std gasser setup help

[geomecc]

quick question on a different note. my bergen is the only bird I have trouble doing rolls. the tail swings out but is rock solid upright. I thought it was my thumbs but tried it all different ways. any other suggestions

[cbergen]

What gyro and servo?

[geomecc]

gy701 gyro/gov and savox1290. i have this same setup on a few of my gassers

[cbergen]

How well does the tail hold in normal mode (non heading hold)?

[geomecc]

I'm not sure. I did set it up to not drift in rate during A hover. next decent day I get I will take it out and see how it holds.

[cbergen]

What procedure did you use to eliminate drift in non heading hold? IOW, what did you adjust?

[geomecc]

i put the gyro in rate and adjust the linkage so it hovers without drifting one way or the other. i might put a futaba 611 and use a gv1 instead of the 701 and see if it makes a difference. the funny thing is if i remember correctly it will roll better one way and not the other

[cbergen]

Which linkage did you adjust?

[geomecc]

tail rotor pushrod

[cbergen]

Then I think here lies the problem. The pushrods is only adjusted to center the pitch slider on the shaft.

To adjust the pitch to correct for drift, you must adjust the links from the slider to the blade grips.

This thread talks about a 401, but ALL gyros should be setup this way. https://www.helifreak.com/showthread.php?t=17886

[geomecc]

I will do it as suggested. it's essentially the same except urs is the only heli I know of that u can track and adjust t/r blade that way as all others are one piece links to t/r grips. I will let u know how I make out hope fully Sunday. thanks

[cbergen]

The difference is, if you adjust the pushrod, then the pitch slider isn't centered on the shaft. Now you have unequal travel from one side vs the other, which is why in a roll, the tail is better in one direction vs the other.

[geomecc]

thanks chris. I reset up my tail rotor linkage the proper way (as per your instructions)!
it rolls straight as can be.

[geomecc]

quick question about the bergen fbl head conversion. the instructions say to use .040 & .015 shim plus the clip I can't get the clip on both sides with the thick shim (measures .0390) on both sides. is there a revised method with what shims to use?

[Skiddz]

The shims will fit, you just have to work at it. Easiest method "we" have found is to install the clip on one end, add the shims and damper for that side, slide it through the head block, install damper and shims.

Slide the clip over the shaft. Find a tube that will just slide over the shaft and slide it on. Now push the tube down hard. You'll compress the damper and the clip will snap into place.

[cbergen]

We did revise this, only use the .040 shim.

Chris

[geomecc]

we're the blade grips changed from the older gassers because i got a new fbl head block with my old grips and I can't get everything together without the bearings being real notchy even without the clip and spacer that go btwn bearing and thrust bearing inside the grip.

[cbergen]

Nope, the blade grips are the same, as is the head axle.

Did you have the c-clips installed on the head axle in the non FBL head block?

[geomecc]

yes I did have them installed but when I assembled everything the grips were super tight so I removed the clips then I removed the spacer washer for the thrust bearings and used the thin shims (they were thiner than the washers) and the grips was still too tight. so I disassembled it and used the original rotor Block with the shims that was almost 040 w/o the clips and the thin shims as a sub for the thrust bearing spacer. (I think they were close to 020 )and it's slightly notchy but much better. idk why it's giving me a problem.

[cbergen]

Ok, there should be no spacer washer between the outer radial bearing and the thrust bearing.

In the grip, there are only the 2 radial bearings and the thrust bearing.