rmh

Iam starting on my H9 Sukhoi- which will be powered with the ZDZ100 twin.
A few easy mods are being done on the fuselage and hatch to save a few aft ounces - The rest of the model will be box stock
Anybody who is flying one now - , Iwould appreciate any feedback on weight, equipment used - and balance point used- less wings if possible.
Also , we have planned a large, custom made in cowl exhaust setup- Our engine choice makes this possible.(no bottom mounted carb).
Thanks

Lew

Sent you an email -------- Lew

rmh

Just completed all lightening mods I thought worthwhile--
I stripped all the sheeting from the belly -aft the cockpit area - and lightened the tail blocks - this removed 3.5 ounces -and shifted the bare fuselage CG 1" forward.
Also cut out floor of canopy -this reduced weight 2 ozs.
Obviously - huge weight savings are not in the book! Nor required - I just wanted to reduce aft weight (balance)
- On these H9 33% kits - tail weight is really the only question--and that is because I use lighter engines.
Actual weights on previous H9 33% models I have done is from 22 lbs to 25 lbs. various changes -
The Sukhoi has a better wing than previous ones --lighter and thinner foil and light ailerons , and a lighter tail group.
I expect to put the rudder servo forward to hold balance -
The kit really looks great.
For those who don't feel comfortable cutting into ARFS, --don't.
At our altitude - we need to loose 10-15% of weight - just to equal sea level performance. so I feel it is worthwhile for me.
The Cap at 23 lbs with ZDZ80 on tuned can was extremely good performer -I expect even more from the Sukhoi.
I sa Mike's CG recommendation (addendum to original ) and that is where I plan to setup this model for initial wring outs.
Typically I like a more forward CG- for best contest performance.
for flogging around - the aft will be better - no question .
So far - I find that these kits setup properly, are completely contest capable -in any class- .
any bad scores I get are my own screw ups.

Gary Travis

My Feedback: (3)

I am flying one now with the zenoah 80 twin I have got the balance set at 2" behind the tube, and the weight comes in at 23 lbs. It seems to fly great. I also have the 1/3 cap, it is alot more agile in the air however the sukoi is alot more rock solid in the air. I am going to build another with the zdz just to go crazy with, and then decide wich I like better. If you want to fly mine shoot me an e-mail as I live about 3 miles from you and would be glad to let you take it up.

rmh

Absolutely!
we fly at Jordan Modelport
going out now --

japan3d

And what is Mike's recommendation? Cannot find any addendum on Horizon's web site.
thanks

Diablo-RCU

My Feedback: (1)

Say DH:
Please give us some rpm data on the ZDZ-100 when you get yours fired up. The numbers shown on the Ammelung Modellbau website don't appear to be better than the 80-single. They tested with the Krumscheid cans and tuned pipes. I was expecting around 6300-6500 rpm with a 27x10 Menz-S and Krumscheid can....but it's not even close.

NSSHERLOCK

RE: H-9 Sukhoi. FYI Be careful when and if you use the rudder to pick up the tail and push the plane around. It is real easy to push your fingers into the balsa sheeting on the fin. Same thing when removing wings from fuselage. If they are a little bit tight, it is easy to stick your fingers into the balsa sheeting of leading edge near the wing root. I have a Zenoah 80 in mine and it is 25.5lbs with no extra weight, but with (2) 1700 mah Ni cads on board. I don't see how one of these could weigh 23lbs with a Zenoah 80, even with the spring starter removed from the engine. A friend of mine has a ZDZ 80 in his, at just under 23lbs. NSSHERLOCK

rmh

The ZDZ100 is now being fitted to the model -
I decided to maximize prop efficiency -so I moved the engine forward -from what is shown on the kit - .
this means, the backplate will be almost one inch forward the cowl forward edge.
for those interested -this means that the standoff from the engine box is 2.5" or less --to 2.25" --your choice.
I will use a 1/4" thick plate -with 10/32 bolts thru 1/2" dowels -drilled to 1/4" id- then washers and NYLOCK nuts.
the back of the carb will be just forward the box and the existing hole in the box will be opened somewhat.- for full airflow.
mufflers will be in cowl type -a few different types will be tried.
Those at the TOC, who saw Quique's Yak - may have noted his model also had the engine mounted forward. as does the full scale Sukhoi--
The idea is to limit any losses from being too close to the cowl.
The engine will require holes for the spark plus - I may all covers - but I will be opening the fake cowl louvers - to get max airflow - this requires a firm touch on the ol motor tool!
Oh yeh - this engine weighs "4 oz" more than my 80 single -
The spinner I will use is a red, CB 4" P51 style -it has an aluminum backplate and I like em - use em a lot .

bladebender

My Feedback: (5)

ANY CHANCE OF A PICTURES OF ENGINE SET UP?

rmh

here is pic of engine -side view -basic mount -which will be boxed on three sides with lite ply

rmh

cowl in place - the engine was mounted forward to reduce cowl interference of airflow from prop.
Full size craft also has prop forward.

bladebender

My Feedback: (5)

