Gcode Mod to invert arms to print more Z

[Ascensi]

Hi everyone, I am inquiring if anyone has tried this.. at some point in a print have the gcode pause a few mm higher than the print then begin to invert each arm then resume printing from paused location then pause at the end of print so you can cool and remove part and manually realign the arms to its original state to be able to print again.

I realize that one would have to take in account the object's print width associated with the delta arms and also the new max z height. I'm no wizard at gcode but hope there is someone out there that might know how to do this and possibly has done this.

[IMBoring25]

I would guess the firmware is not configured to handle that. Gcode is expressed in the Cartesian location of the effector and the firmware performs the kinematic calculations to determine how to move the motors. Horizontal arms and inversion of the logic thereafter are not likely conditions it is set up to handle.

[Xenocrates]

It's much less a G-code issue, and much more a firmware issue. If you could address each motor manually, such as if the firmware allowed you to do it with the U,V,W parameters that are occasionally (read once in a blue moon), used on industrial controllers, and you did it in a relative reference frame (which those specific axis's are only supposed to be used in), you could do it. It would be one hell of a firmware hack, and I question it being worthwhile, as after a certain point, you'd run the extruder into the top, whereas with delta printers additional Z just requires longer belts and extrusions. Say you wanted a total printer height of 6 feet, you can buy 3 6' extrusions for 55$+S/H from 80/20, and belts for a similar amount from seemeCNC. Sure, you'd need new longer wires, but those are pretty cheap. so for less than 150 bucks, you can add a significant amount of Z height, without the compromises.

As for doing it manually, sure it could be done. But the accuracy would be shit, and you'd probably hit your part, unless it's about 3 inches wide. It would also be complicated to slice the part for that. If you need more Z, just buy longer extrusions/wires/belts. It would be much faster and easier than dealing with that, and over time cost less if you need that extra Z for lots of parts, as you'd waste a lot of filament either printing oversize so you can machine it down, or prints failing entirely.

[IMBoring25]

To do it manually, you'd need to design the entire machine around this strategy. Once you start moving things around manually, you have to re-home, and you can't do that on a stock Rostock with the arms inverted. You would either need to add min endstops or to position the max endstops low enough on the machine that the effector won't hit the top structure at the home point with the arms inverted.

[bot]

RepRapFirmware, at least the dc42 fork, supports addressing the individual delta towers for movement in non-cartesian space. This is a very interesting thought.

[bvandiepenbos]

interesting thought.

of course you could also cut the model into two or more pieces, print separately, then glue together for final part.
you can cut models precisely with Netfabb.
Netfabb basic is free http://www.netfabb.com/hobbyists.php" onclick="window.open(this.href);return false;