Mounting a servo on its side.
08-26-2007, 12:16 PM
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Mounting a servo on its side.
I have need to mount a servo on its side.
My nephew built a PT-20. Flew it once, crashed it, and gave up on the RC airplane hobby.
I have the plane now. It wasn't in too bad of shape. The wings broke apart right at the center glue joint, and there was fuse damage. But I'm on the way towards fixing it.
He built the plane without ailerons. I wish to put them in. But the wings are pretty thin, too thin to put a standard servo in vertically.
So I have an idea. I'll mount a standard servo in the center section of the wing. It will be mounted on its side and cross-wise. (The servo arm will then move along the axis of the wing.) Then I'll run control rods out through the wings, to bell cranks. Then from there out through the bottom of the wings to the aileron.
But I need some examples/pictures of mounting a servo on its side.
Any help would be appreciated...
Thanks,
Lyndon
My nephew built a PT-20. Flew it once, crashed it, and gave up on the RC airplane hobby.
I have the plane now. It wasn't in too bad of shape. The wings broke apart right at the center glue joint, and there was fuse damage. But I'm on the way towards fixing it.
He built the plane without ailerons. I wish to put them in. But the wings are pretty thin, too thin to put a standard servo in vertically.
So I have an idea. I'll mount a standard servo in the center section of the wing. It will be mounted on its side and cross-wise. (The servo arm will then move along the axis of the wing.) Then I'll run control rods out through the wings, to bell cranks. Then from there out through the bottom of the wings to the aileron.
But I need some examples/pictures of mounting a servo on its side.
Any help would be appreciated...
Thanks,
Lyndon
08-26-2007, 12:30 PM
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RE: Mounting a servo on its side.
Probably this belongs in the Tips and Techniques forum, But why don't you consider two mini servos in the wings?
You haven't said what model PT-20 it is though. That would give us all an idea and who knows, maybe someone already has done it before.
You haven't said what model PT-20 it is though. That would give us all an idea and who knows, maybe someone already has done it before.
08-26-2007, 04:46 PM
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RE: Mounting a servo on its side.
I should have put in the Tips & Techniques forum.. Brain cramp on my part....
I don't know what model PT-20 it is. It's older. I don't think it's the MK II that's being sold today. 52" wingspan. I even have the original box.
I wish to experiment with the side-ways servo configuration. I may need to use that type of setup in a future airplane. I've added a photo of the area, and the how I want the servo oriented.
The problem I see, is making the mount and surrounding area so I can mount it properly. And maintain it properly later.
I was thinking of using one of these on the servo arm.
http://www2.towerhobbies.com/cgi-bin...?&I=LXGWE0&P=7
I figured to attach this to this to the control rods. Then the servo would be mounted almost totall below the wing. It'd make it easier to screw the servo down. Easier to maintain it.
I'm mulling things around in my head. I hoped somebody had some pictures they could share.
I don't know what model PT-20 it is. It's older. I don't think it's the MK II that's being sold today. 52" wingspan. I even have the original box.
I wish to experiment with the side-ways servo configuration. I may need to use that type of setup in a future airplane. I've added a photo of the area, and the how I want the servo oriented.
The problem I see, is making the mount and surrounding area so I can mount it properly. And maintain it properly later.
I was thinking of using one of these on the servo arm.
http://www2.towerhobbies.com/cgi-bin...?&I=LXGWE0&P=7
I figured to attach this to this to the control rods. Then the servo would be mounted almost totall below the wing. It'd make it easier to screw the servo down. Easier to maintain it.
I'm mulling things around in my head. I hoped somebody had some pictures they could share.
08-26-2007, 07:23 PM
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RE: Mounting a servo on its side.
For one servo per aileron (or any control surface) :
Basically, make a small hatch that's just large enough for the servo on it's side. Cut an opening for the servo arm, and use two uprights made from hardwood (NOT balsa) , the same width as the servo. Screw the servo to the uprights, and install the hatch with screws into a frame in the bottom of the wing. Sizing depends on your plane and servo, may have to adjust the opening for the servo arm to get full travel.
You can use this method in any size plane, I have a small electric that uses the same mounting for the aileron servos, except I used plastic sheet for the hatch and micro servos. same difference.
If you want to use one servo for both ailerons, try sullivan flexible pushrods. Route the outer housing through holes in the ribs, make a gentle bend out towards each control horn and support the tube along it's length with scrap. Run the inner pushrod through and attach at each end.
Basically, make a small hatch that's just large enough for the servo on it's side. Cut an opening for the servo arm, and use two uprights made from hardwood (NOT balsa) , the same width as the servo. Screw the servo to the uprights, and install the hatch with screws into a frame in the bottom of the wing. Sizing depends on your plane and servo, may have to adjust the opening for the servo arm to get full travel.
You can use this method in any size plane, I have a small electric that uses the same mounting for the aileron servos, except I used plastic sheet for the hatch and micro servos. same difference.
If you want to use one servo for both ailerons, try sullivan flexible pushrods. Route the outer housing through holes in the ribs, make a gentle bend out towards each control horn and support the tube along it's length with scrap. Run the inner pushrod through and attach at each end.
08-26-2007, 09:06 PM
#6
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RE: Mounting a servo on its side.
I think you're going to find that mounting it sideways is more trouble than it's worth. It's very hard to get that configuration to center, not to mention all the links that could go bad...inside the wing!
The simplest way is to purchase a smaller servo....mount it in the center of the wing....upright!
Just a suggestion.....
