Wobbling in cheap linear bearing screws

As I experienced, from my 10+ 3d printers only the Prusa mini and the I3 Bear deliver adequate print quality.  Even the Voron 2.4 CoreXY has problems if you look carefully at the printed results.  Though all prerequisites were made to build a good printer, it was never really matching real good quality.  So- in my search for the root cause of this somewhat disappointing discovery, I stumbled on some interesting stuff: The HevORT Advanced DIY 3D Printer project.

I found this website as a link from one of my fact finding searches for the cause of wobble in my linear rails that I am using for my Indymill CNC.

Obviously, the cheaper rolled linear screws with ball bearing nuts are not as good as the ones that are first cut on a lathe and are then grinded on a special machine.  The better linear screws with ball bearings are specified into 10 categories from 1 to 10 where no.1 is most expensive and no.10 the least expensive. Quality is better with higher price.  Prices are over 500 Dollars US for the better ones, but can mount up even higher.

If you look at the category of the rolled ball bearing screws, these take a lot of strain in the material due to the manufacturing process. The strain causes an unequal surface and therefore this can cause lateral wobble.  When using these cheap linear ball bearing screws for 3d printers as Z-drives, the lateral problem can be solved by adding shifting plates as horizontal shift compensator.

On the net, a solution is given by using a couple of bearing balls (3) between magnets that are used as rolling plates on top and bottom.  The shifting plate holders on top and bottom stay aligned with each other by mounting 2 magnets that attract each other on 2 sides of these plates.  Please see the cutouts I took from the movie that is provided in the above mentioned link:

This can be implemented in the HevOrt BUT I feel that my Voron2.4 could really benefit also from this solution. Although the Voron is depending on the vertical linear rails for sliding up and down and a belt mechanism is making the motion happen, the mechanism that compensates for any wobble or different sizing of the frame is only a friction plate of (in my case) 2 PETG surfaces that slides on each other, 1 per vertical axle.

So, I will see what I can find or make to get the above anti-lateral wobble solution built and implemented in the Voron 2.4 asap and see what the result will be!

 

MMU2S on Ender3pro with TT SKR E3 mini motherboard

In 2020 I upgraded my Ender 3 with synchronised Z-axes and a new motherboard, the SKR Mini E3 V2.1.

The Ender 3 is very reliable and has been equipped with a direct drive bondtech extruder but still has the original hotend.

I chose the Ender3 to be the 3d printer on which I will attach the MMU2S.  This also means that I will have to exchange the hotend/extruder combination with a Prusa Mk3S version.

Started this on May 4th, 2021.  Only the printed parts were needed, all other parts were already available through sourcing form a.o. Ali.  I printed everything in ABS, mostly red.  For this I used 2 machines: The Twotrees Sapphire pro with enclosure for black ABS and the Voron 2.3 (300) for red ABS.

The motherboard that is also in the Ender3, SKR mini E3 V2.1.  I used this setup to test the MMU hard- and software together with the SKR mini E3 motherboard
The MMU2S on top of the Ender3, just next to the 6mm belt that connects both Z-leadscrews
The bondtech Prusa MK3S hotend/extruder combination, mounted on a 2020 mounting plate for the Ender3

There is a firmware version for the SKR mini E3 V2.1 on Github that makes use of the MMU2S.  I downloaded this version and uploaded it to the board via visual studio code maker, all works well in the test setup. Some tweaking was needed in configuration.h and in the advance config, since I am using the S-version of the MMU2 and the filament sensor was not standard ON. And- it appears that the communication port needs to change to the 2nd port. You can see it all at the Reddit page, the additional changes to the published config files are these (thnx to fixel112):

Excerpt from Configuration.h:

#define SERIAL_PORT -1

#define SERIAL_PORT_2 2 <————— This has been the issue. Uncomment that line.

#define BAUDRATE 250000

Excerpt: Configuration_adv.h

#if ENABLED(PRUSA_MMU2)

// Serial port used for communication with MMU2.