THANKS FOR THE PICTURES SURE WISH I COULD SEE IT FLY SEEN ONE WITH A ZENOAH 80 TWIN WAS NOT IMPRESSED. HOW MUCH ROOM DO HAVE FROM HEAD OF MOTOR TO SIDE OF COWL

NSSHERLOCK

Dick. Nice pictures. Enclosed is pic of my H-9 SU31 equipped with Zen 80. I have the prop spinner out away from the cowl like you, but I'm not sure what the benefit is. I haven't noticed anything exceptional about the setup. I am having trouble getting the bird to set up a glide for landing because I think maybe the prop 24x10 is pulling a little too hard. I am reluctant to slow down the rpm because I don't want the engine to die, in fact, I have a high idle setting that I use during maneuvers and go to landing idle setting for landing on final approach. NSSHERLOCK

NSSHERLOCK

Dick. Nice pictures. Enclosed is pic of my H-9 SU31 equipped with Zen 80. I have the prop spinner out away from the cowl like you, but I'm not sure what the benefit is. I haven't noticed anything exceptional about the setup. I am having trouble getting the bird to set up a glide for landing because I think maybe the prop 24x10 is pulling a little too hard. I am reluctant to slow down the rpm because I don't want the engine to die, in fact, I have a high idle setting that I use during maneuvers and go to landing idle setting for landing on final approach. NSSHERLOCK

NSSHERLOCK

Dick:attached is pic of my nose of my h-9 su31. I have quite a bit if space between the cowl and the spinner back, but I have not noticed any benefit from this if any. What is this supposed to do. Cover up the fact that I screwed up when I measured and mounted the cowl, of is there supposed to be dome real value??
NSSHERLOCK

WADE

My Feedback: (19)

Dick,
Does the wooden dowels work good for an engine standoff? I was thinking about using a wooden box to stand it off, but the dowels would be easier. Did you use oak dowels? What diameter? I have a H9 1/3 Cap that I'll be putting my ZDZ 80 single on.

Thanks,
Wade

rmh

I use plain ol birch - drilled thru --then I box or use a triangle support on each standoff- on 100's also

WADE

My Feedback: (19)

Ok, thanks!

DrScoles

My Feedback: (18)

Wow, those standoffs are wood??? I coughed up $37 for aluminum ones... too bad you had to cut the holes in the side of the cowl! I have a BME100 in mine and it fits with room to spare. I mounted it 1.5" forward for cg reasons... Got six flights on it so far, lots of fun. Motor is brand new, but still have large surplus of power...

http://home.attbi.com/~m.scoles/airplanes/DSCN2070.JPG

Dick, can I send you my canopy so you can cut the louvers out??? It takes patient man to do that!

Mike

rmh

The wood setup is actually far more rigid than the metal standoffs - as each one has a triangle attached -which extends to each corner of the motor box- I prefer that setup -
Anyway - I have it about ready to fly -
You must have added a bit of ballast yes?

DrScoles

My Feedback: (18)

Not an ounce of lead. I have the cg right at the back of wing tube
did a pull-pull and the stand-offs moving the engine forward made it work out perfectly. Thanks to everyone on RCU who led me to these decisions!


I don't even have the batteries as far forward as I could. I have 4 duralite 3600 packs...the ignition and smoke are forward, the two rx packs are just in front of wing tube... could have put them much farther forward.

I really want to weigh it , too lazy to put it together at home...

Mike

rmh

Sounds about right - -Mine has pull pull rudder - big servo -batts forward - all up engine and exhaust is 5.25 lbs- batts forward etc..
I want CG a bit forward --on the tube
We need to be about 2 lbs lighter than sea level setups - (10%) -just to get same kind of performance.
Two lbs may not sound like much on a 24 lb model - but it can be a real trick.
Friend in Florida has one - DA100 -CF landing gear - pull pull etc --and it is under 24 lbs .
This is about where mine will be - . My revised H9 330 was 22 lbs (sold it ) .
The 26/27 lb setups just are too heavy for this altitude.
Power is not the issue - they just don't fly slowly as well as desired.

Diablo-RCU

My Feedback: (1)

Dick:
Any motor tests yet?
Very interested in finding out if the 100 is stronger than the 80 single! I'm sure you will do your usual exhaustive tests....

rmh

Exhaustive ?
Very punny.
Tomorrow -we start --if weather permits .
This time -I am starting with in cowl mufflers - actually they are DA100 mufflers -which are a direct bolt up .
Next, after first of year - we try others mufflers -
My favorite is always a tuned can or pipe - these engines like a non restrictive - and better yet tuned setup --as I am sure most guys have found out already .
I also have the non tuned cannisters-which alsoseem to be a excellent match on ZDZ engines - finally - I have (ta da! ) a pair of full length tuned pipes -
I do think- (thinking ahead) -that this engine will take some run in - My new 50 -which is flat out great, showed this was needed .
I really don't mind run in time - it ususally means that the fit is close from the factory.
The only engines I have ever seen which were free from needing some breakin- were some of the ABS revvers we ran a long time ago - these were best run - right up to temp, from day one .
Thay usually results in a lower performance engine on these gassers.