trim spring ?

robertstodaro

Senior Member
Has anyone flown a Dom with the trim spring removed?

If so, how did it handle?

It seems we (the gyro world) could come up with a better fix.
 

robertstodaro

Senior Member
I would like a rotorhead that does not require any spring at all.

Isn't the offset in the rotor head for ease of manufacture? Or is the offset required?
 

birdy

Newbie
Theres alot more to it than that Rob. I don't know how to find it, but there would be a good explination on this forum else where on offsets.
 

Aussie_Paul

A reforming stirrer!!!!!
The off set gimal head is a simple stability facility. Chuck Beaty has explained it a number of times. Search the forum using stability or offset gimbal head and see what you get. Use Chucks identity.

Aussie Paul.:)
 

Al_Hammer

Platinum Member
Robert, my Dominator did not have a trim spring. The weight of the prerotator cable apparently provided enough back force to substitute for a spring. I did not build the gyro myself and never thought much about the trim spring issue.

Here is a pic of my 618 powered Dominator. You can see the large Wunderlich prerotator cable hanging off the head.
 

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Doug Riley

Platinum Member
The trim spring on my tandem Dominator goes slack when the electric trim is set on full nose-down (as it is when doing full-power climbs). In this position the spring will disconnect itself if not safety-wired.

The gyro is perfectly manageable with it off, but you must hold constant back pressure once you throttle down. This is tiring and interferes with a good "feel" of the stick. Flaring becomes an upper-arm-muscle builder without the spring.
 

Phil_Ruffin

Gold Member
Once my trim adjuster messed up while in flight. It didn't effect the flying except stick pressure increased.

I knew what had happened when it happened because I had my hand on it at the time, I flew around another 20 minutes or so before I landed and fixed it.

Don't worry, you will be able to continue to fly without it.
 
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Doug Riley

Platinum Member
It could be unpleasant if the spring broke while you were flying hands-off or had a very light grip. I would not expect the result to be deadly unless the aircraft were very prone to PPO -- such the first-generation Air Commands were.

I get chills thinking how much I flew my scary old A.C. (no HS, inverted engine, low seat) hands-off while doing aerial photography back in the 80's. Fortunately THAT spring never broke.
 

Aussie_Paul

A reforming stirrer!!!!!
Doug.....

Doug.....

Doug Riley said:
It could be unpleasant if the spring broke while you were flying hands-off or had a very light grip. I would not expect the result to be deadly unless the aircraft were very prone to PPO -- such the first-generation Air Commands were.

I get chills thinking how much I flew my scary old A.C. (no HS, inverted engine, low seat) hands-off while doing aerial photography back in the 80's. Fortunately THAT spring never broke.
......I did have the trim spring break while training. I had replaced the spring at the annual a few days earlier.

The student was progressing well BUT he was under confident so I had my hand sitting on my knee to give him some confidence. As we Joined a 500' base I put my hand down to that, side stick for me, and placed my fingers in front of the stick. The flight had been very smooth with a frost and still air. All of a sudden a pitch forward and the stick was stopped by my fingers.

I said to the student,” What did you do that for?" and he replied, "What did YOU do that for?"

I told him to gently let go of the stick and I had quite a bit of pressure. I looked around and here was the trim spring hanging by the safety wire. I reduced power and flew down like a fixed wing so I did not have to flare too severely.

My student thought that I had jabbed the stick forward to test him!!!!!

The hook on the end of the NEW spring had broken off!!

If this had happened while my hand was on my knee I am sure that the student would have held it, but not a nice thought with the S X S A/C HTLM trainer.

This is a case of if it aint broke don't fix it!!!

Where is the happy medium between preventative maintenance and if it aint broke don't fix it?

Aussie Paul.:)
 
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