RCU Forums - 1st pull pull setup?

RCU Forums (https://www.rcuniverse.com/forum/)

- Beginners (https://www.rcuniverse.com/forum/beginners-85/)

- - 1st pull pull setup? (https://www.rcuniverse.com/forum/beginners-85/10859362-1st-pull-pull-setup.html)

RE: 1st pull pull setup?

Ahhhh!!! would you believe +/- 15% Gee I sound like Maxwell Smart :):D;)[X(]

RE: 1st pull pull setup?

OK I take your point on the +- 10 % not giving problems with tightness.

I was thinking of keeping the movements of the control surface approx in synch with the servo.

RE: 1st pull pull setup?

Quote:

ORIGINAL: billd76

yep same as mine. I did see the pre drilled holes, but drilled my own and staggered them. Be sure to use more than just CA on the servo trays when mounting them. I'm using Hitec HS-485 HB's servo's for all but the throttle. They are ball bearing Karbonite gear with 66 oz of torque. I also added two washers under the forward two holes of the engine to give a tad of right thrust, not sure it really matters, but just thought a little right thrust would be a good thing. I placed a 1100 LiFe battery in between the the servos on the left wing. I didn't realize the the pull pull wires would be so close to the switch where I mounted it. It will be fine where it is, but had I realized it I would've mounted the switch more towards the outside of the wing instead of where I did. The instructions called for mounting the fuel tank in the wing as well, I decided to mount mine extrenal. I like the ease of being able to access everything with the profiles. Makes the engines easy to tune, and fix fuel lines, etc... I set my CG at 4.5 inches. The manual says 4.0 - 5.25! Will have to see how it flies and adjust as needed. The 55 AX should get this thing airborne in less than 10 feet!! :D:D:D

Billd76, thanks for the pics. Did you get to maiden it yet? servo trays came out a little high.. the servos just touch the hatch cover..

I put the tank in the wing, I'll probably regret it later but I wanted the clean look... If it gives me trouble I'll strap another tank on the outside of the fuse and remove the tank in the wing later. ( will have to remove servo tray...)

steve

RE: 1st pull pull setup?

Since I couldn't find a compelling reason not to keep the servo arm and control horn lengths equal, that's what I did - 3" each. Thanks for your help - my pull-pull system is now installed.

From the back:

http://farm8.staticflickr.com/7148/6...dafd866d_z.jpg

At the servo:

http://farm8.staticflickr.com/7031/6...bd588e16_z.jpg

Where the wires cross:

http://farm8.staticflickr.com/7030/6...a9435f73_z.jpg

RE: 1st pull pull setup?

Quote:

ORIGINAL: Popriv

Quote:

No no maiden, only broke in the engine. I was tempted.:D Also if you see in the pics where I placed the battery switch, it's just under one of the pull pull wires. I'm not happy with that, so I'm going to move it in between the servo wire it's under and the aileron control rod. I'm worried that the wire might catch the switch and turn it off in flight. probably "far fetched" but will feel more comfortable about the maiden with it moved. I'm off of work from the 23rd to the second, so will definitely get her flying soon! Along with whatever else Santa brings me!! :D. i was a little high with one of my servos too, I took an exacto knife and very gently trimmed out the cover so it would fit. Well, got to head for Philly Airport and pick up the youngest Marine of the family. What CG are you going to start wit? 55 AX ran perfect during the break in runs. Lots of POWER!! should punch holes in the sky easily!! :D:D

RE: 1st pull pull setup?

Not sure but from the looks of your picture of the servo arm, you have the attach points aft of the pivot point on the servo. If so you may have a problem as that will give you some negative Ackerman (the lines will tighten up as you move off neutral) which can be very hard on the servo and possible even cause it to stall out and possible self destruct. At the servo end, you want the attach points to be forward of the pivot point on the servo, just the opposite of what you want at the rudder horns. Remember, you want the lines at neutral to be just tight enough to have no sag and it will not hurt anything if the line not being pulled slacks off a bit as you move away from the neutral position.

