't know about the RV-10). The frames aren't very Stout and flex a lot. Some strive for the best fit possible, some accept whatever happens after they cleceo everything in place.

I personally believe I have a 95% perfect fit. This didn't just happen. I had to shim in a few places (not uncommon) and remake the side skirts a few times. In additional after the glass is screwed in place, the width of the completed canopy changes a bit and the fit you thought you had to the cockpit sills isn't what you had prior to securing the glass.

You mileage may very but you can take the time to improve the odds of getting a good canopy fit by not rushing forward too fast.

Food for thought.
 
Clarification

Thanks for the information thus far, but I guess I need to clarify where I am at. I have drilled the canopy frame for the skin (and have had the skin on and off numerous times); I have riveted on the side rails (not the side skirts); I have positioned and drilled the hinges; I have positioned and drilled the roll bar (but not riveted on). Everything fits right now. I realize that things are likely to shift around a bit as stuff gets added (no matter the order of addition), and am willing to accept and deal with that. SO, if I rivet on the tipup 702 skin, rivet on the stiffener package, and install the struts BEFORE cutting the canopy, will I enounter big problems installing the canopy? By big, I mean problems that require me to drill out and uninstall the skin, stiffener, or struts or problems that prevent me from getting a proper fit and attachment with the plexi. I fully realize that no matter what order this is assembled in, there are likely to be some fitting tweaks required. My read of the instructions and comments here so far suggest that going ahead and doing the Al work I describe shouldn't be an issue but....

BTW, Jeff that's a nice looking airplane!

cheers,
greg
 
No. IMHO once riveted together it will be done. On another note; Jeff has the best site I've found for referance.
 
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