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Vernier Throttle approved for S-LSA

E

Ex Bonanza Bucko

Well Known Member
I heard tonight that the Vernier Throttle we have been waiting for in our S-LSAs is available for order. I think I found it on Van's order pages but it is not to clearly identified. I will call in the morning to order this. It is long past due.
EBB
 
Centre Panel

Had a look but can't see anything. However, if now available is there a corresponding revised centre panel? From previous posts elsewhere on this forum the vernier does not fit existing panel without a bit of butchery to the fixing nut.
 
Hole enlargement for the vernier throttle

Guys,
I was the shade tree mechanic that had to butcher the fixing nut. Because I didn't know any better.

Actually, when enlarging the hole using a Unibit, simply hold a downward pressure on the bit as it cuts and the centerline of the hole will move downward. I helped install two other vernier throttles on 12's using this method and the fixing nuts then fit fine.
 
I looked again at the Van's parts ordering site. The vernier throttle is not on it. All of the throttle, mixture and prop cables are for airplanes other than RV12. Guess you gotta call Van's to find out about it.
EBB
 
They are shipping it again - however, you have to use your original Rotax springs for now till they figure out the problem with the weaker ones breaking.

I just got mine yesterday - it had been on order since early Aug.

I'm ELSA, for SLSA though I expect there may be additional issues.
 
The throttle will not work correctly without the correct springs. It will creep no matter what you try to do. It will be worse than the old one. I would wait and not install it until they fix the spring problem.
 
Ok - good to know. I'm on a cert push anyway, so that was going to wait till afterwards anyway.
 
I'm wondering what rocket science is involved here

I purchased/installed the vernier throttle with weaker springs quite a while back--prior to the range spec'ed in the service bulletin. From this I conclude that they must have had the right spring manufacturing/annealing process at that time, but no longer seem to have that process available. Either that, or they never had the proper process, and I therefore also might be using suspect springs.

JetGuy's perspective on the various throttle configurations is valuable--He's flown his RV-12 with the normal throttle with the strong and weak springs, and flown our RV-12 with the vernier throttle with (hopefully good) weak springs. My favorite pilot/wife certainly appreciates the weaker springs/Vernier combination. (I also had to shorten the Flap handle springs for her--her thumb muscles couldn't quite handle the stock spring.)
 
Before I put in the Home Depot springs I found I tried some Harbor Freight ones that I cut down. They broke at the point where I formed the hook after about 50 hours. Next I tried the reduced tension springs discussed on the forum, but they were too strong to stop throttle creep. Finally found some Goldilocks springs at Home Depot --- just right! No creep and smooth throttle action. Sorry, don't have the part number.
 
I used light springs from Lowe's Aero. They worked great until one of them broke. However, a friend of mine is building a Kitfox powered with the 912 ULS, and he told me the Kitfox demonstrator doesn't use the springs at all.

I know the Rotax theory behind the springs, but how likely is it for the throttle linkage to break? Just wondering....

Walt Shipley
 
If the throttle is operated by the normal "stranded cable" you must have the return springs as the cable will not "push".
If you use a solid "push/pull" cable, you might be able to do this.
Of course this would only be acceptable on an ELSA, after certification.
 
Walt Shipley said:
However, a friend of mine is building a Kitfox powered with the 912 ULS, and he told me the Kitfox demonstrator doesn't use the springs at all.
Click to expand...

I have a Kitfox, and the other day compared my throttle cable to on on the RV12, they are not the same. The one on my kitfox is much thicker and stiffer. I have been running for 300 hours with no springs on it just fine. The carbs balance just fine etc, but I don't think the thinner cable would push it the same way on the RV12.
 
RFSchaller said:
Before I put in the Home Depot springs I found I tried some Harbor Freight ones that I cut down. They broke at the point where I formed the hook after about 50 hours. Next I tried the reduced tension springs discussed on the forum, but they were too strong to stop throttle creep. Finally found some Goldilocks springs at Home Depot --- just right! No creep and smooth throttle action. Sorry, don't have the part number.
Click to expand...

You and Walt shop at all the best places!:D
 
Mel,

You have a lot of experience and I respect your opinion. However, my springs both broke and I did not notice it in operation. I picked it up on preflight.

Rich
 
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