RE: 1st pull pull setup?

will check it when I get home, but pretty sure all of my attach points are forward (between Servo and horns. It could be that one of the control surfaces was turned one way another when I took the picture.

RE: 1st pull pull setup?

Billd76, I'm off work next week also so I'm hoping for weather at least in the mid 40's so I can maiden this thing... I mounted my switch so it is on top of the wing when upright. I dont have to flip plane over to turn on/off.... My OS. 55 was bought used a few years ago and is well worn in.... Runs great.
I'm thinking a 12-4 prop? slow it down and get more pull... I screwed up my rudder pull pull, late nite of building I should have gone to bed... I looped the wire directly to the control horn on the rudder.. On the outer most hole. I guess its ok that way I just cant move it to another hole if needed. I'll leave it that way and only redo if I find I have to move to an inner hole on the rudder... I'll do better on the elevator tonight...
IS IT CRAZY TO MOUNT THE ENGINE WITH SCREWS? they would be going into a hard wood block... Or should I just use bolts?

Gettin close, I can taste it.....

steve

RE: 1st pull pull setup?

Quote:

ORIGINAL: Popriv

Billd76, I'm off work next week also so I'm hoping for weather at least in the mid 40's so I can maiden this thing... I mounted my switch so it is on top of the wing when upright. I dont have to flip plane over to turn on/off.... My OS. 55 was bought used a few years ago and is well worn in.... Runs great.
I'm thinking a 12-4 prop? slow it down and get more pull... I screwed up my rudder pull pull, late nite of building I should have gone to bed... I looped the wire directly to the control horn on the rudder.. On the outer most hole. I guess its ok that way I just cant move it to another hole if needed. I'll leave it that way and only redo if I find I have to move to an inner hole on the rudder... I'll do better on the elevator tonight...
IS IT CRAZY TO MOUNT THE ENGINE WITH SCREWS? they would be going into a hard wood block... Or should I just use bolts?

Gettin close, I can taste it.....

steve

Screws should be ok. I used blue loctite on the screws and nuts, seems ok. I did think about going with allen screws and nuts for the engine, but as long as that stay tight, I tihnk the screws that came with the plane will be strong enough . That's the good thing about profiles, you can keep an eye on everthing without having to take it is apart! I'm going with a 13 X 4 APC prop. mainly because I watched a guy at the field fly a .40 profile with a 55 AX and 13 X 4 and it did really well. My last 55 AX was on a decathlon and used a 12.25 X 3.75 APC prop and it was terrrfic as well. I hope to maiden mine soon. finally got around to starting to put my PT 19 back together last night. If you maiden before I do, good luck! What glow plug are you using for your 55.? I use an OS No 7.

RE: 1st pull pull setup?

hey bulld76, Have you maidened yet?
I maidened yesterday.. Got only one flight in but it flew great.. a couple clicks of right alieron was all it needed.
I do my own maidens now ( with knees knocking ) but I asked one of the instructors to stand with me which was good.
I was wrong about my engine, I have the OS .50 max sx ringed engine. Funny, keeps flying at 1 click above idle... I had a 12x5 prop. It was suggested to switch to a 13x4 to slow it down. Just flew a few curcuits , 1 roll, 1 loop then made a couple approaches and finally landed slow and smooth. The wind picked up abit so I didnt fly it again, hoping to get out on Saturday with it.

Very different from any glow planes I've flown before...

steve

RE: 1st pull pull setup?

Yeah actually maidened mine on Saturday. Two flights, flew just fantastic. Glad your maiden went well. Using a 13 X 4 X roar on mine. Blast to fly!! :D:D:D

RE: 1st pull pull setup?

The AMA rule book has instructions on how to do a proper cable crimp in the control line section. After all, what is a control line plane but a pull-pull setup using 60 foot long cables?

A reasonably snug fit of the crimp tube is most important. If its sloppy enough that it gets mashed flat rather than dimpled inward, then the crimp will fail under high stress. If diagonal cutters are used to crimp, that crimp can fail.

The wire wrapping method of cable termination shown in the AMA rule book is the best. My own destruction testing of terminations showed, unlike crimps, it produces a cable termination that is stronger than the cable.