My coreXY design is progressing to the build stage

HDDs are designed to run continuously for years, and to spin multiple, relatively heavy (compared to a single CD) platters, so I would guess that HDD motors are built better and have higher torque than CD/DVD motors, but it's just a guess. I'll see if I have a CD/DVD motor to test somewhere...

The printed impeller seems to be OK right off the printer, without balancing it.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

OK, I have finished messing with it (for now). The final design is here.



Blower with 80 mm impeller

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
the_digital_dentist
OK, I have finished messing with it (for now). The final design is here.

I found some good videos of someone who has detailed his different impeller and housing designs for best efficiency and noise:

[www.youtube.com]
[www.youtube.com]

Another interesting design that is used in Apple's laptops are the asymmetrically positioned blades, which makes it appear quieter by spreading the sound over several frequencies(16 minutes into the video here)

[youtu.be]

What are your thoughts on it Mark?

Edited 6 time(s). Last edit at 05/01/2018 03:28PM by klcjr89.

Will it fit any HDD motor? Just for the record, which one did you use?

I used this type, which seems to be a very common form factor for HDD motors:



All of the aluminum looking stuff is a single piece that spins. The black frame is also aluminum.

Here's a CAD model of the motor.

Edited 2 time(s). Last edit at 05/02/2018 06:51AM by the_digital_dentist.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

You take a look at the links I provided? Thanks!

Yes. I like the techniques used to test different configurations. I copied the general shape and size of the CPAP blower that is optimized to provide pressure/flow with minimum noise. The blowers in the video are intended to maximize flow/pressure where a high noise level is more acceptable (dust collection in a wood shop). If I were going to pursue this further I might adopt some of the techniques used to optimize the design, but I'm moving on to other things- specifically trying to get the Duet board installed in UMMD. As far as the apple fan goes, I am pretty sure a printed impeller with evenly spaced and identical vanes will be balanced when it comes off the printer (and it does seem to be pretty good), but I wouldn't know how to balance an odd spaced vane design so that it will be OK at 10k rpm. Maybe Fusion360 has some special feature that will show the center of mass of a complex structure and allow it to be manipulated, but I'm not there with Fusion360 yet.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
the_digital_dentist
Yes. I like the techniques used to test different configurations. I copied the general shape and size of the CPAP blower that is optimized to provide pressure/flow with minimum noise. The blowers in the video are intended to maximize flow/pressure where a high noise level is more acceptable (dust collection in a wood shop). If I were going to pursue this further I might adopt some of the techniques used to optimize the design, but I'm moving on to other things- specifically trying to get the Duet board installed in UMMD. As far as the apple fan goes, I am pretty sure a printed impeller with evenly spaced and identical vanes will be balanced when it comes off the printer (and it does seem to be pretty good), but I wouldn't know how to balance an odd spaced vane design so that it will be OK at 10k rpm. Maybe Fusion360 has some special feature that will show the center of mass of a complex structure and allow it to be manipulated, but I'm not there with Fusion360 yet.

Yeah, the Apple fan is really neat! Everything is detailed in the patent on how to design and optimize it: [patents.google.com]

As far as center of mass in Fusion360, if you right click on a body and choose 'Properties' it will tell you the center of mass coordinates. Alternatively, if you click on 'Inspect' in the top toolbar and choose Center of Mass, it will visually show you where it's at with a glyph.

Something I threw together real quick:



Edited 1 time(s). Last edit at 05/02/2018 10:12AM by klcjr89.

Well, there you go!

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

It's about time to put real topics on these posts
"My coreXY design is progressing to the build stage" probably has run long enough?

Last few posts "cooling pump" not specific "core XY"

FWIW

Could be "the Digital Dentist sez"

I think you're right. Back to coreXY...

I'm printing some parts to mount the Duet board and The Panel Due. When the printing is done I'll start the rewiring...

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
cozmicray
It's about time to put real topics on these posts
"My coreXY design is progressing to the build stage" probably has run long enough?

Last few posts "cooling pump" not specific "core XY"

FWIW

Could be "the Digital Dentist sez"

I agree
I felt the same when the subject was DIY worm gear. So many good ideas/designs dissappear in the endless 20+ pages.

