Gyro problem - search no help

Idecided to start routing and mounting my radio electronics while I'm waiting for my motor package and my Profi Gyro's showing behavior that I could find info about by doing a search.

Without gyro hooked up, tail servo is in neutral, horn at 90*, tail arm at 90* to boom, servo travel direction correct.

I hooked it up like the instructions say - pretty straight forward: gyro oriented like the diagram; no jumpers; sens left at factory set 50%. When I turn on thr Rx, after I get the ready light, the servo cranks to the extreme left, beyond the travel range it has without the gyro hooked up (without the gyro there is still space beween the slider and the blade holder) until it hits the blade holder.
<<pause while I had an idea and tried it>>
Ok, I tried it with the "Program select" jumper on - I'm assuming jumper on=HH - and it initialized to server neutral. Compensation was opposite so I put on the Reverse jumper, and with both jumpers on it works right.

Now I have two questions:
1) Is jumper on, in fact, HH? Instructions doesn't say ( big shock there...Ikarus instructions, vague? No way!!)
2) With the jumper off, should the gyro be pushing the servo to its physical travel limit? I was half tempted to disconnect the linkage at the tail and see if the servo would travel any further!

Remember, I've got the PoorMan's Package Laser 4, with the only mods for rudder channel being reverse - no ATV.

Another thing I observed during assembly is, if you mount the rudder servo "horn up" like the manual says - at least with my radio - you need to reverse the servo direction. Am I wrong in thinking all radios have the same servo rotation in relation to stick movement: i.e.: stick right/up = servo clockwise, in normal mode. If that IS the case, wouldn't it have made a lot more sense to have the servo shown mounted "horn down" to begin with? And you would THINK the correct axis diagram would show how the gyro should be oriented in NORMAL direction, maybe with a note that says " If you mount it 180* out you'll need the REVERSE jumper." It just doesn't make sense.

>>after I get the ready light, the servo cranks to the extreme left, beyond the travel range it has without the gyro hooked up <<

What happens when you bump the rudder stick. Does it come back? That is a characteristic of a HH mode. The servo seems sluggish and the tail position does not return to neutral. Once you fire up the heli and bump the rudder stick it will stay in the proper position.

The best bet is to set up and test fly the heli in rate mode and make sure everything is ok then change over once everything is trimmed out. Even that you may still need minor adjustment because of temperature drift.

>>Ok, I tried it with the "Program select" jumper on - I'm assuming jumper on=HH - and it initialized to server neutral.<<

No, mine is HH mode with jumper off and if your trim is not centered the servo will drift off to the extreme. It is in the manual (about the servo drifting in HH mode).

>> Compensation was opposite so I put on the Reverse jumper, and with both jumpers on it works right. <<

Did you try the compensation while the program select jumper was out? Was the compensation proper? Regardless compensation has to be the same between HH mode and rate mode.

>>1) Is jumper on, in fact, HH? Instructions doesn't say ( big shock there...Ikarus instructions, vague? No way!!)<<

HH mode is jumper out unless you have a different gyro.

>>2) With the jumper off, should the gyro be pushing the servo to its physical travel limit? I was half tempted to disconnect the linkage at the tail and see if the servo would travel any further!<<

Yes, adjust with your rudder trim.

>>Another thing I observed during assembly is, if you mount the rudder servo "horn up" like the manual says - at least with my radio - you need to reverse the servo direction. <<

The rason for horn up is to get rudder pushrod as close to tail boom as possible. The farther away the less direct the linkage. Don't get hung up on servo reverse. In the old days before servo reversing feature we get real hung up on servo reversing because we have to make sure linkages are ok. We even buy reversed direction servos to ease installation. With servo reversing feature on the Tx you just flip it which ever way you want.

BTW yes, different manufacturer have different servo rotation direction.

Ok, I did what you said, Seiz. Direction is good and moving stick/ trim did make a difference. I think I'm ok as far as the gyro goes. Once I get to actually spinning up I'll see how things go. Thanks.

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>>I think I'm ok as far as the gyro goes. Once I get to actually spinning up I'll see how things go. <<

Great! Once you spool up and flying the gyro will do the right thing. Assuming all your tail rotor linkages are smooth as silk and free as the wind.

It may sound easy but it is a constant work in progress. I just re-did my tail pushrods and changed the ball links.

Yes. Linkages are pretty smooth. The tail assembly itself moves REALLY easily. I'm sure I'd get better results with the tail mounted servo setup, and I'll do that when the time comes. I've already deviated from "stock" by bypassing the tail mix with the mech mixer and running the tube just from servo to control arm. I also didn't use the z bend in the wire at the tail because that could be a future headache should I need to adjust belt tension. I used one of those round fittings with the hole through the center and a set screw; that way I can make adjustments at either end easily. The z bend way is just too limiting.