// For AVR enable the UART port used for the MMU. (e.g., mmuSerial)

// For 32-bit boards check your HAL for available serial ports. (e.g., Serial2)

//#define MMU2_SERIAL_PORT 2

#define MMU2_SERIAL MSerial2

//#define MMU2_RST_PIN 23

// Enable if the MMU2 has 12V stepper motors (MMU2 Firmware 1.0.2 and up)

//#define MMU2_MODE_12V

// G-code to execute when MMU2 F.I.N.D.A. probe detects filament runout

#define MMU2_FILAMENT_RUNOUT_SCRIPT “M600”

#define MMU2_DEBUG // Write debug info to serial output

#endif // PRUSA_MMU2

Next is to put everything physically on the Ender, and exchange the hotend/extruder.  Then, the settings for the extrusion lengths will have to be determined.  And- the buffer for the filament between the MMU2S and the filament spools has to be installed. As soon as I have it all properly installed, more pictures will follow!

I discovered that the dual display I now use for the Ender3 will only work for Marlin LCD and no longer for TFT, since the serial TFT pins will be used to drive the MMU2S unit.  I exchanged the TFT/LCD unit with the original Ender3 LCD, I kept this in storage and tested it today with the Ender mini E3 V2.1 , it works very well!

The twotrees SKR Mini E3 V2.1 motherboard is really perfect for the combination with the MMU2S and the new  filament sensor in the new hotend/extruder. The firmware has been updated to include the MMU2S and the AUX’s serial that was previously used for the TFT screen is now in use by the MMU!  It all works!!!

Now the next thing was to get the new extruder, F.I.N.D.A. and the filament sensr to work properly.

That took some time and next on the agenda is the filament management.

I already decided to go with the original Prusa filament box with plates to hold the retracted filament for all 5 spools. The spools themselves will hang at the wall, behind the printer.  I don’t have space for standing spoolholders.  Underneath the spools the filament box with plates gets its place on the wall and from there the 5 PTFE tubes will run to the MMU!

Penta extruder on A30M

Today I received my 5-in, 1-out hotend, non-mixing  air cooled with 1 nozzle and 1 heater//temp sensor.

I will install it on my A30M with the Duet2wifi board+extension board (5-fold with plug-in drivers). The A30M already has independant Z-stepper motors.

The Duet2wifi has 5 stepper ports, and the expansion board also has 5 stepper ports.  X,Y,2xZ, 5 Extruders is a total of 9 so this will indeed fit!

I will make new wiring for the 5 extruder steppers on top of the A30M frame with 5 bowden tubes to the hotend.  Since the hotend is non-mixing, this will be a  simple task to get into config.g.  For the slicer- it will also be easy. Just add the extruders to a total of 5 pieces. Add the correct filaments/temps/ no offset so set offset X and Y to 0..  The work will primarily be in  the tool changing files for T0-T5 where retraction- and extruding  settings will be needed.

For the hotend, I have a new setup available that allows me to quickly change the nozzle.

This will make it possible to use this setup for all kind of applications.

Mellow FLY-CDY-V2 motherboard

recently (3-2021) I have been setting up my new 3d printerboard from Mellow, an STM32 board that is named FLY CDY V2. It is (almost) fully compatible with Duet2Wifi and also uses its wifi-based 3d printer management system DWC.

The config file I made for this setup is HERE

The FLY_CDY_V2 board comes completely empty so I added the firmware.bin in the /sys directory, after I had an empty SD card filled with the clean reprap directories and -files.

Next to the firmware.bin. also a board.txt is required to be available in /sys with some settings, with the following content:

//Config for fly-CDY
board = fly_cdyv2
led.neopixelPin = D.15;
//wifi pins
8266wifi.espDataReadyPin = E.10;
8266wifi.TfrReadyPin = E.12;
8266wifi.espResetPin = E.11;
8266wifi.serialRxTxPins = { D.9, D.8 };
heat.tempSensePins = { B.1 , A.3 , C.4 , D.14}; be aware that D.14 is not a temp pin but a heat pin, is this wrong??
stepper.numSmartDrivers = 6;
serial.aux.rxTxPins = {A.10, A.9};

This board.txt is already OK for 2209 drivers and for the use of the neopixels output.

In the pdf that is provided by Mellow on the Github page for the reprap STM32 boards, section FLY-CDYV2, everything is explained as to get wifi up and running,  configure config.g et cetera.  

