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Trying to Lighten the Midwest G-202

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Trying to Lighten the Midwest G-202

Old 08-28-2003, 01:48 AM
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Rcpilot
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Default Trying to Lighten the Midwest G-202

Is this a good plane for 3D? I think it will be a very good IMAC plane. But, I'd like to get started with practicing 3D.

Has anyone built and flown this plane? Any construction advice for me?

Having just completed the MW Extra 300S, and learning a thing or two about the MW kits and their construction; I am ready to begin construction of the G-202.

The MW kits seem to favor large boxy fuselages made entirely of lite ply. The wing is standard built up construction with balsa ribs and spruce spars. I plan to scrap a lot of the lite ply in the fuselage and use balsa longerons with formers to construct it. I'll probably build the wing per the plans. I can't see any way to remove a significant amount of weight from the wing without sacrificing strength. The tail surfaces are built up and about as light as you could build them.

I hope to shave a few pounds off the fuselage during construction.

I plan to use a 35cc gas conversion engine on this plane. I'll use JR 4721 servos on ailerons and elevators. Probably a JR8411 on the rudder, with a standard 537 on choke and throttle.

Can anyone who has built this plane offer any suggestions? In general, what kind of flight characteristics can I expect from this plane?

Thanks
Old 08-28-2003, 04:19 AM
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Default Trying to Lighten the Midwest G-202

This is a awesome aircraft especially when flying knife-edge. I have a OS 1.60 installed and it has unlimited vertical, doing knife-edge loops are a snap. I didn't try to make it light and it came out around 13 lbs. Midwest didn't a good job on this one.

Mike
Old 09-01-2003, 08:02 PM
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Default Fuselage framed- too heavy

I looked at the kit and decided that I can't use balsa longerons to tie the fuselage together. The fuselage is all tab and box-lock construction. Removing the formers and using balsa longerons will just be too much trouble. I'd basically be scratch building the kit at that point. I'd end up using the fuselage sides for the wing saddle and side profile- and reinventing everything else. I'm no top notch expert builder- and DEFINETLY not a scratch builder. I do okay with kits, but trying to modify this kit to the extent that I originally planned is just beyond my expertise.

I've got the fuselage framed about 80% now. Just need the turtledeck and hatch sheeting. Kit calls for 1/32" birch ply, but I might try 1/32" balsa instead.

The fuselage weighs 2 pounds now with the LG bolted on. I've drilled a few 3/16" holes in the belly stringer formers, but not a big help in removing weight. I've got to get the weight down on this plane. I can't see a way to remove any weight from the fuselage as it sits.

I've thought about drilling holes in the fuselage with a 3/16" or 1/4" bit and trying to reduce weight that way, but I'm afraid to weaken the structure. The existing lightening holes in the lite ply fuselage are fairly large, but there is still about 1/2" of wood around all the joints. Could this be hogged out to 1/4" or less wood without sacrificing strength?

I will probably stay away from trying to lighten the front up too much. With a gas engine up front- I need strength to absorb the vibration and shock.

The rest of the fuselage and wing are fair game though. I need to get the wieght off this plane to make it fly decent. With only 960 sq.in. of wing- I need to shed a lot of weight to get a gasser on it and not require Mach 2 landings.

If anyone can offer some tips here I'd appreciate it very much.

Would a sheeted foam wing and foam tail be any lighter?

Thanks
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Old 09-01-2003, 08:03 PM
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Default Trying to Lighten the Midwest G-202

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Old 09-01-2003, 08:08 PM
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Default Trying to Lighten the Midwest G-202

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Old 09-01-2003, 08:14 PM
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Default Construction techniques

Ive used thin and medium CA to build this fuselage. I used 30min epoxy to laminate the engine box parts together and to glue the firewall and engine box into the fuselage. I used the epoxy VERY SPARINGLY. I used only a very thin coating on the parts and pressed them flat with about 25 pounds of weight while curing. All excess epoxy that squished out was wiped off with a paper towel soaked with rubbing alcohol. Not a bunch of excess weight there.

The LG blocks and triangle stock were epoxied in with 15min epoxy. Very careful about the use of epoxy here. All excess epoxy was wiped off with a rag and alcohol.
Old 09-02-2003, 06:12 AM
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Default Trying to Lighten the Midwest G-202

just a few suggestions:

be careful how you replace 1/32 ply with 1/32 balsa, you could have handling problems later on when you are trying to carry the model.

