SoliForum - 3D Printing Community — dual purpose switches?

Re: dual purpose switches?

null@example.com (solijohn) — Sat, 26 Jan 2013 17:35:44 +0000

vince7c95 wrote:

Thanks guys, I may try the adjusting the g-code at some point. I recently switched to RH and it looks like adjusting the g-code will be a lot easier than with skeinforge, (never really figured out how in the first place).
I always home everything before starting a print so there shouldn't be any confusion with the the printer thinking it's somewhere where it's not. I tried pushing the end stop with my finger once on the y axis just to see what would happen and it stopped fine and didn't seem to get confused about directions so I may still install another end stop just as precaution at some point. I'll post what happens if I get around to it, but school is starting and tinker time will be at a minimum now.
Thanks for all the info guys.

You should change the file "start.gcode"

Re: dual purpose switches?

null@example.com (vince7c95) — Thu, 24 Jan 2013 01:41:07 +0000

Thanks guys, I may try the adjusting the g-code at some point. I recently switched to RH and it looks like adjusting the g-code will be a lot easier than with skeinforge, (never really figured out how in the first place).

I always home everything before starting a print so there shouldn't be any confusion with the the printer thinking it's somewhere where it's not. I tried pushing the end stop with my finger once on the y axis just to see what would happen and it stopped fine and didn't seem to get confused about directions so I may still install another end stop just as precaution at some point. I'll post what happens if I get around to it, but school is starting and tinker time will be at a minimum now.

Thanks for all the info guys.

Re: dual purpose switches?

null@example.com (devilman2075) — Wed, 23 Jan 2013 05:07:28 +0000

If you adjust your end gcode to move the bed to an absolute point instead of just lowering some number of mm, you won't have this problem. This is a simple solution, for example, my bed lowers or raises to 75mm by default, I change it if I'm doing larger pieces.

Re: dual purpose switches?

null@example.com (ronsii) — Wed, 23 Jan 2013 03:25:30 +0000

Stoney wrote:

you don't need linkages, just add a second switch either in parallel or series with the current Z switch depending on whether its NC or NO currently. parallel for NO.
it will likely need a little firmware kludge to determine which way it needs to step, its patently obvious if its at 150mm and just increased the printer will have no difficulty in determining its the bottom switch triggered and not the top.
then i guess it needs to be setup again as a dual end stop on the Z.
it would need a little bit of coding change but its absolutely possible.

The problem comes into play when you turn on your printer and it does not know where it is....if it is on the lower limit and you tell the bed to go down for all it knows it is on the top limit and will therefore go down, of course as long as you home it every-time you power up you should be okay... then again if you home it on power up it knows where it is and you shouldn't need a lower limit???

Re: dual purpose switches?

null@example.com (coleke) — Wed, 23 Jan 2013 02:06:55 +0000

Based on the fact that the end stop is tripped when you remove the connector from the sanguinolu, I'd say the end stops are wired NC, so series.

Re: dual purpose switches?

null@example.com (Stoney) — Fri, 14 Dec 2012 23:27:38 +0000

you don't need linkages, just add a second switch either in parallel or series with the current Z switch depending on whether its NC or NO currently. parallel for NO.

it will likely need a little firmware kludge to determine which way it needs to step, its patently obvious if its at 150mm and just increased the printer will have no difficulty in determining its the bottom switch triggered and not the top.
then i guess it needs to be setup again as a dual end stop on the Z.

it would need a little bit of coding change but its absolutely possible.

Re: dual purpose switches?

null@example.com (cmetzel) — Fri, 14 Dec 2012 14:44:15 +0000

customize your end gcode so it doesn't move up as much after the print

Re: dual purpose switches?

null@example.com (vince7c95) — Fri, 14 Dec 2012 14:42:51 +0000

Okay thanks. That's what I thought would happen more or less, but figured I'd ask anyway.

Re: dual purpose switches?

null@example.com (Cwalster) — Fri, 14 Dec 2012 14:06:07 +0000

It wouldn't be able to tell if it's at the top or the bottom then. If you limited out on the bottom, it would think its at the top, and the next Z+ move would cause a crash.

dual purpose switches?

null@example.com (vince7c95) — Fri, 14 Dec 2012 12:33:26 +0000

I was just curious if the stop switches and programing still function properly if you were to utilize the stop switches for both directions on the axis. Like if you design a set of linkages and levers that could interact with the current switch and trigger it once the bed has gone to its lowest point. I tend to do a lot of tall things and it's unnerving to hear that grinding noise when the bed moves down after finishing a print.