In my config.g everything needed to work properly is already done, as is with my board.txt.

I made the config for a.o. a  Cartesian printer with single X,Y,Z steppers and a triple hotend with 3 extruders, 1 heater and 3 nozzles.
Included is: Neopixels, BLTouch, 3 filament sensors on the X,Y- and Zmax inputs, active fans for hotend tool on fan1 and object on fan0
If so desired, sensorless homing is possible with the correct driver boards. In this version, 3 optical endstops have been used on inputs xmin, ymin and zmin.
Retraction is set OFF in this firmware by default, but may be swiched ON to make the triple hotend drip less (2 mm retract and -0.5 extrude without Z-hop), do experiment with these settings!
Please be aware that some pin names for the FLYCDYV2 board differ from the Duet’s naming convention like “bed” versus “bed-heater” et cetera.
Plus, some typical Duet2wifi extensions are NOT available like the GPIO bus.
The FLYCDYV2 has some interesting standard extra’s though, like the BLTouch connector with power, driver pins and Z probe pins, the Neopixel connector AND the 6 driver slots and 3 extruder heaters/sensors/fans!
It is quite simple to change this setup to a dual Z axis with independant Z-motors and either single extruder or a dual setup, single or dual nozzle, mixing or non-mixing.
Please see my complete ready-to-go config directory setups for this board HERE to get you  started! 

Also: Check my CNC Indymill running with the FLY-CDY-V2

Please donate $1 to my paypal account if you use (parts of) my developed materials so I can continue to share nice stuff for you to download

 

Magnetic dual parking extruders reprap I3 Bear with Duet2wifi and sensorless homing

My most recent and probably last build from scratch is the dual carriage I3-based printer as shown in the below picture, in the building phase.  This printer can be used either for 2 colors or for printing with soluble support PVA filament.

I decided to use sensorless homing for this build due to problems when using endstop switches.  When using endstops, problems may come up because f.i.  homing to the left means that the left tool will be parked against the endstop, should you use endstops.  Same on the right hand side when the right hand tool is parked.  I encountered difficulties that the driven sensor carriage in the middle can then get into an unknown state (or position) when both tools (carriages) are in the parked position.

If you home one of both Tools with sensorless homing, the status of the sensor carriage is always automatically known.  So, since the XY position of the center (sensor) carriage is known you can always do a Z-homing at any given X-Y position and you can also do G32 and G29 without the need to carry T0 or T1 along.  And- you can easlily reset an unknown status of the sensor carriage by homing it, either left or right.

Get my build plans and Configuration files for Duet2wifi HERE

The box at the left rear is for the Duet2wifi board.  The 24V fan-regulated power supply is already positioned at the rear,  right side.

The main challenge with this build was to get the settings perfect for the dual tools.

It took me 2 months before I got it to work perftectly for both PLA and/or Petg.

As with my previous dual color dual nozzle builds, the basics is very simple. Just define 2 tools with 2 heaters, 2 temp sensors, 2 fans et cetera.

I already envisioned the approch with the slicer(s): All offsets are done ONLY in firmware, NOT in the slicer! As far as the slicer(s) is/are concerned, the nozzles of Tool0 and 1 are at the same (X0/Y0) offset.

For the Duet, the only addition in the slicer is an M0 command as stop command for the printer.  Define 2 nozzles of 1.75mm without any offset and you’re done in the slicer.

Then, you will need to set everything in your config.g at the tool section like XYZ offset and so on.

I decided to get T0 as reference, and set everything to 0 there. X=0, Y=0 and Z=0.  Then, measure the differences at T1 versus T0 with calipers to start with and inport these values in the T1 toolsection in config.g.

Start a testprint and measure what to amend, take little steps and the metrics are done!

But- the hard part is- as I experienced- to get good prints without blobs and unexpected stringing, both incoming as outgoing (into and out of the printed object(s).  Drying the filament also helps a lot!

In the end, I just took the same approach as with the tool settings: As little as possible retraction settings in the slicer and all except the basic print retractions are now in the configuration files that are called upon Tool changes tpre.g,  tfree.g and tpost.g (for T0 and T1).

