- User Since
- Mar 28 2017, 10:36 AM (99 w, 4 d)
Thu, Feb 21
I have completed wiring diagrams for the TAZ Pro. They are 2 PDF files, 1 of the Main Chassis and 1 of the Print Head.
Fri, Feb 15
I am designing tow boards, one with spring contacts and one with contact pads for use with swappable cores.
FCC and CE testing is scheduled for the week of February 18th with EMI Test Labs (Dennis King).
This board had a cold solder joint on the replacement Hall effect sensor. The sensor was re-soldered, tested and returned to stock.
Mon, Jan 28
I have a test board constructed to test the Filament Sensor assemblies. The test board is powered by a 5V wall wort and has LEDs to show activity on the Filament Sensor Hall sensors. I am currently using the board to test modified Filament Sensor boards. The modification is a change of the Hall sensor from a Toshiba TCS40DLR to a Diodes Incorporated AH3365Q. I'll bring the test board to MER when I have finished modifying boards.
Fri, Jan 25
Jan 18 2019
Jan 16 2019
I just completed a test board that can be attached to the filament sensor cables of the control box as part of this test. The board is simply attached to the two 3-pin plugs of the filament sensor harness and is powered by the 3.3V lines of the harness. 2 red LEDs will indicate whether the power lines are wired correctly and the board will provide signals to mimic the signals of the filament sensors. A push-button selects 5 test modes: E1-E2 Off, E1 pulsed, E2 pulsed, E1 andE2 alternately pulsed and E1-E2 On. Yellow and green LEDs will indicate the state of the pulses.
Jan 10 2019
Jan 3 2019
Dennis claims he can do all the needed FCC and CE testing, leaving Intertek to do the UL testing. We are waiting on a quote from Dennis to see how his charges compare with Intertek.
Testing of the Archim 2.2b board will take place on January 4th.
The latest versions of these boards are REV. D for the Dual Extruder Basic Interface and REV. C for the USB Reader. REV. D of the Dual Extruder Basic Interface has a 22uH inductor added to the shroud fan circuit. REV. C of the USB Reader has a 12MHZ MEMS oscillator instead of a crystal and has a new 3.3V linear regulator with a delayed enable.
The prototype boards with a 12MHz MEMS oscillator and delayed 3.3V turn on are performing well. 40 REV. C versions of the USB Reader have been ordered for our "Beta" run.
I have added ferrites to the J20 sensor cable and the Bed-Temp/Z-Min wires in an effort to reduce ESD susceptability to ESD discharge. Further ESD testing may show whether these ferrites are needed or not. If they are, we can use the clip-on type ferrites on existing cable assemblies instead using cylindrical ferrites and incorporating them in new cable assemblies.
Dec 28 2018
Dec 21 2018
As part of ESD mitigation, I am adding a second TVS diode at that same attachment point. The cathode (white line) side of the diode will be attached with a ring terminal along with the ring terminals of the green probe wires. The anode side of the diode with connect with a 16 gauge wire (via EL-MS0146 Solder Sleeve) that will run back the chassis ground. I have yet to design the details of the cable assembly but I had to carve out a trough in the plastic part over the ring terminals to accommodate the third ring terminal. Adding this third terminal was difficult so I would advocate a change in the design of the plastic part. I will discuss this with Josh.
Dec 19 2018
We received 3 first article USB Drive Reader boards. These boards were the same as the previous boards with the exception of the C5 and C7 capacitors being 18pF instead of 20pF. The board layout was the same so I kept the boards at REV B. These boards have proven to still be unreliable as their crystal oscillators do not always turn on. I have a new board design for the USB Drive Reader that uses an oscillator module instead of a crystal. Prototype raw circuit boards have been ordered from OSH Park. I will build 3 prototypes of this new design and test it before ordering more boards.
The current board is called USB Drive Reader REV. B. The new board, if it works, can be called USB Drive Reader REV. C.
Dec 18 2018
I have noticed that many USB Reader boards do not come up when first powered. This is a failure of the crystal oscillator circuit on the MAX3421e chip. A possible cause for this failure is the time required for the 5V and 3.3V power supply circuits to fully turn on. Observations with an oscilloscope show that is takes a little over 3ms for the two supplies to come up to their proper voltages. I am ordering a new type of voltage regulator that will have a faster turn on time and will mock up a few USB Reader boards to see if this fixes the problem. I have also done a re-design of the USB Reader board that uses an oscillator module instead of a crystal. Once some prototype boards come in, I will test this new design to see if it performs better.