Hello, I am following this project... I saw the Digital Dentist ribbing problem. It is really strange, I think that I have a similar problem too. But completely different z axis configuration. I am going to be crazy, because the z problem is not always present. For example I print an abs vase (open printer, 300° hotend) it was really good in quality, then I print a bigger one in PLA, and the first 10cm ribbings are negligible, after the ribbing is really evident like Digital Dentist one. I use mk4Duo, 8bit ramps, big coreXY, one plane centered z good quality acme screw.
Tomorrow I will post some image. Sorry for poor English :-D

Latest happenings with UMMD: I have reworked the top of the machine for electronics enclosure, and replaced the smoothieboard with a Duet Ethernet board and 7" Panel Due touchscreen. It took a couple days to work through some issues with heater configuration, but it's all working now. Now I need to do the final tune-up, but it prints very nicely using parameters that I was using in the smoothieboard.

The machine is not silent, but it is MUCH quieter than it was. 256:1 interpolated ustepping FTW! Video of first test print here.
Compare the sound level to that on this video.

Prior to the change over I had installed a very low cost hot end from China that came with a very quiet fan. I found that when I get the enclosure temperature up to 45C, the quiet fan isn't so quiet. It goes back to being quiet when the temperature goes down.

Edited 1 time(s). Last edit at 06/13/2018 10:38AM by the_digital_dentist.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

i’ve made some water cooling jackets for my v6s.. i think if i get my part cooling straight i can have an almost silent printer.

Is a pump quieter than a fan?

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Would love to see the water cooled jacket as well. I'm using 40mm 5v fans for all my V6s and they're near silent. The original 30mm fans sound like jets.

Quote
the_digital_dentist
Is a pump quieter than a fan?

In my experience, a low pressure/high volume water pump is almost silent. ( aquarium pump )
OTOH a 12V inline gas pump is louder than a fan.

Yes, the pump is silent (I used it on a water cooled block for a chimera a while ago)

I recently installed a Duet Ethernet controller board, modified Chinese-made aluminum Titan extruder, and Chinese made hot-end. I've been running some test prints while I make sure everything is working right and tuned properly and it all seems to be working.





The machine runs much quieter than it did with the SmoothieBoard, and of course, the firmware updates and config changes are very easy- just edit and reboot using the web console. I am unable to print by plugging in an SD card, which I miss, so I'm still figuring out a work flow that works for me. As a temporary measure, I am using a netbook connected to the Duet board via the network interface to upload gcode files to the uSD card on the Duet board, then print them.

Video here

Edited 2 time(s). Last edit at 06/22/2018 02:02PM by the_digital_dentist.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

If you really want to print by plugging in an SD card instead of uploading via the web interface, it's possible in two ways:

1. You can take the SD card out of the Duet and put in in a PC adaptor, then copy the file to it on the PC, then move it back again. Then you need to send M21 to the Duet to re-mount the card. In a future firmware release, we will detect the insertion and mount the card automatically.

2. If you have a PanelDue in your system, and it is connected to the Duet via the ribbon cable connector, then you can plug an SD card containing your GCode file into the PanelDue. Select card 1 in either PanelDue or the web interface to access the files on that card.

However, normally the PC that you slice the files on would be on the same network as the Duet, so it is easier to upload the GCode file via the web interface. There is a plugin for Cura to do this automatically.

HTH David

PS - I like that filament spool holder. Can you share the design?

Edited 1 time(s). Last edit at 06/22/2018 02:45PM 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].

I'm aware of the uSD slot on the Panel Due. Unfortunately, neither the Duet board's uSD card nor the Panel Due's card slot are easy to access the way my printer is built, so I'll struggle a little longer until I figure out a work flow that works for me. I may add a switch to the network drop in my work room.

The Duet board has a connector for one of the ribbon cables to the Panel Due labeled SDCard. Is there any sort of interface chip required or can I just add an SD card slot on a breakout brard to the front panel of my printer and connect it there?

The spool holder is on youmagine.com here. It uses F608zz bearings and 8mm bolts for the axles, so it's pretty heavy duty. I drilled holes and added a couple bolts on the vertical pieces so it could rubber bands to keep the top roller pressed against the spool flanges. Springs would be nicer, but rubber bands work OK. I was using it at the makerspace but it was too complicated for people and they kept taking it apart and hanging the spool from the top roller! Doh! I think deckingman recently used a modified version to hold 5 spools for his printer.

I designed another one based on a design I saw on Thingiverse. It uses the spool's weight to keep rollers pressed against the flanges. It's a little more delicate/elegant, and the small spools don't work very well, but it's perfect for "normal" 1kg spools. It uses bearings taken from scrapped hard disk drives. See it here: [www.youmagine.com] This one has been at the makerspace for almost a year and no one has broken it or tried to take it apart yet. It can be a little tricky to load it with a spool because you have to hold the spool and deal with two moving arms on the holder.

Both spool holders effectively prevent the filament from springing off a full spool and tying itself into knots.

