QU-BD Extruder steps per setting.

[deejayspinz]

Wondering of anyone else here who's done a 3D printer add-on for their ShapeOko AND is using the QU-BD extruder can tell me what your steps per setting is for the Extruder motor? Also what microstepping (if any) are you using?

[edwardrford]

I found this over on the buildlog.net forum:

#define DEFAULT_AXIS_STEPS_PER_UNIT {78.7402,78.7402,2519.68,106.707} // default steps per unit for ORD Bot Hadron

I'm wondering if the 106.707 is the qu-bd extruder steps per mm? Seeing that 78.7402 would be X and Y, and 2519.68 would be Z axis, that leaves the 106.707 to be the extruder.

-Edward

[alpha]

Yes, Edward is correct - that last number are the extruder steps! I don't have this extruder on my Shapeoko but on my Ord Bot.
If my memory serves me right I'm using something like 96 right now... however I think I did start with 106 too. You will need to measure and adjust your value for best print results. I did follow this guide and it did help me very much: http://richrap.blogspot.ca/2012/01/slic ... s-and.html
As the people of the Buildlog.net forum suggested I did take a M3 tap to give more grip to the hobbed bolt drive. I never used the standard from QU-BD drive, so I don't know if it was really that bad, but I never had any issues so I guess it did solve those issues people had. I put the M3 tap in my drill and had my wife hold the drill on a low speed. I put the drive on an allen key and run it over the tap turend it a little bit and ran it again until all the sides were done.

If you don't have digital caliper yet you will need to get some soon, I never had these before but around a 3d printer you will uses these all the time. I did order some for <$20 and I'm happy with those.

[jluther]

Wouldn't the quick method be to calculate using the circumference of the gear multiplied by the area of the filament, then divide by the nozzle diameter?

Some of the other extruders use gearing and I seem to remember 106 being a number I crunched for a wade's extruder... Either way, worst that can happen is it doesn't lay a good bead, or it lays a fat bead, regardless of how far off the calculation is.

[cvoinescu]

Wouldn't the quick method be to calculate using the circumference of the gear multiplied by the area of the filament, then divide by the nozzle diameter?

Current versions of Skeinforge no longer use the E steps-per-mm to refer to the extruded length; that parameter is now the number of steps to feed 1mm of unextruded filament, regardless of its diameter and the diameter of the nozzle. The filament diameter enters the calculation elsewhere, and the nozzle diameter factors out, so it's not required anymore. Not sure how it works in Slic3r.

So, in theory, all you need is the circumference of the gear -- and that's what you start with, then you measure the actual length fed when you command, say, 100mm, and adjust the parameter. You need to do it for PLA and ABS separately, because the gear digs deeper into ABS so the effective radius (and hence circumference) is somewhat smaller, so it feeds less of it. You don't need to change the E steps-per-mm when switching material, because it can be compensated in the slicer (the packing factor, iirc).