I have two choices...OS 46fx and OS70 4 stroke. Which engine would be better for this plane. The 46 fx weighs 13.2 oz. and 70fs weighs 20.10 oz. Will the difference of approx 7oz. be a lot? I plan to use an APC 14x4 W with the 70 or an APC 12.25x3.75 with the 46fx.

I want to 3d with this plane. Any advice?

Anurag

I believe that weight you have for the OS46 is without the muffler. With the muffler I think it is about 16.5oz which is real close to the Saito 72 at 16.6oz. I use the Saito on my fun fly airplanes because they have alot of torque and can swing a much larger prop. If I were you I'd try the OS70FS. It's a little heavier than the OS46 but you should get more enjoyment from it. If you could get a hold of a Saito 72 then were talking... As for the extra weight 7oz is alot when were talking about a 4-4.5lb plane.

If I can ever get in the first flight on my just finished lanier taylorcraft, and finish a rocking horse for a pregnant friend of mine (swear to god it's not my child ) I am gonna finish and put the os70fs on my omp edge. It's a little heavy, but I think it will be very well worth it with the 14x4 wide prop that everyones talking about.

Hey Ragz.

I'm running an OS .50SX on my OMP Edge540P. Same size and weight (1/2 oz heavier) as the 46FX just a little more kick. Turning an APC 12x4 it's a rocket ship. I was running a MACS pipe, but switched back to the stock muffler...no big change, maybe a couple hundred RPMs.

You want this plane as light as possible, but with enough power. The 46FX has more than enough power. With the 46FX installed the CG is just right without adding anything, moving the battery around in the radio compartment allows for fine tuning. Installing a 7oz heavier engine will mean even more weight in the tail to get the CG right...just a thought. I'm sure the plane will fly good with the extra 1lbs from the OS70 and weight in the tail, but it will fly AWESOME without it!!!

I recommend the 46FX...

-DRW

Where did you mount your engine on the rails ? Front,middle or rear ?
Thanks, I am putting one of these together and plan on using a 46 two stroke.

I will put it depending on the CG...

Towards the rear of the rails. The back of my spinner is about 1/8" to 1/4" from the fuse.

FYI I also used Hitec HS-225MG servos all around (saves about 4oz weight over standard size servos) except throttle that was a Hitec HS-85. Battery is a AAA NiMH 720 mA. My CG is 2" behind the spar.

-DRW

Thanks, that is what I needed. I am at the stage of putting the ply plates on the rails.

docwatsn i cant beleive you didnt notice a change with the macs muffler.i got 1000 more rpm than stock.btw i have a 46fx on a 5lb sig se and it pull from a hover like crazy.i cant imagine it on a 4lb plane.

1K RPM seems a little high...wow!!! Seems that I only saw about 300 - 400 increase. The main reason I went back to the stock muffler was the noise level...I like them as quiet as possible...the MACS pipe was a little obnoxious. But if you're reporting a 1K increase I'll try it again tomorrow.

My 50SX on my 4.25lbs OMP Edge 540P is very easy to imagine...take the above picture, pretend that your holding my radio and you give it full throttle, 20-30 seconds later it's a little dot way up there, then you get to flat spin it all the way to the ground...he he he!!! Lovin my Edge 540P!!!

-DRW

Just wondered where you guys are getting the gear for your OMP profiles? I just ordered one and would like to throw out the wire gear.

Thanks

I have built several of these little omp edges. I either use the stock wire or use the crazy legs. Both work fine. Do a search on here for crazy legs. They are great and they even have a heavy duty set if you plan on pounding them hard.
Chris

I plan on putting an Irvine .46 on mine

Sorry to ask but I have never had a 40 size plane before. What size fuel tank are you guys using on these profiles. Just ordered a 540p and a GMS 47 yesterday. I want around 8 min flights.

Thanks

Of the two you have mentioned, I would go with the OS46FX due to it's 4 oz lighter than the OS70. I would at least remove the baffle from the muffler, or better yet replace the muffler with a MCP, Tower Muffler, or Macs.

You can try the 12.25 x 3.75, but if you don't change the muffler, it probably will be too much prop. Get you a few 12x4, 11x4 and 11.5x4 to try as well.

I'd put an 8oz tank if it will fit. Use a 6 oz only if the 8 won't fit.