Which Swash System and Why?

[Steve]

I've decided to purchase a JR Airskipper as my next 50 sized heli, having seen them go last Sunday morning at Chelmsford (Cheers Garry).

These kits come with all the bits to make it either CCPM or normal 90 degree 3 point system, so which one would you recommend and why?

I've already got 2 Hirobo helis with the 'normal' system, a JR heli with CCPM and a Millenium with their 45 degree system, so have no problem setting it up anyway.

What are the pros and cons?

CCPM has a smaller parts count, but requires longer servo arms and therefore more expensive servos to accurately control the swash plate. Normal system applies just one servo to each control axis, but uses shorter servo arms which therefore can be done with less powerful, cheaper servos.

[mchristyuk]

The_Manager,

I'd recommend going with the CCPm setup. Nearly all modern servos are accurate and powerful enough for a CCPm setup on a 50 size machine.

The big difference is the CCPm parts are all push pull and fully ballraced.. the standard mechanical mix parts in the kit are just bushed (I believe...) and they are not push pull.

Cheers

Mark

[Ade_Law]

as mark pointed out how the servos are linked up to the swash is more important than the control method.

a good example is the millenium. its a great mechanical mix setup so with the right servo choice there is no need to go to CCPM. However stuff like the hawk or shuttle has such a crap mechanical mixer system that there are real gains to be had with going to CCPM.

in this case the linkage for CCPM appear to be of better quality than the mechanical mix.

Ade

[Raptorite]

I would go with a conventional 90 degree 3 point system, just to put another perspective on it

The reason I go with this one, is because CCPM systems by design have a far more direct link to the servo, made up of shorter pushrods and in some cases more or less direct from the swash to the servo's. This is fine and is easy to get a nice non slop setup, so building and setting up a ccpm model is nice and easy.

However, there are good points and bad in the controls being more directly linked to the servos, for me the bad point is that in a crash, there is that much more load put on the servos that in most cases you will take out the gear sets in at least two, if not all three servos, whereas with a conventional 90 degree 3 point system at least there is some flex in the system which will usually protect the servos to a certain degree.

I think for learning and general flying, a conventional system is a better bet, as it makes crash repairs that little bit cheaper, and not to mention quicker in the rebuild time.

Cheers,
Pete.

[Ade_Law]

Pete. I actually think its the other way round. on the collective pitch servo on a mechanical system there is actually quite a lot of leverage available. When crashing raptors i regularly did do a gear set.

on the knight i quite regularly get away without doing a gearset. eg that big smash at masters didnt strip any servo gears!

on a side note, gearsets are cheap and easy to change would rather do a gearset than break a servo horn or control lever

Ade

[col9]

I've got 90 degree 4 point ccpm there is always at least 2 servos doing the work so hopefully it gives them all an easier time of it. Not all Tx's have 90 degree ccpm as an option.

I have a 3 servo 120 degree on my Extreme but I havnt flown it so I dont know if there is any benfit other than 1 less servo to buy. It was a bit tricky to setup, working out what channels needed reversing and which needed + or negitive travel in the swash mix got a bit confusing

Col.

[Raptorite]

Ade,

More often than not when I have had a crash with a raptor, I got away without breaking any of the servo's gear sets. I have had one or two go from time to time, particularly on the tail servo which in my case is mounted on the boom and has a fairly stiff carbon rod to the tail, so in a boom strike, I have taken out the gear sets in the tail servos.

I have also from time to time taken out a gear set in one of the servos up the front, usually the aileron servo on the top of the collective lever, but that is a pretty rare occurance.

When I used to have an original sceadu with a ccpm upgrade on it, whenever that went in, which at the time I was learning so it was a fairly frequent occurence, I almost always took out at least 2 of the ccpm servo's gear sets.

Robbe's system 88 is also a bugger for taking out servo gear sets in a crash, the mossie conquest I had was a pain in the neck for that, and more recently the two crashes on the predator turbine, which also being a ccpm model, lost 2 of the servo gear sets the first time it went in at charmouth. The second time it went in because it went into failsafe took out all 3 ccpm servo's gear sets.

So in my experience I have taken out more gear sets on ccpm models than on a traditional 90 degree 1 servo 1 fuction setup.

Cheers,
Pete.

[Steve]

I'm watching this debate with interest........

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Keep it coming lads.....


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