Linked dimension?
Linked dimension?
(OP)
When sketching I like to set things equal about the origin so that when the part is formed the planes are in central positions. So, if I want a rectangle with a total height of 100mm, I'll constrain it by dimensioning the total height at 100mm then dimensioning 50mm from the origin to the top/bottom, thus placing the origin in the middle of the sketch.
What I'd like to do is simply link the dimensions so that if I come back and change one value, the other changes. So in this instance, my first dimension is X, and my second dimension would always be X/2. Possible without more effort than typing in?
I know the rectangle is a bad example because I could draw a centre rectangle, but hopefully you know what I'm getting at...
What I'd like to do is simply link the dimensions so that if I come back and change one value, the other changes. So in this instance, my first dimension is X, and my second dimension would always be X/2. Possible without more effort than typing in?
I know the rectangle is a bad example because I could draw a centre rectangle, but hopefully you know what I'm getting at...






RE: Linked dimension?
RE: Linked dimension?
I guess this is a bit of a habit more than anything, but I seem to find myself doing it a reasonable amount. My ideal would be when I've dimensioned and the value box comes up for dim no.2, being able to click dimension no.1 and then add /2 and hit enter. I tried it thinking it might work because you can populate tables in this manner but unfortunately it doesn't :(
RE: Linked dimension?
mncad
RE: Linked dimension?
RE: Linked dimension?
Heckler![[americanflag] americanflag](https://www.tipmaster.com/images/americanflag.gif)
Sr. Mechanical Engineer
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RE: Linked dimension?
(Also, if everyone exposed to SolidWorks creates parts in the same manner - troubleshooting or editing the part is made significantly easier.)
RE: Linked dimension?
Also, I disagree with Nella. I firmly believe keeping the part centered about the origin, or as closely as possible, is a good rule of thumb. I can remember opening models, then zooming to fit, only to find that the model was some vast distance from the origin. I think centering just makes things neater.
Jeff Mirisola, CSWP
Design Manager/Senior Designer
M9 Defense
My Blog
RE: Linked dimension?
Another option would be to use the "center rectangle" option from the drop down menu in the sketch and mate the center to the origin.
RE: Linked dimension?
RE: Linked dimension?
RE: Linked dimension?
RE: Linked dimension?
I vote for the diagonal construction line, centred on the origin. Alternately, you can draw a centreline, and impose symmetry around it.
Usually, I try to model my parts from the datum edges. Much of the time, when I prepare my drawings, I use some other edge as the datum.
RE: Linked dimension?
Sometimes it gets frustrating, when working with someone else's model, trying to figure out why you can't move a line, and then you find that it is constrained to some other feature in a way that isn't intuitive to you.
RE: Linked dimension?
Firstly, a star for mncad (I know others have offered the same tip but you were the first) because I think that'll be the winner for me in normal use. Other comments mention increased use of constraints too, so will give it a shot.
Nella95 - because I work in a bureau, our models go out all over the place, and we send everything to our clients so that a) if people want to go elsewhere they can (although we hope they think we do such a good job that they come back to us
Also, lots of the things I model are very likely to need a 'tweak' at some point. Clients often only know exactly what they want when you show them something very close to the finished product (this isn't a problem or a moan - it's why they employ me as a design engineer!) so pragmatic modelling makes my life easier down the line.
JMirisola - Perhaps a bad example using a rectangle, but I just wanted a simple illustration of what I meant. Re. an assembly miles from the origin, that would drive me INSANE. Toys out of the pram insane...
ArtL - that's what I aim for. I also drive some features (holes are a regular) with features from earlier parts. Let's say you make your engine block part 1 and mate your heads to it. If for some crazy reason you want to shift the position of one of the bores, it would be handy for the combustion chamber in the head to remain aligned with the bore. Maybe.