Reversing the "Z" reading

When my printer, Delta Metal Max, with Marlin 1.6.1 RC6 firmware homes at the top all axis are at zero. When I run the Z axis to the bed the Y axis and X axis are still zero but Z axis is 270. Is this the way it's supposed to be or is there a way to make that Z reading "0" also. Is there a way to reverse this? It just seems confusing to me the way it is. I know this is a newbie question but I have to learn somehow.

Are you reading this on a display on the printer, or in Pronterface or Repetier Host?

I'm reading it in Mattercontrol and also on the LCD.

z endtsop should be max and you need to take it down to the bed Ii think its G92 z0 then home machine

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My Z endstop is set to max as is X and Y. But when I lower it to the bed Z is 270. These are the numbers I want to reverse. I want Z to be 0 when it's at the bed.

Upload your configuration.h

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Thanks for the reply. Here is the Configuration.h. Configuration.h

I can't see anything wrong with it.
Perhaps someone else can see what is going on?

I presume this is the version currently uploaded onto the machine?

With the Marlin 1.1.0 RCx firmware the configuration.h files change a lot from one version to the next (one day to the next at times). If you went through and manually entered everything to the correct values that's fine. If you literally copied and pasted a complete configuration.h file from a previous firmware version you will likely have problems.

I have just started using RC7 and it does seem to be better in few ways, but I'm using it on a corexy not a delta.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Yes, that is the version I'm using. I didn't copy anyone elses, I filled it in myself. I tried using the latest version but had problems with the automatic versioning, The developers didn't update the "examples Directory" and the new version firmware would not compile with the old Examples directory Configuration.h version. And you have to use the file from the examples directory for a Delta machine. The last time I checked they were updating the versions in all the example folders. I posted this on the SeeMeCNC forum also but nobody there knew how to fix iy because they all use Repetier firmware. I wish there was something written with more depth explaining the Marlin firmware.

Well I think there will be when they actually release 1.1.0 but at the moment its all beta.
If you want to use 1.0.2 then its stable but a lot of the good stuff isn't in there.

I use Rich Cattels version for my mini kossel, if you have a z probe it does auto-calibration which certainly gets you going faster. My new delta uses reprap firmware as I have a DuetWifi board. So I haven't really used up to date Marlin on a delta.

There's definitely something in there we are both missing though. I suspected it was manual home positions but you filled that in perfectly. Might be worth trying to change that to -277 and just upload it and see what happens - just a stab in the dark.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

You need:

// Invert the stepper direction. Change (or reverse the motor connector) if an axis goes the wrong way.
#define INVERT_X_DIR false // DELTA does not invert
#define INVERT_Y_DIR false
#define INVERT_Z_DIR false

#define min_software_endstops false // If true, axis won't move to coordinates less than HOME_POS.
#define max_software_endstops true  // If true, axis won't move to coordinates greater than the defined lengths below.

Be careful when homing! It might move your carriage the wrong way. You need to have one hand on the power switch and turn off if it goes the wrong way. It should home to the top of your towers.

I've attached my config file from when I was using Marlin. This one was working fine. Do a diff on this, compared to yours, and see what's different.

Well, the stab in the dark worked. I commented out what was there and put 270 for the value. And now 0 is at the bed and 270 is at the Max endstop. Thanks, my friend, I've been playing with that problem for a week and a half. Now I have to calibrate the Z distance. When x and y move 100mm z only moves 80mm.

Hmm the x and y moving further than z is very odd unless your drive pulleys on your motors are not all the same? Do you have 16 tooth pulleys on x and y and a 20 tooth pulley on z.

I can't think of another explanation. It can't be the firmware as this is going to send the name number of steps to each motor based on your configuration.h and it can't be a 0.9 deg motor mixed in with 1.8 deg motors or the difference would be 50% not 20%.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Quote
jmalinski
Well, the stab in the dark worked. I commented out what was there and put 270 for the value. And now 0 is at the bed and 270 is at the Max endstop. Thanks, my friend, I've been playing with that problem for a week and a half. Now I have to calibrate the Z distance. When x and y move 100mm z only moves 80mm.

[attachment 84379 homing.png]

You have eeprom turned on, so the bad steps per mm might be stored in eeprom.

What does Pronterface say when you first connect to the printer?

Thanks, Nebbian for replying. I don't know if it's exactly twenty percent but when I drop z down to the bed the x and y carriages stay at the same level but z drops back. so that when I reach the bed the effector is not centered but pulled to a -51 on the y axis.

I solved the problem, Nebbian was right earlier, or I should say on the right track. The pully was screwed up. Those aluminum gears are really made of three parts pressed together, and the end flange had seperated and the belt was riding half on the gear and half off. I replaced it and everything is good now and I can finally start the calibrating. Thanks everybody for your help.

Glad you figured it out. That kind of physical problem can be really tricky to find.

Good luck with the rest of the calibration