Lynn S

What do you think? Looks like it would do well with a .061....I hope it does, I just ordered it.

I liked the Extra also, but this plane has more wing area.


http://www.hobbypeople.net/gallery/128406.asp

flyinrog

My Feedback: (1)

saw a guy who put a .061 on a crazy max.. hope it holds up for you ok....Rog

cabanestrut2002

i bought the extra made by jamara (same plane, same factory,different badge, different colour, different price!)

i put in a sc .12, flies very well, not quite enough for true vertical, but close. i think a .061 would be marginal, unless its a really high performance one.

DICKEYBIRD

Lynn the 220 sq. in. looks good but the 28-32 oz worries me! What will it come out to with glow vs. electric....maybe 4 oz. lighter? Still not as lightly loaded as we'd like. I think your Norvel .074 would do better if yours runs as strong as everyone claims their's do. If you could find out what the bare plane weighs you could compute an accurate final weight/wing loading.

Lynn S

Dickeybird,
The electric motor turns a 7X4 prop just like the .074 so that would probably be a better choice for the engine. Thanks for the suggestion.
It should weigh quite a bit less with glow power. I'm not sure what the 7 cell battery would weigh.
I can keep the .061 on the Simple Extra and try out the new larger wing.

Cabanestrut- How much did your plane weigh ready to fly?
Your Extra looks good!

cabanestrut2002

i didnt weigh it! i put the servos under the tail as it was not tail heavy as i like it.
it would weigh a lot less than the leccy version.
i am running a 7 x 6 prop after some experimentation.
it WILL hold a steady knife edge and the stall is a nod nod nod nod action!
i am sure the giles is much the same. the conversion is easy peasy.

Lynn S

They had a 8 cell battery listed @ 293 grams.
That is = to 10.33 oz. according to metrication.com
So that will come off the EP weight.

AndyW

My Feedback: (1)

Lynn,

I did up the Extra for .061 power and was happy with the conversion. The Wattage planes are very well done, with design, wood selection and covering on par with any good builder.

Mine came in at 18 ounces with micro everything including a 150 mAh pack. The paint on the cowl and wheel pants isn't raw fuel proof so I used spray urethane. It's held up well.

Initially I had cooling problems with a Wasp .061. The Norvel, with its larger cooling fins did much better. As suggested by DB, the .074 would be a better choice. You might want to consider getting a heat sink head from Litemachines in case cooling is an issue. The small engines seem to be more sensitive in this area.

Even at 18 ounces and the .061, I'm quite pleased with the flight characteristics. Smooth and solid with most basic aerobatics done with ease. Knife edge would definitely need the .074.

With the extra wing area of the Giles, yours will fly even better I'm sure.

Lynn S

Andy,
Glad to hear about your experience with the Extra. If it can fly well with a .061 and smaller wing, this one should do great!
Did you have to strip the original paint off or just paint over it?? A clear coat might do the job.
I'll go with the Norvell .074, and open up the cowl to let it get plenty of cooling.
thanks, Lynn

AndyW

My Feedback: (1)

Lynn,

I didn't strip the old paint off because I wasn't sure I could get a colour match to the covering. I used 320 grit paper to buff down the finish so that the clear urethane would stick.

I arranged the engine mount so that the down and right thrust of the original electric was maintained. Use the cowl and the backplate of a spinner as a guide. This worked perfectly, the plane flew "right off the board" with only one click of up needed. Also, there's no change in pitch from high to low throttle. Just throttle back and the Extra smoothly settles in. Wattage really does their homework to give you a good flier with no hassles. I really enjoy flying mine.

Lynn S

I appreciate the information...good to know what to do when I get it.
It should arrive here on the 20th.

cabanestrut2002

very well done, with design, wood selection and covering on par with any good builder.
----------------------------------------
yes, for an artf i was well impressed, nice wood selection, not the oak like most artf's and proper glue, not hot glue which is useless on balsa!

knife edge will need more power, point rolls are good with these things coz they can be set up well

DICKEYBIRD

Lynn, make SURE you open up the EXIT area of the cowling! I'm not familiar with your particular installation but it is CRITICAL that you have more exit area than entry. It really doesn't take much entry area to keep the engine cool as long as it is located in front of the cyl. & head and the exit area is at least 150% of the entry.

I can't tell you how many overheating cowled engines I've helped fellows cure by BLOCKING OFF entry area and enlarging exit area.

If set up incorrectly, you can usually set a decent needle on the ground, but as soon as the plane gets up to speed, the high speed air flows in the front, can't flow out due to the restriction and packs up or stagnates inside the cowl. Can't cool a hot engine with dead air! Instant overheat, lean mixture and......

cabanestrut2002

a general rule of thumb is that the exit should be 3 times larger than the entry

DICKEYBIRD

Geez, you Brits must have BIG thumbs!

Seriously though, I've heard the same thing for years but real world experience with small engines has proven (for me at least) that 150% is adequate, even in here in the broiling south. Hoot mon, on some of my soda bottle "radial" cowlings, 3x entry area wouldn't leave you with any cowling to look at! Maybe it has something to do with the relative size of the entry hole vs. overall cowl frontal area as well (??)

cabanestrut2002

i was thinking of normal planes and forgot we are dealing with the little 'uns! you are probably right.

Lynn S

I knew the exit had to be larger, but I didn't know by how much. I think I read that for an electric motor in the instructions somewhere. 150% sounds like it would be plenty of opening. This is kinda like rolling the rear windows down on a car with four doors. You can feel the vacuum created.
This will be my first experience with a cowl. - Lynn

William Robison

My Feedback: (3)

Two pictures.

irst, here is a frontal view on one nacelle on my Tiggerkitty. And yes, Dickeybird, the cowls are made from aluminum drink cans.

You can see the inlet area, and the cylinder head outside in the free air flow.

William Robison

My Feedback: (3)

And here is a rewar quarter view. The cowl flaps you see go all the way around except directly behind the engine cylinder. They, and the clearance around the cylinder, are the only air exit from the cowling. I have had no overheating problem, even though the area for exhaust is much less than the inlet area.

I thnk I get away with it because the cylinder heads are out in the breeze.

Bill.

William Robison

My Feedback: (3)

A larger view showing both nacelles. (Yes, it's the view in my avatar.)

Bill.

AndyW

My Feedback: (1)

Bill,

Yes, you're cheating with the heads out in the breeze. The Giles and the Extra have them completely enclosed.

Now that I see the nacelles on your T-Kitty, I just have to say that they're just begging for a pair of Norvel .074s. Looks like plenty of room for the conversion. The idle will be 6K or less with tons of power.

Lynn S

The Giles G-202 arrived Weds, It is a beautiful plane, construction looks excellent, better than I could build.

I'm not sure what to do about the wood motor mount beams for the electric motor. I am using my Norvel .074 engine. Do I use the same mount as the electric motor or build a plywood box to mount the engine??

thanks, Lynn

William Robison

My Feedback: (3)

Lynn:

Block the holes in the firewall, and fuelproof everything.

Mounts? That picture looks like the beams would be strong enough for the engine, but give it a good eyeball - the piston engine will have a lot more vibration than the electric motor.

Bill.

Lynn S

Bill,
It looks like the engine will work fine if inverted on the wood beams.
I'm not sure I want to mount it that way or not.

William Robison

My Feedback: (3)

Lynn:

If you want to mount it with the cylinder horizontal you wont have any choice. Cut the beams off, check how far out the engine has to be, then using whatever radial mount you come up with, space it out as needed.

But still seal the holes in the firewall, and fuelproof everything.

Bill.