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Section 43: Cabin Top - Tips?

RudiGreyling

Well Known Member
RVators,

I am getting ready to start Section 43: Cabin Top. I've pre-read the plans a couple of times but I am apprehensive to start with it, maybe because it is such a big structure. Any tips before I delve into it?

fuse_113.jpg


Thanks
Rudi
 
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Most is very straight forward but here are my thoughts:
- Recommend not trimming the interior door flanges very much until later when you're actually working on the doors. The scribe marks aren't very good and there's nothing gained from doing it early.
- Do as much of the interior finish as you can BEFORE final attach. This includes sanding, filling, paint, headliner, etc.
- If you're putting in an OH console it's much easier to install with the cabin top off.

Bob
RV-10 N442PM
 
You could start by slitting your wrists... just kidding, sort of.

There is a lot of cutting and it's not fun. Arm yourself with some good tools, such as a die grinder with a new wheel. I'm also impressed with the vibrating saw that was invented to cut off casts for broken bones, although I don't think it's strong enough for the thicker parts. Look into those small handheld belt sanders that use 1/2" or 3/8" belts. A bigger handheld beltsander is also useful.
Do it outside and use a real respirator and goggles. Start with just getting it to fit on the fuselage. Once you get it to snug-in, you can move on to the rest of it. If you can find all of the scribe lines, it's pretty safe to cut to them, but be careful. Don't let a die grinder cut get too close to a corner - use sanding drums, etc.
The bottom that is attached to the door rails is surprisingly thin by the time you get it to fit. Same goes for the blend at the bottom corners of the windshield area. If you can possibly look at a finished RV-10 first, it would help a lot.

Good luck,
John
 
Cutting

I experimented with several tools for cutting and found the best results with a sabre/jig saw using a carbide tipped blade - cuts like butter with little dust, just chips - and lasts forever. For thinner material, I used a diamond wheel for a dremel and roto/zip tool. The dremel is underpowered but the roto zip is plenty powerful. The kerf is almost paper thin but it can bind up in thicker material. The jig is better for cutting curves, but you can do it with the diamond wheel if you're careful. The right tool depends on the thickness of the material being cut and the angle you need. I agree to leave the door flanges uncut for now. I may have taken too much off by cutting to the scribe line. Won't know for a bit yet. All in all, it wasn't nearly as bad as I was expecting.

Good luck and ask for help/suggestions if you need it. When in doubt, don't cut.
 
Oscillating saws?

I have a Fein Multimater oscillating saw/tool that comes with diamond disk blades, carbide disk blades, toothed saw disks, etc. It reminds me of the bone cast saw mentioned earlier. I'd be interested in seeing if anyone else has tried it for this task or the canopy cuts :eek:.

Dremel has come out with one along with Craftsman and a few others. I'm sure at least one of you has one of these things.

It looks like this: http://www.mcfeelys.com/shop/feinmultimaster
 
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Additional Thoughts on Cabin

I agree with not cutting the flanges until you get the doors. I cut mine according to the plans and thought I cut too much. I then built them back up only to find out I did not cut them too much when I put the doors on.

In the US I bought a 2-3/4" x 17-1/2" inline sander from Harbor Freight that has 3,000' strokes per minute when I was doing the cowl. I wish I had it when I was doing the cabin and the doors. I put emory cloth on it and it creates a very straight plane and cuts less fast than a belt sander.

Cut a little at a time and test fit. I hoisted mine off and on many times.

Last think through the door opening against the fuselage. When you attach the cabin to the fuselage there needs to be an allowance made for the doors to fit flat against the fuselage. The plans give you some dimensions but never really explain why.



Dave Syvertson
Finishing and FWF
40625
Sugar Land, TX
 
I just mounted mine for the last time last week.

One of the handiest tools for me was a cheapo pneumatic disk cutter from Harbor freight. It's been on sale for $4.95 but even full retail is less than $10.00 I bought some of their Russian thin cutting disks and cranked that bad boy to about 140 psi and it was a trooper.

I also really used the heck out of my Craftsman cordless multitool sander. It's their version of the Fein multitool but a lot cheaper. You need an extra battery to always have one charged up. I went through a couple of the base pads and a couple of dozen sanding pads, but it really helped. I used a belt sander and a Black and Decker mouse for the big stuff. I used half a kit of Super-fil at least. I bondo'd and sanded for the last time at least a dozen times.

