UM too old for Marlin?

[hp-65 4]

Hi all,

I bought my UM around 9/2011.

Until now, I never used anything else but 0025 with 5D FW,

and I never had any problems.

Recent tries to upgrade to 0035 or Cura failed due to some,

yet unknown, incompatibilities with the Marlin firmware.

As soon as Marlin is loaded, nothing further happens...

Where can I find a description or history of the UM hardware?

Do I need any new electronics or can I build a Marlin compatible

version for my old stuff?

thx

[Daid 306]

Can you check if you have an Arduino Mega 2560, or an old Arduino Mega?

Also, check if you have 1.5.4 electronics or older. (It's on the green PCB, near the On/Off switch)

See the difference:

http://arduino.cc/en/Main/ArduinoBoardMega

http://arduino.cc/en/Main/ArduinoBoardMega2560

New machines are shipped with the 2560, but a few old machines have the older Arduino, causing the Cura updater to fail.

A few old machines are also shipped with 1.3 electronics, which require different settings to work.

[codemaven 0]

Hi Daid,

What settings are required for older electronics? What are the known symptoms of running marlin on the unsupported hardware? I know I have the Mega2550 Arduino and I believe I have the 1.5.4 electronics, but I have had issues with the newest firmware myself. I've not posted about it before because I just haven't had time to collect appropriate details and experiment...

Basically, I'm running a very old 'experimental' build of Marlin built by Bernhard Kubicek around October or November of last year. It works great, but I've tried a few times to update to a current version of Marlin and every time I end up going back to the old build. I currently print at an extrusion temperature of 175 with this firmware, but on the newer Marlin I cannot get any extrusion at all below about 220 degrees. And I don't get consistent flow and layers that stick together under 240 degrees. Even at 240 as soon as I try to take the object off the platform it just de-laminates and basically crumbles. I also get bowden tube plugs when trying to print with the new Marlin firmware at these high temps, but have no problem with them on the old experimental build... Is it possible that my temp is reading way off on the new one? Is there a setting somewhere for the thermocouple raw value to temperature mapping?

Thanks,

Troy.

[Daid 306]

If you try to install the wrong Marlin on a Mega (instead of a Mega2560) it will not work, but Cura's updater will fail before that, as it only supports the Mega2560. If you install Marlin on older electronics, it will most likely start, but fail to do anything as the pin settings are wrong. But there are very few 1.3 electronics boards out there. Most run 1.5.4 and new machines get 1.5.6 (which are compatible with each other)

[hp-65 4]

but Cura's updater will fail before that, as it only supports the Mega2560.

If this is true, my board is a Mega2560, because I used Cura to update the FW to Marlin, but

it refused to program it back to 5D. I had to use 0025...

I will open the machine and take a look inside, when I'm back home...

Are there any additional, external HW changes?

Temperature sensor, inverted end switches or anything else that could

interfere here?

 

But there are very few 1.3 electronics boards out there. Most run 1.5.4 and new machines get 1.5.6 (which are compatible with each other)

I am pretty sure my board is 1.5.4...

I found schematics of 1.5.3 and 1.5.4. The only differences are the fan connectors and minor

layout changes around the screw terminals.

Where can I find the docs for 1.5.6 (or 1.5.5)?

[Daid 306]

There are no hardware changes that I know off that causes incompatibilities, except for the 1.3 electronics. You could try the firmware from Cura RC4, I am getting some strange reports from the Cura 12.07 firmware from other people...

Electronics 1.5.5 was never released. The 1.5.6 schematics are on thingiverse.

[hp-65 4]

I disassembled it and found:

- Mega 2560

- UM PCB rev. 1.5.4

As far as I understood, this should work with Marlin, but it doesn't...

I really would appreciate any help or hints on this!

I am getting some strange reports from the Cura 12.07 firmware from other people...

What do they report?

Minor issues like bad printing results or real blockers, like "nothing is working",

like here?

But as I already wrote, this is not (only) related to Cura.

0035 (with Marlin) does exactly the same:

Absolutely nothing...

[hp-65 4]

A little late, but maybe this is of interest for others, who have

comparable issues (though this is somehow unlikely ;-) )

I wrote some test programs and discovered some defective

SRAM cells. I replaced the MCU and made a tiny step forward:

At least I was able to connect to the machine, control X, Y, Z,

the heater and everything else, except for the extruder.

I hooked up a scope and found out that the extruder was operated

at a ridiculous low speed, only a few ticks per second (on fastest

extrusion settings).

After browsing the source code, I found the magic and undocumented

modal code M92.

BTW, stuff like this is really brilliant >8-(

 

           if(value < 20.0) {             float factor = axis_steps_per_unit[i] / value; // increase e constants if M92 E14 is given for netfab.             max_e_jerk *= factor;             max_feedrate[i] *= factor;             axis_steps_per_sqr_second[i] *= factor;           }

 

Adding a

M92 E865.888

which I read in a post somewhere else, feels like the extruder is

running with the right speed, but at this point a lot of other problems popped up.

(E865.888 is a ridiculous value, at least regarding the physical tolerances

of an extruder).

Until now, I wasn't able to print with with 0040 or Cura.

Maybe only a few or more steps forward...

;-)