XY jogging: Software goes beyond endstop?

[Qdeathstar]

Hello.

The issue i am having is that i have a printer that has software endstops coded in at 300mmx x by 300mm y. The printer will not move past those endstops.

In simplify3D, i have the printer configured so that the bed size is 300mm x by 300mm y. HOWEVER, if i am jogging the printer, and i send the command to to to y=300 x=300, and then press plus 10mm on the jog controls, simplify3D will show my location as y=310 x =300, but my print head will not move. So, now if i press minus 10, simplify3D will show my location was y=300 x = 300, but my printer will move, causing its actual location to be y = 290 x = 300.

I know i won't be jogging the printer around too much and it doesn't affect printing, but this still rather annoying because when it happens i have to rehome the printer. Is there a way around this?

Thanks!

[dkightley]

You'll find this is a common thing for whatever software you use....

Printing is a one-way communication process as far as movement is concerned. There's no feedback from the printer to the software to indicate whether or not the movement commands have actually been successful. So, if the print head movement is restricted by either physical means (eg nozzle hitting printed part) or printer settings (eg limits in printer hardware/software) then the slicer software is totally in the dark.

This is why you can get the printing errors like this: https://www.simplify3d.com/support/prin ... salignment

[Qdeathstar]

I hear you, but i would expect that if you set up a printer to be a specific size, head movement should be confined to that space. Or at least there should be an option :-/

[brian442]

Just to reiterate what others said, the printer has no feedback on what the actual position is. So when you turn it on, the printer has no way of knowing if it's a X,Y of 0,0 or 57,85. It literally has no sensors to allow it to know it's position. So that's why ever print typically starts by homing the toolhead. That allows it to move to the 0,0 location and hit the endstop sensors. Now the printer knows exactly where the head is at.

So basically, make sure you home the printer first, then the software endstops should work fine.

[Qdeathstar]

Hmm, I guess maybe what I'm saying is misunderstood.


This happens after I home the machine. I home the machine but simplify3D allows me to move the head past the stated bed size. E.G., I tell the software the bed is 360mm x 360 mm, simplify3D will let me jog the machine to y=400mm x=400, however the machine stops at x=360 y= 360.

So, simplify3D knows where zero is, and it knows the size of my bed, why doesn't it stop when it jogs to the end of my bed?

[brian442]

You said that you have max virtual endstops configured in your firmware, correct? That's what should prevent this from happening, so I would assume that your firmware is not setup correctly if you are able to home the machine and then move beyond the max X or Y limit.

So check your firmware to make sure the maximum virtual endstops are enabled and set correctly.

[mroek]

@brian442: No his firmware and endstops are perfectly OK. What he is complaining about, is that S3D actually sends the command to move beyond the configured bed size. In other words, he'd like S3D to also include virtual endstops so that it would not send movement commands to the printer if those commands would cause movement outside the max size. The printer will not actually move, but S3D doesn't know that, and updates it's internal virtual position as if it had moved.

For this to work, it is of course necessary to set the S3D position to zero when the printer is homed, but it would still be a system without feedback, so if the printer skips steps or something prevents movement, then it would all go out of sync again.

[Qdeathstar]

The printer stops as it should. However, the display on simplify3D still increases the reported position. The printer acts like expect, simplify3D does not.

The software goes beyond endstops, the hardware does not.