Dec 10 2018
A heat shrink tubing printer I use for my home business is the Kroy K4350. It prints black lettering on white or yellow tubing. The tubing is from Kroy and comes in several widths. The printer retails for $599 and 100 ft. rolls of tubing start at around $130.
Dec 7 2018
Never mind. I was looking at an older LCD assembly. The standoff length on the newer LCD Back piece now accommodates the long speaker pins. The bowing on the new assemblies is very minimal but may be caused by either the LCD Back plastic piece bowing when installed or the brass M3 inserts not being exactly perpendicular. As long as the bowing is minimal, it should not cause any problems. If, however, the bowing is excessive, the plastic parts of the LCD assembly should be examined and replaced, if needed.
I took a look at an LCD assembly and the CLCD PCB assembly. The pins of the speaker on the CLCD board are slightly longer than the height of the standoffs, causing the board to bow when installed on the plastic LCD Back piece. A possible fix would be to add an indentation on the LCD Back at the point where the CLCD board speaker pins are located. Another possible fix would be to lengthen the standoffs on the LCD Back by 1mm to accommodate the length of the speaker pins.
Nov 26 2018
Nov 21 2018
Nov 1 2018
Test Results from 10-26-18 and 10-31-18.
Oct 30 2018
Oct 29 2018
After EMC testing and further examination in R&D, I found that the primary cause for the USB failures was from noise generated by the shroud fan. This occurred when the shroud fan was at a setting other than 0% or 100%. The noise was present when the shroud fan was driven in PWM mode. I was able to minimize the noise by placing a 10 uH inductor on the extruder interface board, in series with the shroud fan circuit. I have ordered 22 uH and 33 uH inductors to test and hopefully further reduce the noise.
Oct 17 2018
I took a closer look at USB failures and intermittent operation and found that one cause is unstable operation of the crystal oscillator used to drive the SPI to USB chip on the USB Driver Reader board. The crystal oscillator circuit currently uses load capacitors of 20 pF. By replacing the 20 pF capacitors with 15 pF capacitors, I was able to make the oscillator circuit more stable. USB boards that would not start up when the TAZ 7 was powered on began to work with the 15 pF capacitors.
Testing at EMI Test Labs on Friday, October 12th showed excessive conducted emissions when the shroud fan speed was set at levels other than 0% or 100%. Testing in R&D showed that the PWM frequency being sent to the fan was 100 kHz. On other printers this PWM frequency was around 122 Hz. Changing the Archim2 controller board firmware to have a 122 Hz fan PWM frequency eliminated most of the emissions as observed with a spectrum analyzer and a near field probe.
Oct 9 2018
The Z-Brake board as REV. C appears to be working well with no problems from an engineering point of view. Let people buy all they want.
Sep 21 2018
The prototype filament run out sensor PCB assembles appear to be working well with Quiver. The schematics and PCB designs are in the "Kettle" GIT repository. We currently have 6 assemblies made from OSH Park PCBs.
Sep 18 2018
Sep 14 2018
Sep 12 2018
Looking at the Archim schematic, it would be best if we could use J20 Pin 15 and J20 Pin 16 for the filament sensor signal lines. These pins correspond to IO lines PB 15 and PB 16 on the Archim SAM3X8. We will have to check with the Marlin code to see if these pins can be configured as general purpose IO and be polled for activity. We already use an 8-Pin box header connector to connect to J20 Pins 17 to 24. Changing to a 10-Pin box header connector would give us access to J20 Pins 15 and 16.
Sep 10 2018
The 20 first article boards are working fine in the Quiver prototypes. No need to update the design. Production boards can be ordered when needed.
Sep 6 2018
The current board is Rev. B and pushed to the diffusion rGREEN GIT repository. Currently, we are having no problems with this design so it should be the board used for production units.
The above addition of a user accessible "Erase" switch works well on prototype Quiver printers. This should resolve this issue.
Aug 28 2018
Aug 24 2018
A new Z-Brake board, REV. C, is now being used in the Hibiscus (Mini 2). This assembly has varistors added to the connectors that go to the stepper motor windings. These varistors limit the voltage spikes that are created when the relays disconnect the motors from the motor drivers. This should prevent the failures we had been seeing with the REV. B boards. All REV. B boards in stock have had varistors added.
20 first article USB Reader assemblies have been ordered from Ultimachine and should arrive on August 24, 2018. These assemblies will be installed in Quiver (TAZ 7) prototypes and tested.
