An Ormerod in 2020 ...



  • I have too many projects. So I did the sensible thing and laid the foundation for a new one: I got an Ormerod from 2014 (according to the packing list date, January 22nd 2014). I never knew there were times where you'd get signed letters with your printer ....

    All the plastic parts are deformed, cracked, cracking, broken, and in parts fixed with wood replacements or superglue plus baking soda. I'll reprint them in ASA. Not sure what to do about the hotend and extruder, but I did scour the Ormerod improvements and will likely add some of them en passant.

    IMG_20200620_103351.jpg
    IMG_20200620_100251.jpg



  • FIRMWARE_NAME:RepRapFirmware FIRMWARE_VERSION:0.57a ELECTRONICS:Duet DATE:2014-01-16

    Alright then, time to go spelunking (-:


  • administrators

    Latest firmware for the Duet 0.6 is version 1.26.1 at https://github.com/Duet3D/RepRapFirmware/releases/tag/2.05.1. You will need to install Duet Web Control on the SD card to use it. You will also need to make some changes to your config file, in particular reverse the X axis direction (M569) and add M574 commands to define the endstop switches.

    There was a change to the pin that the proximity sensor is wired to, but I don't remember whether that was before or after firmware 0.57a.



  • Thanks, I'll take it slow here (-:



  • Thanks to the documentation conserved on the RepRapLtd website, I found the right pin -- it was indeed on another one before!

    The usage of the proximity probe for both X and Z is quite ingenious, I like it. But before I can run this printer, I need to fix up a couple things: More broken parts to replace, the extruder is sketchy (but might work), the hotend thermistor shows about 15C too cold (12.5C at an ambient temp of 24) -- not comfortable with that considering the offgassing of the PTFE liner will start at 200C and be dangerous for humans at about 240-250. I may need to switch out the full print head (it's still an original one and in bad shape).


  • administrators

    @oliof said in An Ormerod in 2020 ...:

    ...the hotend thermistor shows about 15C too cold (12.5C at an ambient temp of 24) -- not comfortable with that considering the offgassing of the PTFE liner will start at 200C and be dangerous for humans at about 240-250. I may need to switch out the full print head (it's still an original one and in bad shape).

    Your best bet may be to generate new configuration and homing files using the online tool at https://configtool.reprapfirmware.org/Start.

    Low reading at room temperature was a common issue with early Duet 0.6 boards (the ones with 1K thermistor series resistors). The reading will be more accurate at printing temperatures; however you can correct for it using the H parameter in the M305 command for that heater. The value of H can be positive or negative and is normally in the range -60 to +60. In theory, all heaters should need the same H value.

    BTW I found the original Ormerod hot ends extremely reliable, much more tolerant of retractions that all-metal hot ends. But of course the PTFE liner limits the materials you can print with.

    HTH David


  • Moderator

    @oliof nice to see one getting renovated! I was tech support at RepRapPro, and took most of the pictures and wrote a lot of the words for the documentation.

    Worst bit of Ormerod was the connection between the Z upright and Y horizontal extrusion, and the acrylic Y ends. The weight on these tended to make them droop, causing one end of the X axis to drop closer to the bed than the other. Look at alternatives to strengthen these areas.

    Otherwise they were pretty reliable, though we never swapped out all the Mendels in the print room for Ormerods!

    Ian



  • There we go:

    https://photos.app.goo.gl/nQznDbaVBKxtwcVL9

    @dc42 @droftarts thanks for the kind words (-:

    I'm trying to motivate Wes Brooks from the reprap forums to share his work on Ormerod in 2019, but if they don't follow up, I'll add some of the improvements from the wiki ...

    The Ormerod was great in 2013 -- it's interesting to see how much and how little 3d printers evolved since then at the same time. I think it would still be great to have something like it in 2020.



  • ormerod-riskable-vase.jpg

    far from perfect, but even unmodified with just some replacement parts printed, I am happy with the result.