Both designs were made when I was using DesignSpark Mechanical, so there are no Fusion360, STEP, or IGES files available.

Edited 1 time(s). Last edit at 06/22/2018 11:31PM by the_digital_dentist.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

If you are not using the CONN_SD connector to connect the PanelDue, then you should be able to connect an SD card socket breakout board to it. The pinout of that connector is the same as is used on one of the two connectors on typical LCD+SD card boards, except that it doesn't have a Card Detect pin and we added TxD and RxD for PanelDue at one end. So you might have to cut those 2 conductors at one edge of the ribbon cable, if they are connected to anything on your breakout. The power feed is 5V, so your breakout must include a 3.3V regulator.

However, if you can put the Duet on your main network then I think you will find it more convenient to upload GCode files through the web interface.

Edited 2 time(s). Last edit at 06/23/2018 04:03AM 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].

Update: new electronics enclosure is finished and looks much better than the original arrangement.



I'll look into adding an SDcard reader in the future- too many other things going on right now.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

I have been testing the limits of the mechanism, running test prints at ever increasing accelerations in an effort to get the thing to shift layers. The latest test was with acceleration set to 10,000 mm/sec^2 in both X and Y, and speed for all features in the print set to 200 mm/sec, with lots of jerky movement. At this acceleration, a straight line of 2 mm is all that's required to get the speed to hit 200 mm/sec. I am pleased to report that there was no layer shifting at all. The extruder seems to be operating at its limits here (or I have set the acceleration and maximum speed in the extruder too low- more tests to follow).

Here's a video of the printer running at these settings, and unlike most of those youtube videos of printers running at crazy speeds and accelerations, I have included a close look at the final print.

If the machine is printing at 200 mm/sec, laying down a 0.4 mm wide line that is 0.2 mm thick, the extruder has to squirt out 0.4 x 0.2 x 200= 16 mm^3/sec. If that much goes out, that much needs to go in... 1.75 mm filament has a cross sectional area of 2.4 mm^2. So printing at 200 mm/sec requires 16 mm^3/sec / 2.4 mm^2 = 6.65 mm/sec filament speed coming into the extruder, which should be very easy for the controller and motor to handle. With acceleration, I think the thing you have to worry about most is the drive gear teeth tearing up the filament, and the limit will have to be determined experimentally, and will depend on pinch roller tension, geometry of the teeth, hardness of the filament, etc. Time to run some more tests...

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

That's an impressive speed for a non-delta machine! Did you use any pressure advance, or the non-linear extrusion feature of RRF?

What extruder drive are you using? At that extrusion rate, you would probably benefit from using a double-drive extruder such as the Bondtech.

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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].

The most surprising thing is that the X axis assembly weighs about 1.5 kg. I never expected it to be able to move as fast as it does. The extruder settings I was using were fine for the relatively low speed/low acceleration printing I was doing before, but it is definitely struggling to keep up now. I'm going to try running the M122 command to see if there are any hiccups or skipped steps.

I've been lurking in the nonlinear extrusion threads at the Duet forum for a while, and expect to dive in soon.

I am using a slightly modified, Chinese-made aluminum Titan, with an XCR3D (also Chinese made) hot-end. The pair have been working well, though I haven't been printing that much recently.

I don't intend to leave the acceleration so high- it just shakes everything too much. It's fine for low altitude prints, but if they get tall, I'm sure the shaking will take its toll on print quality. There isn't any way to automatically reduce acceleration and speed as a function of the Z coordinate, is there?

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

I wonder how belt length influences the chance of skipping steps? A longer belt ( CoreXY vs Delta ) might act as a buffer, but would create more ringing.

Quote

There isn't any way to automatically reduce acceleration and speed as a function of the Z coordinate, is there?

A 6DOF acceleration/rotation sensor like ABS-brake sensors ( seen on multicopter- or camera gimbal controller ) would be helpful. I have one of these on my balancing bot. They are extremely sensitve and easy to read out ( I2C protocol IIRC ). Just have to set thresholds: et voilá auto speed control.

I was filling out my application for the Milwaukee Maker Faire (the largest free Maker Faire in the free world) coming up on Sept 28-30th in Milwaukee at State Fair Park, and needed a photo of UMMD for promo purposes, so I dragged him out of the dungeon and took a couple pictures. This is what the whole thing looks like with the Duet, Panel Due, and new electronics enclosure:



Yeah, I know... how does blue filament turn into fluorescent pink???

Edited 1 time(s). Last edit at 07/22/2018 10:52PM by the_digital_dentist.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]