It has been decided that Quiver will only use a USB thumb drive reader. No further development of the SD Reader is planned at this time. The board design has been saved to "Shared J" drive and pushed to GIT and will be available for future printer designs, if needed.
We are using Archim 2.1a boards for Quiver (TAZ 7) prototypes. These boards have 4A +5V power supplies to provide the extra power needed by the dual extruder servo motors. They also have modified header connectors to provide +5V to the Quiver Color LCD Panel and USB board. So far, these boards have worked well in the Quiver prototypes. If any critical issues arise from these boards, we will contact Ultimachine but, as of now, all looks good.
We are currently using basic interface board for the prototype TAZ 7 dual head. This board is called TAZ7 Dual Extruder Basic Interface Board RTev. B. The board does not have any power supply circuit on it as the latest Archim boards have a 4A +5V supply that is now routed to this board. The board simply routes connections to the 2 extruders from a single cable chain. The board does have circuits that boost the 3.3V digital servos signals from the Archim board to 5V signals needed by the servos. We have ten boards on hand that were ordered as raw PCBs and hand built by me. If we decide to go with this design, we will have the boards built as complete assemblies by Ultimachine or a similar manufacturer.
Aug 14 2018
A PCB has been designed and prototypes ordered from OSHPark for a Hall Effect sensor. The sensor will be mated with a magnetic disk attached to an idler that will rest against the filament. The output of the sensor will be feed into the Archim control board. Any change in the output of the sensor, either Low-to-High or High-to-Low, will indicate movement. I am also hand wiring a couple of sensor boards that can be used to test the design.
Aug 9 2018
SDS added to Mini-Hibiscus GIT.
Aug 8 2018
The ATSAM3X8 ARM processor may, at times, require manual erasure. This often is the case when firmware "locks up." The Archim controller board has a push button erase switch for this purpose but it is not easy for a customer to find or push and requires that the TAZ 7 cover be removed. Johnny Russel has added pins on the latest Archim board to allow access to the "erase" input of the SAM3X8. We are adding a push button switch directly below the USB Thumb Drive connector on the top of the TAZ 7 control box that will allow a customer to erase the SAM3X8 before loading new firmware. This switch is the same switch as the limit switches used on older printers. It is attached to the plastic USB hlding frame accessed through a 2mm hole in the plastic USB bezel and holding frame. A customer wishing to erase the SAM3X8 would activate the erase switch by sticking a paper clip in the hole and pressing the switch.
Aug 1 2018
I'm not sure what OSHW certified involves. I designed this board here at Aleph and everything about it has been open source and placed in our GIT repository. I added the OSHW logo to the board's silkscreen artwork. If there is anything I need to do for OSHW certification, please let me know.
Jul 30 2018
Modification is the addition of 4 varistors to the motor connectors. These varistors are 0805 SMT packages and can be soldered across the pins of the P3 and P4 connectors. Before adding the varistors, the boards should be examined for any solder bridges across connector and/or relay pins. Any solder bridge found should be removed as well as any solder "balls" or splatter found on the board. A modified board can be used as an example and photos of the board can be used for re-work instructions.
Jul 9 2018
I examined the Z-Bake board on a Mini2. The problem occurs when power is removed while the stepper motors are energized. Releasing the motor windings with the relay causes large (~100V) spikes. While these voltage spikes are not directly connected to the Z-Brake control IC (an LM397), there is enough capacitive coupling to allow some spikes to enter the LM397. I have added 6 varistors, as a modification to the affected motor winding connections. These varistors (AO Part EL-CA0220 or AVR-M2012C390KT6AB) limit any voltage spikes to 30V when the motors are disconnected.
Jun 12 2018
2 more LM397 failures have been reported and verified. Another failure involved a bad K1 relay. The relay was tested and verified to have intermittent electrical contacts. I will check a Mini 2 on the oscilloscope to see if any voltage spikes are present on the 24V power supply, especially when it is first powered on. Other than a voltage spike, I do not have a cause for the LM397 failures.
Jun 11 2018
May 24 2018
We still plan to use some type of interface board on the X carriage to connect the extruder(s) of the tool head. Not using an interface board would require extra Igus cables as each extruder would need its own set of cables. We have the option of adding some smarts to the interface board to further reduce the cable count and add features such as a filament movement/run-out sensor.
