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Engine Discussion Board / Re: AeroVee Aeroinjector woes!
« Last post by Smokyray on Oct 21, 2017 »
JJ,
 I agree with Kevin, 994SP's small rudder is VERY effective, you'll like the positive response. SP also has a single rod steering arm and a tiny API solid tailwheel that works quite well on my home turf strip here in TX as well as several others I have visited. I can safely compare it as the Three RV's I built, (4,Rocket,6) all have API tail-wheels and 2 with single rod steering (and twice the weight on the TW). In 4500 hours between them, no issues whatsoever. I've never cared much for chains and springs however, I went with twin SS cables from Van's on my Harmon Rocket. It's a 1400lb airplane with an IO-540 up front and alot of P factor on takeoff, the twin steering cables are necessary. On the Sonerai, not so much. The new owner (Ken) had no problem taxiing 994SP around on the grass on his first try.
Try it... :D

 My bigger concern would be static and takeoff/climb RPM, critical when flying off grass. 3000RPM minimum during the roll and 3100-3200 in climb at 80MPH I found to be optimum.

V/R
Smokey
PS: You're welcome...
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Engine Discussion Board / Re: AeroVee Aeroinjector woes!
« Last post by Kevin R. on Oct 21, 2017 »
Shocktrooper,

Instead of the tailwheel steering rod I use the old school compression springs and chain setup and have found it to be totally satisfactory.  Also, that "very small rudder" has a LOT of authority.  Note that the tailwheels we use (API) have a very small footprint and therefore limited authority which I am pretty confident can be overridden by rudder at relatively low speeds.  I am quite sure that if I totally lost tailwheel steering on landing that I would have plenty of rudder authority with which to steer until I got slowed down and chose to transition to differential braking/steering.

Best Wishes,
Kevin
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Sonerai Lessons Learned / Re: LTS Gear Longeron Damage
« Last post by Thaddeus on Oct 21, 2017 »
Wafer-

If you want to eliminate the twisting moment caused by bolting through the gear, you have to reinforce.  Original design is too weak to handle the torque exerted on the bosses.  Otherwise, move bosses to outside of gear, do not bolt through the gear, and use a strap under the gear to secure it to the frame.  See the sketches and pic attached.

My system or Sonerai.net system is not allowing pics and sketches.  I'll try to up-load to my album if you want to take a look.

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Wanted to let all of you know, who have offered their advice and solutions to my "AeroVee Injector Woes", that; attempting to run the engine with the cowlings (off), was apparently the major issue preventing smooth idle and throttle response! WHODATHUNKIT!? Man what a difference! I am still 'learning' the ideal procedures for the pre-start prep, the 'order of operations', if you will.
Now must get my dance steps down-pat, e.g.. getting the just-right amount of prime, pulling the correct number of blades through before making the mag hot, getting the throttle 'cracked-open' enough but not too-much, getting spun around & my hand to that cockpit fuel valve in time after she fires...whew! This little-bird is quite demanding of her pilot, to wake her up!
I did get it to idle as low as approx. 1,200rpm ind. but any lower and she starts to stumble and die. I will address that after I get the WOT settings dialed in. I wanted to taxi test it with a new (additional) 2nd tailwheel steering rod that I fabricated and installed on the left side to match the right side... So it was not chained down for a full WOT/EGT range test. And obviously, the plane, nor I, am ready to rotate out for flight yet! I am not crazy about the idea of having only one steering rod back there, since my home field is grass, and I will be visiting numerous such private strips in the area, as well as the public paved airports, etc. The thought of only one rod, that could fail, and then there would be nothing but throttle-powered prop wash over a very small rudder & diff. braking, to safely steer a short coupled, fast little tail dragger with, seems quite dangerous (to me). Has anyone else considered this and added a 2nd rod to the tailwheel assembly?
But in closing this reply...again...I am SO grateful to you guys for your your inputs thus far and now see that I can likely get this little bird dialed in and ready to run, "like-ah-scalded-dog", as we southern NC country-boys sometimes say!
Thanks to you as well Smokyray, for the vet-recognition kudos & YOUR service to our great nation too, 'brother'!
I ask that we keep this thread alive for as long as anyone has more to add and advise, to help me along as a rookie (Sonerai) owner, mech. & E/AB pilot. :o
Thx, JJ
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Sonerai Lessons Learned / Re: LTS Gear Longeron Damage
« Last post by Thaddeus on Oct 21, 2017 »
Here’s a sketch, I’m sure someone can do better than this.
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Sonerai Lessons Learned / Re: LTS Gear Longeron Damage
« Last post by Thaddeus on Oct 21, 2017 »
It’s late, I forgot how to multiply! 1,000 lbs torque on the long side of the gear attachment. The Acro has a much more robust attachment that prevents the external rotation. Basically a gusseted attachment.
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Sonerai Lessons Learned / Re: LTS Gear Longeron Damage
« Last post by Thaddeus on Oct 21, 2017 »
Wafer, I thought about this since you posted and came up with an idea of what is causing the issue. I've marked up one of your photos. The cracks are from rotation forces that cause the longeron to twist. Basically, the gear legs are fulcrums that attach to the longerons via the two mounting bolt flanges. When the plane lands, the weight of the aircraft divided by 2 is transmitted up each gear leg to the two bolt attachments, which are welded to the inside of the longerons.  Consider that the gear is about 3 feet long, so at least 300 plus pounds of torque is being applied to the longeron on each side in a twisting motion. The gear is trying to rotate up along the outside of the fuselage and all that prevents the rotation are these two little bolts attached to the longerons on the inside. After a few landings, the gear wins and the longerons twist and fracture. It's like a teeter totter with one side being 40 times longer than the other!

