Author Topic: Sketchup STL size issues  (Read 4241 times)

pedwards2932

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Sketchup STL size issues
« on: August 25, 2017, 03:56:55 AM »
Well, got my printer working and have printed one or two of the test files and it works.  I am amazed at how little information is available on how to process your own files but as usual with enough internet searching I was able to get it to print a Sketchup drawing I made but the size was all wrong.  When I imported into CURA it was too large for the table and this was a shim that was 5/8" in diameter.  I exported in mm and then it would fit in CURA.  Next issue was figuring out how to get the Gcode (also getting the PLA into the extruder is a bear).  That problem solved and it printed!  But it came out about twice as large as needed?  I am guessing maybe 2.54...something to do with converting inches to mm.  So long story short does this mean I need to do all my drawings in mm so the conversions won't mess up?  Can I do my drawing in inches and then convert to mm in Sketchup?  All this for a simple shim that I could make in a few minutes with hand tools but where would be the fun in that.....welcome to the world of 3D printers.....a tool we get and then have to search for a purpose.....

Lob0426

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Re: Sketchup STL size issues
« Reply #1 on: August 25, 2017, 12:16:06 PM »
When you export the .stl from sketchup it gives you a choice of inches or mm's. Export in millimeters. Most (all of the ones I have checked) 3D printers are set for G21 which is metric. Sending gcode in inches to a metric firmware will always end up way large!
Richard
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ThothLoki

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Re: Sketchup STL size issues
« Reply #2 on: August 25, 2017, 12:47:46 PM »
You know, like NASA.
Calculate in feet, program the lander in meters! https://www.youtube.com/watch?v=SiNWnQYXifA
Laser: 2x EleksMaker A3s
3D Printer: Monoprice Maker Select v2 / Sovol SV01
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Lob0426

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Re: Sketchup STL size issues
« Reply #3 on: August 25, 2017, 02:00:38 PM »
You know, like NASA.
Calculate in feet, program the lander in meters! https://www.youtube.com/watch?v=SiNWnQYXifA

LOL!
I am bad about that too! Draw in inches then export as millimeters". Other times draw in metric. My designs look like 1980's Ford and Chevy's. Some parts in metric some in American.
Richard
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pedwards2932

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Re: Sketchup STL size issues
« Reply #4 on: August 25, 2017, 05:02:48 PM »
But that is what I did......I drew in inches exported in mm and it was still too large.  It was a round shim and it came out 27.4 mm but it should be 5/8" or 15.88 mm.  I went thru some Cura tutorials and was able to resize it there.  I'm guessing I need to start using metric in Sketchup for drawing.....sometimes hard to get an old dog to do new tricks

ThothLoki

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Re: Sketchup STL size issues
« Reply #5 on: August 25, 2017, 05:08:32 PM »
I was the same way at the beginning but I am staring to think in metric now.
Laser: 2x EleksMaker A3s
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Lob0426

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Re: Sketchup STL size issues
« Reply #6 on: August 25, 2017, 06:05:24 PM »
But that is what I did......I drew in inches exported in mm and it was still too large.  It was a round shim and it came out 27.4 mm but it should be 5/8" or 15.88 mm.  I went thru some Cura tutorials and was able to resize it there.  I'm guessing I need to start using metric in Sketchup for drawing.....sometimes hard to get an old dog to do new tricks

First of what method are you using to export your .stl file? Are you using a plugin for sketchup?
I use a plugin called STL exporter from the extension warehouse.\

There are a couple of things that could be going on here. You got it to the right size in CURA by exporting MM. But then it printed large. If I am reading it correct, this time.

Look in the "start.code", under the Start/End-Gcode tab in CURA, make sure it shows G21 (see picture)

The other is to see if your firmware is using Metric or inch as default! It should be metric, but might have been accidentally been switched to inch. Either will work on most machines. if it is inch you may have to change the G21 to G20 (start.gcode) and see if it prints right then!

Which printer are you using? Never mind I went and looked. That A8 should be set to millimeters as default. But check and make sure it is, or that will be your problem. Most likely it is the G21 in CURA somehow got changed.

« Last Edit: August 25, 2017, 06:10:08 PM by Lob0426 »
Richard
A5 2.5W w/homing switches on L7
A5 2W diode self upgraded from stock 500mw
Printrbot Play. Ext bed, integrated tablet control.
Printrbot Simple Metal
USA

pedwards2932

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Re: Sketchup STL size issues
« Reply #7 on: August 25, 2017, 09:07:31 PM »
I am using the Sketchop plugin.  No when I changed to mm it was at least small enough to fit the table but when I checked it in Cura the dimensions were wrong it was 27.4 mm and should have been 15.88.  When I get a chance I will check the firmware and gcode.  Thanks for the help

Edit -  I looked at the g code in Cura and it is set to G21 metric values - it is printing the part accurately it is the dimensions coming from Sketchup that are incorrect.  I will try it using metrics in Sketchup and see what it does.

Edit - Now I feel stupid.....radius versus diameter.....Sketchup uses radius and I was punching in diameter dimensions.  I also found that there is a template for 3d printers....used the inches one and pulled into Cura and dimensions are correct.  Just shows never try something new when you are in a hurry.......
« Last Edit: August 26, 2017, 06:24:27 AM by pedwards2932 »