Measuring plots 1

[ctopher]

Most of you know when plotting a dwg, the plotter/printer sometimes isn't exactly to scale ... especially after making copies.
I have a plot from a customer that does not show a scale and does not measure to the scale they told me.
Does anyone know of a web site (or any trick) that will allow you to measure the plot with a scale/ruler and convert for you the proper scale?
i.e the dim shows 10', but measures 3.0313 on the plot. The cust told me it's 1/8 scale.
Thanks.

Chris
SolidWorks 06 5.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 02-10-07)

 

[dgowans]

ctopher,

What am I missing here? If you have a 10' dim that measures 3.0313 (assuming ' also) is the plotted scale not 0.30313, regardless of what your customer said? Or do you have a plot that's been copied numerous times, thereby introducing some unknown scale factor?

What do you get if you measure a dim that's perpendicular to the 10' dim? Same scale? If not, I'm guessing you have no accurate way to determine the scale.

 

[ctopher]

Correct, I have no accurate way to determine the scale.
But, I want to come as close as possible. So, if the dim on the paper shows 10', but physically measures 3.0313", I guess a can assume that scale factor for the entire dwg.
I guess what I'm asking is if anyone has come across this and what did you do?
Sorry if not clear, it's been a hell week.

Chris
SolidWorks 06 5.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 02-10-07)

 

[dgowans]

I'd measure a bunch of dimensions, determine their individual scales, and try to develop an average. You may want to tag the dims as either horizontal or vertical and see if there is a consistent scale in either direction.

What's your end goal?

 

[ctopher]

Thanks.
This isn't a mechanical part, it's a floor layout. I'm just trying to make parts/assy's that are close to the real thing, but don't have to be 100% accurate.
I'm trying to come up with an average scale of the plot. Your suggestion to measure a bunch of dims may be how I have to do it. Thank you.

Chris
SolidWorks 06 5.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 02-10-07)

 

[handleman]

I would echo dgowans on the multiple measurements, especially the horizontal/vertical part. We have a large-format scanner and plotter. Both rely on the speed of pulling the sheet through the machine to reproduce in that direction. It can be easy for the horizontal and vertical scale factors to get off from each other due to that.

 

[TateJ]

See if you can call someone whose name is in the title block & ask for a better drawing... or maybe a CAD file.

Windows XP / Microsoft Wireless Optical Mouse 5000
SolidWorks 2007 SP1.0 / SpaceBall 5000
Lava Lamp
www.Tate3d.com

FAQ376​

 

[ctopher]

I tried that. As usual, no one knows anything about who created the dwg, what format it is ... and ... there isn't any format/title block on the plot! It's the typical c**p I see lately! Must be from outsource!

Chris
SolidWorks 06 5.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 02-10-07)

 

[TateJ]

Well then... Can you can get it scaned to an image file?

Then you can insert it into a part & scale it to fit.
Then you can sketch over it.

Windows XP / Microsoft Wireless Optical Mouse 5000
SolidWorks 2007 SP1.0 / SpaceBall 5000
Lava Lamp
www.Tate3d.com

FAQ376​

 

[ctopher]

It's an E size dwg. I could get it scanned, but don't have time to wait for it. (plus it probably would come back scaled diff again!)
Thanks for your help.

Chris
SolidWorks 06 5.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 02-10-07)

 

[smcadman]

I run into this problem from time to time when a client brings in a drawing and dims are missing. Usually a drawing has been scanned (read re-sized) a time or 3 and they do not have the original drawing file because it was outsourced. I usually do this on my calculator, but I made an Excel sheet to do this.

Scale_finder

SW07 SP2.0

Flores

 

[TateJ]

After you figure out the horizontal & vertical "scales"...
You can print 2 "rulers" and then measure without having to re-calculate everything.

Windows XP / Microsoft Wireless Optical Mouse 5000
SolidWorks 2007 SP1.0 / SpaceBall 5000
Lava Lamp
www.Tate3d.com

FAQ376​

 

[ctopher]

Flores,
That works very well!
Thank you!

Chris
SolidWorks 06 5.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 02-10-07)

 

[fcsuper]

Yikes! There's a pretty big rule against the physical scaling of drawings. It is normally a forbidden activity. Is the drawing missing dimensional information?

Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA

http://sw.fcsuper.com/index.php

 

[smcadman]

I know it's a no-no and I'm sure Ctopher is aware of this so I simply replied with an answer rather than tell him not to do it. You can find Ctopher in the Drafting Standards, GD&T & Tolerance Analysis Forum also.

SW07 SP2.0

Flores

 

[ctopher]

Thanks Flores.
Matt,
Yes, the dwg is missing a lot of info. Only the mid-area of the dwg was sent to me. It was outsourced by coworkers across the country who don't know 99% of what a dwg should look like. I'm stuck with what I have.
This happened to once a few years ago with a part for military application. I asked for more info for months. I gave in a gave them what they gave me. Of course ... the part didn't fit!
s**t in ... s**t out !
Thanks.

Chris
SolidWorks 06 5.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 02-10-07)