Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
[-]
Slideshow

[-]
Stats
» Members: 726
» Latest member: OvrDriver
» Forum threads: 590
» Forum posts: 3,135

Full Statistics

Printer Dimensional Accuracy
#1
So,

I am designing from scratch a printable periscope.  I'll post on that soon.  However, one of the biggest challenges I have had is getting my pieces to print that will fit the hardware (such as bearings).  After several frustrating attempts at this, I finally found the proper solution!  Obviously the 3D model should account for clearance to allow the pieces to fit.  However, I was finding that my printer was not producing the proper dimensions.  I am using Simplify3D as my slicer and I was finding that if I printed a part it was about .5mm too big in the XY plane.  The upshot was the outer part was too big and if I had an hole, it was too small.  I designed a 30mm x 30mm x 7mm square with a 22.5mm hole in the center that should fit a standard 608 bearing.  The result was a 30.5mm x 30.5mm x 7mm square with a 21.5mm hole.  I was printing in PETG which has minimal shrinkage.  


[Image: attachment.php?aid=1476]


Then, I adjusted Horizontal Size Adjustment on the Other tab of the slicer settings to -.25.  This value is the horizontal print error divided by two (.5mm/2).  BAM!  The part printed with 30.09mm x 30.08mm x 7mm with a 22.54mm hole!


[Image: attachment.php?aid=1477]
Grrr... This photo is a little blurry, but its late and you get the point... it works!
Oh, it looks like the bearing doesn't fit flush. However, it actual fits perfectly, I just didn't notice it was not all the way in the print when I shot the picture.

Eebel


Attached Files Thumbnail(s)
       
Reply
#2
In the past,
when I had the out dimensions too big and inside dimensions too small,
I found it was caused by over extrusion.

There is a setting in S3D that will allow you to adjust the extrusion on a per filament basis.
It's called extrusion multiplier.

You also have a small amount of ringing on the corners.
This is a good indication of either loose parts in your printer, or more likely printing to fast.
Reply
#3
(03-05-2019, 09:57 PM)Cyber_One Wrote: In the past,
when I had the out dimensions too big and inside dimensions too small,
I found it was caused by over extrusion.

There is a setting in S3D that will allow you to adjust the extrusion on a per filament basis.
It's called extrusion multiplier.

You also have a small amount of ringing on the corners.
This is a good indication of either loose parts in your printer, or more likely printing to fast.

I set my E-Steps and I don't think the I was over extruding.  The setting I described above works like a champ. Now my parts print with incredible accuracy.  

Eebel
Reply
#4
I found with mine, the E-steps can be spot on, but the filament diameter can vary between rolls of filaments,
If the diameter is a little larger that the 1.75 mm you end up with over extrusion,
and if its less than 1.75 mm you end up with under extrusion which is worse. (easier to file back than to try and add material)
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)