Performing loops (not flips) with stock mcpx

[sleeperaus]

Hi all,

My MCPX v2 is pretty much stock except for extended solid CF tail boom.
It's still got the original motor I got with it about 10 months ago and probably couple hundred flights on it.
I can flip it pretty good forward and back, roll it OK too, though it does loose height when I do all of these (which I'd expect since it's not brushless).

But the other day I was trying to do a proper loop, (ie. not just a small flip but actually a full circle in the air carrying horizontal speed through it) and no matter how much speed I tried to carry into it I couldn't get it to go past vertical with any speed left. It would get to vertical, have no speed then I had to abort the loop and pretty much turn it into a stall turn!

So my question is : can a proper loop on a (pretty much) stock mcpx be done (anyone got a good youtube if so?)? Or do I need to reign in my expectations and do a much smaller/tighter loop? Or is it just not possible because there's not enough power to carry the speed past the vertical?

One thing I have noticed lately with my mcpx is a dramatic shortening of flight times and occasionally the motor seems to quit (like it had reached LVC) at a point in my flight when I know there's juice still left in the battery (this usually happens after I push it through a hard bit of flying). Is this a sign that the motor probably needs to be replaced (batteries not too old so don't think it's them)?
If I replace motor will it give me the extra power to do a proper loop?

cheers.

[ArchmageAU]

Originally Posted by sleeperaus

...
But the other day I was trying to do a proper loop, (ie. not just a small flip but actually a full circle in the air carrying horizontal speed through it) and no matter how much speed I tried to carry into it I couldn't get it to go past vertical with any speed left. It would get to vertical, have no speed then I had to abort the loop and pretty much turn it into a stall turn!
...
One thing I have noticed lately with my mcpx is a dramatic shortening of flight times and occasionally the motor seems to quit (like it had reached LVC) at a point in my flight when I know there's juice still left in the battery (this usually happens after I push it through a hard bit of flying). ...

Proper loops, you need to fly them. The section past vertical is the hardest to get right. Can you do them in a sim on a larger heli. A heli loop is different to a plank loop although the CG follows the same path, the heli attitude is different.

Learning Loops - RC heli flight school v1.1 (3 min 59 sec)

If you watch the sticks carefully, you will note positive collective almost to the apex.

I feel I need to add a "kick" of positive collective to accelerate the heli into the top part of the circle, then counter this pull with negative. Flatten the top part and then allow the rest of the loop to continue as expected.

The shortening flight times is usually a sign of battery fatigue. Lipos do wear out. Try a new battery. Also check the 3-in-1 wire connections solder point these seem to degrade over time. If neither of these, then replace motor.

[sleeperaus]

Loops on sim with bigger helis are pretty easy.
I just can't get my mcpx to do it in RL

Anyone got any footage of a brushed mcpx doing a proper loop?

[ArchmageAU]

Originally Posted by sleeperaus

Loops on sim with bigger helis are pretty easy.

How about when you reduce the head speed to 50% or below. (just enough that 75-80% collective required to hover, but not too much that the tail blows). This is where your mCPX is at. To loop it requires much more collective control.

A big heli in the sim will loop (badly) from FFF just by changing elevator. Since your mCPX has very little mass, you cannot use momentum to hlep you. Neg collective management round the apex will be essential.

I am in Brazil at the moment. I'll try with my nano's when I get home and report. If lucky I may get someone to video.

[Tasteles]

IRL, I find that loops on bigger birds are much easier and smoother. As mentioned, collective managment is the key. It's a matter of timing when going from positive pitch to negative pitch. I find loops on a stock mCPX is easier to start by diving towards the ground at about a 30* angle to get the momentum up, then pull back. When you get about 3/4 inverted transition to negative pitch. And of course, pointing into the wind helps with lift going into the loop.

[tkranz]

Originally Posted by Tasteles

IRL, I find that loops on bigger birds are much easier and smoother. As mentioned, collective managment is the key. It's a matter of timing when going from positive pitch to negative pitch. I find loops on a stock mCPX is easier to start by diving towards the ground at about a 30* angle to get the momentum up, then pull back. When you get about 3/4 inverted transition to negative pitch. And of course, pointing into the wind helps with lift going into the loop.

+1 on the diving a bit to gain speed before the loop

[sallen48]

Same deal with me... lots of head speed and forward speed. Pull back on cyclic and the bird runs out of steam when vertical and I have to bail out. I'm no 3D flyer just want to do a simple loop. Can do them all day long with my airplane but not with this heli. Can do them with simulators for this heli but again not in RL. Oh well, have to be happy just flying circuits.

[Stubbz]

V2 just doesnt have enough ass to do it correctly imo

[boykster]

Originally Posted by Stubbz

V2 just doesnt have enough ass to do it correctly imo

I agree....with good collective management, nose down prior to starting loop, and some squinting you can almost get a round loop with this little heli, but it's tough. Its WAY easier with a 450 and larger heli.

[ntwaddell]

yeah i can't get mine to loop either, but my larger heli's are no problem

[MotorG525]

I can get mine to do it, fast foward flight then up on the collective for the first half of the loop, not the elevator