control hook up prob;em
#1
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Thread Starter
Join Date: Nov 2012
Posts: 315

First of all, I want to thank those who replied to my question on laser cutting services. For now I will just continue to cut things out the old fashioned way, with a knife and plenty of sharp blades. Now the main question, The plans for the Das Mini Stik show the ailerons using just one servo with the wire running to bell cranks and then another rod going to the ailerons. But I am having trouble getting the right servo to put in the middle of the wing, as the middle of the servo winds up in the middle where the control rod goes. Or I can just put servos at either end of the wing in line of where the ailerons are connected, just a problem with one servo, because it needs to be reversed, but that's no problem. thanks in advance.
#2

Correct.
Install the two servos halfway of the ailerons.
Rotate one of the two servos along its longitudonal axis and you don't have to reverse its direction. Put another way: install the servos mirror-imaged, all of/in the wing is sysmmetrically installed
If you have one receiver channel per servo you can reverse one of the servos in the transmitter.
You can also introduce some differential by offsetting the servo levers, or ailleron levers, by say 30°.
Install the two servos halfway of the ailerons.
Rotate one of the two servos along its longitudonal axis and you don't have to reverse its direction. Put another way: install the servos mirror-imaged, all of/in the wing is sysmmetrically installed
If you have one receiver channel per servo you can reverse one of the servos in the transmitter.
You can also introduce some differential by offsetting the servo levers, or ailleron levers, by say 30°.
#3

hkeelljr
From your description I am not quite sure what the problem is using a single central servo. It was certainly how the original was set up. At the time it was common to do it this way particularly as servos were then bigger and heavier.
Now it is more common to use a servos to work each aileron. The servos are now small enough to be easily buried within the wing. The result is the linkage is simpler, more direct, mechanically more efficient and as the servo only has to drive one aileron it can be significantly smaller. If you do this as Ron says just install each servo installation as a mirror image left to right. This way identical servos will work the ailerons in opposition automatically.
From your description I am not quite sure what the problem is using a single central servo. It was certainly how the original was set up. At the time it was common to do it this way particularly as servos were then bigger and heavier.
Now it is more common to use a servos to work each aileron. The servos are now small enough to be easily buried within the wing. The result is the linkage is simpler, more direct, mechanically more efficient and as the servo only has to drive one aileron it can be significantly smaller. If you do this as Ron says just install each servo installation as a mirror image left to right. This way identical servos will work the ailerons in opposition automatically.
#4
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Thread Starter
Join Date: Nov 2012
Posts: 315

Thank you both for the info, the biggest problem is that just about any servo I will use is going to be a tight fit. I've already run into some problems with the size scale. The one provided is exactly one inch , but if it is correct the the wing span should be 32 inches instead of 36 inches. But I managed to make things work, hopefully. The rib height is not tall enough to lower the servo down or it will be sticking through either the bottom or the top of the wing. I am going to cut out a hole, in the side of the rib, and place the servo on its side, and try to reinforce the rib by making some extra ribs out of 1/16th sheet and gluing it to maybe make it some what more rigid. So far it weights right one pound and 7 ounces. but that don't include the landing gear, wheels and covering. Not sure what the motor size is I believe it's one I bought from Heads Up Hobbies before they closed shop. I believe the all up weight will be around 2 maybe 3 pounds. Where can I find the main land gear, it is configured as a trike but I will make into a taildragger. Stay safe out there! One other question, should I add shear webs to the wing spars?
#5
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Location: Lacey WA, 1 mile E of Mushroom Corner
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There are thin wing servos about 1/2" thick, they mount sideways.
Another possible servo sideways is the Diamond D47 they are 5/16" thick, small but good servos, I have 2 in the back of a contest glider, one is built into the rudder.
Another possible servo sideways is the Diamond D47 they are 5/16" thick, small but good servos, I have 2 in the back of a contest glider, one is built into the rudder.