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As there doesn't seem to be an official mounting location for the endstops on the H1.1 I just wanted to confirm that I put them on the correct end of each axis.

Z - bottom (nozzle against table)
Y - Back of table (nozzle at front of table)
X - left of machine (nozzle at left of table)

Is that correct?

That's the usual convention for printers.
I home my Z to the top (like a mill) and modify the firmware to home Z first, I then specify the known offset from the stop to the table so that Z=0 is on the table.
This prevents several issues.
Since I'm specifying an offset for Z, I don't need to micro adjust the Z endstop to get it exactly on the table, I can just fasten it securely then measure the offset.
It also prevents running your printhead into whatever is holding your buildplate to the bed when homing.
I stole the idea from http://hydraraptor.blogspot.com/2012/06 ... is-up.html

Wouldn't you run the risk of crashing the tip into the table if your measurement wasn't exactly right?

Yes, but you run that risk every time you change the table surface if you want to experiment with various surfaces. Since you're going to have to adjust Z zero anyway, might as well do it from the top where you know that homing your machine will not crash the head into anything.

For those that are never going to change their bed, micro adjusting Z zero to the bottom at the bed makes sense, as long as you're careful never to home your machine when you have anything on the bed.

My experience with "microadjustable endstops" is they aren't and they tend to creep. It's much easier to do the measurement once when you replace the table, than trying to fiddle with the endstop adjuster. In Mach it's trivial since the DRO's are accurate, if you're using an arduino based controller, you just set Zero at the endstop, move the head down to the table using some sort of feeler gauge (say a piece of paper) type M114 and note the Z value, that's the measured value from the stop to the table.
I rigidly mount my table (no springs), which means I rarely have to level or re-measure the value. I can usually tell if it's off by the way the first layer goes down.
If the measurement is miles off and the head does crash into the table as it approaches 0, the Y bars flex and the stepper stalls, you move it back up and no harm done.

But as I said it's usually the case on printers that people mount the endstop at Z = 0, it's just never made any sense to me.

Anyone have any guidance for modifying the firmware for a RAMPS 1.4 board to make homing that the max position work? I can't get it working.

Should the endstop be plugged into the max connector on the board or still on the min? What do I change in the firmware to get this to work. I've tried everything and can't get it to work. the endstop always acts as a min endstop.

jasco, John here. which firmware are you running? Marlin, Sprinter, Repetier? I've included a screenshot of

Marlin
And Repetier




The configuration.h files are where you need to make those changes. Don't be afraid to hack away at the firmware, you learn most by breaking stuff!

I'm Using Sprinter currently. I tried Marlin, but had the same problem.

Yeah I changed the z to 1 from -1, but the behavior seems to be the same either way I set it. Triggering the endstop only stops movement when moving in the negative direction. If travel in the positive direction, triggering the endstop doesn't do anything.

The endstop trigger is being registered. Using Pronsole I can send M119 and see that endstop status changes when I manually trigger it.

If I use the endstop to the max position do I still plug it into the min pins on the board or use the max. If I use the max pins the endstop doesn't currently do anything when triggered.

Do I set the max length for Z to be a negative value?

Did you change the Z home position from 0 to whatever your max Z is? It might be reading your max Z is zero, and therefore looking for home in the Z direction relative to where it is?

Sure didn't. Wasn't entirely sure what routine it was using to figure things out. I'll change that this evening and see what I get.

Thanks,

Matt

Hey, no problem. I'm not entirely sure either, so I'll wait to hear your results! Lol.

Could you please post a complete working version of sprinter, marlin, or some other firmware for RAMPS. It would be very, very, very, very helpful. At least If I knew I had a fully function firmware I could then begin to troubleshoot the endstop issue. I think I must have other firmware problems.

Matt

Just had a moment! Take a look at the attached pic, and see the #define_Z_max_pin, by default it is set to -1 or disabled. If you are using a Z limit at the top, try enabling that pin (looks like pin 19 on a RAMPS 1.4 setup) and try that. The board may not be recognizing that there is a max (positive) limit/home switch, and that could be causing the problems!

I also added a zip file of the repetier fw i'm running, notice the pins.h have been modded, so you might want to use your pins.h file

i think that may have been my problem with the sprinter firmware. The version of Sprinter I had did not have very many endstop options. couldn't define a z max. Couldn't define a homing position. Switched to Marlin. More choices. Got everything up and running last night and the homing is working correctly.

Last problem I have is with repetier. when I home in repetier it goes through the proper routine, but the software shows the home position for Z as 0. If I send M114 the board does say that my position for Z (at home) is 150.5. So the board knows where it is, but repetier thinks it is at zero. If I manually send G-code The Z-axis moves to the correct position, but I can't get repetier to display the correct z axis value. I think it should print correctly since printing runs off G-code and not where the software thinks it is.

Looked all over and couldn't find an option to configure the endstop position in repetier. Any Ideas on that one?

Pronterface works fine, but it doesn't display positions unless you send M114 so it seems to work entirely off the board.

I just looked at repetier, and see there are boxes to check for x and y at "max" positions, I'm emailing him to see about adding Z to that as well. That's why repetier is showing Z=0.00

Yup, saw that. Not sure why there isn't a check box for Z. Maybe in an upgrade. I did do a dry run just now and the homing and return to zero work as they should during printing. It is just the software display that is wrong.

Now to sort out my starting G-code routine and I'll be off printing/calibrating.

jasco,I emailed rep, and he said no problem, he will add that to the next release of repetier. He hadn't heard of anyone with a max z home switch, and I told him it's fairly common in other CNC's to have the Z home at the upper travel limit. Give it a few days, and I'm sure it will be on there.

Sorry for a slight hijack but the subject is endstop mounting

Could somebody (or everybody) post pics of how and where they physically mount the endstop switches? I plan on placing the Z at max. For Y I am planning to put the switch in the front so homing gets the part out toward the operator. X will be on the right so the wiring can route with the stepper bundle. It's interesting that the design doesn't include switch mounts. The X belt attachment seems like an afterthought too.