Z-axis out of scale

Hi,
I am trying to make my TZ Huxley with Monotronic work....
Slicing with slic3r and sending the code to TZH with Repsnapper. It prints the Z-axis about 82% of what it should be.
When moving in Z-axis with Pronterface it also moves about 82 %.
The Z-threads are greased and the current is set rather high, so I doubt that it skips steps.
Any suggestions?

That's the techzone specific firmware, it doesn't limitate Z speed properly when also doing X or Y moves together, resulting in Z going too fast and skipping steps.

As a workaround you need to separate the Z movements from others in your slicing software.

I made a solution for skeinforge and one for slic3r, but I have more experience with the skeinforge one.


Note that this is not perfect, it will create a little bit more oozing... Proper solution would be to correct the firmware.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Thanks.
I am running Win7, and have installed citrusperl.
How do I make the script executable?

I don't think you need (or actually have a way) to do that under windows.

I'd say you experiment further and see if it works - I have no experience of running perl on windows.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Thanks,
I looked into the G-code, and the G1 z.. are already isolated, but I am surprised about the feed rate:
....
M104 S200 ; set temperature
G28 ; home all axes
M109 S200 ; wait for temperature to be reached
G90 ; use absolute coordinates
G21 ; set units to millimeters
G92 E0 ; reset extrusion distance
M82 ; use absolute distances for extrusion
G1 Z0.400 F7800.000
G1 X88.300 Y88.850
G1 F1800.000 E1.00000
.....
Is F7800 a normal value?

No, that's way too big for Z (130 mm/s). That's because Slic3r doesn't define a specific speed for Z movement (when I requested it, I was said my firmware should limit it anyway, and as I am stuck with whatever crappy firmware techzone provided, I've gone to making that post processing script instead).

Moreover, you'd need to have a line for defining the start speed of the movement before that. Otherwise the start speed will be whatever was used last.

Something like :

G1 F100.000
G1 Z0.400 F100.000

would be a good start (you can up those speeds, especially the latter, once you found what's your machine specific max Z).

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

I am afraid the problem is more profound. When I send this code:

G28 ; home all axes
G90 ; use absolute coordinates
G21 ; set units to millimeters

G1 F100 ; or 200, makes no difference
G1 Z50

Then the Zaxis moves 40,6 mm....?

Ah, then you have your Z axis miscalibrated.
I think I had something similar too at first now that you mention it, sorry for not remembering that earlier.

You must update your firmware Z_steps value, get sure to use an old arduino software to do that (I use 0.022, but anything under 1.0 should work I think).
Have a look at [reprap.org] for instructions if needed.
I use the Feb 18 2011 firmware from there : [reprap.org]


Attention, you must change values in the "#if MOTHERBOARD == 3" section
Related lines in my setup (old value on first commented line, new good value on second line) :

//#define Z_STEPS_PER_MM   805.030 // had to be multiplied by 1.242189732
#define Z_STEPS_PER_MM   1000

You probably have a similar adjustment to do as 50/40.6 = 1.2481

Other things I changed while we're on the firmware values setting :

extruder steps per mm, found empirically :

//#define E0_STEPS_PER_MM   3.5      // original stock techzone value !!!
#define E0_STEPS_PER_MM   172.0

Communication speed, remember to change in repsnapper too

//#define HOST_BAUD 19200 // *RO
#define HOST_BAUD 115200

Not exactly sure what I changed there, I didn't keep original values. And You could probably use slightly different values depending on how well you mounted the frame.

//our maximum feedrates in mm/minute
#define FAST_XY_FEEDRATE 4800.0
#define FAST_Z_FEEDRATE  120.0

// Data for acceleration calculations
// Comment out the next line to turn accelerations off
#define ACCELERATION_ON
#define SLOW_XY_FEEDRATE 1200.0 // Speed from which to start accelerating
#define SLOW_Z_FEEDRATE 10.0

Damn that machine was far from plug and play now that I remember all those tricks

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Thanks a lot,
I have been a little reluctant to uploade the firmware.
Former I have had problems with having 2 different versions of Arduino, and one thing more, can I be sure that the Feb 18 2011 firmware also is the working on my much younger board?
In the mean time I have printed a 10 teeth pully and replaced the 8 teeth pully. It works almost, but now it skips a few steps.
Thanks

Nice idea about changing the pulley, 8 to 10 is nearly the needed ratio. Note that the pulley you printed is probably a bit too fat X/Y wise, due to the bad Z ratio you had before.


Younger board ? When did you buy your TZ kit ? AFAIK techzone died (well, their website vanished) a few months ago.

I never heard they updated the Monotronics board, but if you can show a picture of your board, I'll try to see if there's any difference from mine.


Also if you're reluctant to upload new firmware, there is a way to backup the existing (using avrdude or a similar command line tool I think) to get on the safe side first. Sorry I don't have the link at hand.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Thanks for your assistance

Did you solve it ?

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Well... yes.. partly. It is printing with OK Z-axis now with a ten teeth pully. But as you know, there are many other problems with it. One is that "M109" kills the monotronics. An other is the Z-axis stop, that is of hopeless construction.
Some day when I have the feeling I will go into the code and make the changes, but I have not had the baud rate of 19200, so I thought that perhaps I have a newer firmware, - that is also the reason, that I would like to have a backup before I change it.

