Howdy from Corona, California

New user in this forum can introduce yourself here. Pictures of new UP Printer, fresh prints from UP Printer, and more.
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Raldan
Posts: 2
Joined: Sat Dec 27, 2014 10:53 pm

Howdy from Corona, California

Post by Raldan » Tue Dec 30, 2014 7:44 pm

Hi everyone!

I brought home an UP! Plus 2 last week. I found one on the shelf at my local Fry's Electronics outlet.
This being my first printer, I'm happy with my choice so far. The auto-leveling and auto nozzle height
adjustments got me started, and I was printing in no time.

I'm working through the steps to model parts for a second printer. I'm searching the forum for info on
how to model in mm, and get that same scale to the UP software. I've done some research going from Blender
to Up via STL files. It seems that a 2 meter box exported from Blender via STL (2 units), is interpreted by the Up software
as 50.8 mm. This coincidentally equates to 2 inches. Can I assume that the UP software is seeing the units in the STL file
as Imperial units, and then converting them to mm. (50.8mm / 2 = 24.4mm = 1 inch)
If this is true, how are you working on your models to insure your scaling is correct?

Also, Can a setting in the UP! software be created to select which system (Imperial or Metric) to use in converting STL units to UP mm.

I'll be glad to continue this discussion in the proper area, but , I'm hoping this has already been discussed in length elsewhere.
If so, please let me know.

Pete

mr6k
Posts: 327
Joined: Tue Feb 14, 2012 11:47 am

Re: Howdy from Corona, California

Post by mr6k » Wed Dec 31, 2014 12:17 am

Pete,
The UP assumes all dimensions are in mm. However, if a model is loaded with a very small overall size, like a box with a dimension of say 2 x2 x2 the software regards this as to small to print and further assumes that the model dimensions are in inches it therefore multiplies the model sizes by 25.4 to convert the units to mm, exactly what you are seeing. So always ensure your STL model is in mm. I believe it works conversely, if you apply a model with ridiculously large mm numbers it divides the result by25.4 ! You can overcome the scale error in the scaling pulldown menuc where their is a 25.4 scale and a 0.03937 scale.

cheers

Peter

Raldan
Posts: 2
Joined: Sat Dec 27, 2014 10:53 pm

Re: Howdy from Corona, California

Post by Raldan » Wed Dec 31, 2014 6:54 pm

Thanks, Peter.

This fills in the holes in my understanding. I also found that if I set up Blender in Metric, and set Scale to 0.01, then setting the display Grid to 10 lines and a Scale of 0.01, I can work with mm easier as I build models. I created a 140mm cube which I then exported to STL. I loaded into Up! 3D Print and applied a scale of 10 and it translated perfectly. I will also test this with a pass through Netfab, as I'm sure I'll need to clean up future models.

It appears that my use of the default 2 meter cube in blender's startup was not the best choice as a test for scaling. The exported STL translated into a 2 unit cube (internally STL knows nothing of mm or inches, only units), which as you described is an object "too small" to print, therefore triggering the conversion. The 140 mm cube showed no such conversion. (Sigh of relief)

I'm working on using vector art (Illustrator, it's what I know best) to extrude from. Before using Blender, I was trying 123D Design which looked promising, but I got side-tracked by the scaling issue.

Thanks again for the info, it helps knowing what's going on under the hood. cheers!

Pete

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