CMP Edge 540-T .40-.50 size
 

Anyone have any comments, good, bad or ugly about the 40-50 size CMP Edge 540-T.
Started the assembly process on mine this weekend, should be ready for maiden next
weekend weather permitting.

Magmun 52 w/Bisson Pitts muffler, Hitec servos doing the pushing and pulling duty,
Futaba PCM RX

RE: CMP Edge 540-T .40-.50 size
 

Are you using the four stroke Magnum .52?

If so I'd recommend a different engine. The 4S .52 is closer to a 2 stroke .32 ABC engine in performance.

You want something the equivalent of a .50 2 stroke engine in that plane or better.

That would mean using a 4 stroker in the .80+ range or better.

RE: CMP Edge 540-T .40-.50 size
 

No I stay as far away from Magnum 4-strokes as I can, have had nothing but bad luck
with them, but I have several 2-stokes and that is what is going in this bird.
Magnum .52 2-Stroker with a Bisson Pitts muffler.............

RE: CMP Edge 540-T .40-.50 size
 

That should be fine then.


I haven't had problems with my Magnum four strokers, though the ones I have tend to be the larger sized ones.

I do find that the needles are the most touchy of almost any engine I've tried.

A quarter turn is the difference between a well running engine to one that does not work at all.

Just finding that 1/4 turn "range" can be problematic at first.

-

Anyway make sure that the elevators hit the same points when they are fully deflected up and down.

My plane was pulling to one side in tight loops because the pushrod moved sideways. Once I corrected this, it flew fine.



I find that at stall one wing will drop a bit, but then almost immediately recover, leading to a bit of a rocking motion. If you see this happening just give it a bit of throttle.

I've never had mine enter an uncommanded roll at stall though.

RE: CMP Edge 540-T .40-.50 size
 

A little off the subject but I had 2 Magnum 91 4 strokes and they both went
back to Global Hobbies, twice, for problems, cams were replaced,could never
get them to idle below 3500 RPM. Our club 4-stroke expert worked with both
engines for a total of 4 days and still couldn't get them to idle down, so sent
them back and traded out for 2-strokes. Now the only 4-strokes I own are
Saito's.

On the Edge 540, did you used the supplied hinges and control horns?
The only one I am having trouble with is the rudder one, don't think it
is glued to good in the fin, will have to drill a small hole and try and inject
some epoxy into the cavity and see if that will hold. I also used a different
tail wheel assembly, the Dubro #955.

Will be posting some pics in the next couple of days of my assembly progress.
I know that there are more out there as Alex @ A-K Models has sold out of these.
The actual plane is far more attractive than the pics shown in the advertisements
for it.

RE: CMP Edge 540-T .40-.50 size
 

Sorry to hear about your Magnum problems.

I'm pretty sold on the Saito's myself. They seem to tolerate mistuning like no other engine made.

The biggest problem with them is that people do not realize this, then complain about fuel consumption, etc... while they actually have their engines dumping excess fuel into the chamber.

I helped someone out last weekend with this very problem. He did not realize his engine was so out of tune.... yet it still ran fine albeit very rich.


FYI when the Magnums are new I've found that I MUST use props with more mass to get the idle down.... such as the APC's.

Once I've adjusted and tuned the Magnums, then run them for a couple of gallons, I can then swap out the prop and keep the same lower idle.

Re: Tail

I do not recall having problems with the tail control horns, but I did swap out the tail wheel assembly.

Tower sells complete tail wheel assemblies as a "part" for some of their planes for a whopping $2.00/ea.

This includes the entire and simple to install assembly, plus an aluminum hub tail wheel.... quite a bargain!

I've purchased them by the dozen.

That is what I used on this plane and many others.

Here is a picture of the whole assembly:

http://origin-images.rcuniverse.com/.../lg-200508.jpg

RE: CMP Edge 540-T .40-.50 size
 

Thanks for the tip on the tailwheel assembly, will have to get some of those
on my next Tower supplies order.

Opjose I am having a heck of a time with the elevator linkage on this one, once
I get both elevators centered with the stab, when I apply up the left or port side
travels higher than the right side, not good ! ! ! ! ! ! I have the servo mounted
as per the instruction booklet, might try turning it 180 degrees to see if that will
fix the problem, if not might go with 2 seperate servos but still keep them under
the cockpit.

What do you think the problem is and what might the solution be?

Thanks

RE: CMP Edge 540-T .40-.50 size
 

Please refresh my memory...

Are both the elevator control surfaces driven by a single pushrod which you've put together with the provided parts?

Thanks.

RE: CMP Edge 540-T .40-.50 size
 

Yes they are, there is a double wire fitting in the rear end of of fiberglass tube and a
fitting for a single wire in the forward end of the tube. but although the 2 wires are of
equal length to the elevator halves the servo is not on fuselage centerline. I think
I will have to make a bellcrank and use indiviual wires for each elevator half instead of
doing it as per instructions show.

Checked it again this morning and the trailing edge of the left half is deflecting 1/2" more that
the right elevator half in the up position, not good when going to flare out on landing or taking
off for that matter. Cecked the incedence on the stab and also check to make sure the elevator
wasn't wharped, all seems OK.

Thanks

RE: CMP Edge 540-T .40-.50 size
 

Yup, that is the problem I was alluding to in my prior posts.

The control rod deflects to once side causing unequal movement of the control surfaces.

On one plane I installed a few bits of wood to act as a guide to the rod, preventing lateral movement while keeping it centered.
On that plane this stopped the problem altogether. You do have to make sure that push rod wires end up with the same amount of "bend" to them.

On the small Flying Dream Extra 330L EP I had exactly the same problem, and I was too lazy to fix it, so I ended up changing the control horn linkage point on the surface that moved less, so it was in another hole or two. That solved the problem there too.

RE: CMP Edge 540-T .40-.50 size
 

Moved the elevator servo around 180 degrees and it is a lot better,
after adjusting the clevis's on both sides I am within 1/16th inch of
having everything equal. Also got the rudder cables hooked up this
evening and will mount the engine tomorrow evening. Trying for
Saturday morning maiden.

Anybody know the recommended c of g location for this model. I have bought oone second hand but unfortunately no instructions.