This means that you can play with retracting and extruding of filament length and speed directly at, during and after Tool changes.  And- in my experience it is all affected by the type of filament you use and the temperature you are at with the hotend. Also, the fact whether you use a lower temperature during waiting has great impact.

In my experience, you should finetune the config settings for the mentioned settings per object and per type of filament.

Therefore, I decided to used this printer for only 1 goal and make the settings perfect to accomplish this goal.  Right now, I have optimized this printer to print 1) PLA from 123print in the Netherlands, of a specific type and 2) PVA from the same supplier.  This gives me the possibility to print complex objects with soluble supports and it works extremely well at doing this!

PM: I also added LED lights on top of the printer as an integrated feature.  This makes use of a heater pin as GPIO (with a M42  P [pin] S[value intensity]) command), like the solenoids that I use to catch the carriages T0 and T1. To come from the 3.3V and max 1mA from the GPIO pin to the required 24Volts, I used small mosfet boards.  All programming is done in the Duet’s config and macro files, view the below example of my stop.g file which is called from the slicer’s stop setting: M0.

; stop.g
; called when M0 (Stop) is run (e.g. when a print from SD card is cancelled)
; Also called by slicer end gcode by M0
;
M400 ; Finish move queue
M117 Cool down ; Update the LCD screen with “Cool down”
M83 ; Extruder relative mode
G1 E-2 ; Retract filament 2mm for both extruders !!
M106 S255 ; Fan at 100 to cool nozzle and bed
M104 S0 T0 ; Extruder T0 heater off
M104 S0 T1 ; Extruder T1 heater off
M140 S0 ; Bed heater off
G28 X ; Home X
M220 S100 ; Set speed factor back to 100% in case it was changed
M221 S100 ; Set extrusion factor back to 100% in case it was changed
M42 P4 S0 ; Magnet T0 off
M42 P5 S0 ; Magnet T1 off
M104 S41 T0 ; set extruder T0 to cool down
M104 S41 T1 ; set extruder T1 to cool down
;M568 R41:41 S41:41 ; set standby and active temperatures for tools 0 and 1 (or single M568 T0 R41 S41)
M116 ; wait for Tools actions as specified in above M568 instructions
G90 ; Absolute positioning
G1 Y200 ; to get objects removed easier, move bed forward
M106 P0 S0 ; Fan L object T0 off
M106 P2 S0 ; Fan R object T1 off
G28 X ; Home X
M84 ; Steppers off
M98 P/sys/ledflash.g; Perform execution of ledflash.g in specified directory
M42 P6 S0.008 ; Led light setting almost OFF
M117 Jantec=done! ; Update the LCD screen with “Jantec=done!”

G1 X5 Y5 ; Move to corner
M140 S{print_bed_temperature} ; Set bed temp
T1 ; Select extruder 1 (or 0 depending on how your printer is set up)
M104 S{print_temperature} ; Set extruder temp
M116; Wait for temperatures

 

Please donate $1 to my paypal account if you use (parts of) my developed materials so I can continue to share nice stuff for you to download

 

Our 3d printers, managed by OCTOPI OR Duet’s web-based app

Above: Our Dual Bear I3 dual color 3d printer with independant carriages, remotely managed by DUET’s webinterface

The Octopi solution works with a Raspberry PI, and on it the Octopi firmware.  The device you set up on your wifi and you connect it to your 3d printer’s USB. Then you have a web interface on the Raspberry’s IP address that allows you to manage all the things about your connected printer.  All the settings like temperature, mesh, and basically anything else you can manage through a local LCD.  And- you can upload your jobs to the raspberry and start/manage and adjust temperature and such.  What I really like is that you can connect a raspberry camera and follow your jobs.

The Duet I find in use and possibilities more pleasant. because in addition to everything that the octopi can, you can also modify the system files online.  And printer updates can do, directly in the firmware.  Moreover, you do not need a separate box because the Duet2wifi already has everything on board.

The disadvantage is that you can’t attach a camera to the Duet. There is a possibility em an IP camera to integrate into the DWC, Duet’s web based remote app.  And such a wifi IP camera is easy to make yourself with a cheap esp unit.

