Greg's accessible extruder body bridge error

Hello all,

I have printed almost all parts for Prusa Mendel printer using Slic3r, and I am satisfied with the results.
Now I am trying to print Greg's accessible extruder body and something went wrong.
My printer does very strange movements when printing the bridge for hobbed bolt hole, and all was broken (it looks like printing on air) Is there any hint for Slic3r setup to do this appropriately ? Has anyone printed this part successfully using Slic3r ?

This is my *.ini file

bottom_layer_speed_ratio = 0.3
bridge_flow_ratio = 1
bridge_speed = 60
duplicate_distance = 10
duplicate_x = 1
duplicate_y = 1
end_gcode = M104 S0 ; turn off temperature\nG28 X0 ; home X axis\nM84 ; disable motors
extrusion_axis = E
extrusion_multiplier = 1
extrusion_width_ratio = 0
filament_diameter = 2.92
fill_angle = 45
fill_density = 0.4
fill_pattern = rectilinear
first_layer_height_ratio = 1
g0 = 0
gcode_arcs = 0
gcode_comments = 0
infill_every_layers = 1
infill_speed = 50
layer_height = 0.35
nozzle_diameter = 0.5
perimeter_speed = 40
perimeters = 3
print_center = 100,100
retract_before_travel = 2
retract_length = 1
retract_lift = 0
retract_restart_extra = 0
retract_speed = 7
rotate = 0
scale = 1
skirt_distance = 6
skirt_height = 1
skirts = 1
small_perimeter_speed = 30
solid_fill_pattern = rectilinear
solid_infill_speed = 40
solid_layers = 3
start_gcode = G28 ; home all axes
temperature = 230
travel_speed = 130
use_relative_e_distances = 0
z_offset = 0

Thank you in advance
(sorry for my English)

I have seen this as well.
I have to wait next to my printer and blow a fan on the bridge because it makes the bridge in an odd direction. If you don't get the first layer nice enough, all the subsequent layers in that spot will be weird.

I lost my first attempt at this part because of it.

Thanks for help, but my first layer goes very well. The problem starts on this particular bridge, and it looks like there is a lack of support (strange printing in the air). Maybe it is a matter of infill ratio ? Maybe this is a problem of a single wall that's not supported in Slic3r ?

I had no problems printing Greg's, the first bridge layer was not perfect, but good enough for the next layer to rest on. Partly caused by me not tuning the bridge settings
Greg's with slic3r

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regards,
Tom

Hello,

I see on your pictures that the hole for hobbed bolt is built on a closed surface (on bridge). Is this a matter of stl file ? Some files are with, and some without a hole for M8 honbed bolt.

I have mine from Greg's github, maybe yours come from the Prusa files??

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regards,
Tom

I've brinted the extruder from Prusas STLs using SFACT and had a similar issue. So I ended up printing it with support which is not possible with Slic3r at the moment.
But good to know that there is a version with closed holes out there!!! Look great!

I printed a few a while ago that had that. Just drill it out when you are done. You'll be fine. I'm printing with one like that right now..

Thanks for help. I've got Prusa's version of STL files. Is there any source for STL file of greg's extruder body with groove mount and 16 mm. dia ? Of course without a hole for hobbed bolt.

Or maybe is there a hack to modify SCAD file to close the surface for hobbed bolt.

Tom, you must have modified slic3r file, to make a bridge for the M8 hole.

no, really, I didn't!

The only thing I did was hack Greg's openscad file a bit because I want the idler to use m4 instead of m3......

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regards,
Tom

here's how it looks when I run greg's unmodified openscad with groovemount: Greg's openscad

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regards,
Tom

Well, it seems, that there is no hole, but a solid surface (this is what I am seeing on the picture). My OPENSCAD file is different. It has M8 hole through the all body. I took the file from Prusa's page. Could you send me a link to OPENSCAD file that you use ?

Regards,
Arek

sure, here's the original from the designer: Greg's wade V3

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regards,
Tom

Thank you a lot! You've helped me veru much. Now I will try to print again

Regards
Arek

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regards,
Tom