OldFart1

I'm going to run aluminum servo arms. My notes indicate that 1.25" is correct for the tail, but I didn't note the ailerons - 1.25" or 1"?

a1pcfixer

My Feedback: (7)

I have 2-GP Ultimates w/DA-50r, 1 SD 260 Extra w/DL50, and an Aeroworks Yak w/DA-50r, none have your issue. However, on each one I've cut an opening for the carb to get stable air from the fuselage area (photo's included here). Also, I have NO remote vent lines either.

Last idea I have for you is to properly tune the carb/engine (snitched from somewhere online)(g);

Start it, run it at about half top speed, say 3500 rpm. Now adjust the L needle in, the rpm should increase, slow it back down to 3500 rpm, and readjust the L needle in more, keep repeating this until adjusting the L needle doesn't increase the rpm. Now adjust the H needle, start at 2 turns out, adjust it to max rpm. I don't back the H needle off from max rpm like I would with a nitro engine, with gas when you reach Max rpms you are a long way from lean.

With the engine adjusted like I said try popping the throttle open, if it dies, turn the L needle out 1/16Th of a turn, repeat that until you are happy with the response, then go back and reset the high needle as before.

My DL50 really benefited from those tuning directions!

a1pcfixer

My Feedback: (7)

On both of mine I'm using the stock blue ones that come with Hitec Digital servo's (7/8"). Does just fine!

OldFart1

Are you getting full throws on the tail with those?

kwhite.6

Wow! Lots of responses. To start off the only time it cut off was in knife edge with the right wing down but I'm not sure I held it the other way as long as I did coming from the left going to the right with the right wing tip down. Every time it was about half stick on the throttle, just past the mid range burble that it has. I adjusted the carb just like A1 said trying to get it to run better in the mid range but I couldn't tell any difference so after it went dead on me I richened both screws just a hair but it still cut off again. I just checked and my low screw is 1 1/4 out and high is just a hair more than that. I'm running a 22x8 hawk prop and it peaked about 7400 rpm. If I richen it up to 7000 rpm it sounds like it's missing at WOT, so I leaned it back up to about 7200. Every time after it cut off, it started with no choke and 3 or less flips on the prop. I never could get the mid range burble out so I'm guessing that it's loading up in the air. Maybe I've answered some of your questions if you can understand what I'm trying to say? Any other suggestions?

O, I almost forgot to mention this thing even dead stick perfect. I LOVE MY ULTIMATE!

66-stang

My Feedback: (3)

You need to get rid of the burble. there is no reason to have it. Try and lean the low end a hair and richen the high.

a1pcfixer

My Feedback: (7)

Those are only on ailerons.

JoeAirPort

My Feedback: (41)

Try putting an 8-32 barb fitting on your metering diaphragm vent and plumb it into the fuse. It really made mine run better. You're getting air disturbances...it has nothing to do with tuning....except maybe that the air disturbances are changing your tuning as you fly. No tuning will fix that. Two places on the carb are sensitive to pressure changes and turbulant air: The metering diaphragm vent hole and the carb's air inlet. In my case I only modified the metering diaphragm vent. It made it much better. BTW, my mixture was changing in knife edge with right wing down also. It still does it a little but much less than before I installed the 8-32 barb. I think now I'm just suffering from the air inlet not breathing getting stabil air. The DL seems to be sensitive to the in cowl air conditions. Really all gassers are but some more than others. Also some people just don't notice it.

See pic's. I just tapped the vent hole on an angle without drilling it. Then I used thread locker and tightened it as much as I could without stripping the threads (careful!). After the thread locker cured I dremmeled the threads close to flush on the inside of the vent plate so it didn't keep the diaphragm from moving (careful, don't dremmel where the plate sits on the gasket). You can also silver solder this on. That's the preferred way but I never mastered it.

As far as the air inlet I have heard of DA recommending to build a balsa box around the carb to keep drafts from hitting it. Since it does it one way knife edge and not the other, I wonder it it's the exhaust cutout letting air in.

Ok, I will not talk about this anymore and keep this on topic. I have a question, does this bipe fly better than other 50cc bipes out there? For example, Wildhare or World Models, Nitro Models etc? I think Aeroworks has a new one too. I think my next plane will be a bipe.

OldFart1

Out of curiosity, what are you using on the rudder/elevator?

Thanks!

a1pcfixer

My Feedback: (7)

For the Elev & Rudder;
AW60-032-02 Air Wild 1.25" MLP servo arm - (Hitec) from T.B.M.
[link=http://www.troybuiltmodels.com/ns/acce/servos/servoarms/airwild/index.shtml#airmlp]MLP servo arms for Hitec....[/link]

On my second GP ultimate, I'm using the stock long/double black ones included with Hitec digital servos, with one half cut off.

Also, on the Rudder; Dubro - No. 866 Heavy Duty Control Horn System (For .91 & Above)

OldFart1

Thank you sir!

(Ordering ALL my remaining "little stuff" this week!)