 

Above: The Voron 2.4, dimensions 300x300x220 mm

Prusa Bear I3plus with mods dual Z axis control

 

Kingroon Kp3S heavily modded with new firmware and tool fan

 

Twotrees Sapphire PRO with new firmware

 

Voron 2.4 for Nylon and ABS printing, with external exhaust and 300+ degC printhead, bed up to 150 degC

 

Prusa i3 mini original, the production monster for PETG

 

And the Twotrees Sapphire pro, our perfect printer for fast production

 

And the multicolour completely rebuilt Geeetech A30M dual head printer with a new Duet2Wifi motherboard, dual Chimera heatblock and direct drive extruders

 

 

Our 3d printers, managed by OCTOPI and Duet Web Controller

Above: Our Dual Bear I3 dual color 3d printer with independant carriages, this one does not run octopi and is remotely managed by Duet Web Control (DWC).

Above: The Voron 2.4, dimensions 300x300x220 mm

Prusa Bear I3plus with mods like dual Z axis control. This printer runs Duet and  DWC.

 

Kingroon Kp3S heavily modded with new firmware and tool fan. This printer runs with Octopi for remote management.

 

Twotrees Sapphire PRO with new firmware, also with octopi.

 

Voron 2.4 for Nylon and ABS printing, with external exhaust and 300+ degC printhead, bed up to 150 degC.  Also runs octopi.

 

Prusa i3 mini original, the production monster for PETG. Also on octopi.

 

And the Twotrees Sapphire pro, our perfect printer for fast production, also on octopi.

 

And the multicolour completely rebuilt Geeetech A30M dual head printer with a new Duet2Wifi motherboard, dual Chimera heatblock and direct drive extruders.  This one runs Duet with DWC instead of Octopi.

 

 

VORON 2.4 20″x20″x20″ and DUET2WIFI

Get the documentation, specs, config.g, macros and build docs

LEES IN HET NEDERLANDS

After my succesfull buildproject of a Voron 2.4 3d printer in the fall of 2020, I still wanted a really big 3d printer with a print surface of over 20x20x20 inch.

My Voron 300x300x300mm build plate size

Imagine to have a print of more than double the size compared to the below picture!

During the build and at using the Voron 2.4 printer, I found the documentation on the hardware build really excellent.  But, the electronics part was scattered around several places, and although the Klipper implementation is very good I have experienced that the combination of 2 SKR 1.4 turbo motherboards with an Octopi controller does not provide enough operational stability to me. And- I feel the need to control more settings than I can do with the Klipper solution.  I think I probably am just more into the Duet and the reprap solution than the Klipper one, due to previous positive Duet – and MKS reprap experiences.

In a couple of previous builds I used a Duet2wifi, and I also experienced the add-ons for Duet2 like driver boards, PT100 boards and more hardware that is also very well implemented in the new RRF3+ firmware.

Duet wifi board , used for my dual head setup I3bear-based with sensorless homing

Reasons enough for me to choose the Duet2 and the 5-ports expansion board , or possibly an additional Duex board for my new to build Voron 2.4 ‘big 3d printer’.

At this page, I will share my progess on this build.

I have all required hardware laying around and since I already built a Voron 2.4, I will first focus on the electronics.  For the hardware, I still need the plexiglass sides, top and front doors.  I  do have all extrusion, bed, bed heater 230V, linear rails, all printed parts and so on, neatly stored at home.

So, I am setting up the electronics to know beforehand that everything works well.  I don’t want to start building the hardware and find out afterwards that my Duet2wifi will not do the job I want it to do.

Yesterday (October 4th,2020) I put the electronics and config.g together. I used:

  • Duet2wifi board with 24V PSU and 4.3 inch TFT/LCD
  • 5-port expansion board with 4 plug-in 2209 drivers V3.0
  • Z-switch mechanical
  • X-and Y end switches (hall-effect)
  • Hotend 24V with NTC connected including tool’s fan (I am missing the PT100’s interface board, have ordered one but I did this before so should be no problemo)
  • Hotbed simulated with another hotend including NTC
  • Stepper motors connected to X(0),Y(1) and 1 x  stepper on the expansion board Z(5) (Driver5)

The Duet2wifi board is a Chinese MKS clone with electronics version 1.02 which works fine.  The expansion board is also a Chinese one, but this is a bare-bone  implementation of the 5-ports driver add-on board that comes without drivers.  the nice thing about this add-on board is that drivers can be plugged in directly.

