Jungle Gym Gyro Update

[magilla]

OK, fellas (and ladies):

I have hesitated posting, because the gyro is still not 100% completed, but I see light at the end of the tunnel... Any emotional and psychological support is welcome.

Some recent advances to the "Jungle Gym":

2276cc motor running smoothly, with new carb anti-ice built in - just replaced the existing cross-tube that the Holley model 1920 single barrel downdraft was sitting on with a modification to the "original" VW cross-tube manifold with exhaust bypasses to heat up the aluminum manifold. It runs like a charm.

Cut new rudder and vertical stabilizer and painted with "invasion stripes" and the pre-1943 red and white stripes...

Just ordered a new double-bearing rotor head from Ernie Boyette at RFD. With 800-850 All-up GWT, I was too close to the design limit with a single-bearing rotor head. Will be a simple bolt-in swap.

Due to tailwheel interference with the rudder (you can see in the first two pics), I reformed the sprung steel, and torched and stress-relieved it in oil, and then put on a 5" MATCO wheel (not pictured). No interference now!!

Have designed a new pre-rotator to work off the flywheel end of the VW motor. I took the two Gresen MD 20020 pumps/gerotors and have figured out a way (Thanks to Tom Milton) to create a cone clutch system using an aluminum nosecone attached to the keyed driveshaft that will connect with an aluminum bowl with rubber insert used to start LARGE RC aircraft. (it the end that attaches to the electric starter) As the aluminum block (shaped like a nosecone) is pushed into the opening at the rear of the Diehl accessory case, it contacts the rubber and aluminum receptacle that is bolted to the flywheel (it is the original drive plate for the magneto system). Should prerotate to approx 300 rrpm.

Anyway, thanks to Bob Gregory, here are some pics at the June "fly-in" we had in Arkansas, where 10 gyros showed up.

I have been gone for a month due to work, but hope to have the Jungle Gym ready for trial runs in late August / early September -

It is so close I can taste it!!!!!

PS - the pics are of the Jungle Gym without the mods to the rotor system or the pre-rotator. It pulled 370 thrust on Joe Terminella's meter...but is suspect because his blue-head 582 with three-blade 72" Warp Drive only pulled 270... In any case, it pulled 100 pounds more than a Rotax 582.

And I had my brakes on, I realized after the fact.

Anyhow, enjoy the pics!!

And ask any questions you want! Please - the more questions, the more I am driven to make sure it is good to go.

FYI - pulling 3650 rpms (about 1750 prop rpm) with a Culver 84" x 56 prop. I felt like it was going to launch me into the sky without a rotor...

Again, I purchased the airframe from Joe Terminella in November 2006, so it has been a labor of love and pain (prop strike and unrelated complete engine rebuild last year), and I am eager to get this thing off the ground.

Last small thing to do, after installing the new double-bearing rotor, is to hook up the rotor tach to my bicycle tachometer (mounted in center of dash).

Again, all comments, positive and questioning, are welcome.

[Mike484]

Looks good, just wondering where the exhast goes, looks like it night be blowing back on the pilot. It's great to see tractors, afterall, they were the original autogiro.

[magilla]

Exhaust system is currently an interim standby - it is an aftermeket dunebuggy system (read: HEAVY!) that was mounted in opposite direction...

In fact, the wind created from the prop blows the exhaust right by - you can't even smell it, even at idle (exhaust is below and outside of pilot, right in the slipstream).

The plan is to cut the exhaust tubes, and weld a setup where the exhaust meets in the middle of each side, about 6" under the valve covers, with an exhaust port. Should save me about 10 lbs on each side (that chrome is heavy!)

Good point, though.

I am going to build an a cowl for the Jungle Gym between the motor and the dash, with the exhaust exiting out the bottom.

Right now, it works fine, and keeps the neighbors happy!!

