Originally Posted by raflyer

I don't think i would want hot air flowing in to radio compartment but I guess if you have the cannister tunnel running thru fuselage then it wouldn't matter.? Does the 35% version have the 2 panels underneath for cans and airflow?

Yes it does.

Hey Raf, I noticed your comment on the 30 degrees of elevator throw. On my IMAC plane, I have only around 10-15 degrees of throw up and down. For IMAC you really don't need that much, so I wouldn't worry about trying to increase your throw, unless you intend to do 3d with this plane as well.

Originally Posted by JIMZACH

I have two suggestions if you plane on flying this bird for IMAC. 1) I highly recomend investing in a set of canisters for the DLE-170, I had one in my pilot-rc yak 54 and used there cans and it was quiet quiet quiet! You can get the set from valley view RC for like $350 bucks, and theese are DLE's headers and cans which work awesome and are of good quality or you can get DLE's headers for the 170 from chief and use Pro-Flows. This setup will be quiter and perform flawlessly with gobs of power, however its a lil bit more money. The headers and a set of Large rear exit pro-flows will run ya about $550. But with the stock mufflers, throttle management, and a 3 bladed prop you can control your sound for IMAC. 2) The 32x10 Mejzlik on this motor is not enough prop for it, she will rip it! I used a 30x13 evo and a 29x12n Mejzlik 3 blade. If you plane on flying IMAC I highly recomend the aboue for sound and performance, especially the prop mainly the 3 blade, it will give you great performance and a very constant speed and very good downline breaking. And as far as the engine spacing is concerned i would build the fire wall with the pins as sleepy suggested, and move it back to get the spinner clearance you want and use 1/4'' stand offs, this is what i did on my yak to get the cylinder heads away from the firewall. Which is good for cooling reason.

Zach Bloomquist

What is the drop on the DLE header? I need 90mm and wonder if it is that much? Any other sources for a header for the DLE 170?
Appreciate the help.

After looking at the pictures you posted, it appears you intend to run only one servo on your rudder, if this is a 40% SBach you are going to have trouble. I currently run two Hitec 7990's whiich rate somewhere around 600 oz's each on all of my 40% planes. The only single servo with enough juice to run that barn door rudder would be a Seiko.

Raf, not trying to give you grief but it looks like you may have also used the plastic servo wheel to mount the servo arm for the rudder to. This would be very dangerous, the plastic wheel will not hold up and could cost you an airplane as well as be unsafe. Like I said I'm not trying to harass you just point out by your pictures what looks wrong and hopefuly stop something bad from happening.

Originally Posted by lowslow

Raf, not trying to give you grief but it looks like you may have also used the plastic servo wheel to mount the servo arm for the rudder to. This would be very dangerous, the plastic wheel will not hold up and could cost you an airplane as well as be unsafe. Like I said I'm not trying to harass you just point out by your pictures what looks wrong and hopefuly stop something bad from happening.

I'm not going to 3D this plane for awhile. It is IMAC only and Basic at that so my plan was to run the one servo and upgrade in the future as from what I have seen in other planes, 600oz is plenty for IMAC.

As for the plastic stock servo arms, you can't tell by the picture but the stock arms that come with the 79xx hitec servos are not plastic. They are a fiber reinforced resin arm that according to the Hitec engineers, they are more than strong enough for my intended application. Hope they are right.

My plan was to upgrade to longer arm's (only at 1.2" now) add another rudder servo, and maybe a 3rd aileron servo, all this next spring to get more into 3D.
If you look at the manual for the 42% Yak arf they detail the difference for 3d vs imac set-ups. I used their advice as well. Also in the magazine build, they only used one rudder servo and were doing all kinds of 3D.

Correct me if any of this is wrong as i'm going by others advice/experience/and set-ups so i'm always looking for input. Sometimes I play the devils advocate. lol Thanks for the input!!
Rob

Originally Posted by GMD

Hey Raf, I noticed your comment on the 30 degrees of elevator throw. On my IMAC plane, I have only around 10-15 degrees of throw up and down. For IMAC you really don't need that much, so I wouldn't worry about trying to increase your throw, unless you intend to do 3d with this plane as well.