The Duet2 came with firmware 2.1 installed.  To get to FFR3.1, you must first install 3.0 and after this, you can move to 3.1…  be aware!

After updating the paneldue and the Duet2wifi board, I activated the wifi and put the ssid and PW in. (This procedure goes via USB between PC and Duet, using a terminal emulator like YAT)  This is a bit tiresome but given the security you get from it, I feel it is OK.

The settings that are needed to get the Chinese expension board to work are not too difficult.  Add the Z-drives, and change some other settings. On top of this page, you can download the latest doc with all info I have, and a direct download to the adapted config and macros is available in the documentation.

The rest of the build including photos will be here later!

Update 3-2021: I recently built 2 other 3d printers using Duet2wifi boards: a cartesian I3 with independent extruders and a Delta 2GS.  Not much time to work on the big Voron.  I also just rebuilt my Geetech A30M  (330x330x400mm build size) from the smartto board to Duet2wifi, Check ik out on this site!

I will probably not build the big Voron 3d printer after all,  and if I don’t, I will rebuild my existing Voron 2.4 300×300 from Klipper, octopi and 2x SKR1.4 to Duet2wifi+Duex.  That will be interesting and achievable.

Since I am currently running 10 different 3d printers, my space is getting cramped in the house. I don’t want to expand into another room.  One should be enough. Having more printers gives me the best possible fit of a specific  filament type per printer.

The Voron is due to its perfect prints with ABS really only used for/with ABS or nylon.

The I3Bear dual carriage works best with dual PLA or PLA&PVA.

The Prusa mini works perfect with PETG

The I3Bear solo goes perfect with PETG or PLA.

The A30M & its mixing extruder goes perfect with PLA and/or PETG

And so on….

3d applications – self-folding materials

3D printing became a hot item around 2016,  and quite a few 3d printing machines have been sold over the years.  But, at some point it seems that the use for products from these machines has faded away.

Due to the availability of 3D printers and the fact that these printers are getting better and are producing prints with better quality as they evolve over time, more applications have been developed.

In this article I will sum up a couple of these new areas in which 3D printing became a driver for new developments, which are sometimes just scratching the surface of possible future developments.

  1. Dental products.  For over 40 years , dentists are using Services from laboratories to produce Ceramic protheses for teeth.  The base for this is a mould, taken from the patient.  I recall that this was indeed not a very pleasant process for the patient.  This process was time consuming and it required also some adjusting and fine-tuning at delivering the protheses at the right place.   Currently all dentists are either producing the protheses themselves or use online deliveries that are mostly available with a production- and delivery time of less than 4 hours.  the process starts with a 3d-scan from the patient’s mouth, compared with (if available) older pictures and/or X-rays.  All is fed into a normal PC, and the software makes the 3d print data.  After that, printing the protheses is quite simple with the new ceramic printable filaments. Placing the protheses with UV-herdening glue means that someday we will be able to do this at home. Although the prepping of the place to put the protheses will still be done by a dentist, I presume.
  2. Technical parts.  For many tehnological industries the availability of 3D printers has made it possible to have faster development processes of new parts and applications,  You can think of modeling new tools,  household objects, cars and -parts, and so on.  Since new materials can be printed like aluminium, copper, gold, silver and carbon much is possible. After the developments has produced a complete product, mass-production can start and for this, the 3D design files can be handed over to make the work easy.nn In this way both time and money is saved.
  3. Art.  Maybe not the most obvious development yet, but lately I ran into some artists whom actually used 3D printing in most expressive ways, as art may do.  If you check the internet for this, some interstingexamples can be found.
  4. Medical developments.  Since 2017, a new development achieved the ability for 3D printed parts to shrink and expand, based on the printed structure.  Read this article about self-folding materials
  5. Fun printing. Many hobbyists are printing 3D objects just for fun.  To add-on applications to their 3D printer, build new ones or print household applications.

 

 

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