How about servos. I'm about to order some. Should I go with HS-225s all the way around or smaller like HS-85s?

http://servocity.com/Products/Hitec_...c_servos_.html

If the 225s are regular "mini"(not "micro" like the 85s) go for those. I would not be happy with anything less than 30 oz/in, and the plane has "mini" trays. You could, of course, fill out the holes in the trays with a little scrap ply. The throttle can use anything, but the weight is not much of a savings.
Funny, the instruction manual shows FULL SIZE servos, I guess they did not have any minis around when they were taking the photos.

The instructions I got with my A-7 show four S135 servos and an S3101 on throttle. The photos are a little fuzzy, but I think I read the numbers correctly.

The S135 is a mini (0.6" x 1.2" x 1.2") and the 3101 is a micro.

I plan on using, and I hope this is right, :

Ailerons- 2 x HS-225
Rudder- HS-225
Throttle- HS-81
Elevator- HS-225

I thought about using HS-85s on the ailerons but don't know if they will fit.

Easytiger-
I just read thru this thread and thought that was Floyd Bennett Field where you took those pictures. All the "pros" were giving you all kinds of "advice" huh? Some things never change!
I learned to fly there and then after a few years of racing cars I've started flying again, but this time at Bethpage. Only bad thing is it's grass so no jets, I may have to slip back down to Brooklyn and see this thing fly.

Regards,

Mark

Just got my A-7 Yesterday...got to working on it and I'd have to say that even a beginner should not have any problems assembling this kit. I should be done with the assembly but Im still not sure which servo's to put in it...right now Im looking 5
Hitec HS-55J Servo Economy Sub Micro J . What do ya'll think about those servo's? Will they work? I know they are the cheapest but i've run out of money If anyone wants pictures of the A-7 inerds, let me know.

Luis

Easy, what were your thoughts on retracts for this thing?

If you are old enough to remember, That Fox Eagle .60 had a unique design, The head and upper cylinder was bolted to the crankcase. You could rotate it so the exhaust was on the right or left or to the rear.

I rotated mine to the rear, and used the Byron Tuned pipe. It worked quite well, had lots of power and was reasonably fast......... Until it would over heat and quit.

If I wouldn't have gotten the Rossi, I was gonna make a heat sink head for it. I stil have it I might try it just to see what it'll do!

B1DRIVER- From what I've heard so far, the HS-55s are way too small/light duty for the A-7. Look up the thread titled "TOKI 18", they talk about retracts.

I would love some pics of the plane so I will know what to expect!!

Im charging the digi cam batteries right now..... Im new to the mini/micro world of servo's..>Been a full size kinda guy till now Whats a good/cheap servo for this plane? And reliable?

Luis

B1Driver,

Something in the 30 oz.in range is probably required.

If you have to buy servos, minis are cheaper than micros for a given torque rating.

www.balsapr.com have GWS servos. The plain bearing mini is $10.

Heh, heh! Floyd Bennet has been not so bad for the last year, the new President has been cracking down on some of the biggest knuckleheads, it seems.
It is still, though, Brooklyn! You know what I am saying. In Brooklyn everybody knows everything about everything!
There are some grass field jets, but it sure is limiting. Floyd Bennett, in a lot of ways, is paradise for the jet flyer. Lots and lots of pavement.

Can't beat that with a stick. I have a few of the Balsa Products servos, some super duty ones, on the stabilators of a sixteen pound F8 Crusader, with no complaints. And the price is sure right on them.
I think the HS55 is a little on the wimpy side for this plane...

RETRACTS.
I'm sure it CAN be done, but before any major surgery, what I ought to do is remove the fixed gear and try to bungee launch the thing over grass, to see what kind of speed improvement can be had. If the plane is not much faster, there is not much point in adding the weight and expense of retracts.
I hope to get a chance to try that out sometime this week.

I'm using Hitec 81's all arround in my A7. This is no rocket, and they handle it fine. The box claims a weight of 1900 grams. Mine came in at 1550 grams.

I did have one problem. I ran a few tanks with my motor on a brake in stand, then a couple in the jet, waiting for the weather. While running it at my shop, there was suddenly this weird sound, and the motor picked up revs. It had sucked the top of the front inlet down. I formed a wire to the contour, and fiberglassed it in, from the canopy side. Been flawless since.

Can you check your scale? How did yours come out ten ounces lighter than mine? I am using similar servos...

The scale is an electronic postal scale. The jet balanced on the exhaust. I used a 5 cell 1600 Mah nmh pack to get the CG right on. Maybe they were in a rush that day, or low on glue. Looks like hot glue in places. I haven't seen another HB A7, but the glass work is incredibly thin.

4th flight today. Still timid with the look of slow flight. But the loops were big and round, and rolls smooth and straight. The scale look of slow low flybys just looks cool.

Flamed out turning downwind after a low pass. Stalled , bounced the landing way down field. Slight bend to nose and one side of landing gear. No other damage. Figure it was just on the lean side.

I thought about that...ten ounces of glue, though?
Who knows? I will double check my scale.
Are you using 30%?
Yes, probably just lean. You should have a very decent smoke trail coming out. I played with leaning it out, the plane was not faster tweeked to the very maximum revs.
Swap out the plug after a lean run, it is probably pretty beat...

Using 25%. Nitro cars for years. This is my second plane, first nitro, DF yet! LOL. Other is an Electro streak.

It seems to real sensitive on needle setting. Will 4 stroke, and chug trying to peak. It does seem better as I get flights in.

Running it on a stand with a 9*6 prop didn't allow it to rev like it does now. So I'm thinking it is still breaking in.

Been reading the thread on Moore's Turbines. I live in his home town, and the guys I fly with helped him out when he first started. Think a turbine for a 2nd. jet a little early? LOL

Plugs??? Forgot to ask, what plug IS recommended for the Toki 18?

I changed mine out to a McCoy 9, pretty much the standard plug for DF.
Yeah, it sounds like you may just need more time on the engine. Mine is pretty easy to tune.
Turbine, sure, why not? Depends what airframe, of course..

I did not bench run mine. Just put a few tanks through on the ground, then flew the puppy.

My wife thanks you Phile for pointing out them cheap micro's. Was just wondering what they meant by "plain bearing" Is that somehow a weaker type of servo? Will it not hold up as well? If it EVER starts to clear up here in Texas I'll be able to go fly.

Luis

Well I just got mine last night and just finished some taxi tests. The little TOKI runs like a top. I set the needle about 1 3/4 turns out. I wound up using HS-81s on the throttle and ailerons and HS-225s on rudder and elevator. I should have used 81s all the way around. Kit went together in no time. I must be getting good at this arf building. Two planes in two evenings. I'm running 30% and it is screaming so far. Hope to get it in the air tomarrow. Awesome looking plane!!

Easy, do you think the O.S. A3's would work in that engine?

Luis

They would probably be fine. This engine does not seem to be as hard on plugs as the bigger DF ones, which pretty much toast a plug every ten flights or less...

Plain bearing means no ball bearing on the output shaft. Just less accurate and smooth than the BB ones. Will not matter on this plane...
Sawyer, wasn't the kit great? REALLY prefabbed, really fast to put together. Loved those clevis attcachments, with the holes in them for solder...