Pull-Pull for rudder in 2M planes - recommendations.
04-22-2018, 06:10 AM
#27
Can't get much lighter then this. Control horn is CF tube with CF rod inside. Dubro aileron connector is glued onto CF rod with thin CA. Cable is nylon coated Kevlar, crimped with aluminum tube and thin CA for insurance. Shrink tube over crimp cleans it up a bit. Adjustment at servo only but Kevlar won't stretch so after initial tightening of the cables it never needs adjusting again.
04-30-2018, 02:47 PM
#28
Hi all,
First thanks for all Your photos and descriptions of Pull-Pull solutions in various planes.
I got all the hardware needed some days ago for my Pull-Pull solution for my Galactika. I have finnished it now.
I use the Sullivan Pull-Pull #521 with Aramid fiber lines and Sullivan #549 4-40 steel eyebolts. These eyebolts fitted in my existing blue links (original Oxai links shipped with my Galactika).
In my experience now I think installing Pull-Pull system is not that easy. It was rather much work on my Galactika. First I checked carefully present CG with Xicoy Balance and Weight meter, with old setup with rudderservo in the tail and the 5000 mAh LiPo (Hacker Eco-X 20C 5000 mAh) I used before. Then I removed servo in the tail, Futaba BLS171 SV, the servo mounting plywood, and the S.BUS hub mounting plate I had in the tail.
The rudder servo in the tail has a weight of 53 gram, the plywood mounting removed 9 gram, total 62 gram. I mounted the S-BUS hub with contact glue instead to side of fuselage inside tail and saved some grams there also since I do not use the mounting plate for the S.BUS hub I had before.
Then I placed the plane on the Xicoy Balance and Weight meter again, mounted the new lighter Hacker Eco-X 4600 mAh 20C F3A Edition LiPo, and rudder servo just behind the wing adjusters (temporarily) in the front of fuselage. I use 8x8 mm square carbon tubes as mounting for the rudder servo in the front of fuselage and 4 round glass-foam laminate holders I made glued to fuselage sides.
After some adjustments back-forward of the LiPo battery on the tray in the fuselage It was nice to see that I was able to have the new lighter LiPo batteri in the middle of it's tray in the plane and have same CG as before, so I glued the carbon tubes for the rudder servo permanently in fuselage.
The Sullivan aramid fiber kevlar lines has a breaking strength of 100 lbs, is nonmetallic and will not cause RFI, is lighter then steel, will not stretch. To cut aramid line one need very sharp scissors. The Sulllivan #521 Pull-Pull contain 12 ft (3.65 meter) aramid line.
The reason behind going through the trouble changing from rudder servo in the tail with short rods, to the rudder to servo in front of fuselage and Pull-Pull system to rudder was the desire to get my Galactika lighter. Now my Galactika is down to a take off weight including LiPo of 4880 gram, and lighter then that is hard to get with my present equipment in the plane.
So all in all I think the job changing to Pull-Pull system is worth it. We will see if the change in weight, in my case, will have any noticeable effect on flight characteristics. Maybe the plane will climb little easier in vertical maneouvres, and mabe the lighter tail (by 62 gram) can have some nice impact also for example on stall turns, in general it is no good to have extra weight in the tail since the goal is to have as much mass centered close to center of gravity for good flight characteristics, as with most planes.
Now I have 5 new LiPo packs to assemble (changing and solder to bullet connector, and mount cardboard on underside, little boring job but must be done).
The weather seems not to be good in near future here so I will have to wait some for flights with the new Pull-Pull system.
I hope this thread can be of interest to others when doing Pull-Pull for rudder in a plane.
/Bo
Things needed for the Pull-Pull system: Sulllivan #521+549, 8x8 mm square carbon tube, shrink tube and some light glass-foam laminate for round mounting points on fuselage sides for the carbon tubes.
The aramid fiber line, shrink tube, copper crimp tube and eyebolt. I made an extra loop throught the copper tube.
After copper tube has been crimped.
I used a crimp tool (for electric contacts) with the hole marked with 18-22 (AWG No.).
Shrink tube mounted and heated, all finished.
Tail servo removed and S.BUS hub relocated and mounted on fuselage side. Dental floss used to secure the servo connector in the S.BUS hub connector. Sullivan red tubes glued as exit guides (glued with epoxy-micro ballons paste).
The Pull-Pull on outside in the tail.
The Pull-Pull exit in the tail.
The rudder servo after relocation to the front in fuselage, just behind and between-below the wing adjusters.
The aramid lines going to the tail.
First thanks for all Your photos and descriptions of Pull-Pull solutions in various planes.
I got all the hardware needed some days ago for my Pull-Pull solution for my Galactika. I have finnished it now.
I use the Sullivan Pull-Pull #521 with Aramid fiber lines and Sullivan #549 4-40 steel eyebolts. These eyebolts fitted in my existing blue links (original Oxai links shipped with my Galactika).
In my experience now I think installing Pull-Pull system is not that easy. It was rather much work on my Galactika. First I checked carefully present CG with Xicoy Balance and Weight meter, with old setup with rudderservo in the tail and the 5000 mAh LiPo (Hacker Eco-X 20C 5000 mAh) I used before. Then I removed servo in the tail, Futaba BLS171 SV, the servo mounting plywood, and the S.BUS hub mounting plate I had in the tail.
