Armerod - Ormerod and ABS printing
Posted by chrishamm
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Armerod - Ormerod and ABS printing March 19, 2014 03:11PM |
Hello everyone,
I'd like to share my experience about printing ABS with an RRP Ormerod. First of all, huge thanks to dc42 and iamburny for their software (and hardware) improvements (can't say it often enough)! During the last few weeks, I built my custom Ormerod made for ABS printing, called the Armerod
It took me a couple weeks to get to the point I am at right now, so here are a few suggestions and improvements for printing ABS, as well as some hints for those struggling to get their Ormerod up and running. I love the idea of open source projects, so I hope the following description is useful.
Issues getting the Ormerod running
While building my Ormerod, the first thing I noticed was the Y rib not being hold tight to the front Y bearing. Because I couldn't print any support parts at this time, I simply took a cable tie and tied it through the hole around the bearing. Not ideal, but has been proven to work.
After putting all parts together, the next issue I had was the SD card. The shipped one was simply not working (some SanDisk microSD card). After a little searching I found out why and tried three different microSD cards until I found one 8GB card that works.
Later, I noticed my heated bed had become very unstable and this was caused by the Y bearing clamps. They detached from the two rear bearings (I guess due to missing friction) so I decided to drill a small hole into each clamp and screwed some short self-tapping screws into these holes to grab into the bearing notches. RRP, wouldn't it make sense to modify these clamps so they grab into these notches right during assembly?
To add a little more support, I took out the aluminium heat spreader (as seen on this forum) and mounted it on top of the MDF plate.
I know there are several attempts to improve the heated bed, but I bought this kit to get started with 3D printing and didn't want to spend extra time on excessive modifications.
I also experienced many firmware freezes while printing until I adjusted the heated bed using some M3 washers, so its maximum offset is less than 1mm (thanks, Ian).
Improved power supply
To be honest, I bought my Ormerod along with 6kg of ABS filament, so I intended to print ABS only. ABS generally requires more heat than PLA and as it turned out, the delivered ATX PSU (unfortunately mine was an ACE) didn't deliver enough current at a stable voltage to get the heated bed up to 120°C. I noticed that when I measured the output voltage and while the heated bed was on, it dropped to 11V. This is just not enough to keep the heated bed over 100°C.
That's the reason I bought a cheap 12V 300W LED PSU for ~30 Euros, which even allows me to adjust the output voltage using a little potentiometer. This can't be a lot more expensive than the delivered ATX PSU, so why not ship this kind of PSU along with all Ormerod kits?
Okay, I must admit I modified the PSU a little by replacing the little 50x50 fan with a bigger 90x90 Arctic Cooling fan, so I don't even hear it any more. Anyways, now my Ormerod is operating at rock-solid 12.5V and I haven't noticed a single voltage drop since replacement. This results in the heated bed heating up to 120°C without covering it with aluminium foil or anything else.
Customized heatsink+fan ducts
While printing ABS, I had to learn draughts are poison for warp-free printing. I modified the heatsink and fan ducts to reduce backwash as much as possible, replaced the stock 40x40x20 fan with a 40x40x10 fan I got from an old ATI graphics card and added some proper mountings for all cables around the nozzle. In addition, I modified the duet enclosure to be rotated by 45°, as I don't need that spool holder anyways and to provide additional space for the custom fan duct.
In case you're interested what these parts look like in detail, take a look at my GitHub repository. There you can find all my custom parts, including the PSU parts. You will need two M3x16 screws and two M3 nuts for the heatsink assembly, though, and make sure you have an extra hole in your heatsink to allow it to be rotated by 90° just like iamburny did it with his heatsink duct.
KimBrown's fan duct looks good, too, but I didn't like the way the cables are mounted and one of the chimneys broke right off when I tried to assemble the printed part. Well, I kind of copied his idea of adding a grill on top and it does work nicely - thanks for the idea
ABS adhesion problems
One of the major problems I had was the fact that none of my parts wanted to stick to the heated bed. I've tried lots of different ideas, including kapton tape, self-adhesive laminating foil, sugar coating on glass but none worked as good as a thin UHU glue stick coating. Apply it on glass as even as you can, heat your bed up to 120°C and wait until you can't see any more steam coming off the heated bed. Then you're ready to print.
