I am building a GP Ultimate 40 kit and need to put the battery/rec/servo toward the back of the plane for CG reasons.
I need to build a hatch at the back of the fuselage that is easily accessible and securely fastened.
Any ideas on "hatch building" would be appreciated.
Thanks

You are not only going to have to build a hatch, but you are going to have to build a platform that is secure enough to deal with the weight of the battery. Although it's not that heavy under normal conditions, G-forces will "increase" its weight so you might want to construct something out of 1/4 x 1/4 stock and covered with 1/8 ply, shape it like the battery, attach the battery with velcro, perhaps a velcro strap, and secure that where you want it to be.

I'd make it long enough to be able to slide the battery frontward and rearward to accomodate minor adjustments in CG location (no fuel on board for this, by the way).

So, work this out so that you do this during the kit building process.

Now as far as a hatch is concerned, well, some sort of lightly reinforced panel that you make fashioned similar to the plaform, but with tabs that slide in. Make up the hatch hole in the fuselage with a little flush mounted lip around the edges that the hatch rests on, then secure it on one end with the tab that slides into the fuselage, and perhaps a servo screw or two at the other end to hold it in place. Make this hatch similar to how you make the platform, but perhaps out of some light ply. You don't really want to make it entirely out of balsa, but there is no reason that the cover itself can't be balsa as long as the supporting portion, the frame, in other words, is made out of something that will give it structure and some light strength.

That's how I'd do it if I was making it. It's glow, so a what little weight you add should not matter all that much for the added ounce or so.

That's my take. I'm sure there will be others.

CGr.

I am doing the exact same thing as we speak on my GP Stik 60. I completed the reinforcement yesterday, and working on the hatch lips now. I'll take a picture or two when I get to it later today and post it for you. Basically it's exactly as CGRetired explained below, with the only difference that I am making a "window" out of clear Monokote to show the lights on a VoltWatch since the Stik doesn't have a canopy.

I cut a slot just a tad bigger than the Voltwatch LED viewing area in the side of the fuselage (opposite side of the engine exhaust). I then painted it black where the bare wood showed, put a length of clear monocoat over the slot, then mounted the VW inside with the LED's facing out (of course.. ) and held it in place with Blenderm. Works fine.

You may wish to get a tad more fancy, but it is not something that someone would pick out as being out of place. I took the effort to make the cuts straight and to match up with the trim lines of the fuselage. Then I made sure that if there any rough edges, I either sanded them smooth or filled them in with some filler like spackle, then sanded it smooth. I then painted it flat black so it didn't glare. Looks good and the VW is clearly visible to me because I know it's there, but to the casual looker, it's hardly noticeable.

CGr.

Thanks to both of you for your advice. As they say, "A picture is worth 1,000 words" so if you can post a few pix it would be appreciated.
This is my first kit and I'm having a blast! No major issues so far. The fun part seems to be engineering everything.
Regards

Yeah. That's what's nice about kits. Now, I've re-engineered a few arfs in the past, made them work with what I wanted, needed, out of them. So, even with arfs, although you are somewhat limited, you can play with them.

Enjoy.

CGr.

I'll finish it before I post pictures as it will make more sense that way, but won't get to it today. The New Year's "eve" party we are invited to starts at 5:00 PM. Gotta love kids!

.

If John can do it so can I, maybe not as well??

Like I said, not as well!!! Too much Brandy too early. Nothing like a shot of my cheap sander!!! Happy new year guys!!!!

Ya'll have a happy and safe new year up there tonight GB.

Love that airplane, OK now let me guess. I keep wanting to say Curtiss P-6E but the top wing taper don,t seem right so I,am gonna guess it as a Boeing P-12?

John[8D]

You are the man, I really mean it. How many people could pick out an F4B-2 P-12 upside down with one wing off?? I scratch built it years ago for IMAA events, had an OS 1.20 in it but decided to change it out for a Brison 2.4 gasser just to see if it would fly better. It didn't, so I just pulled it apart again and it's hanging on the wall again. Just a pain to haul to the field like any big bipe. I really am impressed!!! How about that sander?? Got it at a cheap tool sale.

Cool, that horizontal stabilizer is kinda distinctive.

I just recently had a long term wall hanger sort of like that, a Pica Waco I had flown it quite a bit some years ago but had not for maybe six or seven years now and had an inspiration. There is a small struggling museum here of the Army air corps gunnery school during WW11. When I approched them about donating the model they were quite excited and sent someone to pick it up.

It was without its OS 120FS and gave them a plastic engine faceplate for the cowling and some props. When I visited the museum several months later it was hanging in a prominent location under some skylights in the roof over a display area of artifacts . They had done a wonderful job for a static display and I felt very good that the old girl would go on pleasing folks for a very long time. I have an old Midwest Corsair I built sometime late sixties I guess that I am thinking about doing the same wiith.

John

It will indeed be a happy new year in a couple of hours.

I like to put the VoltWatch near the Instrument panel.

120V asthma attack if you ask me!

The sander does bring on some major sneezing, if I have a lot of sanding I now go over to my wood working club and do it there, keeps the dust off all my stuff.
A cool scale trick with the volt watch, you can pull the lights and mount them behind some insterments or on the dash board. Looks cool and people wonder how you got things to light up and change colors.

Jigeye,

Try not to cut the original fuse wood.
In that way, you will keep the original bending and twisting strength.

If possible, try using the openings of the bottom side of the fuse.

Happy New Year!

Here is what I did to my Tiger 60, You are just putting the hatch in a different place.

Sorry for the delay. I still haven't finished the work, but here are some pictures to give you an idea on how I am going about it. The first picture shows the reinforcement inside the fuse to handle the weight of a 2200mAh battery when the plane is thrown around (I put the "lips" on top of the fuse just to show them. Sorry if they seem out of focus, I had the wrong aperture lens on my camera when I took the pictures.) I then glued a thin rectangular piece of plywood about the size of the battery on top of the three cross bars so that I could wrap the battery with two pieces of velcro; this is shown in the second picture.

Hope this helps and little, and good luck with your project.