Block Scaling too Large

One of my colleagues reminded me of an age old problem I have encountered several times and never got to the bottom of, when inserting a block it scales to a strange size and doesn’t fit to the page.

This turns out to be yet another setting between the “American Imperial” measurement system and the “International ISO Metric” measurement that exists in AutoCAD.

It turns out that changing MEASUREMENT setting to 1 (metric), from the default of 0 (imperial) only changes the way hatches and linetypes scale and not the inherent way the drawing works. The underlying unit scale of the drawing is governed by other setting. So old drawings created when out-of-the-box AutoCAD defaulted to imperial might still have all the old settings.

DWGUNITS command line options
DWGUNITS command line options

The option in question is DWGUNITS. It appears that the default is 1, which is inches. This is why a block drawn in a drawing using DWGUNITS of inches is inserted into a drawing set to mm scales to a differing scale!

As an aside DWGUNITS also sets linear display precision, which is also set by LUPREC.

The options after DWGUNITS is typed appear in a pop-up command line box for easier reading, they are as follows:

Unit for length:
This is the overriding base setting between metric an imperial, here we note that the original setting was 1 for the block template and we changed it to 3, which is the system we use in the office.

Linear display format:
This changes the output reading for items like DISTANCE from 2000.000(decimal) say to 2.000E+03 (scientific). I find the decimal easier to read so we will select 2 here.

Linear display precision:
This governs the number of decimal points in the output reading for items like DISTANCE. 0 gives a measurement of 2000, 1 results in 2000.0 etc. I tend to leave this at 3, but this is personal preference. (LUPREC system variable also changes this setting, and is also found in the dialogue box after typing UNITS, found under menu –> FORMAT –> UNITS).

Scale objects from other drawings upon insert:
This is the one that makes the drawings scale from one unit set to another. I have left this as YES as it will highlight any other blocks and drawings that might not have been set to mm in the first option. Otherwise the block will be inserted without scaling and the error persists.

Match INSUNITS to drawing units?
INSUNITS is another option to scale BLOCKS on insert. It is best to say yes here so they do match, otherwise errors could occur!

Scale objects in current drawing to reflect change in units?
This one you need to say no to. The reason being is that you have drawn a line that is 2000 units long, and in this case before changing the DWGUNITS this would have been interpreted as 2000 inches. AutoCAD can scale the drawing (which is sometimes useful when say changing from a drawing that was actually drawn in inches to metric) however in this case you want to preserve the “2000 units” as 2000 and just change the unit type from inches to mm.

Then the drawing and block drawn in the drawing will be compatible with other drawings drawn in mm.

Please note that DWGUNITS and UNITS are completely different commands.

Please also note the DWGUNITS command is undocumented in AutoCAD both 2013 and 2014 help, it might be present in previous versions but probably need to go back many years to obtain anything!

Dimension Tips

As always in AutoCAD there are numerous ways to do the same thing, mainly due to the way the program has matured over the years. Items that existed way back in R12 are still there in R19.1 (2014), even if they have been replaced with a “better” implementation. These legacy options can sometimes be useful and also if you are encountering a problem its likely that something has been drawn using an older method that in not compatible with newer options.

Dimension without any text added
Dimension without any text added

Take for instance text suffices for dimensions. The usual way to append text is to either set it as default in the Dimension Style Editor or append it for an individual dimension using the properties box (see above).

However you can also append text using <> then whatever text in the Text Override box. This is useful as you can have this as well as a Prefix and a Suffix. The <> represents the dimension. For instance if I have a prefix of SO and a suffix of mm, I can use the following in the Text Override,

Overall <> opening

to achieve,

Overall SO 1045mm opening

This can be useful for one off dimensions where the text needs to be padded out to make the dimension clearer and the dimension style is carrying suffices that are required to be kept.

Dimension with text suffix option 2
Dimension with text suffix

The override box can also be used to place text below the dimension line whilst the dimension remains above. This is done using the <> X modifier! For example;


Dimension with text below the dimension line
Dimension with text below the dimension line

Note that if you want the text to be centred no space is required between “X” and the text required otherwise a space precedes the text below the line.

The major drawback with using text override as the main method for applying suffices is that Match Properties will not carry the text override from one dimension to another, it has to be retyped, whereas a dimension with Suffix used will carry over.

Match Properties Settings

A quick post to highlight that AutoCAD has a lot a “hidden” settings that most people (including me) don’t use or even know about.

Take for instance Match Properties, this actually has a selective settings box so that only some of the properties from the source object are matched!

Match Properties Dialog Box
Match Properties Dialog Box

Note that when Match Properties is clicked and the source object is selected AutoCAD lists the current settings under “Current Active Settings”, usually this is everything, however you can type S (or click settings in 2013 and above) and you will be presented with the dialog to turn off (or on) various properties to copy.

