RC Constrains

Hi,

Does anyone how I can constrain my wing, so that when the servo moves 90 degrees clockwise the aileron goes up and when it goes 90 degrees counterclockwise, the aileron goes down?

Probably best to use a rotational constraint...

Here is a simple example but you get the idea:

Use the pivot points on the servo and the aileron hing point for your rotational axis.

This constraint cannot be driven so you'll have to use another constraint probably angular to drive it...

KC

What if I have my servo on the wing and I have a wires and parts connected to the aileron? No matter how hard I try the aileron doesn't go down. I attached the files so you can better understand it. Just extract and combine into one folder.

What if I have my servo on the wing and I have a wires and parts connected to the aileron? No matter how hard I try the aileron doesn't go down. I attached the files so you can better understand it. Just extract and combine into one folder.

I don't have 2010... Maybe you could send a screenshot where exactly the problem is...

If it's linkages, then it's, (possibly), even easier. Have you check that the aileron is not constraint in another location or possibly grounded...

KC

something like this maybe:

You are missing several constraints. Think about the real world connections - I would forget about the motion for now and get your parts properly connected.

I just opened your assembly file, It doesnt make the aileron go down because of physical limitations, nothing to do with your constraints( sort of). But your bracket on the aileron isnt located, its floating on the surface. You can see from kencaz's picture that your actuator arm needs to be at 90degrees. Also your aileron is free floating on the back edge of the wing. You need to make sure each component only has degrees of freedom where it should. Also at the aileron you only have 1 rotational degree of freedom, at the actuator you also have one but its in a different axis, you actually need 2 here or the linkage binds.

If your using linkages then you could benefit from using adaptive sketches to get your linkage lengths...

You can then use that data to extrude the linkage itself.

I have not seen your assembly so I am just guessing here but this is a good technique that you can adopt for other assemblies as well...

Good Luck...

KC

Ken, other than what jd pointed out of just missing constraints, his issue is that at the aileron the linkage needs to move left/right as well as up down with a mis-alignment bushing like a spherical bearing. If he were to apply the proper relations to hold his brackets everything would be fixed with no DoF.

Here is a screen shot of his assembly. The second image shows how the bracket moves on the aileron.

your actuator arm needs to be at 90degrees.

Yeah I think adding a true ball joint to each side of the arm would help with the alignment and failed constraint problems.

Thanks for uploading the screens...

KC

Would you add a ball link to the one circle in the picture or to the smaller holes? and How do you use adaptive sketches?

The ball joint that kencaz showed, i would add one to each end of your rod. Instead of using the clevis on the aileron side.

Also you need to locate your bracket on the aileron. When i was messing with your file to locate it i drew two holes in the bracket and two holes in the aileron an "bolted" them together.

i would add one to each end of your rod. Instead of using the clevis on the aileron side.

Exactly... a ball on each end of a threaded rod (just like they do irl). You can always adjust the rod length from the sketch to match the servo and aileron positions. That's probably even easier then using adaptive sketches which can be tricky...

KC

So like this on the servo and one added to the clevis and then I'll make the wire?

What you want to do is leave your actuator arm alone and your aileron bracket alone. You want to have a rod as a single part, then you want to add rose joints, ball ends, heim joints(they go by many names).

These joints allow misalignment. I wouldnt add it where you have indicated.

Does anyone know how I can make a straight wire from the actuator arm to the control horn?

Okay, I created the rods but I'm still a bit confused on the ball link or whatever they're called. I'm still not sure where you mean to put them.

Okay, I created the rods but I'm still a bit confused on the ball link or whatever they're called. I'm still not sure where you mean to put them.

Looks pretty good so far...

I think most RC'rs use Rod Ends instead of ball joints they are a little more rigid, however, they may be a little heavy if you have a light plane... I have seen a lot of simple nylon joints that probably work just as well.

Do a google search there are lots of examples...

Good Luck

KC

Okay so I made the ball link, it's a little too big so I'll adjust it. And so basically I just attach it to the clevis and all my problems are solved?

Well your rod still has a 90degree on the end, you need to loose that and have the rod only be straight. Then put a rod end on each side and some of your problems will be solved. You still need to located your bracket on the aileron, which by the screen shot looks like you have modified already.

The big difference in the last picture kencaz posted is the actuator. You can see the actuator and the bracket are both pivoting in the same plane. Your file has them in different planes which is why you need these rod ends to take up mis-alignment. If you change your actuator to be oriented like the one in the picture you could use it as is.