Constraaint issue Alibre atom

[justisla]

I am a new DIY user so please be gentle
I have drawn a shaft with a woodruft key slot each end. The ends of the shaft are smaller diameter than the main shaft so shoulders are formed near each end
On to each end of the shaft I want to put an arm such that as the arm is rotated one end the arm turns the other end. Each arm will have a woodruff key slot
I have located & constrained one arm to the shaft using the face of the smaller part of the shaft & the inner face of the arm. That lines up the with the axis of the shaft.
Then I used the face on the end of the shaft & the outer face of the arm so that when they are aligned the arm sits on the shaft.
I have also tried using the shoulder of the shaft & the inner face of the arm, so that the arm is pulled tight to the shaft.
I did originally construct & use concentric axis of both the shaft & the hole in the arm but changed after I could not get the arm the right way round ie it went on upside down. I could not work out how to turn it over --Grrrrrrr!!!!!
So far so good
Now I can rotate the shaft. I can rotate the arm. But the 2 are not tied together. So I thought that I could use some sort of constraint to tie the 2 woodruff key slots together. That would be a third constraint. But I just get an "over constrained" pop up all the time.
Whatever I do I cannot tie the arm to the shaft & then continue to move the arm from side to side so it rotates the shaft ready to rotate a similar arm arm the other end of the shaft
How do I lock the arm to the shaft & maintain the rotation of the shaft & arms?
Thanks

 

[Ex Machina]

I am not sure I completely understand what you're after but as a general tip I would say, do not use coincident constraints if you can only use an angle constraint with a 0 or 180 degree value. That will avoid some over-constrained warnings.

Now, it might help us if you create a package (File-->Package) of the assembly and upload it here so we can work on the file and perhaps give you a finished assembly back.

 

[DavidJ]

Either

Option A : right click the shaft and 'show reference geometry' - then apply a free offset (parallel condition) between suitable reference plane of shaft, and one side of the lever (or use its refence geometry)

Option B: apply free offset between side face of woodruff slot and a side (or reference plane) of the arm

Option C: constrain side face of slot in arm to side face of slot in shaft (unless dimensions match perfectly, a free offset is probably still best option).


Over constrained is a common thing to see. Can sometimes be avoided by using an edge or a point in place of a plane as one member of a constraint pair (it is less restrictive).

A free offset (parallel) is less restrictive, and is tolerant of slight mismatches of dimension that a co-incident constraint will fail with.

 

[GIOV]

Please, this subject is into "Using Alibre Design".

 

[justisla]

Apologies
I will take care -IF- I post next time
I have tried the methods suggested by David J but not entirely successfully
So I decided to just draw a shaft & use his 3 methods & they all work. So that suggests a problem elsewhere in my assembly.
I will just work my way through it & find out why. Sometimes I can get the arm to rotate the shaft & sometimes not.

I have watched the you tube video on assembly but it is not really solving my problems. However, I am not giving up. I think that it is more a question of familiarity
Thanks for help so far