H9's Sundowner

[teuchter]

	Quote: Originally Posted by nesikachad
	Progress!! I got my tuned pipe to fit inside the fuse with my Moki 210. No maiden yet, photos coming.

Nesikachad have you pictures to share, would like to see how you teased the big Moki’s manifold to line up that powerpipe inside the fuse ..

[Captinjohn]

	Quote: Originally Posted by teuchter
	Nesikachad have you pictures to share, would like to see how you teased the big Moki’s manifold to line up that powerpipe inside the fuse ..

Yes ...how about the photos...hope it soon. Best Regards Capt,n

[MX304]

	Quote: Originally Posted by P-51 Dave
	Ive got a DA 50 I'll be putting in mine. We'll see if it can stay in one piece. I'll have photos as I get to it.

There was one at our field with a DL50 in it. Make sure you re-hinge everything. The vibration tended to make various control surfaces fly off his at random times when the factory hinges came apart. It was pretty fast, but the prop length required a much taller LG than stock so it looked really funny on the ground. The landing approach required was FAST due to the weight, so it ate a ton of real estate once it touched down.

[P-51 Dave]

Thanks, I'm still anxious to see anyone else's results with an oversized motor. I have planned on using Robart 308 hinges and figured I would have to use a taller gear. I'll give it a go and if its too out of line, may go back with a Moki 2.10. I have an extra cowl. I chose the DA50 after comparing weight amoung other recommended engines. We'll see if you really can't go wrong with a DA. I realize there is a bit of idiot factor figured into this one. What the heck!

[MX304]

	Quote: Originally Posted by P-51 Dave
	Thanks, I'm still anxious to see anyone else's results with an oversized motor. I have planned on using Robart 308 hinges and figured I would have to use a taller gear. I'll give it a go and if its too out of line, may go back with a Moki 2.10. I have an extra cowl. I chose the DA50 after comparing weight amoung other recommended engines. We'll see if you really can't go wrong with a DA. I realize there is a bit of idiot factor figured into this one. What the heck!

It definitely was not slow. I tried to get him to stuff a tuned pipe in it, or down the side, but he pulled the motor off for another project.

[ken crane]

guys i have 2 brand new wings and tube short money

[nesikachad]

	Quote: Originally Posted by Captinjohn
	Yes ...how about the photos...hope it soon. Best Regards Capt,n

Hey guys.

Sorry, that plane went to the grave late last summer. A servo wire wandered its way onto the pipe and you can imagine what that did.

Meh. . .


Basically it went like this. I had a no frills header pipe that I bent the snot out of using a tubing bender that a buddy has for building vintage HD chassis. i had to use a length of flex pipe as well. Not a good idea as it pisses oil after awhile.

The pipe laid inside kinda diagnally. I had to do a great deal of surgery inside to shoe horn this thing in. Lots of cutting of gussets and what not. I then went back after and reinforced as best as I could.

Next subject. . .Heat.

Obviously the inside gets a bit warmer now. What i did to cope with this was cut a port back by the rear servo access hatch. I fitted some screen from a Fram air filter so it'd look more purpose built. I then took a thin sheet of balsa and skinned it with aluminum HVAC tape to serve as a heat shield for the reciever. Basically I just made a deck surface that screwed into the side supports bechind the wing tube hole. I mounted my receiver above it. I used a Spektrum 7 channel. My intake port was where the exhaust header poked through under the motor plate and above the aluminum supports for the gear. I just opened it up a bit more for the air exchange.

The problems:

Getting the pipe to seal. I had oil all over the inside of the plane up by the gear and it was only a matter of time before it killed the glue joints.

Tuning the pipe to work like it should. I never got it right.

I had to cut a chunk of the wing tube sleeve out of the center. Didn't seem to hurt anything though.

That about covers it i think. I bought a new SD a few weeks ago and I'm debating on trying it again or just pussing out and going with the pitts muffler on the Moki. I really like the idea of the pipe for the novelty and performance potential but I'll have to take a more serious approach this next go around.

