Question about trap2.moveby()

[watters16j]

Is there an estimate for the error for the different traps moving in different directions?

For example, when I call trap2.moveby(dy=-7,speed=1), pause, and then call trap2.moveby(dy=7,speed=1) the trap is not in the same place as the starting point. For me to get it to align I have to multiply the return motion by 1.36 (so 7*1.36 instead of 7) and I would like to know if this is normal behavior/if there is a better way to plan around this than trial and error?

Thanks for any advice you can provide.

[eugeniocataldo]

Hello,

Thank you for your question.

Trap 2 is indeed the "less precise trap", without closed loop (i.e. it doesn't know its absolute position and it can only do relative steps). There can indeed be some non-repeatability in the steps, especially when changing directions.
The ways to work around it could be to either use trap 1 or trap 1+2 (which both have an absolute readout of their position). Alternatively, if you really need to use trap 2, you can take small steps and use the bead tracking in a feedback loop, which is something you would need to implement yourself via ctrap scripting.

As a side note, we don't actively monitor the comments in the GitHub project. If you have any questions or suggestions, it is handier for us if you send them to support@lumicks.com, so that you can get a quick answer and we don't risk losing your question. Please also direct there any possible follow-up that you have to this question.

Kind regards,
Eugenio