Wednesday, 1 May 2019

V2.1 FYSETC Mini 12864 panel on RAMPS

I got one of these to play with, but the documentation provided on is out of date.

The documentation seems to be for a earlier version.

I found some measurements and schematics on their github This helps a lot.

The main difference seems to be that the earlier version just had transistors to turn on the 3 separate RGB LED's. V2.1 has WS2811 chips (aka neopixels)

First set up the basic display and LEDS

In Configuration.h

You still need to enable minipanel


But then  enable the neopixels. there are 3 of these on the board and they are connected to D25

// Support for Adafruit Neopixel LED driver
  #define NEOPIXEL_TYPE   NEO_RGB    // NEO_GRBW / NEO_GRB - four/three channel driver type (defined in Adafruit_NeoPixel.h)
  #define NEOPIXEL_PIN    25        // LED driving pin on motherboard 4 => D4 (EXP2-5 on Printrboard) / 30 => PC7 (EXP3-13 on Rumba)
  #define NEOPIXEL_PIXELS 3        // Number of LEDs in the strip
  #define NEOPIXEL_IS_SEQUENTIAL   // Sequential display for temperature change - LED by LED. Disable to change all LEDs at once.
  #define NEOPIXEL_BRIGHTNESS 127  // Initial brightness (0-255)
  #define NEOPIXEL_STARTUP_TEST  // Cycle through colors at startup

Then setup the screen almost the same as described on the wiki. The encoder is backwards and the kill pin was wrong.... so set it up as below.

in pins_RAMPS.h

#elif ENABLED(MINIPANEL) #define BEEPER_PIN 37 // Pins for DOGM SPI LCD Support #define DOGLCD_A0 16 #define DOGLCD_CS 17 #define LCD_BACKLIGHT_PIN -1 // backlight LED on A11/D65 #define LCD_RESET_PIN 23 #define SDSS 53 #define KILL_PIN 41 #define LCD_CONTRAST 200 #define BTN_EN1 33 #define BTN_EN2 31 #define BTN_ENC 35 //the click switch   #define SD_DETECT_PIN 49

You do need to do step 4 from the wiki


Step 3 is optional, if you want the LCD Control Menu

This will give you a display and the LEDS.

Don't forget to enable sd card support In Configuration.h  if you want that to work


And it all works (as far as I can tell)

Tuesday, 2 April 2019

Dangerous products from China, Bad power cords.

We have all heard about them

The most notorious are the "Death adapters" Physical converter that change from one plug type to another.

Today I was wiring up a power supply for a test rig. Made my own little C14 socket box, to insulate it and make it safe

I plugged in a C13 cable and tested my wiring.... It failed!!  My Neutral and Live where crossed over.

I thought ok.. maybe I screwed up, it does happen, this is why you test before applying power.

But nope....

The C13 power cord I picked at random from my collection is wired incorrectly. It came this way from the China factory!!!

So I re checked everything, making no assumptions.

Starting at the the NZ/AU plug I verified that the live and neutral pins where labeled correctly in the molded plastic.

The molded plug in question matches, even has the Insulated pins (another rarity)

Next the C13 Plug

The molded female plug in question matches nicely, no issue in the labeling.

Testing with a multi meter L to L,  no connection!  N to N, no connection!!!
But N to L and the other N to L are connected!!!

The faulty cord is labeled on the NZ/AU end is "KENIC N18070 KE-13B 10A250V~"
Lots of labels on the C13 end  "N15074" and "KE 24 KENIC 10A 250V~ A003828"

I opened up the cable. It has Yellow/Green(earth), Blue (neutral) and Brown(live) wires. It is real copper, not the copper plated aluminum rubbish (but that is another story)
The NZ/AU plug end is correct, but the C13 end is flipped

So if you have any "KENIC" branded cables, you might want to check them

Sunday, 3 March 2019

Making a cheap 20x4 lcd fit a Prusa MK2-MK3 case

For a while my replica Prusa MK2 has been bugging me.

It works great, just like a real one, but...  the LCD is the wrong colour!
My LCD is a yellow colour and the real ones are blue.

So I searched online for a blue 20x4 LCD. Most suppliers would not promise a particular colour.  But I did find one that promised and supplied blue.

Although the general shape was what I needed, there where several issues that made it incompatible with the MK2 and MK3 LCD cover.

