2014-04-15

Makibox - the next steps

The default hotend of the Makibox is ...crappy.
The thermal barrier is not enough to print anything larger then a test-cube in ABS or PLA. Even with no retraction at all, the filament above the heater block expands and stalls even the strongest extruder after 30 inutes of printing. (Using the supplied Makible filament and higher temperature settings. With Makibox-supplied default settings it's much worse.)

I already have a stronger and spring-loaded extruder and a thinner bowden tube. They help but alone they don't solve the issue. They just postpone the failure.

I'm currently waiting for a modification from a forum user in the US that adds a cooling block to the existing hotend. The modiciation is as simple as screwing it on and mounting a fan.

In parallel I already have an E3D hotend version 5.
During Easterhegg I'll try to find someone to print me a mount (or another mount for LM4UU linear ball bearings) for that and follow the instruction of user my_makibox to install it.
If not, that mount looks simple enough that maybe I can CNC mill it out of a piece of wood.
(Having E3D print a mount for me was not avaliable when I ordered my hotend.)
Not that is does require a firmware update because it has a different thermistor.
my_makibox supplied a compiled firmware here .

2014-04-14

CNC6040 updates

Just to give everyon an update:
This weekend I made a few modification to my larger CNC.

The new E-Stop button got it's cable properly mounted to the wooden case I build.
Just below the thick glass front.

Proper sockets for 3 end-stops have been added. The original end-stops I got where too small to fit mechanically but bigger ones where in stock this weekend. They have not been installed yet.
I'll install them together with bellows to protect the Y axis from dirt and shavings.

The probe input didn't want to work when using 5V from one of the Enable-outputs of the PLCM-B1 breakout board. I added a separate 5V supply just for the tool height probe and it works now.
Here is the answer from Purelogic regarding this issue:
  Hello Marcus,

  Thank you very much for your notice.
You are right that you need another power supply for external sensors.
PLCM-B1 has too many inputs and we could not place another on-board power supply which could power all inputs. (Of cause we could make it, but will be too expensive and large).
  Small on-board power supply with limited current (for ex. enough for 5 inputs only) can cause more problems because not all users read a manual carefully and they can easily overload this power supply. Nevertheless this way seems most right for me now.

  We will consider your notice in feature. Thank you very much.

Oleg Gladyshev,
Purelogic R&D, Russia. 

The earth cable of the spindle VFD got ripped out. I repaired it and secured it somewhat better.

The power sockets for all parts of the CNC are now permanently screwed onto the frame and can no longer fall off due to the drag of the heavy cables.

My cheap MACH3 remote is still acting up. The jog buttons get stuck and the machine just keeps moving.
I replaced the keyboard with the flaky USB port and the constant USB attach/detach cycles no longer mess up the communication of MACH3 via Ethernet to the PLCM-E3p+B1 boards.


For the smaller TravelCNC I managed to drill an XL timing belt pulley from 5mm D-shaped to 8mm round shafts. It shall replace the 3D printed one I made a while ago because that one developed some serious backlash after 6 month of usage.

I will give a small workshop on CNC machining for people who have used only 3D printers during Eaterhegg next weekend.

2014-03-27

Accidentally deleted FreeCAD development VM :(

I just accidentally deleted my FreeCAD development VM. :/
Now I need to download my empty VM again, checkout my own GitHub repository, add the upstreams of the other developers, the main upstream and then continue developing.

2014-03-25

Blackmagic Pocket Cinema Camera 25fps endurance test

Setup

25fps, 180° shutter, ISO800
2x Sandisk Extreme Pro 64GB
USRobotics dual UHS-1 USB card reader
iMac
manual lens, drawing no power for autofocus or optical stabilisation.
focus peaking ON

Test 1 raw

  20min 3 seconds of raw footage.

