topic Re: Locking dimension reduces dimensional accuracy & value in 3D Part & Assembly Design

Locking dimension reduces dimensional accuracy & value

JB_9361288 — Tue, 25 Mar 2025 15:05:53 GMT

Creo Parametric 8. When an unlocked dimension is toggled to lock, the dimension automatically changes accuracy to be 2 decimal places, and also appears to round the original value to the rounded value. This is causing large unintended geometry changes. Is there a config.pro setting or other setting that can be modified to fix this? The list of options I've already modified is below:

default_dec_places

live_dim_precision_decimals (appears to have worked for linear dimensions but not radii)

default_ang_decimal_places

Re: Locking dimension reduces dimensional accuracy & value

pausob — Tue, 25 Mar 2025 15:44:23 GMT

Not sure, because I believe the behaviour you are seeing is governed by several options. In your system, what is the state of the option "sketcher_strnghtn_to_def_dec_pl":

The other one comes to mind is the option "round_displayed_dim_values"

Re: Locking dimension reduces dimensional accuracy & value

tbraxton — Tue, 25 Mar 2025 15:49:51 GMT

This is unlikely IMO. Just because what is displayed changes, it does not guarantee that the value of the dimension is altered by locking it. It also appears from your pictures that you are observing the "change" in sketcher, please confirm this (your post is labeled 2D drawing). Is this a drawing issue or a modeling issue?

Check this first (not in sketcher mode):

You can lock/unlock the dimension of the feature using RMB after selecting the feature for modification (this will show the dims) the graphics window.

With the dimension locked and unlocked, query the value using the relations editor. They should produce the same result regardless of lock status. If the value is the same for locked and unlocked, then Creo is very likely not changing the value of the parameter, just what is displayed. If you find evidence otherwise, report back.

I have this dimension set to be rounded to 6 decimal places.

Re: Locking dimension reduces dimensional accuracy & value

JB_9361288 — Tue, 25 Mar 2025 16:46:27 GMT

I can confirm that locking the dimension does change the value, confirmed using the relations method described. Below images represent before locking and after locking. Generally I have my tolerance to 4 decimal places - in this case it is rounding it to 4.

I should note that a workaround is to copy the original unlocked dimension value and paste it in directly after locking to revert it. In my use case I am trying to lock a large number of dimensions at once, so trying to avoid doing this for every single one.

Re: Locking dimension reduces dimensional accuracy & value

JB_9361288 — Tue, 25 Mar 2025 16:50:18 GMT

sketcher_strngthn_to_def_dec_pl is set to yes

round_displayed_dim_values is set to yes

Re: Locking dimension reduces dimensional accuracy & value

tbraxton — Tue, 25 Mar 2025 17:50:11 GMT

Interesting, you might be on to a potential issue. I am testing this in Creo 9. This is a sketcher dimension as denoted by sd1 in your testing. Would you try locking this dimension at the feature level (assuming it is possible) and evaluate the values when locking the feature dim rather than the sketcher dim? I want to see if locking a feature dim behaves differently.

In the relations editor the look in would be set to "Part" and you would lock the dimension of the feature that is controlled by sd1 in the sketch.

Re: Locking dimension reduces dimensional accuracy & value

tbraxton — Tue, 25 Mar 2025 18:25:18 GMT

I have found a support article that may be relevant. There is an SPR assigned with no plans to fix.

Article - CS208421 - In the Sketcher, Dimensions with Round Display Value switch on when using Lock menu, values are losing some decimals in Creo Parametric 2.0

Do you have the round display on for the dimensions in question? Check the trail file output immediately after locking the dim. If you see this message, then it is likely the same issue exists in Creo 10.

In the Trail, when locking the Dimensions, the message The selected dimension value will be preserved. is displayed

Re: Locking dimension reduces dimensional accuracy & value

pausob — Tue, 25 Mar 2025 18:48:00 GMT

Seems you want to set

sketcher_strngthn_to_def_dec_pl no

I'm on Creo 10; with the above setting, then my system no longer rounds a weak dimension has many decimal places to something that is based on the current value of default_dec_places setting.