Small IDs

I cannot print any tube-like object (washer or tube) where the inside diameter is not too small. I've calibrated my TAZ for X, Y and E steps. I've tried to run this calibration routine (http://blog.mcmelectronics.com/post/3D-printer-calibration#.Ue7-AdKRCrA )and get almost perfect ODs, but the IDs are small. I've tried multiple Slic3r 0.9.10b iterations with no success. I'm using Repetier-Host V0.90C. I'm using natural 3mm ABS. Can anyone shed some light on this? It doesn't seem to be related to shrinkage, since the very fist layer measures small as soon as it is printed.

; generated by Slic3r 0.9.10b on 2013-07-23 at 16:58:40

; layer_height = .21
; perimeters = 2
; top_solid_layers = 3
; bottom_solid_layers = 3
; fill_density = .4
; perimeter_speed = 30
; infill_speed = 60
; travel_speed = 150
; nozzle_diameter = .35
; filament_diameter = 2.78
; extrusion_multiplier = .95
; perimeters extrusion width = 0.24mm
; infill extrusion width = 0.42mm
; solid infill extrusion width = 0.24mm
; top infill extrusion width = 0.24mm

G21 ; set units to millimeters
M203 X192 Y208 Z4
M104 S230 ; set extruder temperature
M190 S85 ; wait for bed temperature to be reached
G28 ; home all axes
G90 ; use absolute coordinates
G92 E0 ; reset extrusion distance
M82 ; use absolute distances for extrusion
G1 F2400.000 E-1.60000 ; retract
G92 E0 ; reset extrusion distance
G1 Z0.350 F9000.000 ; move to next layer (0)
G1 X86.780 Y119.430 ; move to first skirt point
G1 F2400.000 E1.60000 ; compensate retraction

Hi,

Not sure this is your problem, but you might want to read this excellent blog post by nophead.

http://hydraraptor.blogspot.co.uk/2011/02/polyholes.html

Craig

Thanks Craig, the article pretty much explains it. Lulzbot Tech Support gave me the same answer and referral that you gave. My friend's Afinia machine produces accurate inside and outside holes without tuning the part's STL file or G-Code. Seems the Slic3r software could use a bit of tweaking in this area. Any takers?

I think that some commercial machines with their own firmwares and slicers may interpret them a little bit wider than in the file. It's probably in the slicer software now that I think about it.

It's slic3r, there is a discussion about it over in the Slc3r forum now. Doubt it's going to be fixed anytime soon.