no1speshal

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Hello All,
I am an intermediate pilot taking on the unreal task of building an old Mig-27 from Carl Goldberg products (the old military drones). In reading a lot from you all, I have read that I can place the tanks right at about the CG and they will be fine if I use a hopper tank. Can somebody please tell me the best way to set this up? I have worked very hard to make this plane nice and I would hate to find that I did a crappy job on the internal workings and the outsides looks great.
Just in case anybody asks, I have done a lot to this airplane. I have fiberglassed the entire airplane from glass I got at work. It is extremely lite and has only added about one pound to the total weight. (I told you it was lite!) Also, I have installed dual tanks and added cosmetic missles to the wing tips, installed a rudder - as it did not come with one - and put a very nice gear configuration on it. If anyone has anything to add, PLEASE tell me! I am always open to suggestions as this is my first scratch build.
Thanks to all!

Red

ZimboRaider

That looks pretty good no1,
Are your tanks the oblong things stuck together and standing on the right??
I am no expert on jets or anything but are you using a turbine or duct?

DBCherry

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What are you powering it with. Judging by the nearly solid fuselage, it's obviously not turbine or ducted fan. Are you putting an engine in the nose or tail?

MinnFlyer has a great graphic of a "hopper" tank. Hopefully he'll post it for you, but....

Use pressure line from muffler to your tanks, then clunk line goes from tanks to the hopper, just like it was a vent line. Clunk line from the hopper tank to the carb.
Dennis-

MinnFlyer

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Found it!

DBCherry

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I knew you'd have it Mike.
Dennis-

no1speshal

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Thanks everybody!
The tanks are just aft of the "inlet" (or where the inlet should be.) I am using a Tower Hobbies .75 for power and I am putting it up front. The dual tanks are going to feed the hopper which I will put up front. I tried to put the fuel tank up front but it did not allow for everything else and really messed the weight up when the tanks are full. I got the plane from Ebay, knowing that it would be a lot of work but I had no idea that there would be this much work!
The oblong things are going to be the wing tip dummy "missles". I work at Boeing and cool stuff like that is common stock and frequently thrown away.
The motor will have electronic glow starter to minimize the starting problems and help the running idle. As you can see in the picture, it has dual tanks that -thanks to minnflyer- will feed a hopper.

When I bought the plane, I got two of them. The second one, based on how well or not well this one flies, may have a ducted fan. Turbine is out of my realm of affordability.
Thanks again for all of the help. I will post more pictures as I get nearer to completion.

Red

MikeL

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They're generally called header tanks, and are quite common on helis.

no1speshal

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Hello All,
I just finished my Mig. Tell me what you think!!!

CafeenMan

Red - you said glass added a full pound to your plane? That seems like a lot for that size plane, but then it does have a lot of surface area. I just glassed a 600 square inch wing and it added just under 2 ounces. Do you scrape off as much resin as you can? Maybe I would have had the same result. It's hard to tell looking at pictures, but I'd think you could have maybe kept it to around 10 ounces. Not a big deal though.

Plane looks nice. Looks like Red Flake paint of some type. What paint did you use?

Have you flown it yet?

no1speshal

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Cafeenman,
Thanks for the reply. The airplane has been in work for a LONG time! I am so happy to see my workbench again without all of the Mig pieces strewn all over.
The covering is all Ultracote. Metal flake red and Black baron black. My wife did the "Red Devil" stencil on the top of the wing. She did it so that someone would have to look very hard to see it or it would just look like flames. She did a good job!
I think the reason the glass added so much weight is because I used all aircraft grade cloth. I thought it was 1 oz cloth but it seemed to be heavier than that. It is ultra dense and turned into a great finish. The epoxy I used cured in conjunction with the cloth to create a nice rigid shell with a slight amount of flex. Aircraft style!
I haven't got to fly it yet. I am under the impression that the engine I have will not be enough to power it though. It is only a Tower .75. I am looking into getting a 1.20 two stroke or something like that. I have been warned about overpowering it, but with the glass and some of the other things I did to it, I have no qualms about putting that size of powerplant on it.
After I fly it, I will let you know if I change my mind (or if I need to rebuild it!)

Red

CafeenMan

Is this plane using glass as a shell over a foam structure with no sheeting? If so, then that's a different thing and you do need heavier glass cloth for strength. In that case, 1 lb isn't bad at all.

You put UltraCote over the glass?

Mighty Mouse-RCU

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Red,

I dont think the "hopper" tank will solve your fuel delivery problem. The suction created by your 2 stroke will not be able to "pull" the fuel from the center of the CG. The small tank is just seen as a big fuel line. You engine still must pull all the fuel from the back tanks. Your solution may be to put a pumped engine in it. How much does you mig weigh and how much wing you have (square inches)? That will determine whether your ST 75 will pull it. I think you are right about the engine being too small.

raptor5900

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i agree the engine is too small and wont pull fuel well......you can get a perry pump for $30 and that will fix it. but i would get a OS 1.40 in that thing