cmoulder

The Magnum is an OS clone, so I know it will work with the short cowl because I used it with the OS .91FS. You can mount the engine with the stock engine mount and position and all that will be needed is a small cut in the cowl for the valve cover.

faulknej

My Feedback: (9)

Thanks Bob. Ididn't think I'd need that huge cowl, but better to be sure.

buddyd

I built one of these planes for my 12 year old son and he loves it. As far as the landing gear goes, I simply drilled a small hole in the gear a few inches above the wheel on each side and ran some 12 lb fishing line between the two sides to keep the gear from bending outward on a hard landing. He's got about 50 flights on the plane so far and has had a couple of harder than normal landings, but the landing gear is still in good condition.

maynardrupp

OK all....Here is the answer for our landing gear problems. I received my new gear from TnT in Swanton Ohio. It fit perfectly. I used the factory gear as a drilling template for the mounting holes and just eyeballed the wheel axle hole. The gear is well made and has a satin finish. I have it all assembled and it should work great. They make it from 6061T-6 alloy which I know to be the best for this application. The charge was $40.00 and $11.00 for shipping. If any of you are interested, their phone # is 419-868-5408. They take the order over the phone and your gear arrives in about 10 days. If you mention my name and my invoice # 20062, I am sure they can duplicate this gear without you having to provide dimensions. I did have them make it slightly wider where it lays on the fuselage as the recess has plenty of space fore and aft. Mine is also a bit wider ,(fore and aft), where the axle hole goes. I had to dremmel a tiny amount from the front and back of the gear opening in the fairings. All is good....

cmoulder

Yes, I think it is sometimes referred to as "spring aluminum".

It's like going from Stone Age to Jetsons.

maynardrupp

Oops, I forgot the invoice # in post 1276. I edited it in there, but here it is again.20062.

flyboy25

My Feedback: (5)

I got a saito 180 and im going to put that in the extra till I get the gasser figured out .

unfmoose

A 180 will be insane!!!!!!!!!!! My ST G90 pulls it around just fine, however, I am thinking about moving to a 120 4 stroke. Even a 90 as I don't intend on 3D'ing the plane, just IMAC stuff. I put in a few more flights on New Years Day, snow makes for soft landings! With the wheel pants it actually ran through an inch and a half of powder better than on a half inch of packed snow. I probably only have 10-12 flights on it now and am finally comfortable, It does couple towards the gear really bad in a knife edge. It is also nose heavy due to the fact that at the CG in the manual the plane needed lots of down trim and was very elevator sensitive. Rolls are fairly axial, overall I love the plane and how it flies, just need to get comfy with it!

cmoulder

Nose-heavy planes don't need down trim.

Search this thread for "wing incidence"

flyboy25

My Feedback: (5)

120 fs will be awesome. I have flown it on the 91 and the 120. Do you guys think a 16oz tank will be alright for the 180, propbably wont ever go to full throttle. Thanks!

cmoulder

You're kidding, right? A 1.80 4-banger on a (nominally) 7.5 lb airplane?

Usually 20-24 oz, but 16 should do. But geez, it's like putting a supercharged hemi on a lawn tractor.

Aerobatx

My Feedback: (1)

A 180 is way ovekill, this plane would fly good on a 70 four stroke...it'll probably get shook to pieces.

flyboy25

My Feedback: (5)

I will let everyone know how it goes soon. I am using a vibration reduction mount so it shouldnt be that bad but I will definetly fly under 1/2 throttle.

unfmoose

I should have phrased that differently. It seemed really tail heavy with the CG from the manual so I moved it forward and now it is on the nose heavy side. It nows fly with a touch of up elevator trim. Before it needed down trim. Just to clear that up so I don't look too retarded.

flyboy25

My Feedback: (5)

cmoulder, the gas motor was 24oz heavier than the 91 and is 10oz heavier than the saito. The plane only weighs a little under 9 pounds. It weighed almost 10 with the gasser!

flyboy25

My Feedback: (5)

I also didnt add any weight, Just moved the battery to the tail.

flyboy25

My Feedback: (5)

Here are some pics .

cmoulder

Only slightly less insane than gas.

Get some video.

flyboy25

My Feedback: (5)

I would appreciate your opinion cmoulder, Do you think it will work?

cmoulder

It will fly, but IMHO at that weight it will fly like a warbird and not an aerobat.

I have an idea how it might fly because a few weeks ago I maidened a friend's kit-built GP Extra that was the heaviest (wing loading) Extra I have ever flown. Extremely tip-stally and had to keep the speed up, really a handful just to keep from crashing, and tremendous concentration to keep wings level on landing approach. The only plane I ever flew that was even close to that hard to fly was a very heavy KMP FW-190.

But I've been wrong before, and maybe it will float like a butterfly. However, arithmetic suggests otherwise.

bigdanusa

Or sting like a Bee!

I don't think that airframe would like a gasser. Mines getting a .75 2 stroke whether it likes it or not.

maynardrupp

Mine has an OS75AX and it is just OK. I would think the new OS95AX would be a better choice except that the price for that engine is more than the 120AX. I guess I will stick with my 75.

faulknej

My Feedback: (9)

I'm going to maiden mine today. It's the first day the wind has been manageable in quite a while. Temps below freezing, but doable. The Magnum 91 4 stroke should fly it fine, no?

FentonFlyer

My Feedback: (11)

I fly mine with a Saito 100 and I think it's perfect. About 7.5 lbs if I remember right. A 1.80 will be rediculous power and will kill this airframe in short order either from vibration or a high wing load induced tip stall...

cmoulder

IMVHO, the Saito is perhaps the best 4-stroke for this plane because it has got more displacement yet is lighter than an OS/Magnum .91, and the best 2-stroke (which I have used, and am using in my re-furb project) is the OS .91FX with a slimline Q-series Pitts, which is lighter than many .60's with standard mufflers.