Z-axis steps too small / Extruder too enthusiastic

Hi all, I've just completed my Ormerod 1 build.

I've got it homing all 3 axis and done the bedset.

When printing the "ormaxis.g" file, the extruded PLA gets squashed as it comes out.
When the next layer is extruded it gets squashed even more. after around 4 layers either the nozzle, fan housing or IR sensor board contacts the print.
I can't understand why this would be, especially when I'm using RepRap supplied g code.

I thought I'd try a different print and tried the thin wall test object (thankyou to RepRap forum users) but this has had the same result.

I'm using firmware version Ormerod v07

Any ideas?

Hi Mr_Bodge_It,

Please clarify what firmware version you are using, as v07 either doesn't exist, or is very old indeed! You can retrieve the firmware version by sending M115. Current official firmware is 0.78c AFAIK.

Did you calibrate the extruder steps/mm as described in the instructions? If so, what value did you put in the M92 command in your config.g file?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Sorry, I took the name of the file, thinking it was the version number (oops). M115 gave me this: RepRapFirmware FIRMWARE_VERSION:0.78b

The only reference to 0.78c I can find is in the "Master" branch, not the "Duet" branch. Should I be using that one? Here's the link:

[github.com]

I haven't uploaded this firmware yet - I thought I'd better check first.

The next oops was indeed the value sent with my M92 command - I'd worked it out to 442.1, but for some reason, entered it into the config.g file as 4421.
I've now changed this to 442 and the printer is currently extruding spider silk thin strands of PLA instead of the toothpaste that was coming out yesterday.

DC42 you are a star - many, many thanks

You should use the Master branch of RRP's repository, not the Duet branch (which is obsolete). If you are feeling brave, you can try the Dev branch.

Alternatively, quite a lot of Ormerod users are using my fork, which you can find here [github.com] (use the dev branch). The differences between this and RRP's 0.78b version are listed here: [github.com],

However, if 0.78b is working well for you, you can stick with that for now. The significant change between 0.78b and 0.78c is that 0.78c supports the M305 command to adjust the thermistor parameters, which you don't need to use unless you have one of the very recent Duet boards or a non-standard thermistor.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I didn't know it was obsolete - there was an instruction somewhere that I followed that directed me away from master, to duet branch - I'll see if I can locate it. Good to know though.

I'm not having any trouble with my thermistor. I used heat-sink compound on it when I assembled it. The hope was that it would read a more accurate temperature and more quickly with good thermal contact. (I put it on the fan heat-sink too).
Since I'm still setting up my Ormerod, I'm going to shy away from the scary Dev branch for now.

Z-homing is not too reliable and I end up doing it manually most of the time. As such, axis compensation also has to be done manually. Eventually, I'd like the differential IR Z sensor so I'm sure I'll end up on the Dev branch.
I dare not ask my boss for any more Ormerod money yet, since he's not yet seen a successful print. Although that seems about to change - the Ormaxis print has just gone over 50% to completion and is looking very good

Again, many thanks.