Thanks for the answers tig and blruuska!
Yes it's tricky to change these parameters.
specially when ther are no documentation.
I have tried to use _lenx_formula and ended up with unscalable components because
lenx is stored as '=value' and not value.
If i manually put in a value and not a formula it is stored back without "=" inthe formula field.
so there should be a way to do this in ruby.

For other attributes i created myself, i managed to go from formula back to just a value
but for default attributes like lenx this method is unusable.

I have now spend days trying to turn every stone on the web.
And found out that there are many developers stuck with the same result.

Maybe i cold use transformation and scale for the length.
but i would still not end up with an exact value.
Because scale is % of length and values are internally
stored in inch and not metric the result is that i end up with a lot of decimals.

I don't see that it's specially related to dc
I think its more a developer issue that you are not able to change x, y, z position and length of an object dynamic or not
you are able change everything else as layer, material an so on.

I hope that somebody can give me a solution or maybe I need to send an change request to the developer team of sketchup.

please can somebody tell me if there is a solution for this
or does i have to make change request to the sketchup developer team?

How do i change the length attributes lenx, leny, lenz to a value without using a formula.
if i use the set_attribute('dynamic_attributes', '_lenx_formula', number)
the component will not be scalable anymore

How do i change the length attributes lenx, leny, lenz to a value without using a formula.
if i use the set_attribute('dynamic_attributes', '_lenx_formula', number)
the component will not be scalable anymore