Another flickering update

It appears that changing AecCore.crx in C:Program FilesAutodeskAutoCAD LT 2014 to AecCore.crx.old or similar (in order to stop it working) fixes the flickering symptoms, making the program usable again. However this will most likely break something else as this file is an object enabler. The underlying issue appears to be with the new mapping feature (which makes sense as there is a greyed out map pin next to unrecognised when the bar flickers) and that is not working properly.

We all wait now for a Service Pack or Hot Fix for this from AutoDesk. Please check out this page regularly to see if the hot fix or service has been posted. I will update my blog when it arrives to see if it fixes the issue!

Secure Load

If you, like me, use LISPS you will find that a new very useful feature has been added to AutoCAD 2014. They have introduced Secure Loading of executables, which in principle is a good thing.

However if you like me are struggling to get the Trusted Locations to work, you can go back to the “legacy” behaviour (load everything anyway) by going to settings –> system –> executable file settings and turning off this feature.

Secure Load
Secure Load

AutoCAD LT Flickering

We have a rolling subscription in the office and one of the guys wanted to be the “guinea pig” for the new version of AutoCAD LT, 2014.

Install went OK but the status bar at the bottom of the screen kept flickering, with “unrecognised” coming and going.


We already had the certified driver installed and tired turning off hardware acceleration to no avail.

However so far this seems to have been solved with upgrading to the latest driver for the ATI Firepro V4900.

Hope this helps someone.


One of my colleagues was asking, why can I not turn the frame off around this imported image? IMAGEFRAME was not turning the frame off. It turns out that the drag-and-dropped image was actually a PDF, and therefore the frame is controlled by PDFFRAME, so its worth noting the imported image type in order to control things like this.

However, it should be noted that all “frame” commands (IMAGEFRAME, PDFFRAME etc. can now be controlled by one single command FRAME. This appears to be valid from version 2012 onwards.


Excerpt from help, AutoCAD 2013 (c) AutoDesk.

Changing the setting for FRAME changes the IMAGEFRAME, DWFFRAME, PDFFRAME, DGNFRAME, XCLIPFRAME, POINTCLOUDCLIPFRAME, and WIPEOUTFRAME settings to the same setting as the new FRAME setting.

0 – The frame is not visible and it is not plotted. (The frame temporarily reappears during selection preview or object selection.)

1 – Displays and plots the frame.

2 – Displays but does not plot the frame.

3 – The settings vary for all objects with frames in the current drawing: images, underlays, clipped xrefs, clipped point clouds, and wipeout objects do not all have the same frame settings.

Power Command Line

I discovered today that some code can be typed straight into the command line in AutoCAD. I had not realised this, I thought all code had to be loaded as a routine.

The following changes the PSLTSCALE for all layouts!


(foreach lay (layoutlist)(command "_LAYOUT" "_Set" lay "PSLTSCALE" 0))


UCS World

I received a set of drawings today from a colleague, whilst this is not unusual, the drawings all had differing UCS settings, which was unusual, most of my colleagues do not touch the UCS.

Usually I reset the UCS to world and carry on. I like my modelspace to to be set to world so when I copy and paste the rotation stays the same to the screen. I tend to then rotate the UCS in viewports as and when required.

This time, typing UCS, W to reset to world UCS left me with this, a wonky UCS.

Wonky UCS
Wonky UCS

The UCS is wonky, or Y is not up the page. The square in the UCS indicates it is set to WORLD, so I was confused.

The problem was not that the view was set to the UCS but the UCS was (kind of) set to the view. I will explain. (See bottom of post for a quick explanation).

If you type VIEWTWIST, it should be set to 0 for the UCS to be the way I wanted it. I found it was set to 270!


Now I have run into another problem, the VIEWTWIST variable is readonly!

So lastly I found that typing PLAN and setting to WORLD reset everything to how I wanted.


Interestingly this problem seems to be similar to the one a while back with rotating the view in AutoCAD LT.


For a quick method of the above, if the UCS is not in the default position and it is set to world, then the view has been rotated. To rotate the view back, type PLAN, then WORLD. Or click on the arrows above viewcube in full AutoCAD.

Rotate from Viewcube
Rotate from Viewcube

Not the Point

One of my colleagues had put a point in a block to stop it from “growing in size”. Whilst this is an ingenious work-around, it is easier to control the size of points if you don’t want them to be massive when zoomed out in a drawing.

If you type DDPTYPE into the command line you will get this dialogue box.


The circle with a cross is my usual selection for style, the point size can be relative to the screen, where 5% is usually about right, or for my colleague’s requirements, absolute. This is in the base units for the drawing, e.g. MM or INCHES.

Note that you can set POINTS to be tiny dots and therefore nearly impossible to see and these do not scale at all. This is useful as sometimes a drawing can be full of points that are “invisible”.