CSM 420 setup problems

[cypher007]

ive got a CSM 420 on my heli which im having problems with. several guys at my local club have been very helpful trying to setup my heli and get it hovering. trouble is it doesnt seem to matter which way they adjust the gyro gain, the heli tick-tocks, as they descibe it. they have now suggested i ditch the CSM 420 in favour of a Futaba 401. the only other idea they had was to move the gyro from the front of the heli, where the gyro was fitted when i bought the heli off ebay, to the rear of the heli main chassis. any ideas or tips on setting this gyro up would be appreciated.

[Ade_Law]

the CSM 420 can be a reasonable gyro...

it can also be an utter pain in the arse.

the 401 with a 9254 is going to be the best bet if you just want to get it flying nicely with little time effort... its def not the cheapest option tho!

what servo do you have on the tail rotor?

Ade

[Steve]

What radio are you using and how do you adjust the gain?

CSM 420 is (in my opinion) ok - is the same as the 560, but without the computer interface, and I've never used the damn computer interafce on either of my 560s! Not had any problems with my 420.

I had problems when I transfered from my old Sanwa transmitter to my new JR one, but that was only down to a misundertsanding on my part as to how the transmitters control the gain. The gyro was fine.

Hence the original question.

I also agree with Ade - I've got 3 CSM gyros and one Futaba 401, all with 9254 servos, and the Futaba is in my biggest, bestest, most expensive-est heli, as it simply is the easiest to set up and the most hassle-free use.

[cypher007]

ok

im using a Hitec eclipse 7 QPCM TX and a Hitec HS 425BB servo.

[Ade_Law]

theres ya problem. the 425 is not a tail servo, it will never work properly on that servo.

Ade

[Steve]

Ask, and ye shall find..........

[cypher007]

nice one

i was starting to come to that conclusion myself, after reading the specs for the required servo in the gyro manual and checking this information against the Hitec HS-425BB servo's specs. needless to say the servo is way too slow for this gyro. my guess is the servo is responding so slowly to the gyro that the gyro is over compensating and sending a back and forth signal to the servo, thus creating the tick-tocking. cheers once again Ade. guess im now off to ebay to find a Futaba 9254 servo.

[Disc]

Cypher007: 9254 or 9253 futaba servos,

ebay 40 pounds ish....

[3dbasher]

yep futaba 9254 or JR 8700g, unless using a GY601 GY611 or CSM 720 then its gotta be a 9256 awesome! little word of advice though if using a JR tail servo with a Futaba gyro turn the high frame rate off
Your best bet for your money is a 9254 though, come to think off it i've got a nearly new 9253 going cheap £20 if you want it. only had 2 flights and thats was on the throttle with a gov. simlar specs to a 9254 but not as much kg pull but if your not doing out and out 3D you'll not notice the difference.
let me know

[cypher007]

what about this?

ive just fitted a FMA PS 500MBB that i hand fitted to an RC electric car. it has a: "Transit time for 90 degrees is 0.15 sec @ 4.8V". is this gonna be ok for now or do i really need a £50!!! on ebay Futaba 9254?

[Ade_Law]

yes you really need to spend the money on a 9254

3dbashers 9253 is worthwhile too.

Ade

[3dbasher]

Futaba 9253 and 9254 are your best bet, you really need a servo for gyro use all there specs are under 0.10 per 60 degrees of travel and usually digital. you just "won't" get the tail to act right unless you do, i'm afraid with heli's you need decent gear in to get them too get the desired peformance.
£50 is cheap for 9254, here have a look at this http://www.fatlion.com/sailplanes/servochart.html
gives lots of servo spec's

[Ade_Law]

yup... tail servos are very special beasts. If they arent designed for it, chances are they wont work properly.

Ade

[Steve]

Just sold a used 9253 on here last week to Dedcalm for £17.

Got 9254s in all my helis now.

I don't know anything about your transmitter, but here's a synopsis of the problem I had when I got a new transmitter. My old Sanwa RD8000 had a gyro setting in each of the flight modes - no problem at all. When I went over to my new JR transmitter, I used the Gyro function in exactly the same way that I had previously done with the Sanwa. The gain on 2 of my helis was spot on at the first attempt so had no problems. However, on the 3rd one, the gain was a bit high and the tail wobbled from side to side, so I reduced the gain a bit in the Gyro function. This had no effect, so I reduced it a bit more. This went on until I had the gain set at 0%! The heli still flew, but just had that usual high-gain wag from side to side. I then tried it at 150%, with no change!

The problem was that the Gyro function wasn't actually controlling the gyro at all. My gyro gain lead was plugged into channel 5 (that's quite normal) which is the gear channel, and the JR Gyro function controls channel 7 (and that particulat heli only has a 6 channel reciever!

Anyway, the answer to alterring the gain was to adjust the end points of the travel on channel 5, and inhibit the gyro function all together.

Hence the original question - if your transmitter is anything like mine, there could be some confusion.

[3dbasher]

gyro sens

yep i've never used the gyro function in my tx as it can cause some confusion. i use pcm 9x mk2 just plug the gain lead into the gear channel on the reciever then the atv's on the gear channel control the gain one side hh the other normal simple... sorted