Scaling and Horizontal Offset

Post your advice, tips, suggestions, etc...

Scaling and Horizontal Offset

Postby zemlin » Fri Jul 08, 2016 3:03 am

I'm working on some parts that require a high level of dimensional accuracy on large and small features.
Attached you will find a part I'm calling a Calibration Cross - STL and JPG drawing. It includes internal and external features, both large and small. I have also attached an Excel Spreadsheet (Zipped) which enables (by trial and error) to see the impact of scaling and horizontal offset values in correcting part dimensions.

Print off a Calibration Cross with no scaling and no horizontal offset. Enter the measured values into the spreadsheet and experiment with different X & Y scale factors as well as the horizontal offset value to minimize the resulting error on all of the measured dimensions.

I've only run one calibration with this using ABS, but it worked out great. All dimensions on the second run were within a couple hundredths of a mm of the predicted values. and overall accuracy was greatly improved.

Capture.JPG
Attachments
calibration-cross.zip
Spreadsheet updated 2016.07.08
(9.11 KiB) Downloaded 100 times
Capture.JPG
calibration-cross.stl
(74.69 KiB) Downloaded 110 times
Last edited by zemlin on Fri Jul 08, 2016 12:12 pm, edited 1 time in total.
User avatar
zemlin
 
Posts: 439
Joined: Thu Feb 04, 2016 9:32 pm
Location: Indianapolis, Indiana

Re: Scaling and Horizontal Offset

Postby Jules » Fri Jul 08, 2016 4:06 am

Nice! I've downloaded in case I ever print something that needs to be spot on. (You ought to post it on Thingiverse in the MakerGear Group too, so we can find it again.) :D
User avatar
Jules
 
Posts: 3150
Joined: Wed Jan 21, 2015 1:36 am

Re: Scaling and Horizontal Offset

Postby zemlin » Fri Sep 16, 2016 3:14 am

Updated the design with a some intermediate dimensions and heavier sections that work better over a wide range of settings and heavier nozzles.
I print one of these off when I am trying a significantly different layer thickness, extrusion width, or multiplier.

Calcross2.JPG


calcross1.JPG


calcrossXL.JPG
Attachments
calibration-cross.zip
Excel Spreadsheet
(9.89 KiB) Downloaded 98 times
calibration-cross.stl
(130.55 KiB) Downloaded 112 times
User avatar
zemlin
 
Posts: 439
Joined: Thu Feb 04, 2016 9:32 pm
Location: Indianapolis, Indiana

Re: Scaling and Horizontal Offset

Postby zemlin » Tue Mar 07, 2017 2:42 am

Another Update.
I've added a few useful fields to the spreadsheet, and also added a Z-Axis calibration. I have attached an updated drawing, the latest spreadsheet, and the STL file for the Z-Axis scaling.

Capture.JPG
Attachments
Calibration-Cross.zip
PDF drawing and Excel Spreadheet
(33 KiB) Downloaded 85 times
100mm.stl
for Z-Axis scaling
(136.8 KiB) Downloaded 82 times
User avatar
zemlin
 
Posts: 439
Joined: Thu Feb 04, 2016 9:32 pm
Location: Indianapolis, Indiana


Return to How-to/Guides/Tips

Who is online

Users browsing this forum: No registered users and 4 guests

cron