CNC pitch + roll levers.Help.

[Basejump]

When using the CNC pitch and roll levers you can fit the balls with no offset,Unlike the plastic.
This might seem a silly Q, but you have a choice of 2 positions to mount balls.Do you have them the same position on pitch and roll?

[Mikej]

I'm away from home at the moment, so can't take photos - sorry. when you look at the levers you will see that there are two straight lines through the pivot point. One side is top left + bottom right, the other side is top right + bottom left, basically use the pair that gives you the closest to 90 degrees between the link rods and the servo arm.

[worldofmaya]

Hi!
Yes I use the same positions on both sides. But it should make no difference. What you should have in mind is that the line between the balls has to go through the middle.
-klaus

[Vinger]

Check here, has been discussed at lenght. Basically you still have to use offset.

http://www.helifreak.com/showthread.php?t=56972

[mjdee14]

This has been hashed around for a long time...and several have stated due to the front servos working through a different arc than the rear the ofset is required to keep the swash straight...

I recently installed the CNC pitch and roll levers and was unable to get servo wheels for my servos...I installed them straight...I can not visually see any different movement of the swash...and my test flights have proved no different handling...so although it may be needed....it does not make enough difference in my flying to be noticed....so take that for what its worth....( 2 cents)...

Although the CNC can be set with offset..it's not as much as the plastic.

[istandalone]

i've got full cnc, and after trying this both ways i've decided the difference it makes will only be noticed by someone who is an expert or near expert. i've got mine set up now with zero offset on the levers and zervo offset on the wheels. i can't notice any binding what so ever.

[Pinecone]

The CNC front levers can be used with no offset.

Servos work through the same arc. The bellcrank changes the angle.

[bjosko]

In the latest manuals from Gaui, they said that you can use them with no offset.

I found my manual here: www.ezfly.se (http://www.ezfly.se)

On the left side, click on the link named "manualer". There is a description on how to assemble all Gaui CNC-parts.

[worldofmaya]

Hi!
The new manual says different positions on each side. I don't really see why... if you measure it, there's no change which means no bending.
-klaus

[Basejump]

Thanks for the replys.I will go no offset route.
I can not get my head around geometry and thing i can not get is. If the front metal levers need to be offset for proper interaction(as some say) WHY is the ele lever made for no offset only? Being the plastic parts are all offset.

[worldofmaya]

If you have all three CNC levers there's no offset. You should get a parallelogram... if you check it the way Bob describes it with one link and measure at different positions (extremes and middle) you should always get the same distance.
-klaus

[istandalone]

that's one thing i was not clear on, whether i needed 90 degree angles or a parallelogram like you stated. worldofmaya- you put my mind at ease! thanks!

[worldofmaya]

A 90 degree angle is something one should always want to achieve at the neutral position. But even if you have 90 degree as soon as you change your pitch (...) they'll rotate -> parallelogram...
That's why I wrote that I don't understand the "Important" note in the new manual about different position at each lever. If all of your (imaginary) lines are parallel and your rotation point goes through the middle of this line, you shouldn't get a difference in distances between servo-lever balls and everything is fine.
I think an heli is a nice example for how useful mathematics and physics could be :)
-klaus

[Vinger]

In the latest manuals from Gaui, they said that you can use them with no offset.

I found my manual here: www.ezfly.se (http://www.ezfly.se)

On the left side, click on the link named "manualer". There is a description on how to assemble all Gaui CNC-parts.
Look carefully at the option parts installation of the CNC bellcranks and you will see that they indicate to mount the balls at an offset which is in the same direction as the plastic ones. If you measure the offset between the plastic and CNC ones, you will notice the CNC ones to have less offset and that is why the elevator bellcrank now needs to be 90 deg.

As mention in the other post, I set mine up with the offset, and using a bubble swashplate levelling tool, I set the sevos to have a perfectly level swashplate throughout the travel from +12 to -12 deg. Then all I changed was the offset to zero on the front bellcranks and the bubble tool now indicated interaction between the servos, especially near the center stick position, but less at the extreme ends of the collective throw.

Set it up anyway you like, but for my own peace of mind I did it the way it was designed, although I am nowhere near an able flyer to notice it during flight, but my engineering mind is at rest.

[Mikej]

Look carefully at the option parts installation of the CNC bellcranks and you will see that they indicate to mount the balls at an offset which is in the same direction as the plastic ones. If you measure the offset between the plastic and CNC ones, you will notice the CNC ones to have less offset and that is why the elevator bellcrank now needs to be 90 deg.

The manual that you mention says to set the servo arms up without an offset for the CNC levers and if you use the holes indicated for the CNC levers then there is no offset at that end either - i.e. no offsets at all for the CNC. The positioning of the holes for the link balls on the CNC arms is different from the plastic lever arms

"Use the standard 180 degrees servo horn for the CNC parts 204612 and 204614 (no drilling necessary"

[Vinger]

The manual that you mention says to set the servo arms up without an offset for the CNC levers and if you use the holes indicated for the CNC levers then there is no offset at that end either - i.e. no offsets at all for the CNC. The positioning of the holes for the link balls on the CNC arms is different from the plastic lever arms

"Use the standard 180 degrees servo horn for the CNC parts 204612 and 204614 (no drilling necessary"
Look at the exploded diagram, it is clear there. Anyway as I said before mine set up with offset and it flies great. Everyone to his/hers own belief. It makes sense to me, but maybe I am to inclined to investigate why, or maybe it made mathematicall/geometrically sense to me.

[Basejump]

Mikej,
You are completly correct.If you mount the balls on the cnc levers like the new manual states there is no offset for sure.
I just mounted mine and the balls cross right over the pivot point on servo.

[Mikej]

Look at the exploded diagram, it is clear there. Anyway as I said before mine set up with offset and it flies great. Everyone to his/hers own belief. It makes sense to me, but maybe I am to inclined to investigate why, or maybe it made mathematicall/geometrically sense to me.
I think that we are probably just using different terminology or something - here is a picture of one of my CNC arms set up as per the manual - as you can see from the red line the balls are in a straight line through the pivot point - this is what I meant by no offset.

http://www.helifreak.com/attachment.php?attachmentid=41706&stc=1&d=1205362279

[Pinecone]

Agreed, the manual shows the CNC witho no offset.

I wil have to check and see, but I bet the difference in each side will make the lever to the swash at 90 to the link on each side, while the servo horn is 90 to the links from servo to CNC arm. Remember the two front servos are at different heights.