I echo what others said about doing as much off as possible. I installed the aerosport overhead console and full padded headliner before installation. If you do a console remember to put in the four rivits in the cargo upright before final install. The plans have you do that after install, but you can't with a console.
 
Fein

I used the Harbor Freight Fein knockoff on the wing tips and it worked pretty well, but I was not happy with it on the canopy and doors. The material is much thicker and there is lots more of it, so the blades get dull much more quickly. That's why I loved the jig saw with carbide tipped blade and the rotozip with the very thin Dremel diamond cutting disk. I also used my belt sander extensively for sanding door and window edges and openings as someone else mentioned.
 
tools

I used 2 tools for the cabin top and also the windows. A die grider with a 3 inch cutoff wheel, and a belt sander with 80 grit. You can do a little with a double cut file, but dont plan on doing much hand work.

The hardest part is getting it to fit around the door opening and the windshield posts. The scrib lines are not very good so be careful not to cut away to much, specially around the door frame. Cut and fit, Cut and fit, Cut and fit. Have some muscle handy to help lift it on and off. Awww, its really a lot of fun. :)
 
PLexi

By the way, the very thin dremel diamond disk on the rotozip tool works great on the plexiglass as well.
 
Thanks Guys,

I started today, neatly fitted the canopy on top of my table.
fuse_120.jpg


My scribe lines are very visible so I marked them.

I have 2 questions still
1) I measured the fuse door opening and the scribe lines seem at least 1/8" to big around the outside door frames, did you guys find that you have to take out much more that the scribe line say initially?

2) Looking at the inside cut for the door frame. I guess you need to leave a gutter for water. But at what angle do I cut the inside door frame?
Along the green line the cutting disk move in the plane from tail to spinner,back to front; OR
Along the blue line the cutting disk move parallel along the wings plane, left to right; OR
Along the red line cutting perpendicular to the hollow curve between green and blue.

fuse_122.jpg


I hope it makes sense.
Thanks in advance.
Rudi
 
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I have 2 questions still
1) I measured the fuse door opening and the scribe lines seem at least 1/8" to big around the outside door frames, did you guys find that you have to take out much more that the scribe line say initially?
>>> Yes, you take off much more than you initially think. You've got the right amount taken off when the door part will slide into the metal cabin structure and the joggle along the aft part sits properly aligned (might be a small gap but should be parallel) with the aluminum.

2) Looking at the inside cut for the door frame. I guess you need to leave a gutter for water. But at what angle do I cut the inside door frame?
>>> The inner door surface will mate up against the inside door frame with just a little gap. You should trim the inside door frame so that the surface is parallel with the door surface. This is the part that you're probably better off leaving until later - it doesn't affect the fit of the cabin top to the cabin. You will definitely have to do more trimming/fitting on this when you fit the doors anyway no matter what you do now. There are some people that have cut too much off and had to build it back up.

Bob
RV-10 N442PM
 
Green

If I read your lines right, I would cut the angle represented by the green line. I cut mine to the red line and, while I think I'll be OK and will probably need to leave more, I would cut it parallel to the longerons essentially. Bottom line, you can always take more off, hard to put it back.
 
Thanks guys, if the door inner sits flush or little gap, then cutting along the green line makes sense.
Regards
Rudi
 
:( My scribe lines are non-existent. :(

Phil, sorry to hear, I have very good lines all round, sometimes 2 of them maybe 1/32 appart. Guess I am lucky! Ready to start cutting this weekend if the Weather holds, I don't want to cut inside due to dust mess. Rudi
 
My scribe lines were visible, just not very straight. Someplaces it was off by a quarter inch. I had to determine what the appropriate width was and make my own. If I used the original lines, it would have appeared that I had one too many when I performed the cuts.

The other variable on the doors is what type of door seal you plan to use. I like the way Geoff Combs did his. His is mounted on the cabin cover and not the door. Either way you choose, I've beed advised to wait until I have the doors ready for test fit.

