[dabney]

I have a RV6A with all gyro instruments. Just wondering if aerobatics damages gyro instruments gradually, suddenly, or not at all.

 

[Dgamble]

In my experience? Yes. Mine was pretty sudden:

You can avoid the damage by spending another couple hundred bucks to get a 'cageable' one.

 

[Mel]

Yes, aerobatics will shorten gyro life. Most gyro horizons will go 360* in roll. This is fine. But in pitch, when it hits the stops and tumbles, that's where bad wear comes into play.

If you can cage the unit and remove power, it will be OK.
Just caging helps but if the gyro is still spinning, it is still hard on the bearings.

 

[Garage Guy]

Just caging helps but if the gyro is still spinning, it is still hard on the bearings.

Here's another take on non-spinning gyro damage from The Gyro House:
http://www.tghaviation.com/kb_results.asp?ID=32

And some claims about what happens if you don't spin up your gyros regularly:
http://www.tghaviation.com/kb_results.asp?ID=33

BTW I have no idea if any of those claims are true. Solid data on what causes gyro failures seems kind of hard to find.

--Paul

 

[SteinAir]

Yes, Aerobatics will shorten gyro life significantly. As Mel said, Horizons don't care much about rolls, and DG's not so much about loops, but do the opposite with either one and they get pretty bent out of shape!

Just an FYI on "Cageable" Gyros. Most current gyros sold to GA as "cageable" gyros are not in fact permanently caged. They simply re-erect the gyro and don't hold it in caged positions. There are a few that do, but not many. If you look closely at most of the Cageable Gyros for sale today and read the knob, it says "pull for quick erect". Like I said, there are some others availble, but they are not common and not cheap.

The world as a whole is going away from spinning pieces of metal to solid state...even long time gyro maker RC Allen has a new solid state digital LCD unit. Couple that with the fact that you can buy a Dynon (it doesn't care what you do to it in aerobatics) for $1600+/- or a TruTrak ADI for elss, and it makes the $1500 vacuum and $2500-$5K electric gyros not so attractive.

My 2 cents as usual!

Cheers,
Stein

 

[Mel]

Just an FYI on "Cageable" Gyros. Most current gyros sold to GA as "cageable" gyros are not in fact permanently caged. They simply re-erect the gyro and don't hold it in caged positions.

When I had my electric gyro horizon, I cut a length of aluminum tubing and cut one side of it so that it would slip over the shaft and hold the cage knob in the "erect" position. I then put a switch in the power line so I could turn it off. This worked fine.
Later I replaced it with a Dynon D10 and never had to be concerned again.

 

[Russ Sly]

vacum line shutoff valve to save instruments

I am having to have my artificial horizon rebuilt for the second time in my RV6A. This is due to doing aerobatics which is a common problem. I am thinking of installing a manual shutoff valve in the vacum line but I understand that there has a be a provision for the vacum pressure to be relieved as the pump cannot be allowed to pump against a dead end.
I have not figured out how to solve this problem. Possibly the answer would be to install a tee with another filter. Gets complicated.
Any ideas?
This would be a shutoff valve that I could use before aerobatics and would save the expense/trouble of replacing or overhauling instruments.

 

[Russ Sly]

I might have the answer

I am researching and found a 3 way selector valve with the 3/8 barb fitting and a filter to protect the pump. Will post if this works out

 

[SteinAir]

Hi Russ,

Your vacuum system should already have a regulator in line with it that allows for pressure/vac bypass.

That said, I'm afraid that unless you have a way to actually physically and temporarily/permanently cage the gyro during maneuvers (even with the air source removed), it's still going to bang against the mechanical stops during aerobatics. Anymore, a better investment is to just toss the spinning metal and buy something like the little Dynon D2, the GRT Mini, the D6/D10A, or something like that which doesn't care about attitude and has no mechanical stops inside of it.

Yes removing the air will 'help', but only marginally/incrementally...

Cheers,
Stein

 

[Russ Sly]

Thanks

Thanks Stein for your answer. We low budget folks have a dilemma don't we?

 

[skylor]

Powered Down Gyro

I am having to have my artificial horizon rebuilt for the second time in my RV6A. This is due to doing aerobatics which is a common problem. I am thinking of installing a manual shutoff valve in the vacum line but I understand that there has a be a provision for the vacum pressure to be relieved as the pump cannot be allowed to pump against a dead end.
I have not figured out how to solve this problem. Possibly the answer would be to install a tee with another filter. Gets complicated.
Any ideas?
This would be a shutoff valve that I could use before aerobatics and would save the expense/trouble of replacing or overhauling instruments.

I have a Mid Continent 2 1/4" electric standby AI Gyro in my RV-8. Per the mid-continent instructions, I leave the Gyro unpowered and un-caged for aerobatic flights. This seems to be fine and the gyro basically just lazily floats around during maneuvers. It doesn't seem to have any tendency to bang hard against the stops this way. 400 hours and so far, so good.

Skylor

 

[Ed_Wischmeyer]

Caging doesn't help

I used to sell at AirVenture for a gyro overhaul shop. They said that aerobatics were not good for gyros and that caging and unpowered did not alleviate the wear on the gyro. After learning that, I abandoned plans to install a gyro suction bypass valve. I also learned that gyros that sit too long need to be overhauled.