blocks coming into drawings at wrong scale

[Ragtopz]

Hi all, first post and not sure where this goes so i'll ask here.

 

I recently started working at an Electrical Engineering firm and one of my many tasks is to sort out their AutoCad system and bring it up to date! An issue that has only recently started happening is that our blocks don't insert at the correct scale. Some of our drawings are metric and some are imperial, and currently all our blocks are in one Imperial file (reference file for our palettes). Is this our issue, my understanding is that when you create a block you should create it as a wblock and each block should have its own file.

 

The problem is that some of our blocks we want to come in at scale ex/ a 2'x4' light fixture, however an electrical socket or light switch symbol we want to come in at a slightly enlarged scale so that you can easily read the drawing and see where they are located.

 

I did do a search for this problem and tried some of the solutions others have posted but none seem to work!

 

Thank you in advance for your replies!

[BIGAL]

I bet your scale error is 1/0.3048 seen this before its something Autocad does if blocks have been created with settings for feet and then changed to metric or unitless etc You need to go to the source drawing and make sure all the variables are set consistent units metric, insbase pt.

 

Search more here there are some posts to try to solve just can not remember the subject.

[irneb]

Yep, when you have to mix metric & imperial (and even between different units in the same system - like m & mm, or yards/feet/inch) you'll need to setup your drawings' units "correctly" in all instances. Most important would be to use the InsUnits system variable (or use the UNITS command and change the Insertion scale to what the current drawing needs). This is also needed per block inside that drawing, while in BEdit select nothing and open the Properties palette: at the bottom under the "Block" group should be a "Units" property.

 

Then after this you'll need to also decide what you're going to do with hatches & linetypes. You either need to keep your MEASUREMENT system variable consistent throughout all your drawings and play with scale factors to suit the differences between inches and mm. Or set MEASUREMENT=1 for metric and 0 for imperial, though then you end up with problems when using xrefs.

[ReMark]

Mixing metric and imperial in the same drawing is just asking for headaches. If your clients are on both sides of the pond why not set up two distinct protocols (templates, blocks, linetypes, etc.) and put these on custom toolbars labelled METRIC and IMPERIAL?

[Ragtopz]

Sorry perhaps I should have been more clear, the blocks themselves have all been created in one imperial cad file, however when we go to insert them into another cad file (drawing file) whether it be imperial or metric they don't scale properly. We just deal with the electrical component, its very rare that we actually draft the building we are working on, quite often we get a DWG file from the client or architect, some are imperial, some are metric. One idea that was bounced around the office was to create two sets of blocks, one in imperial format the other in metric. This seems a little overboard to me as there must be a solution without having to do that!

[nestly]

If your blocks have units properly assigned, and your drawing(s) have INSUNITS properly assigned, Imperial blocks should scale properly when inserted into a metric drawing, and vice-versa.

[irneb]

Yes, here's the scenario in your experience:

 

Your block (let's say it's the symbol for a 15W downlighter) is drawn in inches and it's Units property is set to Inches. If it's not set to inches you'll have to adjust manually each time you insert it, so fix your blocks if they're not already correct.

 

Now you get the Arch's ceiling plan and you place your downlighter at the relevant position(s). Say the Arch drawing was done in mm. If that dwg file's InsUnits=4 (i.e. the Insertion Scale in the Units dialog=Millimetres) then your block will automatically be scaled up by a factor of 25.4. If you get an Arch DWG drawn in cm (there are some placed in Europe where this happens) the factor will calculate to 2.54. If so some "strange" reason the Arch decided to draw in yards ... then the factor would be 0.0277777778 (1/32). But as long as the Insertion Units are set correctly, you don't need to calculate these factors yourself - ACad reads them from the ACAD.UNT file.

 

Actually in your case I'd go with a different setup: I'd have my drawing simply xref the Arch DWG into it. My drawing can then be set to inches (or whatever my company's standard is). Then I only have one conversion to worry about ever! I.e. the scale factor for the Arch dwg ... again if the InsUnits in both are set to their relative units I won't need to worry about it at all. But the "nice" thing about this is my blocks would normally come in with a scale factor of 1.0 ... as normal! Thus I can always draw in the units I'm familiar with, without worrying about other's dwg's. Added benefit would be that updating the Arch DWG (when they issue a revision) becomes a simple task of saving the new revision over the old file (no need to isolate and erase and then copy-n-paste). If you do go with xref, then at least do a setbylayer "cleanup" on the Arch DWG (both colors & linetypes) ... this would save you huge headaches later.

 

One thing where it becomes a pain about mixing imperial with metric, is usually the metric dimensions become "strange". E.g. say a passage width of 4' is drawn ... this translates to 1219.4 mm which should rather be rounded to 1220 mm. The other way round ... 1200mm (which would be a "normal" metric dim which would be used) becomes 3'-11 1/4", even 1220mm -> 4'-0 1/32". And (especially in metric) rounding errors can cause embarrassment as well, so simply setting the DimStyle to round to closest 10mm chases the problem to places where you don't easily see the error.

[Ragtopz]

Brilliant irneb! thank you very much for the insight! I will have to try this on our next job and see how it all works out!