New Akromaster first flights

Running a fox .15 slant plug ex-r/c with enya needle. Uniflow plastic clunk with the uniflow vent attached to the clunk. The clunk wont quite drop all the way to the bottom because of tubing stiffness but it draws nearly all the fuel out anyway.

A couple of questions:

as soon as the plane is released, ROG takeoff, it goes very lean and stays that way for several laps. Then steadies out and richens back to normal and stays that way until the end burp.
Is this normal for small uniflow setups?

I have a couple of things to work out with the controls--its hunting a bit and way too sensitive--im going to seal the elevator and also narrow up the handle a little.

Was geting a loss of fuel pickup during sharp pullup into wing overs. I might try pinching a small vee into the end of the tank and/or "fixing"the pickup in place.

CG is about 1.25 back. all-up wgt is 18.7 oz. flying a stock master airscrew 8 x 4. slight engine offset and rudder offset. Line tension is good level flight with 1/2oz in the tip. fixed leadouts, and the plane is flying tangent to the lines. 5.5 sec laps on 52' R.

Any hints?

Thanks

With regards to the stiff tubing, I would decouple the uniflow from the clunk, and simply plumb it (brass or copper tubing) to the tank's outboard edge-roughly aligned vertically with the spraybar. This should allow the clunk (pickup only) to move around more freely. It is the uniflow location which gives you the solid run (once it settles down anway) I don't think fixing it to the clunk buys you anything. Maybe someone else can explain any advantages.

I got to fiddle a little more last evening. I was getting a lot of fuel foaming on the ground and I've now fixed that.

After the initial several laps, the uniflow worked just like it should--real steady, right till the end burp.

I'm using a two oz. straight front--I made it up according to Nils' pictures. Just as you described.

Just for experimentation sake, I built a different tank last night also. I heated and pinched a narrow "wedge" area at the rear outboard corner and used fixed pick up and uniflow vent.

Its all installed and pressure tested just as you described. +1/4"

I'll give it another try tonite--I suspect that fixing the foam problem will make the lean takeoff problem go away.

Other than that, it flys great.

Cant wait to get its Big Brother--Twister flying. I'm just about ready to cover the wing. All the carbon surfaces (stab, el, flaps) are ready for final prime and paint. Fuse is ready for cover and all power components are on hand.

Flew again last nite. The lean early laps problem is gone--do think it was the foaming fuel.

The tank with the fixed pickup and uniflow and pinched side (2 oz clunk mounted horizontal)worked just great--except it would only draw down half the fuel!

So--I'm going to try a clunk pick-up again but leave the vent fixed. I believe I can keep the vent over to the side far enough to not interfere with the pickup.

I think now that the plastic tank setups would work really well in bigger sizes, but the smaller ones might be better off with a metal uniflow.

Taping of elevator gap and narrowing the control handle spacing fixed the twitchiness and "hunting" (me or plane). Its Very solid on the lines, and will do more than I can.

I am also going to try a couple of different style props. Its a Master Airscrew 8 x 4 black plastic now. I want to try a wood and a couple of others perhaps trimmed just a bit (1/4"). THe engine seems very immune to even a 1/4 turn of the needle, and I think this may be a prop issue.

Flying was good--mosquitoes were terrible!

>I am also going to try
>a couple of different style
>props. ..... I want
>to try a wood and
>a couple of others perhaps
>trimmed just a bit (1/4").
> THe engine seems very
>immune to even a 1/4
>turn of the needle,

and
>I think this may be
>a prop issue.

I removed the prop last nite for some cleanup and to my surprise found it was marked 8 x 6.

I'm embarrassed to have made the error in reporting but...

THANKS to all on these CL forums, I was able to connect the engine performance issue I was seeing to a prop problem!! I certainly could not have done that even 2 or 3 months ago..

ALL this info does sink in!!

I'll be replacing it and trying the intended 8 x 4 and variations.

Thanks Guys

Since yours is the slant plug variety, run it in more of a 2 cycle. Your lap times seem slow, as previously posted.

But I know it wasnt running as fast as it could have.

PS Currell: I thought the "Frankenstein" ring jr was heavy at 18-1/2 oz!

Yesterday, I took 4 smaller planes out. It was in the low 40s and windy. My mistake was that I just grabbed my 10%N/25%C fuel for the larger mills. The Fox 15 (plain) and Enya 15 III started OK, but it was hard to keep them lit up. Next time it will be atleast 15%N.

The Streak Jr (18 ounces) flew great with the Fox, by the way. The heavy Enya Ring Jr (21 ounces) just OK. The Streak has the advantage of a much thicker wing.

Later, I just said to heck with it, and flew my Buster with aMcCoy 35 Redhead. I only wish that all of the Redhead detractors out there could have heard and seen this engine. More power than Fox, 4-2-4, this mill has it all.

Hey Curt, did you fly?

I did a couple of basic flights on Sunday afternoon late...

It was cool but the wind kinda died down a bit. I froze out my helper!

Mostly did finishing work on the Twister/Mod fuse and tail group.

We just got a few snow flurries on Saturday.