The rudder servo in the tail has a weight of 53 gram, the plywood mounting removed 9 gram, total 62 gram. I mounted the S-BUS hub with contact glue instead to side of fuselage inside tail and saved some grams there also since I do not use the mounting plate for the S.BUS hub I had before.
Then I placed the plane on the Xicoy Balance and Weight meter again, mounted the new lighter Hacker Eco-X 4600 mAh 20C F3A Edition LiPo, and rudder servo just behind the wing adjusters (temporarily) in the front of fuselage. I use 8x8 mm square carbon tubes as mounting for the rudder servo in the front of fuselage and 4 round glass-foam laminate holders I made glued to fuselage sides.
After some adjustments back-forward of the LiPo battery on the tray in the fuselage It was nice to see that I was able to have the new lighter LiPo batteri in the middle of it's tray in the plane and have same CG as before, so I glued the carbon tubes for the rudder servo permanently in fuselage.
The Sullivan aramid fiber kevlar lines has a breaking strength of 100 lbs, is nonmetallic and will not cause RFI, is lighter then steel, will not stretch. To cut aramid line one need very sharp scissors. The Sulllivan #521 Pull-Pull contain 12 ft (3.65 meter) aramid line.
The reason behind going through the trouble changing from rudder servo in the tail with short rods, to the rudder to servo in front of fuselage and Pull-Pull system to rudder was the desire to get my Galactika lighter. Now my Galactika is down to a take off weight including LiPo of 4880 gram, and lighter then that is hard to get with my present equipment in the plane.
So all in all I think the job changing to Pull-Pull system is worth it. We will see if the change in weight, in my case, will have any noticeable effect on flight characteristics. Maybe the plane will climb little easier in vertical maneouvres, and mabe the lighter tail (by 62 gram) can have some nice impact also for example on stall turns, in general it is no good to have extra weight in the tail since the goal is to have as much mass centered close to center of gravity for good flight characteristics, as with most planes.
Now I have 5 new LiPo packs to assemble (changing and solder to bullet connector, and mount cardboard on underside, little boring job but must be done).
The weather seems not to be good in near future here so I will have to wait some for flights with the new Pull-Pull system.
I hope this thread can be of interest to others when doing Pull-Pull for rudder in a plane.
/Bo
Things needed for the Pull-Pull system: Sulllivan #521+549, 8x8 mm square carbon tube, shrink tube and some light glass-foam laminate for round mounting points on fuselage sides for the carbon tubes.
The aramid fiber line, shrink tube, copper crimp tube and eyebolt. I made an extra loop throught the copper tube.
After copper tube has been crimped.
I used a crimp tool (for electric contacts) with the hole marked with 18-22 (AWG No.).
Shrink tube mounted and heated, all finished.
Tail servo removed and S.BUS hub relocated and mounted on fuselage side. Dental floss used to secure the servo connector in the S.BUS hub connector. Sullivan red tubes glued as exit guides (glued with epoxy-micro ballons paste).
The Pull-Pull on outside in the tail.
The Pull-Pull exit in the tail.
The rudder servo after relocation to the front in fuselage, just behind and between-below the wing adjusters.
The aramid lines going to the tail.
Last edited by bem; 05-01-2018 at 01:43 AM.
10-13-2018, 07:59 AM
#31
computermonkey,
The blue Control horns was shipped with my Oxai (now Hui Yang F3A) Galactika plane. They can be bought via a Hui Yang F3A reseller.
However these blue Control horns can be bought for example from this Japanese hobby shop, Morris-Hobby:
NTS»ƒxƒAƒŠƒ“ƒOƒz[ƒ“iVŒ^j
It is actually Narutech Service (NTS) that make them, at least they are marked NTS on the plastic bags as You can see if You click on the image in above link.
They are very nice and good qualtity horns, it is a small ball bearing on them.
Morris-Hobby has many nice accessories for RC and F3A. Just click around on their site and Yoy will see.
/Bo
The blue Control horns was shipped with my Oxai (now Hui Yang F3A) Galactika plane. They can be bought via a Hui Yang F3A reseller.
However these blue Control horns can be bought for example from this Japanese hobby shop, Morris-Hobby:
NTS»ƒxƒAƒŠƒ“ƒOƒz[ƒ“iVŒ^j
It is actually Narutech Service (NTS) that make them, at least they are marked NTS on the plastic bags as You can see if You click on the image in above link.
They are very nice and good qualtity horns, it is a small ball bearing on them.
Morris-Hobby has many nice accessories for RC and F3A. Just click around on their site and Yoy will see.
/Bo
Last edited by bem; 10-13-2018 at 08:04 AM.
10-14-2018, 08:04 AM
#32
Here is the link your looking for
https://hobbyking.com/en_us/pull-pul...mm-length.html
https://hobbyking.com/en_us/pull-pul...mm-length.html
https://hobbyking.com/en_us/pull-pul...mm-length.html
https://hobbyking.com/en_us/pull-pul...mm-length.html
These may work out for you.
https://www.soaringusa.com/Brass-Hor...ategory_id=136
02-22-2019, 06:10 AM
#33
Join Date: Feb 2008
Location: Tallinn, ESTONIA
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Can't get much lighter then this. Control horn is CF tube with CF rod inside. Dubro aileron connector is glued onto CF rod with thin CA. Cable is nylon coated Kevlar, crimped with aluminum tube and thin CA for insurance. Shrink tube over crimp cleans it up a bit. Adjustment at servo only but Kevlar won't stretch so after initial tightening of the cables it never needs adjusting again.