Thank you sir, i'm actually thinking of going down to the 1" hole so I can increase my resolution. I was shocked I got that much throw on only a 1.2" arm.

Originally Posted by raflyer

I'm not going to 3D this plane for awhile. It is IMAC only and Basic at that so my plan was to run the one servo and upgrade in the future as from what I have seen in other planes, 600oz is plenty for IMAC.

As for the plastic stock servo arms, you can't tell by the picture but the stock arms that come with the 79xx hitec servos are not plastic. They are a fiber reinforced resin arm that according to the Hitec engineers, they are more than strong enough for my intended application. Hope they are right.

My plan was to upgrade to longer arm's (only at 1.2" now) add another rudder servo, and maybe a 3rd aileron servo, all this next spring to get more into 3D.
If you look at the manual for the 42% Yak arf they detail the difference for 3d vs imac set-ups. I used their advice as well. Also in the magazine build, they only used one rudder servo and were doing all kinds of 3D.

Correct me if any of this is wrong as i'm going by others advice/experience/and set-ups so i'm always looking for input. Sometimes I play the devils advocate. lol Thanks for the input!!
Rob

I am not sure which servo you have but the 600 oz rating is for the Hitec 7990's I use, x 2, and thats with a high voltage setup, the way you have it set up now you will end up somewhere around 250 oz's, x 1 , and thats assuming your using something like a 7955. Servo ratings are very subjective and are usually embelished by the manufacurer. Please have someone experienced check your plane over, just say'in.

7980 on rudder at 6.75v should be between 550 and 575oz tq. We'l see when I fly it. For sure won't be doing any knife edge loops My bet is it will Imac fine. Remember less than 20deg throw on all surfaces.

Originally Posted by raflyer

Remember less than 20deg throw on all surfaces.

No hammerheads?

Raf, When flying Imac you would need more torque on a given surface then when flying 3d. What do you think is harder, moving the rudder of center at 80mph or at a stalled airspeed ?? You need more torque for Imac. I have a 40% sbach and when I first flew it my setup was this / rudder two 8711 in a push pull in the tail, ailerons three 7955 per wing panel, eleivator one 8711 per elivator half. this was with regulated liion's to 6.0 volts. It was not enough, snaps looked terriable, knife edge was ok but not really ,really solid like I like. The ailerons would blow back all the time on snaps. I changed the setup by removing the regulators and it made a big diffrace. Planes more locked in and snaps alot better now. You will not have enough servo with your setup period . Hitecs are grossly over rated, and when they get hot forget about it, they down right suck. IMHO. But it is your plane and you can do as you choose.

Plane is done, maiden is tomorrow afternoon. Here we go....

Good luck.... i agree with Scott, you definitely dont have enough torque with your setup of servos. I wouldnt fly it wide open with that setup. Hope all goes well.

Well I got one flight in today. Takeoff was uneventful, climbed up to a safe altitude. I know you won't believe this but ZERO trim was needed on the plane to fly straight and level!! Flew 3 circuits then started with slow rolls and 4 point rolls, then knife edge left and right then a couple of knife edge circles. A loop and a couple hammerheads then it was time to land. Having read about this plane being a floater, lined up for a long low approach with just a click off idle. If you look in the pic below where I am standing next to the plane, in the distant left you will see one tall tree. I clipped the $%^$%$ with my right wing and wheel pant. Broke off a couple of limbs. Split second of panic, plane still flying, ok land it! Floated down the entire 700' runway! Added power for go around, at midfield downwind rt wing came apart as shown in 2nd pic. Plane yawed bad and pitched down. Recovered with rudder and elev, chopped power and made a perfect landing across the runway and finally took a breath. It is repairable, no damage to spar, just leading edge and sheeting.

This is my first big plane and all I can say is WOW! I flew it 7 mins and it was awesome. I can't wait to get it fixed and really get down to learning to fly it to it's potential. Big planes really do fly better than the small ones and much more stable. Just need to adjust to size vs depth perception!!!!!!!

Bummer...