Drawings with "nominal" dimensions

This isn’t exactly a Rhino question but Googling has so far not told me anything.

I’m having a bit of trouble with drawings and spec sheets for products for a client. Whoever is in charge of these things doesn’t like seeing any nasty old fractions on the dimensions of products, which is a problem as they were designed in Metric(and even if they weren’t they’d have round numbers between critical centers not overall…but I digress.) They want all numbers rounded UP to the nearest inch. Not rounded off, rounded up. Which I think is a bit ridiculous, but if it was just on spec sheets I wouldn’t care, but they want the same numbers on the “actual” product drawings, which it’s entirely possible someone might use to verify they’ve put the thing together correctly. That is what they’re FOR. Most of the time it probably doesn’t matter, these things are big and assembled by people who might look at the drawings if we’re lucky, but it could absolutely cause trouble at point and it complicates maintaining the documentation just because someone thinks fractions will frighten their customers.

So I’m wondering how (according to US drawing conventions) I’m supposed to note the difference between the “actual” numbers and what marketing wants them to be? And/or, looking for ammunition to torpedo this nonsense and get back to actual product development.

I absolutely dont envy you. This whole mess started century ago when us decided not to go for SI :frowning:

but if you need to automatically replace all the dimensions in your rhino document i would use grasshopper for the job. Load all dimensions, extract values, do whatever you want to do with them (convert and round up) and bake it back

You should be able to do this with a custom dimension style. In the following example the dimensions are rounded up nominal but the true sizes can be seen in the Boxedit window:

The style used is a modified copy of the feet and inches architectural style - changed in the highlighted cells:

If you want to adopt this, I recommend some in-depth testing as I’ve only tried it with the trivial example illustrated.


p.s. Don’t forget that you can turn on alternate units and show both true and nominal dimensions on the same drawing.

p.p.s. I realise this is not anti-nonsense ammo - sorry!

EDIT: After more testing, this only works for some values, so ain’t a solution after all.

Thanks…you CAN set it to round up always? Huh.

@JimCarruthers - Just to clarify, you want 6-1/4" to display as 7"? Is that right?
I don’t think there’s a was to make that happen by adjusting a few settings.

Yeah I don’t “want” to but that’s what I’m being asked…


The bad news is that after some more testing my “solution” only works for some values - i.e. it isn’t a solution.

The good news is that this is anti-nonsense ammo!