hllywdb

This has been happening to me as my building skills get lighter, the body and tail get light, so I had to move the battery back to the trunk with the elevator server to get the CG correct. All up it came out at 12.9oz

Once balanced, it was off to the field this am. First off I had a burned out Nelson plug from the break in run. The only spare I had was a Hot one, so that cost me some top end rpm, but I wanted to fly.

At that light, take off was a non event and a couple clicks of down trim was all that was needed. Control throws were another issue. It needs more aileron and a LOT less elevator. I had programed in a low rate of 60%, so that got me through the first flight. I fueled it up again and set the elevator throws to 40% low and 60% high and added 30% expo. The second flight was a breeze, but with the engine not completely up to snuff it was a boring 90mph flight.

So I went home and ordered 3 more plugs from Larry, and I still need to cut the prop down some. I do need to find out why it is burning through glow plugs. First thought is too much compression, but usually 1 shim oon the Galbreath is fine with 35% Sig fuel. Any thoughts?

fit90

How big a prop are you turning? My Norvel .061 AME likes one shim on a Galbreath head/Nelson plug combo too, but I only use 25% and the prop is never any bigger than an APC 5.7 X 3 cut down to 5 X 3.. Everything is steady as clockwork with this set up. I live in Naples so I would think we are flying under pretty much the same conditions.

The plane looks great. Your picture with the plane next to the radio made it clear how much thinner the airfoil is and how much shorter the fuse is. Glad to hear the maiden went so well. I hope you have a lot of fun with this one.

Bob

hllywdb

Thanks Bob,
I am running a 4 1/2 X 4 at about 22,500 on the ground.

hllywdb

Ok, an update. I had today off, so I robbed the Nelson plug off one of my TD's where it was just sitting there keeping the after run oil from leaking out of the cylinder. I also increased my aileron throws. Next, I cut the prop down a bit. It came out right at 4.25 X 4. I didn't bother balancing it because I made even cuts by pushing the tip right up to the pin on the toenail clipper before cutting. Everyone in racing uses this technique, I'm sure. I also broke out my last fresh quart of NVX 35% from Sig as I was getting near the bottom of the quart and it looked a bit iffy (sometimes I backwash when taking a sip)

The first flight was a lesson in economics. It launched great, trimmed out fine and then quit after the first couple of passes. I figured I lost another plug. Nope, turned out the throttle servo had a bad case of the jitters. I had used HS-55's on ailerons and elevator, but for throttle had used a more high performance servo. To say the least I was a bit disapointed and plan to fire off a letter to the Chineese about this, not to mention being out another $2 plus another buck in shipping! So no, using a cheap servo on the throttle usually won't cost you a plane, but it will end your flying session.

So after replacing the servo with another HS-55, I went back again. This time I was getting just at 24k on the ground and she unloads nicely in the air. Now this is starting to get fun to fly! I am thinking about trimming another 1/4" off the prop as it really picks up in a dive but then won't quite hold it leveled off. I think there is a bit more to gain and at this weight I have more than enough thrust on takeoff and it climbs right out. I'm glad I went with the color scheme as it makes it much easier to track.

combatpigg

My Feedback: (3)

If you want 100 mph speed, it's got to be a 4 pitch...the 5.7x3 will start acting like a speed brake at 75-80 mph
Plug elements will fracture due to vibration, [weak mount or sloppy engine]......but the element can otherwise look OK.
If all you find after a smokin' run is a black hole with the element missing....then being too lean and / or over compressed is the culprit.
For break in runs I'd use at least 25% oil and 15% nitro and extra shims. Start out conservative and gradually sneak up on the killer setting that allows great performance, cool runs and decent plug life. I'm pretty happy to get 10 to 15 minutes of run time out of a plug when running close to 30,000 rpm with a 1/2A engine.
If your plane is clean enough you might see a little increase in speed with a 4.1 or 4 diameter prop but once you get near "The Wall" it's pretty tough to see significant gains unless the engine is capable of processing enough air/ fuel to make it so.

hllywdb

Thanks CP, I got 2 runs today without blowing the plug. The motor runs strong the whole run, doesn't slow down like it's getting hot. Just thinking it may have just a bit more if I trim it to 4X4 and let it unload a bit more. I don't think I can see much over 27k in the air with an RC carb, but that's just over 100 and still fast enough to be fun.

combatpigg

My Feedback: (3)

Add a few shims and see how it runs. Tuning a high revving glow engine should be no different than if you were playing with a diesel.
Run the least amount of compression that will get your job done.

hllywdb

Yeah, I'll add another shim. I find the Galbreath heads are a bit less compression on the Norvels than the stock heads, but another shim may buy me some plug life. Old gear head habits die hard. When getting high rpm out of a small block, compression was always your friend. To get 9 or 10k you needed to destroke a 327 with a 265 vette crank, lots of head work, aluminium rods and 13:1 venola pistons, flat tops wouldn't get you there without a huffer on the top. I figure the AME has a steel crank, lots of porting and aluminium rods and the RC carb is my restrictor plate to keep the covering on