[RotoPlane]

I think that is so cool looking! The gear geometry looks like it should handle well and I like the large diameter tires. The engine mounts and exhaust pipes are twisted art. Definitely cool.

One thing I found exciting was the belt reduction….it is so small! Would you please point me to the build post that had that information….couldn't find it. I'm interested because I would like one that size, if it can handle ~ 70 hp.

[Vance]

It looks very good Spencer.

Who is going to be the test pilot?

Thank you, Vance

[WHY]

Hi Spencer

Flat outright AWSOME! especially that prop but the prop does give me some concern, I wonder if the "P" factor on that prop might produce a "spin out" if full throttle is applied before sufficient foward speed is reached??

Tony

[Timchick]

It won't be long now. Great job.

[scottessex]

Gotta love an aircraft with knobby tires! Cool, looks good!

[chuter]

Looking good Spencer!

I love the VW motor; I bet it sounds pretty cool.

[magilla]

Thanks for the support.

Ed - belt reduction is from Valley Engineering - look up Culverprops or Valley Engineering and you'll go to their website. It's also listed on the Great Plains VW site. New version III has an idler arm and v-belt.

Vance - You're lookin' at him. Going to Ron Menzie's late this year to get a gyro sign off, and then I have phased game plan for the test flights (used to be a UH-60 test pilot up until 2 ys ago). Until then, ground runs, taxi tests and crow hops. Once the smaller bugs worked out on teh ground, I will get a DAR to sign off. N-Number already applied for.

Tony - P-factor is present with an 84" prop. If you goose it, especially in a left turn, she'll ground loop. Otherwise, she's pretty docile on the ground - you just have to get used to the "turn early, then put in opposite rudder halfway through the turn." It shouldn't be an issue unless you ram the throttle forward at 5 mph...

Knobbies are cool. They have drag, but are cool. I have a set of 21" baldies they use for the PPC crowd that I will try too.

Mike - the VW sounds AWESOME. Runs like a "raped ape," as my dad used to say. The new manifold really makes me happy - even at idle she is warm to the touch, and now, I don't have any vacuum leaks, and no pure exhaust coming into the carb. Mixture and idle are set perfectly now, and she runs at 650-750 rpm at idle, after a 5 minute warm-up (no choke). It has a true VW sound - 4 stroke bu-bu-bu-bu-bu that turns into a roar.

Thanks for the comments

[animal]

Looking good Spencer, I like the paint job and your panel, looks like and old fighter.

[Minnesota_Mike]

Hello Spencer...
I can't wait to HEAR that Engine...from your description it must be a very sweet sound. (I owned a Bradley GT years ago...I know that sound very well)
Really like those tires...WOW...that'll be a softie' when landing with those..!
Your workmanship looks great I too- I will enjoy seeing more as get get to completion, so PLEASE DO post as often as you can...watching it come together is a real thrill on this end too..!

M-M

[All_In]

Looking good Spencer, Yaw Mon!!!!

I look forward to the pilot reports as to how she handles.

Thanks for sharing...

[magilla]

Props to Joe Terminella for building an excelent gyro - the workmanship on the airframe and the gyro itself is outstanding.

Ron Awad flew it back in November of 2005, and he reported a very stable aircraft.

The only things I have changed from the original build are the rotor head (double bearing for single), and installation of the new VW engine, and new dash and electrical systems/engine monitoring instruments. The primary reason I bought it was the fact that it had flown previously (albeit underpowered) and I had gotten a line on the redrive 2300cc motor.

I put the knobbies on it too, so I could maintain a 9" clearance from the prop to the ground when the aircraft was level...

Joe T had his own very unique pre-rotator, but couldn't use it with the redrive. So I am using most of the components (gerotor pumps and hoses) and fashioning my own way to drive it from the rear of the VW engine.

I really hope to continue to get it ready to fly by October/November timeframe.

[RotoPlane]

Thank you Spencer, for the re-drive information. Checked them out and decided I had better make my own....cost more than my new engine!