The simplest way is to purchase a smaller servo....mount it in the center of the wing....upright!
Just a suggestion.....
08-28-2007, 01:33 PM
#9
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RE: Mounting a servo on its side.
Here's a cheap way to get 'L' brackets for side mounting.
If that blue electrical extension bracket is tough enough to meet fire and electrical codes in houses, it should be good enough for our servos!
About 20 seconds on the band saw will yield more than enough brackets.
If that blue electrical extension bracket is tough enough to meet fire and electrical codes in houses, it should be good enough for our servos!
About 20 seconds on the band saw will yield more than enough brackets.
08-28-2007, 03:55 PM
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RE: Mounting a servo on its side.
That is awesome sampar. I never thought of making servo side mounts that way. I will have to try that. One small issue that I see though is that it takes away the length of the servo arm. I have installed plenty of side mounted servos (H-9 planes) and the servo arm always just makes it out of the slit in the ply.
08-28-2007, 05:19 PM
#11
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RE: Mounting a servo on its side.
Use a longer servo arm.
I usually use HS-645's and they come with several different size arms.
You just have to remember that the torque in ounces is usually based on a 1" arm.
I 'over kill' on my servos torque.
Dubro sells separate arms.
I usually use HS-645's and they come with several different size arms.
You just have to remember that the torque in ounces is usually based on a 1" arm.
I 'over kill' on my servos torque.
Dubro sells separate arms.
08-28-2007, 05:41 PM
#12
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RE: Mounting a servo on its side.
You can mount the servo on its side but 'up side' down (pic 1)
and use sullivan high stress rod (pic 2)
http://www2.towerhobbies.com/cgi-bin/WTI0001P?&I=LXFV12
to move the moving surface internally.
Just Glue the outside black tube into the moving surface as you would a robart pin hinge.
Then attach a ball link to the servo arm and then attach the yellow internal rod to the ball link with some 4/40 threaded rod.
As the servo arm rotates up/down, the moving surface moves in the opposite direction.
The yellow rod slides in the black tube.
It's like drilling a hole in the side of your house door nearest the hinges and then sticking a metal rod into the hole.
As you move it left or right, the rod will slide in the hole but also move the door in the opposite direction.
Clean and simple and very scale.
I stole this from Gary Webb when I bought one of his planes.
and use sullivan high stress rod (pic 2)
http://www2.towerhobbies.com/cgi-bin/WTI0001P?&I=LXFV12
to move the moving surface internally.
Just Glue the outside black tube into the moving surface as you would a robart pin hinge.
Then attach a ball link to the servo arm and then attach the yellow internal rod to the ball link with some 4/40 threaded rod.
As the servo arm rotates up/down, the moving surface moves in the opposite direction.
The yellow rod slides in the black tube.
It's like drilling a hole in the side of your house door nearest the hinges and then sticking a metal rod into the hole.
As you move it left or right, the rod will slide in the hole but also move the door in the opposite direction.
Clean and simple and very scale.
I stole this from Gary Webb when I bought one of his planes.
08-28-2007, 08:02 PM
#13
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RE: Mounting a servo on its side.
Servo installations:
http://users.adelphia.net/~pjburke10...onnections.htm
http://users.adelphia.net/~pjburke10...onnections.htm
08-29-2007, 12:46 PM
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RE: Mounting a servo on its side.
These???
http://www2.towerhobbies.com/cgi-bin...?&I=LXK057&P=7
And how tight of radius can these bend???
http://www2.towerhobbies.com/cgi-bin...?&I=LXK057&P=7
And how tight of radius can these bend???
08-29-2007, 12:50 PM
#16
RE: Mounting a servo on its side.
These are what I usually use and I have bent about a 2" radius with no trouble
http://www2.towerhobbies.com/cgi-bin...&I=LXFU90&P=ML
http://www2.towerhobbies.com/cgi-bin...&I=LXFU90&P=ML
09-09-2007, 08:08 PM
#17
RE: Mounting a servo on its side.
ORIGINAL: cwrr5
For one servo per aileron (or any control surface) :
Basically, make a small hatch that's just large enough for the servo on it's side. Cut an opening for the servo arm, and use two uprights made from hardwood (NOT balsa) , the same width as the servo. Screw the servo to the uprights, and install the hatch with screws into a frame in the bottom of the wing. Sizing depends on your plane and servo, may have to adjust the opening for the servo arm to get full travel.
You can use this method in any size plane, I have a small electric that uses the same mounting for the aileron servos, except I used plastic sheet for the hatch and micro servos. same difference.
If you want to use one servo for both ailerons, try sullivan flexible pushrods. Route the outer housing through holes in the ribs, make a gentle bend out towards each control horn and support the tube along it's length with scrap. Run the inner pushrod through and attach at each end.
For one servo per aileron (or any control surface) :
Basically, make a small hatch that's just large enough for the servo on it's side. Cut an opening for the servo arm, and use two uprights made from hardwood (NOT balsa) , the same width as the servo. Screw the servo to the uprights, and install the hatch with screws into a frame in the bottom of the wing. Sizing depends on your plane and servo, may have to adjust the opening for the servo arm to get full travel.
You can use this method in any size plane, I have a small electric that uses the same mounting for the aileron servos, except I used plastic sheet for the hatch and micro servos. same difference.
If you want to use one servo for both ailerons, try sullivan flexible pushrods. Route the outer housing through holes in the ribs, make a gentle bend out towards each control horn and support the tube along it's length with scrap. Run the inner pushrod through and attach at each end.
Mike