My printing temperatures are 120°C for the first layer and 90°C for all others. Using this method, I get absolutely NO warping, yesterday I printed a piece that is 160x80mm big and none of the corners lifted up - amazing!
When your print has finished, wait until your bed temperature reaches ~60°C. At that temperature it is relatively easy to get the part off the heated bed, although you may need a razor blade or a small screw driver to lift it off.
Proof:
There will be some glue on your part, but since my glue is water-soluble, I can simply wash it off with some warm water.
Other issues
I had a few other issues, but I won't describe them in detail. Might be useful for some people though:
- After printing only 300g of PLA, my M5 rod showed wear. I guess it was just bad quality, because I replaced it with another stainless steel rod and I haven't seen any signs of wear since replacement. I heard RRP will ship better rods with future kits, but this certainly was an issue for me.
- The whole IR sensor concept is unreliable and I've had some occasions where the sensor collided with the bed clip near X=55 Y=180, preventing the Y axis from moving properly. I'm not sure whether this is my fault or another design flaw, but I would have appreciated to see an ultrasonic sensor instead of the IR sensor. I use it only to get the nozzle somewhat close to Z=0 and then I do manual Z+bed calibration. This gives me the best results for the moment.
- Add some Kapton tape to your heated bed contacts! I've seen several reports where people reported broken Duet boards due to short circuits, so it's a good idea to add it during the heated bed assembly. Might be worth to be added to the official Ormerod documentation, too.
- The Y axis belt lost some tension after a while, resulting in missed Y steps. Now I'm using iamburny's y belt clamps and these work pretty well.
I hope this helps. YMMV.
Edited 2 time(s). Last edit at 03/19/2014 03:28PM by zombiepantslol.
I'd like to share my experience about printing ABS with an RRP Ormerod. First of all, huge thanks to dc42 and iamburny for their software (and hardware) improvements (can't say it often enough)! During the last few weeks, I built my custom Ormerod made for ABS printing, called the Armerod
It took me a couple weeks to get to the point I am at right now, so here are a few suggestions and improvements for printing ABS, as well as some hints for those struggling to get their Ormerod up and running. I love the idea of open source projects, so I hope the following description is useful.
Issues getting the Ormerod running
While building my Ormerod, the first thing I noticed was the Y rib not being hold tight to the front Y bearing. Because I couldn't print any support parts at this time, I simply took a cable tie and tied it through the hole around the bearing. Not ideal, but has been proven to work.
After putting all parts together, the next issue I had was the SD card. The shipped one was simply not working (some SanDisk microSD card). After a little searching I found out why and tried three different microSD cards until I found one 8GB card that works.
Later, I noticed my heated bed had become very unstable and this was caused by the Y bearing clamps. They detached from the two rear bearings (I guess due to missing friction) so I decided to drill a small hole into each clamp and screwed some short self-tapping screws into these holes to grab into the bearing notches. RRP, wouldn't it make sense to modify these clamps so they grab into these notches right during assembly?
To add a little more support, I took out the aluminium heat spreader (as seen on this forum) and mounted it on top of the MDF plate.
I know there are several attempts to improve the heated bed, but I bought this kit to get started with 3D printing and didn't want to spend extra time on excessive modifications.
I also experienced many firmware freezes while printing until I adjusted the heated bed using some M3 washers, so its maximum offset is less than 1mm (thanks, Ian).
Improved power supply
To be honest, I bought my Ormerod along with 6kg of ABS filament, so I intended to print ABS only. ABS generally requires more heat than PLA and as it turned out, the delivered ATX PSU (unfortunately mine was an ACE) didn't deliver enough current at a stable voltage to get the heated bed up to 120°C. I noticed that when I measured the output voltage and while the heated bed was on, it dropped to 11V. This is just not enough to keep the heated bed over 100°C.
That's the reason I bought a cheap 12V 300W LED PSU for ~30 Euros, which even allows me to adjust the output voltage using a little potentiometer. This can't be a lot more expensive than the delivered ATX PSU, so why not ship this kind of PSU along with all Ormerod kits?
