can linear actuator clutch be glued/removed?

[vascolp]

 

44 minutes ago, Davidz90 said:

No, they are tied to a common crankshaft, you cannot move them to 0 separately. You only need to manually check that LAs are not pushing/pulling on the crankshaft (so their positions are exactly matching the intended one) and determine the exact angle of crankshaft.

Even so, you could try to do it electronically instead of, well,… destructively!  
Are you using pybricks? In pybricks there is the run_until_stalled() method which should do it for one LA, as @Lok24 explained.  Your problem is having more than one LA. But, the run_until_stalled() is just a convenience function that does this (check it here):

my_motor.run(speed)
# Wait until it is stalled
while not my_motor.control.stalled():
    wait(10)
# Stop the motor (you can also choose brake or hold here)
my_motor.stop()

This could easily be converted to two or more motors, so the LAs would move all at the same time and LEGO tolerances would do the rest (as long as your starting point is not very different on each LA!).

If not in pybricks, there should be some similar solution?

Hope it helps!

Edited September 16, 2023 by vascolp
typo

[Lok24]

As far as I know the Liebherr 42100 has LA too, and I think it does exactly the same.

(without glue ;-) )

You can do that with the powered App as well.
I'have shown many examples here.

[glowytheglowbug]

3 hours ago, Davidz90 said:

Yes, and that's why I think that the only way forward is to figure out a driving algorithm that actually alows for some slip/elasticity and doesn't accumulate error but instead uses that elastic feedback to self-correct.

mhm i actually did think of some way to use a force sensor on each linear actuator to sense which position it was at, then realised its not rlly able to be done easily and is expensive as heck

[Lok24]

14 minutes ago, glowytheglowbug said:

to use a force sensor

Then you have just 8mm to move button of the sensor.

As I understood till now:
- you want to move the LA precisely
- therefore you move it by a motor in steps of x degrees
- reading the number of rotations from motor gives you the position
- or just add all steps form the beginning

the only problem I see to get the zero position

Is that correct so far?

Edited September 16, 2023 by Lok24

[glowytheglowbug]

8 minutes ago, Lok24 said:

Then you have just 8mm to move button of the sensor.

As I understood till now:
- you want to move the LA precisely
- therefore you move it by a motor in steps of x degrees
- reading the number of rotations from motor gives you the position
- or just add all steps form the beginning

the only problem I see to get the zero position

Is that correct so far?

this is the current code for my linear actuator engine (this is for the small one) 

 

[Lok24]

Oh, thanks.

A hint: You could variables and "my blocks" to make it easier to follow the code.

[glowytheglowbug]

4 hours ago, glowytheglowbug said:

heya woah theres a ton of replies, i dont have any formula for calculating speed or anything and my current code is quite simple, it uses david's formula to set all motor's relative position and then i make motors go to a certain relative position based on the output shaft angle + 5 degrees

main reason for gluing the la clutches shut is if they slip too much they basically will not go over the dead spot in the engine and thus try to oppose motion, breaking itself

 

4 minutes ago, Lok24 said:

Oh, thanks.

A hint: You could variables and "my blocks" to make it easier to follow the code.

probably should have done that buy anyways the basic logic is there
problem is it is kind of a stuttering engine (and the code does not work)