I would probably be happier with the GLH if we didn't have a guy at the field with a mostly glass racer with a Nelson on a pipe that is well over 170. Hard to get that image out of my head. Plus my own Kaos is over 100. Granted it's a 42" wing with a Norvel 25 on a pipe, maybe if I built a GLH with a 22" wing...... Still hard to get a 1/2A to swing a 5 or 6" pitch, would have to be 2" diameter.

combatpigg

My Feedback: (3)

I think Mike Gordon [the pylon racer in Utah] was saying their AME powered planes hit 110 mph.
IIRC, their only restriction was 200 sq inches and plain bearing engines
It sounds like your local field is a fun place to hang out..!
Our local field is total fuddy-duddy stuff only.

hllywdb

Do you want me to stop by and help you ruin the neighborhood?

airraptor

My Feedback: (66)

there is a NIB kit on RCU now

combatpigg

My Feedback: (3)

The people who bought land East of the field would probably use their "Medic Alert 911" dialers if you showed up there with your GLH. The farmer to the South of the field would blame your plane for sour milk and has taken shots at planes that over fly his corn field.
So yah..come on out here and we'll go on a drunken rampage with our 1/2A speedsters..!

fit90

If you guys do that please video it. It would be hilarious!

Bob

hllywdb

Works for me CP. I say when the planes just cross over into the field, have someone yell "PULL". Wait 2 sec and break right and up. It will make him crazy with those "dangfangled" pigions that won't fly straight.

Anyway, thanks to Mr. Driskill's usual quick packing and shipping, I got my new plugs today (Thanks Larry). Also trimmed the prop just a tad more. Tried different shims, but it seems to like 1 shim, and quickly drops off with more. Right now I am getting 25,100 on the ground. I'm thinking this is probably right where I need to be and should get 26 to 27k in the air. I figure this is pretty good for an RC carb in August in FL.

hllywdb

Video today. I think the motor still has more in it as it still idles way too well.

http://youtu.be/fT1OPVbytnM

[youtube]http://www.youtube.com/watch?v=fT1OPVbytnM[/youtube]

combatpigg

My Feedback: (3)

She looks and sounds real good..!
Does the thin wing hold it's trim OK in your hot weather..?

hllywdb

Thanks CP, nobody is going to mistake it for one of your SWR's with a Fora or Cyclon, but it's still fast enough to be fun, and way more fun than the fat foam wing with a TD. Still can't belive it still throttles that well.

After the first flights when I increased the aileron throw and centered the trims, I haven't had to touch the trims. It could probably use another click of down trim but I've just been flying it and having fun. Yesterday was unbarable hot and sticky when I shot the video and the wing still holds fine. It will be a lot more fun with 60 or 70 degree weather and will be better broken in. It also land nice and slow, no doubt due to the 12oz weight.

By the way, I REALLY miss a KK or TT needle on this.

Aero B

One of the local Hobby shops usually has some old kits for sale and I snagged a wood wing version GLH a couple of moths ago for my son. Got it for $20. Did I do good?

Going to put a new Norvel 061 RC in the nose. This thread really helped me out! Thanks everyone!

hllywdb

Hi Allen,
$20 is cheap. They are great little planes, everyone should build one at some point. I wish someone would start making the old ACE kits again, along with a lot of the old ACE accessories too! They had so many good Cox add-ons as well.

DeviousDave

Feebay is still a good place to find ACE parts, as are swap meets. You wouldn't believe how many throttle sleeves and fine pitch needles there are around here during swap season....

JustGoFly.com

I picked up a GLH last summer at an RC event for $30. I pulled the cox 0.51 and made it electric on 3S - check out the video:
http://www.youtube.com/watch?v=otc9hwqnHsM

Vinnie

Pond Skipper

This plane took some audio tach info for you -13k ish low idle level peak in dive tad over 28.4k down wind into wind level 26K ish best level pass down wind 27.8k.
The TD .020 vid - 21.3k on hand prior launch 26k level in the air down wind 24k ish level into the wind.
Vertical loads 17k all the best readings not averages.

hllywdb

Thanks skipper. I was aiming for mid 27 on the 1/2 a one which is good for a rc carbed motor. That also confirms my thoughts on the 020 unloading quite a bit in the air. I've been busy with other projects lately but I did get th3 2nd motor back from Bob Mattes. Haven't run it on the plane yet but I am getting 26900 on the ground with the 2.75 pitch prop so that is really going to make a difference. I'll post more on that thread but it's safe to say that Bob certainly delivers as promised! Super nice work too.

Pond Skipper

Yes true, I have one of Bobs engines.
Now that you have built and flown the GLH 1/2A size you may find you can shrink it down and still suit a 1/2A engine.
I have 4 modified all aluminum TD .020's on hand for future projects and look forward to using them on a couple of speeders.
Best wishes look forward to your reviewing your future efforts.