I'm not familiar with the kit, but I would look at replacing the undercart with a lighter carbon fibre one, use the lightest wheels you can get away with, dont add any cockpit detail (unless you need it for IMAC), use a smaller servo for the throttle. Make sure that any balsa used in the construction is as light as practical. Look at the rest of the hardware and see if it can be substituted with something lighter and stronger (ie carbon fibre)

good luck

Chris
Old 09-02-2003, 11:07 AM
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Default Trying to Lighten the Midwest G-202

I think there are a few threads on this plane in the kit building forum. One or two talk a lot about lightening, especially the wing, which apparently comes out very heavy stock. Do a search you may find something.

I'm interested in this plane, so will keep an eye on how you are doing.
Old 09-02-2003, 06:26 PM
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Default Trying to Lighten the Midwest G-202

I have a MW Giles G-202. Needless to say, after I got my H9 Edge 540, the Giles went on the shelf. The airplane flies great, very straight and true. Landing is a whole different story. This plane has such a high wing loading. This, in turn, causes a high stall speed. Power management is a necessity for this plane on final approach, however if you are thinking about getting this plane, you're piloting skills are/should be high enough to be able to handle it.

BTW, I had a YS-140FZ on it for power.

I like it...just like my Edge better.
Old 09-02-2003, 06:39 PM
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Default MW G-202

Rcpilet

We have built at least 12 of these kits, (a couple for us, the rest for customers).

All of the lightening holes in the fuse sides can be enlarged by 1/4". Forget drilling all those 1/4" holes and get yourself a set of Forsner bits so you can punch some 3/4" or 1" holes. Leave out the servo tray.
Do not discount the weight savings in the wing. Replace the 3/8" ply dihedral brace with balsa/CF sandwich. Replace the spruce spars w/balsa. Punch some 3/4-1" holes in the firewall and the area around the landing gear plate.

The Avg wt (AUW) for ours rand abt 10.5lbs w/YS-1.20 or SAITO 1.50 and the last one we did was under 12lbs w/OS 1.60.

Do everything you can to keep this bird light and you'll love the way it flys. Let it get "fat" and you won't like it at all.

YMMV,
Steve
Old 09-02-2003, 10:25 PM
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Default Lightening techniques.....

I have ordered .014" carbon for the bottom of the spar and .021" carbon for the top of the spar. I'm talking about both of the main spars here. I plan to use regular balsa and epoxy the CF tape to it-- top and bottom of each spar. Is this the correct way to make a CF sandwich?

How can I replace the main wing joiner with balsa and CF? I'm unsure how to make this piece with the sandwich.

I have drilled a few 3/4" holes in the front of the plane on the fuselage sides. Two holes on each side for a total of 4--3/4" holes in the front. I've drilled 1/4" holes in the rear turtledeck former and the front hatch former. I probably saved an ounce or two there.

I've ordered Contest Grade balsa sheeting for all the tail surfaces and the wing sheeting. I can probably save close to a pound with the Contest Grade balsa. Is this stuff going to be strong enough?

I plan to get a glass cowl and I will order CF landing gear. That should save more than a pound.

I plan to use a 34cc gas engine on the plane. I'm having an electronic ignition installed on it to lighten it and increase performance. I might remove a bit of the fin material on the lower part of the cylinder to save a few ounces on the engine. I'm a bit shakey about doing that, but I'll do it after the plane is built---only if I have too.

I know I should be using a glow engine on this plane- but I can't bring myself to do it. I sold all my glow engines and swore them off about a year ago. Too expensive to run and too messy for me. I'll just have to keep the plane as light as possible to accomodate the gas weight. I'll be using a smaller tank with the gas engine- so flying weight won't be affected too much. I wouldn't build this plane with anything less than a 1.80 2-stroke at this altitude anyway. We need big engines here in Denver at 6000' above sea level. Those big glow engines drink about 20oz. in 12 minutes. So with a gas engine, I'll probably be using a 12 or 14oz. tank.

Thanks for the help so far. If anyone can tell me how to make a CF sandwich for the wing joiner, I'd appreciate it. Also, will my balsa and CF spars work if I build them in the manner that I discussed earlier in this post?
Old 09-03-2003, 01:23 PM
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Default Dihedral Brace Sandwich

Just trace the outline of the ply brace on to some 3/8 Balsa. Snad the sides lightly to accomodate the addition of the CF and epoxy or CA it together. The ply brace weighs abt 8oz as I recall, your balsa sub will only weigh a couple. :-)

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