homemade ormerod?

I'm in the process of choosing a new printer to build for fun mostly and the ormerod is really attractive to me despite its issues that may or may not be fixed yet (idk). I don't want to spend 500 euros on a kit because I think I can source it myself much cheaper. I have a small desktop cnc machine which I'll be able to cut acrylic pieces with so I'm good there. As nice as the duet board sounds, internet capability and the ir homing sound more of a gimmick to me. I was wondering if the ormerod structure would work with ramps? I feel like it would because its the same axis orientation as my prusa, but I wanted to make sure. Plus I can get a ramps board for half of the duet cost.

see thread replicating ormerod. Yes you could save even more by using ramps but is it worth it to depart from standard could cost more in time lost.

Rory

The Duet board is far more capable than RAMPS. Don't forget that as well as the RAMPS board, you need to add four Pololu stepper driver boards and an Arduino Mega.

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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].

gman, I'm with dc42 on the goodness of the duet - it's a pretty elegant all-in-one solution for controlling three axes plus extruder (with a view to expanding extruder numbers), and control of bed heating.
I can see myself building a different mechanism for the duet to control in the long-run, but the way the Ormerod is designed at present is pretty functional. One of the worst design decisions in my opinion is the reliance on acrylic - it's not particularly rigid for its weight, and it's brittle - if your cnc would cope, I'd go for aluminium, if not a composite like whale brand tufnol or similar SRBF (not ruling out glass or carbon fibre SRBF's of course, but glass is nasty to machine and carbon fibre is pricey, and tufnol comes in a wide range of thicknesses).

Looking around there are plenty of cool mechanisms to choose from (tantillus is my favourite so far for many reasons), and if I had time I'd have a go at blending some features from each of these together then hook up my duet to the end product.

Ray

I was considering sourcing the ormerod myself, but the price really adds up more than other printers I can build. Mostly because of the different sized 12mm bearings and the bowden extruder. Buying all the parts yourself is only slightly cheaper than a complete kit unfortunately which makes me want to save my money for a kit and save a lot of time too. Or I'll wait for them to sell hardware kits if they ever get to that. Anybody ever hear of any rumors about the hardware kits coming out?

Aluminum seems like a better solution than acrylic. I've got good bits so I'm sure my cnc machine could handle it but I've only used it to cut plastic and wood so far.

Ian (droftarts on this forum) who is the reprappro support guy, says that the hardware kits are definitely in the pipeline, and I'm sure that with economy of scale they'll be cheaper than sourcing individual parts. If you already have a machine with similar axis layout (like your prusa), you might consider starting with buying a duet (from reprappro or think3Dprint3D) and hooking it up as a controller with reprappro firmware to see how it works on there - you'll need to get an optical Z probe from RRP though if you want to home Z and X (it checks reflected light from the bed, and from a piece of plastic at the right height near the home position of X rather than using two microswitches).

When Ian see this thread I'm sure he'll be able to give you better options and more info on the hardware kit availability,

Ray

Quote
rayhicks
... snip ... you'll need to get an optical Z probe from RRP though if you want to home Z and X (it checks reflected light from the bed, and from a piece of plastic at the right height near the home position of X rather than using two microswitches).
Ray

It would be easy enough to wire a microswitch to work on the Duet for X homing. Assuming the microswitch is normally closed and opens with X in the home position, wire one contact to ground (black wire on the Omerod IR connector), and the other contact to the Duet input (blue wire). To that same contact used as the input, also connect a resistor (2k2 should be fine), and connect the other side of the resistor to 3.3V (red wire). Obviously you won't have any Z homing, but then I've not found that reliable enough to use anyway.

Dave
(#106)

Ahhh, good idea Dave - I've taken my Z probe off (I have a roller bearing mounted there), and avoid hitting any home buttons - I'd asked if gcodes could be added to allow X and Z to be switch based (the hardware's there but no use without the firmware) but didn't get any positive response to that thread from rrp. That's my first project tomorrow

Cheers

Ray

Ray

I thought I'd said how to edit the firmware to turn off the Z probe, and enable the X and Z microswitch terminals? Maybe I dreamt it.