I did notice that the reinforcement plate was not fractured, yet. It was carrying the last of the rotational force and was flexing instead of fracturing.

So, the solution should transfer the gear rotational load to the diagonal or upright frame braces efficiently and not allow the longeron to twist. I think the gear attachment design should be modified to transmit that rotational force up the side of the structure instead of the focal twisting point on the longerons. The present bolt patterns are sufficient to prevent lateral gear movement, fore and aft, but is causing the failure by allowing the landing load to twist the longerons as if someone was using a pipe wrench.

It is difficult to make the longerons strong enough to resist the landing torque that is trying to twist them. Better to weld in gussets that go from the attachment bolt flanges to the upright bracing, which can then counter the landing gear torque.

The other way is to make the center section of the gear structure more rigid so it cannot flex with the gear load. The center has to be flexing down somewhere to allow the rotational force to be transferred to the longerons and twisting them.  In other words, we have to make the gear flex up around the outside of the longerons instead of pulling down on the longerons on the inside and twisting them.  The easiest way would be to weld a chrome moly U channel across the frame over the top of the gear so that it bridges all four mounting flanges (bolts go through it) and then weld to the longerons, the end reinforcement, and to the upright frame members. That would prevent the gear from flexing (rotating) in the center of the frame, would stop longerons from rotating, and it would transfer the rotational landing gear force to the upright frame members. I would also add a gear mounting bolt or two, in the middle of the reinforcement to prevent the center of the gear from down flexing, which it has to do to twist the longerons. Thaddeus
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Engine Discussion Board / Re: AeroVee Aeroinjector woes!
« Last post by Smokyray on Oct 20, 2017 »
Ken,
The 3507 is a direct replacement for the 1821. “TC” the engine builder modified the 1821 with a gear drive float bowl mixture control that is quite the engineering marvel. I had a 3507 on my Ford Jubilee Tractor and it’s literally bulletproof. The 1822 is GP’s model with the added attach plate.

You’ll like the Zenith, especially if you ever prop start somebody else’s without one!

V/R
Smokey
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Engine Discussion Board / Re: AeroVee Aeroinjector woes!
« Last post by kennyw on Oct 20, 2017 »
Hey Smokey, is the FDS3507 the direct replacement for the older Zenith 1821?  I see 1821 listed in your documentation.  But, GPAS doesn't list that number.  They do show an "1822".

Thanks!
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Engine Discussion Board / Re: AeroVee Aeroinjector woes!
« Last post by Smokyray on Oct 20, 2017 »
ST,
Originally 994SP had a 2180 with an Ellison TBI installed. My previous experience with Ellison”s was on my 0320 powered RV4. TBIs by design are finicky with air induction and harder to start than carbs. I used a set procedure every time to start thev2180 which included 3 shots of primer, pre heat below 50degrees and a filtered air intake. The key is no direct airflow into an injector as turbulent air will affect its performance greatly.
If all that doesn’t work, thev1835 I installed has a Zenith Carb on it that works superbly across the board. Additionally they are readily available new and I believe a better match for the VeeDub induction.

https://www.steinertractor.com/FDS3507Carburetor-New-Zenith?CID=FDS3507&gclid=EAIaIQobChMI-c2irfj-1gIVgkSGCh14RQf_EAQYASABEgLZifD_BwE

V/R
Smokey

PS: from a fellow Vet, thanks for your service...
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