Everyone who saw it thought it was pretty cool though. I forget his name but a really well known JR factory pylon racer up in Billings, MT helped with getting the plane sorted out (trims, CG, etc) last June during a fly in up there. Properly set up these things fly really really well.

A hint.

If your using this plane to pylon race and it tries to snap at full elevator instead of dickering with the CG consider adding some weight to the wing that does not dip. That's what we did with mine and it stopped it right away. Pretty cool.


One last suggestion. I despise the idea of butchering a cowl to evacuate heat. Here's what I did for that.

I bought a cheap aluminum "for sale" sign from the hardware store and made a sort of duct piece from it that went from the head side intake port all the way back to the cowl cheek. I cut the balsa support out and grafted in some glass/carbon to support the front of the cheek better.

I then cut the cheek where it dumps over the wing. I did it progressively which resulted in me getting good at dead sticks due to the engine getting hot, but eventually I got it to run cool enough at WOT to sustain a whole flight. It really helped preserve the look of the plane IMO. Pretty simple just get out the scissors and cut away on the duct piece until the cowl slips over it. I used a hole saw running backwards to chew a hole for the head to poke through. It didn't rip the sheet metal do death this way, although it's not good for the hole saw.

Wheel pants: I did find some a bit smaller and less pregnant looking. I hate the ones H9 supplies with the plane. just look dumb to me.

Be sure to clearance the pants a bit as the wheels can grow a bit and they can be prone to catching on the pants and causing a nose pick.

I use a perry pump on the fuel delivery as well.

I'll have to get started on the new one. I'll post some pics as I go along.

Great plane. One of my favorites!

Good luck

Chad

Never had an issue other than cooking the servo wire.

[Captinjohn]

Hey guys....lets keep this thread going....it needs some action! Capt,n

[teuchter]

	Quote: Originally Posted by nesikachad
	Hey guys. I'll have to get started on the new one. I'll post some pics as I go along. Great plane. One of my favorites! Good luck

Yeh we wuz waiting for nesikachad to build his mrk2 version, see what he gets up to this time!

[nesikachad]

A few updates.

I finished the overhaul on my 85cc TOC Yak 54 and am close to maidening my 100cc Edge 540 from AW. Once I get these two up to snuff I'll be starting on the new S. Downer.

Still debating on the tuned pipe set up. I have a TIG welder now but it doesn't work very well on aluminum for some reason. Sucks actually. A buddy has a good TIG set up at his chassis shop and he let me use it last weekend. I may have to hit him up again for this if I go that route. FWIW I have found a great source for thin wall aluminum tubing. Old lawn chairs and old lady walkers are great! I went scrounging at the recycling center last weekend. My 100cc Edge now has straight pipes! I machined up some bases and thread milled the bore. Then wrote a surfacing program for my CNC mill to blend the port to the round body. I threaded the OD of the tubes and they just screw in. Makes for a nice and clean presentation through the cowl and it sounds pissed off to boot!


I really like the idea of a tuned pipe, especially on a racer like this so we'll see.

My other planned change is how the servos mount in the wings. I like the little sundowner's method much better. Keep stuff hidden, clean and hopefully FAST.

We'll see. . .

[ggroyal1117]

Sundowner and Little Toni

[rcign]

A strengthened Sundowner will run 170 mph with a good YS 170 or hot Moki 2.1..Without a pipe...There are at least two, one of each engine type....

[P-51 Dave]

Where are you guys strengthening the airframe? I know the tail has been reported to be weak. Thanks for the info.

[nesikachad]

I was flying mine once on a very windy day (35mph-40mph gusts) and a buddy who's a policeman came by to watch. On the down wind leg we hit 165mph in straight/level flight. It was about 130mph on the up wind side.

Plane flew rock solid that day. I sure would like to see one do 170 on its own though. That'd be something.

[mdavis6211]

what props are you guys using with the evolution 40gx