May 10 2018
I can draw up board designs for a "Simple" interface board and a "Smart" (has on-board microprocessor) and get some prototype boards from Osh Park. We will still need to pick a type of board and control strategy for the final design of the Quiver. Options still include: Simple Interface - Use servo type motors or linear actuators. Smart Interface - Use DC motors or linear actuators with a motor driver chip, be able to add a filament movement sensor, be able to add and control RGB LEDs.
A simple toolhead interface board has been constructed and and tested on both toolhead designs. Also, both an Arduino Uno and Arduino Due have been set up and tested to drive the toohead servos. The input plug of the toolhead interface has been modified to attache to both the Uno and the Due.
May 8 2018
The current Meanwell RSP-500-24 power supply in the TAZ 6 can be turned on remotely by energizing an LED on its RC connector. To use this function, AC would have to be constantly supplied to the power supply, with the supply running in a low power, idle mode. Also, a second power supply would be needed to energize the LED. Any supply using a digital on/off input would have to have an always-on, standby power feature such as those used in most desktop PCs. This feature would most likely add cost to the supply, as would a second (+5V or +12V) supply.
Prototype boards for the SD Card Reader (Hidden) were designed and ordered from OSH Park. Three prototype boards were hand built and are being used for testing and evaluation of Quiver (TAZ 7).
Prototype boards for the USB Reader (Green) were designed and ordered from OSH Park. Three prototype boards were hand built and are being used for testing and evaluation of Quiver (TAZ 7).
Cooling on Einsy control board (Mini 2) has been accomplished by adding an aluminum bar and thermal pads between the control board and the printer case. The aluminum bar (heat sink) is held in place by a printed plastic frame.
Apr 30 2018
Regarding power cables, my only concern is using the same power cable for repeated tests may eventually cause the cable's insulation to fail. The power cord should pass a 1500 VDC test for 60 seconds but may degrade after multiple 60 second tests. This type of test over-stresses components. Our normal power cables are marked as being rated at 300V.
- I would suggest testing the printer with the cord it is be be shipped with. That will insure that the entire assembly is safe.
- I'm not sure what the whole assembly process is but we want to Hi-Pot test units that are as complete as possible. Also, a functional test should be performed on the printers after Hi-Pot testing to make sure they have not been damaged or affected by the Hi-Pot test.
Apr 26 2018
I will need to operate the new, Hi-Pot tester, an SCI 294, before designing an OHAI test procedure. The tester should be delivered to Aleph Objects on Friday, April 27. As I am out on PTO that day, I will set up and operate the SCI 294 first thing Monday morning. Based on my observations with the tester, I can write up a proper test procedure.
Apr 19 2018
U1, an LM397 Comparator, was bad. I replaced the LM397 and tested the board. This is the second LM397 to fail. If another failure of the LM397 occurs. We will need to look into the failure rate and quality of the part. The LM397 is designed to work up to 30V and should function on the Z-Brake board.
Mar 29 2018
U1, an LM397 Comparator, was bad. I replaced the LM397 and tested the board. Everything worked as designed. This ticket can be closed.
Mar 9 2018
If the "Electrical Ratings" is the voltage and current requirements of the Hybiscus, these can be taken from the input ratings of the UL power supply. In the case of the Hybiscus, the power supply is a Delta PMC-24V150W1AA and it is rated at 100VAC - 240VAC, 50Hz-60Hz and 3.2A max.
Feb 22 2018
The EinsyRetro 0.1c boards are good. Temperature readings are now rock solid and EMC testing shows a Mini 2 has the lowest emissions of any Aleph product tested. My opinion is that we are good to go with the EisnsyRetro 0.1c boards for Mini 2 production.
Feb 20 2018
Feb 8 2018
Feb 6 2018
Preliminary ESD Testing was performed on the Hibiscus with an LCD Module attached. The unit failed on both +/- 4kV contact and +/- 8kV air discharge when using a metal front panel on the LCD Module. +/- 4kV contact caused pixels to turn on on the LCD and the LCD Module to act as if someone had pressed the encoder button. +/- 8kV caused the unit to completely reset during a print. The Hibiscus passed ESD testing when a plastic front panel was used on the LCD Module. ESD testing of the rest of the Hibiscus unit (frame, control box, etc.) passed.
Jan 24 2018
Have you tried swapping out the thermistor? If the problem persists, it would indicate an problem with the controller board or faulty connections. If the problem goes away, you probably just have a flaky thermistor. It could be that the quality of the new thermistors needs to be investigated.