kgeb

[8D] If you wonder what to do with a good .30 4 stroke or .25 2 stroke i have the answer.
I completed and have been flying a Mini Funtana X with a Magnum rfs .30 4 stroke in the nose, and its a blast!

Use 5 cs-12mg hobbico servos, 600 ma rx battery (mounted in the rear hatch for balance),Spektrum ar6100 rx, 4OZ dubros tank in battery hatch and a 11x4 ma prop. All up flying weight 42 oz.

You must add a piece of 3/32" ply, some tri stock in the front along with some tri stock around the landing gear and fuel proof every thing you can get to.

This thing is a blast to fly, great roll rate, loops, unlimited vertical, good blenders and elevators, it would hover if I could just do it, very good knife edges with little coupling, but harriers have a lot of wing rock. Easy 10 minutes fuel flying time.

I put the CG at 3 1/2" behind the LE and about 5 deg down and 5 deg right engine thrust to correct flying. It flys as good inverted as up right and lands predictable and slow.

If I had to change something I would use a OS .30 surpass or Saito 30 ( more power but more weight?) maybe lighter servo to cut down all up weight (but scare of sub micros stripping out) other than that this was an easy electric to glow conversion that flies very well.

mike early

This is exactly what I am looking to do to my Mini FuntanaX.

Trying to decide on which 4-stroke to buy. A .30 or a .40?

kgeb

A little update. I have had a little trouble with the Magnum 30, sent back for new head, runs better but not great. I said on an earlier post if I built another one I would use a Saito 30 or OS 30. A .40 anything would be too heavy. An OS surpass .30 would turn a 11x4 prop about 11000 rpm and would have very good pull out. A .25 two stroke would add about 3 OZ. weight but make more power. The extra weight may hurt the way that little plane flies.

mike early

the saito 40a only weighs 40 more grams than the saito 30, and it is more readily available. 30% more power than the .30 to boot.

the .30 has been discontinued for some time...

The Saito 40a weighs the same as the O.S. .30FS

kgeb

my magnum rfs 30 is the lightest of the bunch, thats why I used it. That plane flies a little heavy. I used metal geared high torque mini servos, you could use lighter servo to make up for heavier engine, and the extra power would be good.

mike early

I'd love to see some photographs!

RACJ

I'd like to see some pics of the conversion too. I have 2 of the Magnumrfs I got for a twin project that ain't gonna happen and I'm looking a couple planes for them. Glad to see this thread.

mike early

I am wavering back and forth on the purchase of the Saito 40 for mine....

kgeb

If I get the time I will take a few picture this weekend. I use a nylon engine mount, I don't remember what brand, but you have to measure the length and buy it with long rails to fit any 4 stroker. The engine is mounted on its side, so I had to cut a small hole in the cowl for the head and valve cover. Mounting a engine inverted would look better, but would be hard to put you glower on.

The problem I am having with the magnum rfs 30 is, it runs good with a 15 % fuel with a 10x3 prop 11000+ rpm, no vertical.
It has good vertical with a 11x3 or 11x4 prop, but when tuned for good vertical, it runs very sloppy rich horizontal. I have tried 10%, 20%, and 30% nitro, with 30% having the most power and best overall, but it is still sloppy rich horizontal. and of coarse burns alot more fuel on 30%. Still about 10 minutes on 4 OZ.

mike early

I wonder if the tank pressure is sufficient...to cause it to lean out on vertical....

I pulled the trigger and bought the Saito 40. It's only 169 dollars. I bought the aluminum engine mount, but maybe a nylon one would be better on weight...

kgeb

Got any ideas on the fuel pressure? i have tried with and without the muffler elbow. The front of the tank is only 3/4 inch behind the carb and centered on the barrel of the carb.. I thought about swagging the tip of the muffler down, but wonder if I'll loose power.

I think the saito 40 will be a rocket with about a 11x4 prop. It probably will be about 3 oz more weight than the magnum with the muffler.. To balance you will have to put the battery behind the vent hatch, rear of the wing, and use at LEAST a 4 oz tank. I had a 6 oz tank in mine ( fits fine) but it would run 20 minutes, didn't need that much and just more weight.

You will have a blast with it, very aerobatic, and lands like a trainer.

mike early

I have a 4oz and a 6oz tank. Still waiting on my engine from Atomic Hobbies...

I hope the micro servos can handle the vibration of a 4-stroke.

kgeb

The micro servos scared me with a nitro motor. Those things fail on electric planes. I used hobbico cs-12mg mini servos. (so far so good, just a little heavy)

Good luck on the Atomic hobbies, I order from there once took a month to get the stuff. they said it was shipped but couldnt track, shipped another order, three weeks later the first order came, then the second showed up! Great prices, but shipping ???????????????????????