Arduino ver. 0023 gives compliation error: "serial" was not declared in this scope.
Arduino ver. 0022 gives the same error.
Are you sure that you use ver. 0022?

By using arduino v. 0.021 and sanguino 0018_r2_1_4 I could compile and uploade it.
But now almost nothing works with Pronterface. The temp. is not set. All 3 axes are wrong and "go home" for the individual axes interfere with each other.

Yup, you have to use repsnapper with that firmware.

---

Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

I am using RepSnapper by Kulitorum. Have made the changes you suggest + further ajustments on the axis because my hardware uses 1/16 steps.
I can move around OK.
But when I give this code:

M107
M104 S215 ; set temperature
G28 ; home all axes
;M109 S215 ; wait for temperature to be reached
G90 ; use absolute coordinates
G21 ; set units to millimeters
G92 E0 ; reset extrusion distance
M82 ; use absolute distances for extrusion
G1 Z0.400 F100.000
G1 X61.040 Y66.940
G1 F1800.000 E1.00000
G1 X61.060 Y66.670 F540.000 E1.00796

It stops at the second G1 code.
And the communication dies more or less.
???
I have waited until the temperature is OK.

Communication dying : I had to swap my USB cable to one with ferrites on both ends, and plug both the driving computer and my Huxley on an UPS. Before that, it had random deconnects (not so fast then). Not sure which of those 2 improvements helped really.

Or is it something related with X and/or Y endstops maybe, seeing the first G1 is Z only ?

Anyway, if you can do 1/16 steps, you have a different monotronics board.
The Allegro driver ICs on mine are hardwired to do half steps (I don't think they can do better, old model).

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

There are 2 versions of Repsnapper Kulitorum for windows
It looks like one of them (not the first I tried) called Version r351 perhaps works. (it skips a few Z-steps)
Still having problems with your post script. It works in a Command Prompt:
C:/CitrusPerl/bin/perl C:\3-D_printer\TZ_Huxley.pl ThisObject.gcode
But I can't make it work in Slic3r in the tab with post-processing script.

Now the Post-Processing script works. It was my CitrusPerl, that not was installed fully.
But the fan does not start. I can not start it from Repsnapper eigther.

Ah, I have a modification made in the firmware to make the fan work.

I don't have it right here, let me check that later when home.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Found it lost somewhere on my USB keychain. Hopefully is the last I actually use at home.

For the Fan, use first patch attached.


I also include a diff of my configuration.h against the original for reference, see 2nd file attached. It looks like I also changed some max speeds values, might help you with the Z skipping steps.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Oh by the way, didn't succeed in making the fan speed modulated, it can only be on (M106 Sx with x >= 127) or off (M107 or M106 Sx with x<127).

Maybe the AVR pin used is not PWM able, or I did not initialize it properly to do PWM.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Thanks, I have made the changes, and it compiles - so probably no typing errors -, but it don't work.
The version of the board is. v2.1
Does we not have to tell the board which pin number the fan is on? or is it set up somewhere else?

That's in pin.h (motherboard == 3 section as usual) :

#define EXTRUDER_0_FAN_PIN (byte)16

So, I maybe didn't have to change from the default - or that version I have here is not the working one.



Where is the version string on your board ? I cannot locate it on the schematics at [www.reprap.org]
I'll have a look at my board later tonite.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

No version visible on my board top. You should really show us a pic of yours.
Mine is exactly like the pictures on the wiki.


Apart from that, confirming I use pin 16 for fan (from looking both at the board schematic and in the firmware I use).
Did you plug your fan in the little 2-slots screw terminal on the right of the board on that picture : [www.reprap.org] ? Maybe you need to invert the wires, aren't some fan polarised ?

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

The fan was working before I uploaded the modified firmware.

Oh, that's actually quite different. New motor drivers, and probably some rerouting.

As Techzone didn't - AFAIK - publish the schematics for that version or the latest firmware update sources before going off the grid, you need to follow the tracks from the black square component right under the fan screw terminal - probably some sort of mosfet.

One of the track should lead to a pin on the ATMEL µc, probably after going under the card from what I can see here. And so you can know which is your fan pin number (I think the pins number are going clockwise from the first one ,which is right above the little dot in a corner - you should check the atmel data sheet for that given model).



As an alternative, you could pester techzone people to release their last sources. They did put some solid job into that board, would be stupid to let it die away because they have some business problems (just guessing here).

Here the whois data for their site :

Registered through: GoDaddy.com, LLC (http://www.godaddy.com)
   Domain Name: TECHZONECOM.COM
      Created on: 07-Aug-08
      Expires on: 07-Aug-13
      Last Updated on: 13-Aug-12

   Registrant:
   Kimberly Andrus
   86 S Stout
   Blackfoot, Idaho 83221
   United States

   Administrative Contact:
      Andrus, Kimberly  kymberlyandrus@yahoo.com
      86 S Stout
      Blackfoot, Idaho 83221
      United States
      +1.2085897419

   Technical Contact:
      Andrus, Kimberly  kymberlyandrus@yahoo.com
      86 S Stout
      Blackfoot, Idaho 83221
      United States
      +1.2085897419

   Domain servers in listed order:
      NS1.LAMBERTANDRUS.COM
      NS2.LAMBERTANDRUS.COM

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

It was a typing error, Now the fan works !!!!
Thank you very much for your assistance.

I have send several e-mails to Kimberly without getting answer, sometimes he answers after one week. never knows.