Units vs. Unitless
Comments(14) I am trying to understand why companies use the “unitless” insertion scale (UNITS, INSUNITS) in their drawings as a standard. I’m sure there are uses for it, but I am having a hard time understanding. If you set your drawings to “unitless”, leave a comment here and tell me your reasoning.
My argument against going unitless is that when setting your insertion scale to “unitless” there is always an implied unit used. For example, when you draw a line 3 units long, you are implying some kind of unit. How long is 3?
Another argument against going unitless is that you lose the ability to automatically scale XREFs and blocks that use different units. This is a very powerful feature in AutoCAD now.
I say, if you are creating a drawing in feet, set the insertion scale to feet. If you are creating a drawing in inches, set the insertion scale to inches. This way if drawings with different units ever need to be XREF’d together, AutoCAD will immediately know how to scale them.
Let me know your thoughts.
I suspect it’s either legacy behaviour or ignorance. A bit like drawing in metric without using iso linetypes…
It’s because the units for civil drawings is "Decimal". This implies a unitless drawing for insertion. But I suspect the problem is just a widespread in architectural unit based disciplines.
It more legacy behavior…there are a few blocks libraries and details that haven’t updated in sometime…
my experience is that there are two reasons:1. users that are unaware of how the units and scaling functions work2. companies that deal with many drawings from other firms or use drawings created with much older versions of autocad that can’t be controlled accordingly.
I agree with the other posts here. Legacy drawings is the primary reason for setting the default to 0. The insunits variable has been around for a long time but wasn’t used for anything. Suddenly (2006 I believe) AutoCAD started using this for scaling purposes. Rather then going through and fixing hundreds (if not thousands) of drawings, it was easier to simply set the default to 0.
Dear all,I believe that there is a good use for INSUNITS = 0,but there is another two system variable will work with it :1- INSUNITSDEFSOURCE2- INSUNITSDEFTARGETyou can use them to control automatic scaling for BLOCKS , XREFs. we need it some times to automatically insert blocks in another units sittings. for instance you can set INSUNITSDEFTARGET to 5 (Centimeters) and INSUNITSDEFSOURCE to 6 (Meters) .so try it and watch what will happened.Thanks,
I have experience of dealing with professional architects who draw to a predetermined scale in model space; ie. 1:50 or 1:100 so that the subject will fit the screen. There is still widespread ignorance of the benefits of CAD amongst the old school who have not made the full transition from paper to CAD. This is before we even get close to examining why correct selection of units is made.
The problem solely stems from Autocad users being based in a world that draws straight lines and by people that think the world is flat and has no third dimension (not z but height above and below a dutum). From a survey perspective we have to draw both in metres, millimetres, inches, feet and yards, and then any other unit some ……drafter invents. Unitless allows us to survive and be sane in the ‘real world’ . You try to come across sometime it is a far better place! And yes we do know about all those ather commands!
We use unitless due to a piping overlay using it. If the units are set to anything other then this it will blow the inserted objects out of scale.
We use unitless here at our civil engineering company. We tried for a while to set our drawings to 2 (feet), but it turned out to be a nightmare for us, as we get data from all kinds of entities, constantly import data from shp files, frequently reference in old drawings & have a huge library of municipal data we reference in as well. To make it work, we would have to change ALL of our reference drawings to INSUNITS 2, and I just can’t see that that would be time efficient. Keeping our drawings unitless is a sure bet for us, where as setting the units constantly required detective work to figure out how to get data to reference in correctly, which gets old pretty quickly. Or am I missing some key piece of information here? Please let me know, as I am curious!
i think it is easier and even safer to setup units in your drawings. that way you always know that things are going to be in the right spot. havent really had to deal with too much referencing of external files but only realy internal surveys on structural drawings etc but it only takes 2 seconds to type in units then select the appropriate one. theyr my thoughts anyway!
Would appreciate someone’s help on this,
Reading the previous, I can understand individual reasoning but it hasn’t really helped resolve my own current problem. I most frequently do precision engineering so familiar only with mm. Now have modelled (2D) building site in feet. I think my first mistake was believing format units were model units, because after failing to insert the drawing frame template I modelled in mm, at correct size, I realised the units setting in ‘Format’ is meant for scaling inserted content, so I’ve reverted that back to mm, corresponding to the block drawing of drawing frame. Now the block inserts into Layout 1 at correct size & when I create a single VP filling drawing frame area that looks ok too, but when I interrogate the VP it indicates the custom scale is 0.64 (1:1.56) when I am expecting 0.002 (1:500) so I am asking two questions, why do I have this unexpected scale & not so importantly, why is scale in ‘properties’ expressed differently to the menu (ie. 0.64 & not 1.56)?? I’m slipping a third in! Is there any place the model units need to be inserted, or are they catered for only in dimensioning set up?
Just wanted to give a thank you to Imad Habash VERY helpful and solved my problem!
For me I pefer to use unitless as a standard because of the lack AutoCAD expertise in the other users in the office. It’s hard enough teaching them how to properly use layers, let alone them remembering how to set units properly in the drawings and the variables that go along with that. Most of them don’t even know how to scale a drawing from Metric to Imperial or which scale the drawing they are working on is at. Until I implemented unitless as a standard all the drawings/blocks/xrefs were incorrectly setup, very mix and match when it comes to in and mm.