  • Moderator

    @oliof the same design is still in use in the Cetus machines, and, of course, the Prusa Mini. Though both of them, perhaps sensibly, have more robust mechanics!

    Ian



  • Sure, but the Prusa Mini is skirting the idea of RepRap / Open Source with it's hardware fuse and hard-to-source special parts (and basically not available with it's 3 month lead time), and the Cetus is proprietary from the get-go. So they don't compare to early reprap machines to me in spirit, only in design.



  • PS: Working on replacing the glass-and-kapton print surface with FR4/garolite. Tests later this week!



  • I was asked to print a miniature for a friend's friend in hospital, and I wanted to give the Ormerod a spin. So far, the only change was to bend the M5 rods by accident and adding @droftarts 3 point mount for the bed because the MDF frame seriously warped ...

    For a test run I chose Rocket Pig Games' Kitsune (they make great support free minis). I printed it in JMOTech PLA (pure 4043D resin) at 210C on a 60C bed. I am having a bit of trouble with the proximity sensor, so I used a raft, like it's 2013. Appropriate for the Ormerod (-:

    Here are some close-ups of the model off the printer, with only the raft (mostly) removed. It looks better at two feed. A skilled miniature painter could make something nice from this (-:

    kitsune1.jpg
    kitsune2.jpg
    kitsune3.jpg
    kitsune4.jpg

    Next step is adding part cooling I guess (-:


  • Moderator

    @oliof yes, definitely looks like it printed a bit hot, and without part cooling!

    Ian



  • My first attempt at printing a fan duct for a separate part cooling fan failed because I didn't understand Ian Burmey's design before modifying it in OpenSCAD. Back to the (virtual) drawing board!

    Does anyone know whether the hotend fan is PWMable / supports thermostatic control? The old 4020 is super loud and it would be nice if it just turned off when it's not needed.


  • administrators

    Assuming your Ormerod is still using the original Duet 0.6 controller, there is only one controllable fan output.



  • @dc42 it's currently still using the original board. I'll try to source a more quiet fan then (-: I kind of enjoy the singing of the steppers with these old drivers (-:



  • Progress with some "original" upgrades: tensioning extruder and herringbone gears are a go, at least in this dry run:

    https://photos.app.goo.gl/MfdNzu5QyG21fXnm6



  • And this just came in the mail ...

    IMG_20200715_125602.jpg
    IMG_20200715_131250.jpg
    IMG_20200715_131312.jpg

    courtesy of ddmetalworks. Needs to wait a couple days until I can install it.

    Inspecting the printer I found another cracked part:

    IMG_20200715_125856.jpg

    Which needs reprinting. Unfortunately my roll of rpet is done. I'm considering reprinting this one in ASA.


  • Moderator

    @oliof said in An Ormerod in 2020 ...:

    And this just came in the mail ...

    Nice! I never tried one, but I understood they helped keep everything straight.

    Ian



  • It's elemental to my final plan for this one. I also forgot to show the intermediate state on a new bed (MK2 A4 alu bed, increasing print size to 200x300x250 is the goal).
    IMG_20200715_132432.jpg



  • IMG_20200719_220817.jpg

    Aluminum X arm installed. One Z linear bearing clamp and the hotend carriage did not survive bolts being removed and added again -- I'll replace them in due time. The hotend carriage will get a full overhaul, so I won't waste time and material reprinting the original design.

    I also added an integrated leadscrew stepper I had lying around from a project that never saw the light of day ...



  • This weekend I managed to work on a kinematic mount for the heated bed which is magnetically coupled to the bed carriage.

    IMG_20200726_174935.jpg

    The magnet rides in a slot and the coupling is done via a magnet on the underside of the carriage

    IMG_20200726_175107.jpg

    The magnet coupling in this prototype is strong enough to hold the bed with the t-carriage upside down, but only just so. Still needs some tweaking to be correct, but that's for another night ...


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