how can i just simply draw a circle

Hi everyone!

I have just finished building a rostock RepRap. Everything is set except for the extruder which am still waiting for to arrive.
now, I want to test the printer by printing a circle multiple times or infinite times.
Am really new to the whole GCode RepRap thing..so how do I go about doing this

Thanks a lot

Raiyan

I did not found a circle, but there are few commands to move: [reprap.org]

Edited 1 time(s). Last edit at 12/27/2014 09:21AM by Plasteroid.

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Prusa i3, Ramps 1.4. Catnozzle 0.4mm
SketchUp - Enveloping Globoid Worm Gear - Part One - 3D Printed: [youtu.be]
DesignSpark Mechanical & more precise screw thread: [youtu.be]
Nicer Screw Thread In SketchUp ( Bolts,Nuts): [youtu.be]
How To Model A Heart Shape In SketchUp: [youtu.be]
How To Draw 3D Printable Snap Fit Ball Joint In SketchUp: [youtu.be]

Open up a CAD program
(sketchup -- it's free)
Use circle tool to draw circle
Use circle tool again to draw a smaller circle inside
highlight inner circle -- delete it
highlight washer left over
use PULL tool to pull it up a couple of mm

Save as .stl file (export) or use plugin

or

go out to thingaverse
[www.thingiverse.com]
download thing

Load your circle.stl file into your printer control software (repetier-host)
slice it --- examine g-code
Notice the circle is 64 straight segments (that was set in sketchuo)
print it
adjust

oh print it again because it didn't stick
print it again at correct temperature
100 parameter changes later and about 100m of filament
you'll have a nice polymer washer

I would recommend learning Openscad. [www.openscad.org]
Gcode is far too low level to be practical to write in. A CAD program is used to create a .stl then a slicer is used to create the gcode.

Fun fact, there is no such thing as a circle in most 3D printers of the type we use, just a series of really short straight lines angled to make a circle when viewed from outer space......

Everything is a G01 X__ Y__ Z____ there are circular interpolation G codes as G02 or G03 but not used or usable in our world. Everything is X, Y, Z

Are you trying to create an item (cylinder) or just have the head move in a circular pattern over and over without printing? (like to test)

You can download a cylinder here [www.thingiverse.com] then slice it to print. You can also do a "dry run" without extruding material if that is what you want.

would this help?


here is also gcode that runs circles on printer. you need to load the stl file and generate gcode.

there is however gcode created for both delta and Cartesian machines.


[www.thingiverse.com]

load the delta gcode.

it still needs a few people to test it.

it still has extruder going during process, so if feedstock is loaded it needs to be up to temp already.

Edited 4 time(s). Last edit at 12/30/2014 02:26AM by jamesdanielv.

Not mentioned yet: one can generate G-code with tools for CNC milling machines and run that on a RepRap controller. Just make sure this generator isn't configured to not produce "fancy" G-code like G2, G3, G4 or G-code variables.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Marlin supports arc gcodes G2 and G3
The problem is STLs are all straight lines so slicers do not have the logic to convert to circles or arcs.
The following three lines generate cause my printer to run in a circle.

G1 X0 Y90 F200000
G3 X180 Y90 I90 J0
G3 X0 Y90 I-90 J0

G1 X0 Y90 F200000 = move to edge of area 180 x 180 at maximum printer speed
F200000 is speed in mm/minute ,this is faster than my machine can run so it goes max from config file

G3 X180 Y90 I90 J0 = generate arc of 180 degrees to end at location X180 Y90

G3 X0 Y90 I-90 J0 = generate arc of 180 degrees to end at location X0 Y90

This assumes a bed of at least 180x180 with x0 y0 in a corner.
If center is in the center of the bed it would be different.
** Have not tried this **
G1 X0 Y0 F200000
G3 X90 Y0 I90 J0
G3 X-90 Y0 I-90 J0

If you want to exercise your machine just copy last two lines over and over in a text editor and save as name.gcode file

A slicer could look at the logic that if the normal of two lines drawn from 3 points meet at the same point it may be part of an arc. The problen is a part like a bolt head then would come out round rather than 6 sided. People are able to make a guess that a part is meant to be round or have an edge but computers are not that smart.