I have finally finished the compact CNC Plasma build and after a load of faffing around, got the axes working perfectly. My test profile is a Solidworks drawing of one of the stepper mount plates. Bringing in a dxf resulted in some odd inverted curves and the main hole in the centre had a gap in it (which is not on the model) so I brought in a jpg and created the toolpath in one operation. transferring the G code to the machine results in a correct geometric cut pattern - but it does it twice. Eh? There are no chamfered edges and the drawing and jpg are 'clean' ie no double edges/lines. What is going on?
Use DXF but make sure its DXF R14 Polyline, with all arcs/circles/splines converted to Polylines (even it means a cleanup in an intermediate CAD like QCAD) Learn more on docs:software:file-errors [OpenBuilds Documentation] The bmp/jpg tracer is more appropriate to artsy work (laser, pen plotter). DXF is the best format for making dimensionally accurate parts
No As it is solidworks I can't save an autocad R14 version. I saved as jpeg and used that, but the jpeg only has single ines?
Well, tat turned out the same as the dxf I exported from Solidworks ie: I could not find a way to convert to polyline in Q Cad. The original drawing is just fine
I linked the instructions above ^ Click on the blue link Bitmap tracing is completely the wrong method for CAD drawings. But even so, that image is incorrect too, for a trace to work you want a sillouette not a line drawing : Potrace The dark line is a "shape" it has both an inside and outside edge. Either way, again, more suited to tracing art. Jpgs doesn't carry dimensions, etc If you already have CAD just use DXF. But make sure its all Polyline and exported as DXF R14. Simplest An Inverted arc means you still have an Arc (not a polyline). Convert it to Polyline
Hi Peter. Well the outside shapes and arc converted to polylines but the circles won'r - I selected a circle and went to draw/polylines./ make polyline from selection and it does not change from circle. Hmm?
Yip, no issue. Opened file in QCAD, used Mouse to drag over everything to select it, went to Draw, Polyline, Polyline from Selection I also moved it to proper origin - it was spaced infield a little, would be easier with bottom left origin. Converted file attached, but next time, just give QCAD a go, cleaning up DXFs is simple, and a valuable skill (especially when you start using others' artwork)
No - not working. i imported this dxf into Qcad, dragged over everything and converted to polyline and it does everything but the circles! What am I missing - your dxf shows all as polylines
I am a little ahead of you. V3.22 (You) vs V3.27 (Me) But we are both behind current, yours from 2019 (going on 4 years without an update , actually saturday's its birthday! good excuse from some grilling?), mine from 2022 (Birthday tomorrow lol sucks its a weekday, but hey - crazy we both installed the May version of some year), we should both try the latest though Version 3.28.1
Ta Daah. Fixed! Thanks Peter As an aside as i haven't tried it on the machine (machine in workshop without internet so I have to generate Gcode here and take it down) the Z axis setup is slightly wrong. I set Z+ as down and Z- as up. and force a zero 5mm in the z- direction. The carriage raises to the safe point (near the top) then when it wants to set the plasma it drops down (to what would be the plate surface) but instead of raising 1 mm for the pierce start, it drops a further 1mm ie. wrong direction. If I put a -number in the pierce will it raise instead of lower?
No! Fix the machine! Standards exist for a reason Simple Invert under $3 Direction Invert in Grbl Settings is all it needs
Having sorted all the other minor bugs, fixed polylines in the dxf files and wired all the endstops I have come across a weird problem that only occurred after I finished installing the panel in the box. The X axis was vibrating which was caused by a wire coming out of the connector block. With that fixed everything seemed normal but the offending axis only moved in the + direction. Clicking the - jog direction moves the axis, but in + direction even though the readout indicates it is going in - direction. I killed the power, pulled the plug and checked the connections and replaced and..... spot on + and_ directions working. A little after that I closed the box up and.... Only + direction again. I have opened the box, checked the wires and made sure there is no chance of crossover (I am using 2 twisted pair cable) . The axis moves smoothly but only in + direction so I am not sure where to look. I loaded a job and it does the same. Any ideas?
Almost certainly a connection on one wire being pulled out as you close the box. There isn't much (anything?) else that would cause those symptoms apart from the two wires to one of the motor coils shorting, I couldn't see a reference to what controller you are using - either of the blackbox's would give you a red "overload" light on that motor and it probably wouldn't move at all. Alex.
It is a blackbox. I did have a wire pulled free and the motor just hunted. The motor now runs free but only in one direction. Weird. i have the door open and the wire is not under any strain. As you say, if there was a short I would get an alarm and overload. I will play with it again this afternoon - I will check the coil resistances too.
My answer was because you said you'd fixed it and then it failed again when you shut the box. Another thing to check is if you have a break in the wiring inside the insulation. Is your wiring multistrand copper - not single core? Alex.
docs:blackbox-x32:faq-identify-motor-coils [OpenBuilds Documentation] see the typical symptoms in the first section, inability to change direction is a classic symptom
Ok. So today I checked the resistance across the coils - at the plug to the Black Box. Both the same 2 Ohm from memory. switched the machine on and went to jog - The axis started moving in - direction and within a second switched to + and now only goes + but smoothly. I'm puzzled. if I had damaged the output stage somehow the axis would not move at all? Not sure where to go from here. Richard
Tugging on wiring while moving pulled on loose or broken wiring causing one of the 4 wires to loose solid contact throughout again.