Okay, I must admit I modified the PSU a little by replacing the little 50x50 fan with a bigger 90x90 Arctic Cooling fan, so I don't even hear it any more. Anyways, now my Ormerod is operating at rock-solid 12.5V and I haven't noticed a single voltage drop since replacement. This results in the heated bed heating up to 120°C without covering it with aluminium foil or anything else.
Customized heatsink+fan ducts
While printing ABS, I had to learn draughts are poison for warp-free printing. I modified the heatsink and fan ducts to reduce backwash as much as possible, replaced the stock 40x40x20 fan with a 40x40x10 fan I got from an old ATI graphics card and added some proper mountings for all cables around the nozzle. In addition, I modified the duet enclosure to be rotated by 45°, as I don't need that spool holder anyways and to provide additional space for the custom fan duct.
In case you're interested what these parts look like in detail, take a look at my GitHub repository. There you can find all my custom parts, including the PSU parts. You will need two M3x16 screws and two M3 nuts for the heatsink assembly, though, and make sure you have an extra hole in your heatsink to allow it to be rotated by 90° just like iamburny did it with his heatsink duct.
KimBrown's fan duct looks good, too, but I didn't like the way the cables are mounted and one of the chimneys broke right off when I tried to assemble the printed part. Well, I kind of copied his idea of adding a grill on top and it does work nicely - thanks for the idea
ABS adhesion problems
One of the major problems I had was the fact that none of my parts wanted to stick to the heated bed. I've tried lots of different ideas, including kapton tape, self-adhesive laminating foil, sugar coating on glass but none worked as good as a thin UHU glue stick coating. Apply it on glass as even as you can, heat your bed up to 120°C and wait until you can't see any more steam coming off the heated bed. Then you're ready to print.
My printing temperatures are 120°C for the first layer and 90°C for all others. Using this method, I get absolutely NO warping, yesterday I printed a piece that is 160x80mm big and none of the corners lifted up - amazing!
When your print has finished, wait until your bed temperature reaches ~60°C. At that temperature it is relatively easy to get the part off the heated bed, although you may need a razor blade or a small screw driver to lift it off.
Proof:
There will be some glue on your part, but since my glue is water-soluble, I can simply wash it off with some warm water.
Other issues
I had a few other issues, but I won't describe them in detail. Might be useful for some people though:
- After printing only 300g of PLA, my M5 rod showed wear. I guess it was just bad quality, because I replaced it with another stainless steel rod and I haven't seen any signs of wear since replacement. I heard RRP will ship better rods with future kits, but this certainly was an issue for me.
- The whole IR sensor concept is unreliable and I've had some occasions where the sensor collided with the bed clip near X=55 Y=180, preventing the Y axis from moving properly. I'm not sure whether this is my fault or another design flaw, but I would have appreciated to see an ultrasonic sensor instead of the IR sensor. I use it only to get the nozzle somewhat close to Z=0 and then I do manual Z+bed calibration. This gives me the best results for the moment.
- Add some Kapton tape to your heated bed contacts! I've seen several reports where people reported broken Duet boards due to short circuits, so it's a good idea to add it during the heated bed assembly. Might be worth to be added to the official Ormerod documentation, too.
- The Y axis belt lost some tension after a while, resulting in missed Y steps. Now I'm using iamburny's y belt clamps and these work pretty well.
I hope this helps. YMMV.
Edited 2 time(s). Last edit at 03/19/2014 03:28PM by zombiepantslol.
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Re: Armerod - Ormerod and ABS printing March 20, 2014 03:57AM |
Quote
dc42
[...]
- Fan backwash eliminator (not as fancy as zpl's, but smaller and still effective at reducing backwash, based on Matt's design - but not tested with ABS) [github.com]
[...]
Hi DC42. The fan_deflector scad file includes another scad file for the aerofoil which I cant see in your repository.
EDIT: Might be easiest just to put the module inline in the FanDeflector file
regards
Andy
Edited 1 time(s). Last edit at 03/20/2014 03:59AM by kwikius.
Ormerod #318
www.zoomworks.org - Free and Open Source Stuff
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Re: Armerod - Ormerod and ABS printing June 05, 2014 10:17AM |
Quote
dc42
- Fan backwash eliminator (not as fancy as zpl's, but smaller and still effective at reducing backwash, based on a design by Andy (kwikius) - but not tested with ABS)
now it is, thank you
Erik
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