Ian
RepRapPro tech support

Hi Ian, you did when we discussed it in irc (I'd already seen pretty much what to change in the source files), but that method would involve me getting a development system together I can hack a switch and a resistor, and I could enter a gcode (if the firmware would recognise one to enable the right pin), but just now I'm not able to compile my own firmware and won't be for some time - it would seem reasonable that you (or maybe t3dp3d) do provide support in firmware for gcodes to enable more functionality from the duet, but I know your to-do list is still not short enough for random feature requests to hit the top

Ray

Ah, that was it. I'll dig the logs out, and post what needs to be done here.

Ian
RepRapPro tech support

Hi Ian,

Mentioned it in one of my posts here after seeing it in the build photos or at least one of them. I don't think you posted any details on how to convert?

Dieter

Ormerod #257

There is already some support in the firmware for X and Z low-stop microswitches. In particular, the pin numbers for them are already defined:

#define LOW_STOP_PINS {11, -1, 60, 31}
#define HIGH_STOP_PINS {-1, 28, -1, -1}

These are Arduino Due pin numbers, not mcu pin numbers. The internal pullup resistors for these pins are enabled, so you don't need an external one unless noise pickup is a problem. The firmware assumes you are using microswitches for X and Z if the z-probe type is 0, which is the default if you don't have an M558 command in config.sys. But as I use the IR probe, I don't know whether this code works.

One thing you would definitely need to change is the homez.g file in the sys folder of the SD card. The current one does a G30. Instead of this, you would need to move the head down until the endstop is detected, much like homex.g does.

Edited 1 time(s). Last edit at 01/23/2014 05:53AM by dc42.

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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].

Great thanks dc42!- I'll explore those changes after my print finishes

Cheers

Ray

So... what about that hardware kit? I can't wait!

Eric

Hello

Can someone explain to me the changes that i would need to make to add homing mircoswitches on the software level. And also what pins on what header for the wiring on the due

I have plenty of micro switches left over from another project and the IR on my machine has been fully removed as it was causing me many more problems that it solved

Thanks

The only software change you need to make to use microswitches instead of the IR sensor is to use M558 P0 in config.g instead of M558 P1, or omit the M558 command altogether. Connect the switches just as you have connected the y switch, but of course use the pins near the x and z motor connections.

My IR sensor is working beautifully now - but I have modified it (added modulation) and mounted it on the print head so that it is in line with the nozzle in the x-direction.

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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 got impatient at Christmas and decided to build my own ormerod .... Finding all the parts is going to be a challenge and I just worked out the fixings and screws I need (over 20 different types)... So far I will get my printed parts and aluminium, bearings and motors delivered by the end of the month. Excited about this - but in hindsight ordering the kit may have been a wiser strategy... Too late now,

If you are making your own parts then I suggest you make at least the following changes to the standard design:

1. Redo the bed support in aluminium (see [forums.reprap.org]), or if you use MDF then reinforce it (see [forums.reprap.org]). Otherwise, the back corners of the MDF bed support sag by variable amounts, which means that the bed levelling isn't stable.

2. Add three manual bed-levelling screws described in the Commissioning instructions. That means you don't need to rely on the IR sensor other than for X homing. The IR sensor can be made to work well, but only if you either shield the Ormerod well from sunlight and incandescent light, or add modulation.

3. Use cable ties or some other mechanism to ensure that the y-belt is taut and cannot slip in the slot that it is supposed to lock into.

4. Use photo frame clips instead of foldback clips for holding the glass printing surface in place.

These are the minimum changes that I regard as essential to get good, reproducible prints.

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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'm tired of not getting any advice from RRP about when the hardware kits might ship, so I'll probably start buying the hardware parts/vitamins myself. I've started compiling a BOM here with the parts list in a pdf on githup as starting point. Most of the parts should be easy enough to find, but some are giving me a headache:
- Will any 20x40 extrusions be fine? RRP uses Bosch Rexroth ones, but I guess that any other should fit as well.
- Where can I get all the acrylic parts cut out? Ideally, I would replace them by aluminium parts, does anyone know a service that ships to/is located in Germany?
- Will I be able to use the Mendel hotend kit that RRP sells on emakershop for Ormerod?
- Can I buy the IR sensor PCB from RRP? I know I can use microswitches, but I would love to play with the IR sensor.
- Wires and connectors: not sure what I would need to buy. Will probably depend on the switches, motors etc. that I'll get.
This is exactly why I would really prefer to buy a kit, but all these printed and ready Ormerod pieces are smiling at me all day long...