The following is a photo of Geoff's seal. It's not a great photo for looking at the seal , but you can get a glimpse of the seal. If I recall correctly, Geoff shared the process he used on the Matronics RV-10 list.

bob

Panel2.jpg
 
Plans section 45, page 4, has some cross section views showing the fit of the door to the frame that may help you decide how to cut as well. I'm a long way from here myself so I'm watching this thread with some interest and anticipation.
 
Plans section 45, page 4, has some cross section views showing the fit of the door to the frame that may help you decide how to cut as well. I'm a long way from here myself so I'm watching this thread with some interest and anticipation.

Its clear, the green line! I am going to cut them but leave some extra 1/8" on the gutter to sand down if required. I don't want to do too much cutting on the cabin once it is on the fuselage.
 
<Snip>

The following is a photo of Geoff's seal. It's not a great photo for looking at the seal , but you can get a glimpse of the seal. If I recall correctly, Geoff shared the process he used on the Matronics RV-10 list.

bob

Panel2.jpg

Thanks Bob, do you have more information on those seals...It looks like he took out the entire gutter "spil" edge and trim fitted the rubber on the "gutter" flange? Like a a car door rubber seal

Thanks
Rudi
 
Rudi
Measure the opening on the fuselage and compare it to the part that needs to be trimmed. I did not use any of the trim lines, just cut and trim it to fit the fuse. My total time, including drilling holes was five hours.
 
Thanks Bob, do you have more information on those seals...It looks like he took out the entire gutter "spil" edge and trim fitted the rubber on the "gutter" flange? Like a a car door rubber seal

Thanks
Rudi


Yes, just like a car. You trim the gutter a little shorter and in someplaces you'll need to make it a little more thicker. I sent more details in a direct email. Here's the part that Geoff used from McMaster Carr:

11
1120A411
50 Ft.
Edge-grip Rubber Seal, Bulb Opposite Grabber, 1/4" Edge, 3/8" Bulb Width
 
OK Gents, finished the cutting this weekend

Thanks for all the tips, I can now report back
1) Measure the fuse opening and height, look at the scribe lines and balance your measurement into the center of the scribe lines. Cut to your measurement. My scribe lines gave me at least 1/8 to 1/16 to much meat.
2) I mostly used power tools to cut and sand. An angle grinder with a thin 1mm metal cutting blade for cutting, and angle grinder with 80grit flap sand paper for shaping and material remover. The Belt Sander works great on the long straight pieces.
3) Final finishing enges and corners was done by hand with sanding block.

Below are some pictures.

Angle grinder with guard removed and thin metal cutting disc...BE VERY CAREFULL!!! Before cutting
fuse_123.jpg


After cutting most of the flanges
fuse_124.jpg


The tools used for smooting the initial cut
fuse_125.jpg


The fuselage waiting in anticipation...
fuse_126.jpg


It fits...well almost just had to do 2 small adjustments to get it right.
fuse_127.jpg


It sits just loose for now, this week I will drill it.
fuse_128.jpg


I hope it helps someone as well.

Regards
Rudi
 
Bryan Douglas's experience similar to mine.

After some experimentation, a carbide blade (an abrasive coating, no teeth) was the most effective cutting tool for the thicker parts. I ended getting one for a riprocating saw and grinding some height off so it could turn a tighter corner. One, maybe two blades will do the entire job. A big belt sander for removing material fast. A 5' sanding block for the finish fitting.

Yeah, no need to trim the door opening but don't worry if you do - easy to fix. If you decide early to use the McMaster seals, you can trim aggressively since you are going to remove practically all of the curvature out of the lip.

The most valuable thing is being able to watch someone else do it but that's not so easy.

Bill Watson
 
Bringing up an old topic here, my apologies...

Rudi,

Was the green line the ticket? I hope so because I cut half of my door opening tonight after work. Any other lessons learned when it can to fitting the doors into the holes?

Phil
 
Bringing up an old topic here, my apologies...

Rudi,

Was the green line the ticket? I hope so because I cut half of my door opening tonight after work. Any other lessons learned when it can to fitting the doors into the holes?

Phil

Phill i ised the mcmaster rubber and I had to cut to the green line methos and then take even more off via the blue cut line for it to fit. I you don't use mcmaster rubbers dont use my method. becuase I believe you need a gutter area.
 
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