Disobeying dimension

robert_scott_jr_

Hello all. I'm in the process of learning to utilize variables and configuration tables. My project is a cable gland based on cable diameter. I've come across a glitch I need to solve before I can move on. Up to this point values of the part (body) follow the configuration selected (which is 7mm) except for the dimension from the centerline to a vertical line in the sketch 'compression rib'. The value assigned is (#I_D/2)+.5mm which should be 4mm but the resulting value is 3mm. I have the suspicion that the order of my build is wrong. I've spent too much time going over this suppressing features, deleting constraints , etc. to discover my error with no success so I've come here to seek help as to where that error is; I'd appreciate a bit. - Scotty

https://cad.onshape.com/documents/11e94c9f875850279820af10/w/caaa081c9cc3444e7f739246/e/9d3d5f72fb3416aa64299c0b

_anton

(#I_D/2)+.5mm should be 3mm because I_D is 5mm (and unconfigured). What is I_D? Should that be the cable diameter?

robert_scott_jr_

Yes

glen_dewsbury

Here's a sample of working with configs. Hope this helps. Change configuration and see cable plus gland profiles update.
https://cad.onshape.com/documents/044b2e03ce23f977ae9034ad/w/783efb8244ac9be1cc100338/e/637a137923b82858f326e0f7

_anton

Sounds like, if the config switches between different internal diameters, and you need to use the ID in multiple places, you should configure the feature (just open the feature defining the ID, and right-click-configure the value). Then the variable is the authoritative ID and its value will change as you change configs.

robert_scott_jr_

_anton

Unless I misunderstand you, I believe that is what I have already done since the part's bore(#ID) changes with configuration selection.

glenn

Yes, I follow you there but I keep thinking that there is a way to enter an expression that would automatically follow the #ID.

Thank You both for responding. - Scotty

glen_dewsbury

@robert_scott_jr_
Is the ID (identification or inside diameter?) that of a common size fitting with different wires that will pass through? IE the gland fits in a common punch out. If there are different sized fittings then I would think the nominal size or designation would would be a convenient start point. From which the inside diameter can be associated according to wire size with that when selected then other dimensions can be calculated from that. Sequence to assign variables is important and watch your formatting in the configuration table.
#xx+3mm  Note the "mm" formatting for 3 in the table. Gives an error with out. Any time a dimension is calculated, formatting is important. There are several detailed posts on the subject from previous that are worth looking up.
https://cad.onshape.com/documents/044b2e03ce23f977ae9034ad/w/783efb8244ac9be1cc100338/e/637a137923b82858f326e0f7

robert_scott_jr_

glen

ID is inside diameter. The body outer thread diameter will vary according the ID so the punch out will follow suit. Unless I find the need to change it, I expect that to be the ID+ wall thickness which is now 2.5 mm.

- Scotty

glen_dewsbury

@robert_scott_jr_
Try this sample now and see if it helps. The wire ga is selectable with other dimensions that are calculated. I like named variables even though it's not a requirement because the name is applied to to column headers instead of repeating 'length' & 'dia' as header names.
Your table uses #I_D as the first entry with the rest of the column filled in manually. This column should all be filled in manually to make a selection. Note. The whole column in sample refers back to #I_D. That's why you're not getting changes down stream.
Hope this sample helps. Gotta hit the sack.
https://cad.onshape.com/documents/044b2e03ce23f977ae9034ad/v/d5c52146711435c82ccafde4/e/637a137923b82858f326e0f7

Cheers, Glen

robert_scott_jr_

Thanks Glen but did you post the correct link?

glen_dewsbury

@robert_scott_jr_
Looks like it opened at an old version. Just need to go back to main.
I was looking back to see the original intent. 
https://cad.onshape.com/documents/044b2e03ce23f977ae9034ad/w/783efb8244ac9be1cc100338/e/637a137923b82858f326e0f7