Any comments would be appreciated!

--Eric

Buried in a thread a long while ago is the startings of a complete parts list with suppliers

[docs.google.com]

Parts Threads
[forums.reprap.org]

Matt

Edited 1 time(s). Last edit at 02/07/2014 08:40AM by iamburny.

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Limited Edition Red RS Ormerod 1 #144 of 200 - RRP 1.09fw
iamburnys Ormerod Upgrades Github
Follow me on ThingiVerse My Designs

Regarding the IR sensor, I strongly recommend that you go for a modulated one. I expect that RRP will be selling these within a few weeks. I am also considering making a modulated sensor pcb that fits on the hot end, and that integrates the hot end connector and a light to illuminate the work. See [forums.reprap.org].

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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].

Thanks, Matt, I consolidated the two lists.

[docs.google.com]

Quote
eaj29
...Where can I get all the acrylic parts cut out? Ideally, I would replace them by aluminium parts, does anyone know a service that ships to/is located in Germany?
--Eric

I would go for the aluminum solution, the X-axis in acrylic is not stable and will give you pain, the planned two more extruder's will not better that
Where to get the parts cut? - anywhere in any industrial sector of Germany I would think, here in Denmark I have plasma cutters to the left, laser ditto to the right

Erik

Quote
dc42
Regarding the IR sensor, I strongly recommend that you go for a modulated one. I expect that RRP will be selling these within a few weeks. I am also considering making a modulated sensor pcb that fits on the hot end, and that integrates the hot end connector and a light to illuminate the work. See [forums.reprap.org].

Will it work with semitransparent bed - sanded glass or antiglare relief glass ?

Edited 1 time(s). Last edit at 03/09/2014 12:47PM by karabas.

Quote
karabas
Will it work with semitransparent bed - sanded glass or antiblink relief glass ?

Sorry, I don't know what antiblink relief glass is, and neither does Google. Do you mean can you use light reflected off a particular type of glass, without using white tape? I just tried reflecting off a piece of frosted glass, and the highest reading I could get was about 80. However, Kim reported good results using red glass. I'm not sure whether he was using the reflection from the glass, or from the aluminium bed under the glass.

I am now manufacturing modulated IR (and ultrasonic) sensors, see [forums.reprap.org].

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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].

Quote
dc42

Quote
karabas
Will it work with semitransparent bed - sanded glass or antiblink relief glass ?

Sorry, I don't know what antiblink relief glass is, and neither does Google. Do you mean can you use light reflected off a particular type of glass, without using white tape? I just tried reflecting off a piece of frosted glass, and the highest reading I could get was about 80. However, Kim reported good results using red glass. I'm not sure whether he was using the reflection from the glass, or from the aluminium bed under the glass.

I am now manufacturing modulated IR (and ultrasonic) sensors, see [forums.reprap.org].

Sorry, I want to say anti glare glass. Or maybe more exact name exists...
Now I see it seems no way for me to use IR or ultrasonic as I use 120C 2mm glass (painted with beer)
I never cool the bed between prints just replace glass. That is why I need any reliable Z sensor.

Edited 2 time(s). Last edit at 03/09/2014 12:57PM by karabas.

Maybe you can design a fan duct that blows air over the sensor head to keep it cool?

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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].

Quote
karabas
I never cool the bed between prints just replace glass. That is why I need any reliable Z sensor.

Just for kicks, I stuck a limit switch from a scrapped inkjet printer on the hot-end assembly and it seemed to work just fine. Someone remind me why a dumb switch isn't good enough?

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RS Components Reprap Ormerod No. 481

because it might scrape up some of the print? - mind you a large diameter ball-bearing constrained in a tube, and pushing on the the switch wouldn't...

Ray