OldFart1

Anyone have any strong opinions pro or con between Airwild, MPI or SWB arms?

iflywhenican

My Feedback: (1)

"Ok, I will not talk about this anymore and keep this on topic. I have a question, does this bipe fly better than other 50cc bipes out there? For example, Wildhare or World Models, Nitro Models etc? I think Aeroworks has a new one too. I think my next plane will be a bipe."

In one simple answer....YESSSSSSSSSSS!!!!!!

This is an "off topic" statement, but there has been an awful lot of talk about mid-range "burble" in the DL, DA and other rear carb engines. My Ultimate is powered by a Brison 3.2 engine that has a "side mount" carb and I have never had any burble or quitting problems at any throttle position at all unless I trim the throttle closed. Also, plane attitude does not have any effect either. So, it makes me wonder if this is a natural problem with some of the "D" or other rear carb engines?? I would like to know if anybody else has any problems with their side mount engines in this plane?

bubbagates

My Feedback: (32)

Ifly,

It is a "normal" problem. Most 50cc engines say they need at least a half inch clearance between the carb and whatever (cowl, firewall etc...) but I've found one inch is better. Round cowls are the worst when not baffled. My old Aeroworks 50cc Yak had it big time, My Ultimate never had the problem with the Brison and Da50, maybe because I opened the other side of the front of the cowl to allow cooling air in.

I have a DA100 on my 2.6M Extra 260 do the same thing and that's a bottom carb. When I assembled the plane I notice the carb was very close to the cowl but left it alone. When I flew it a few times, I realized I was not getting full power so I opened a hole right below the carb which fixed that problem but gave me problems in KE, no burbling but a sudden lose of RPM so I placed a piece of very fine mesh screen over the hole and no more problem as it keeps the air from being turbulent. That will not work in this case though

bubbagates

My Feedback: (32)

Personally I like the Airwild arms on my 35% and large planes, they sit lower on the shaft and this do not put side loads on the servo gear but they leave very little roam sometimes for a ball link setup without having to cut the bolt, depending if the servo is inset into the servo mount or not. For this plane, all are excellent choices and will work just fine

kwhite.6

UPDATE. Just wanted to let everyone know that i took the tank back apart and found the clunk line split on one side. I'm guessing that in knife edge one way the clunk would pull the split open and the other way it would pull it closed. I also soldered a fitting and put a hose going from the carb to way back in the fuse. I'll see how it goes when the winds calm down. If I have anymore problems I'll carry them to the DL 50 thread, but thanks for all the help. It just made me think it was related to the spinner because it only did it after I put the spinner on it. That's why I posted it here. My bad!

Back to the Ultimate, I noticed that the engine box is loose where it goes into the fuse. I epoxied some tri-stock where it goes in from the front on both sides. Has anyone else had any problems in that area?

btelliott

Does anyone ever put a fuji imvac BT50ei 46.5cc engine on a great planes ultimate 160?

Inyosi

I was flying my ultimate today and on landing found the gears of the elevator servo had stripped, lucky landing I guess. I am using HiTech HS 6635 servos that have carbonite gears. Do they strip easily or is it a common fault

kwhite.6

Karbonite gears have a wieght limit of 12 pounds I think. There is a warning on hitec's website about karbonite gears. What engine are you using? Never use karbonite gears with a gas engine.

a1pcfixer

My Feedback: (7)

Out of 232 pages here, and 5801 postings on THIS thread....not yet. You going to be the first to try?<g>
Someone, somewhere may have tried it, but I've not heard of such.....yet.

Did you get one free or cheap?

a1pcfixer

My Feedback: (7)

IF you're running a gas engine, using anything other than metal geared servos is a big NO-NO! I'd not run anything but metal geared servos just because it's a 27% model!

What engine are you running?

You recently tore your wing sections apart on a bad landing. What did you do to fix that, and how are they holding up so far?

a1pcfixer

My Feedback: (7)

Ahhhh...the old cracked clunk line trick!

Engine box as in the secondary firewall? Don't remember seeing anyone post about that as yet....you're the first.
I think those side pieces actually extend far into the fusealage, along side the fuel tank. Best re-check that entire area, just to be safe!

btelliott

Yes I got one on ebay for $295 new in box. The guy dropped in and broke a little piece of fin. But nothing major. I just hope I don't have to butcher the cowl. Its a little bigger and heavier the the fuji 43cc.

bubbagates

My Feedback: (32)

Glad you found it, been there had that with the clunk line.

As far as the firewall side loose back at the first former, never seen that or heard about it on this plane. I however did have it happen on the 27% GP Cap232 with the DA50 I had on it. Did what you are going to do with tri-stock and no more problem

Inyosi

My ultimate has been flying great with the wings holding together very well, I keep checking for cracks but it seems ok.

I am running a gas engine, a CRRC PRO 50cc. I am a bit annoyed now as when I purchased the servo's from a dealer I asked for metal geared servo's [ they did not have ] but was told that carbonite gears were still very good.

May be I was an idiot or maybe he wanted a quick sale. But I guess I will now be purchasing metal geared servo's now. Thanks for the help