Firstly the contrast variable resistor.
Back of 20x4
The large blue and white variable resistor sets the contrast, but this particular version is to high. You cannot slide the mounts in place as they hit the top of the resistor.  This board is well designed though, it can also take a small surface mount variable resistor. (The three empty solder points to the left) 

new and old contrast resistors.
These are both 10k. I swapped the large for the small one. That solved this issue.

On the front are two more issues
Controls and buzzer.
The encoder is to tall and the button is to short

The replacements.
The replacement encoder is a "Rotary encoder,code switch/EC11/ audio digital potentiometer,with switch,5Pin, handle length 15mm" the switch is a "Momentary Tactile Switch DIP 6 x 6 x 7"

With these installed the Rotary knob sits at the correct height and the stop button can be activated. 

The switch is a little low a 6x6x7.5 might have been better, but I didn't have any, the 6x6x8 was to high. 
The selection I had... and still not the one I needed
You always need the one you don't have....

Wednesday, 27 February 2019

Prusa MK2.5 installed

MK2.5 printed parts

I had pre printed the MK2.5 parts in black PETG prior to the the kit arriving.

MK2S stripped 
 Removed all the parts as the manual instructed, later the controller cover will also be replaced.
Parts that will get reused

Parts that wont get reused on this machine
 Controller cover parts will be added. One thing I didn't expect is 'they' don't expect you to re use any nuts, washers or bolts. They provide new ones for everything. 
All assembled again
 Just followed the manual, no big issues. One small thing is the heated bed cable cover, it takes 3 * m3x10 screws. But these are two long. In particular the one that holds the cover on the pcb sticks up to far and catches the door of the electronics cover. I replaced it with a m3x8.   
Test print
It still works! and now I have a removable build platform, bondteck gears, quieter fans and a (already obsolete as of mk2.5s) filament sensor.

I also noticed that the new firmware now shows estimated print time and counts down vs the the old firmware that just showed elapsed time.  (This is of course just passed to the printer in the gcode from slicer estimate)

Wednesday, 13 February 2019

Prusa Mk2.5 upgrade

So I finally got my Prusa MK2.5 upgrade kit, and as I am writing this Prusa has released the MK2.5s... Typical...
Standard black package from Prusa.
A nice labeled box inside.


The contents.

Candy!! Almost the most important part.

Fist bag of parts.

Second bag of parts.

Third bad of parts.

Mini Black PETG spool.

Basic Instructions.

A new Handbook

Replacement wire wrappings

The magnet build platform

New bed for the magnetic build platform

Thursday, 25 January 2018

Prusa MK2s Bed thermal runaway issue

Well It had to happen sometime. My MK2s developed an issue! Hard to believe but true!

I was printing something in ABS (bed at 100C) and suddenly the printer just stopped!

I look at the LCD and it says "Bed thermal runaway"

I did some quick testing and sure enough the bed was reading a lot lower temperature than the infrared thermometer was telling me. (yes these infrared thermometer are notoriously inaccurate, but I know mine is close enough, especially on a black surface like the printed bed)

So I removed the heated bed and this is what I found

Lets take a closer look at that thermistor

It has come free from the tape and it hanging in mid air!
So I pealed back the capton tape, no issues.But the alu tape just tore to bits. So I removed it

I contacted Prusa support, but unfortunately they could not tell me anything about the aluminium tape.
Luckly I had Kapton and Aluminium tape
I added a bunch more tape... to try and stop that happening again.

What I don't know is if the adhesive on my Alu tape will be able to handle the temperature. Ill find out soon...

So what actually happened here? My best guess is that the spiral wrap grabbed the cables and pulled the thermistor out with repeated Y movements. All the cable was pulled threw and sitting the in the electronics enclosure.

I suspect this has happened to others, as looking at the build instructions for the Mk3 they now say the wrap the thermistor cables around the heated bed cable. Which I will now do to my machine.

Sunday, 24 September 2017

Core XY update 3.3

Still not quite 200 in Z, but I am determined

So I tried a bunch of sizes for my Z rod clamps and settled on Moving the Z smooth rods 5mm In on the Y and 15mm Down on the Z

This enabled the Build plate to descend the entire length of the rod (there is a plastic bump around a screw head that sticks out level to the end of the t-slot, so it not all wasted space between the bearing holder and the side)

Next I mounted the power supply under the machine using
Now on thingiverse
They seem to do the job.

Next is the re attach the Z Stepper and lead screw
I use the same mounting bracket for the stepper but turn it upside down. So the stepper is completely below the t-slot

There is now about 2 mm space between the Power supply and the tslot.
The power supply also has to be positioned between the two heated bed mounts.