Test 2 raw

BMPCC stops at 19min45sec with 48% battery having filled up the 64GB card.
However it starts blinking a "card full" message after about 15min of recording.
29649 frames
Resolve reports just: 19min 45sec
40minutes to transfer footage to iMac
 => you can't run on 2 cards, dumping one while the other is being recorded to.
59.538.769.788 Byte (59,59 GB on disk)
29.649 frames
3min 33sec to erase all files on the SD-card

With the remaining 48% battery
19 minutes 45 seconds (exactly like before down to the second) onto another SD card.
After 15min 11 seconds the "card full" message starts to blink.
2% battery left
transfer to PC: 42min
59.370.355.068 Byte (59,44 GB on disk)
29.594 frames
Resolve reports: 19min 43sec


With remaining 2% battery left, the camera nearly instantly shuts down in an attempts to record some more.

Test 3 ProRes

39min 43 seconds of ProRes before the battery and not the SD-card ran out.
There was enough space for another 4minutes 52 seconds

2014-03-23

CNC6040 upgrade

I finally found the time to finish the upgrade of my large YOOCNC 6040 from the USB control board (that was already a huge improvement and now works in my smaller TravelCNC) to the russian PLCM-E3 and it's huge breakout board PLCM-B1.

The 4 existing axis all work fine now, both E-Stops (on control box and on the machine) work as does the tool-height-probe input and I have the ability to upgrade to 5 (and even 6) axis later.
I actually want to do that when my "SimpleMultiAxisCAM" is finished.

The dozens of inputs and the 6x 250V 6A relays are not used yet.
I'll connect the 2 E-Stop buttons and the Probe input later.
The relays will probably be used to control the water pump for the spindle cooling water and the compressor for my existing mist-cooling for metal working.

6 axis,
15 inputs,
16 outputs,
6x 250V 6A relays,
controlled via Ethernet and with proper optocouplers and galvanic isolation.
I'll not use the PWM feature as my spindle is controlled via RS485.
28 leds for all axis and inputs can e wired to the front of the enclorure.
...what an upgrade.
BTW: That breakout board is HUGE.

I also found the reson for the "stuck axis" and the "connection lost" issues.
The stuck axis seems to be a fault in the chinese MACH3 remote control and the "connection lost" a faulty USB keyboard that detaches and reattaches from USB and messes up the system for half a second each time.






2014-03-18

Makibox Hotend and power improvements - Version 2

This is my second attempt to fix the issues of the Makibox hotend.
This time In added a number of large and small M4 washers and placed my fan deeper.

Also: Powering the fan and Raspberry Pi from the same 12V supply seems to cause random crashes of the Makibox firmware. Particularly when it's supposed to start heating the hotend. I have gone back to powering the Raspberry Pi via a second power supply and am observing the situation to confirm this as the cause.
Result: It still crashes. Something else must be at fault. Searching...



Results:
The washers are perfectly cool.
The PID control has a hard time reaching target-temperature and usually stays 5°C below what the hot-end should be at. I will need to change the PID settings or block air flow from cooling the hot zone instead of just the washers and shaft.
The bed needed to be leveled again because the length of the hot-end changed a bit.

The TEST PRINT FAILED AGAIN with the same filament stalls as all the others.
At the time of failing the washers where perfectly cool.

Second attempt:
I changed the target temperature to 218°C.
This is a temperature that worked well before and has less mechanical resistance because of lower viscosity.

FAILED


Third attempt:
I changed the target temperature to 190°C.

FAILED

2014-03-17

Makibox Hotend and power improvements

After switching to the AirTripper V3 BSP extruder, I wanted to improve the hotend to finally get reliable printing...

But the first thing that happened was, that the BSP connector of my extruder ...fell out.
I did add a small heat sink and a 12V fan to the top of the hotend.
Since I cannot prevent heat from creeping up from the hot zone to the parts of the hotend that are supposed to stay cool. the intention is to cool the upper parts and dissipate as much of that heat as possible.


While connecting the 12V for the fan, I also connected power for the camera-equipped Raspberry Pi that lives inside the Makibox.
Beware that you need a gas powered or very strong electric soldering iron to solder anything to this PCB. It dissipates all the heat you put into it before the solder has any chance to melt.



test:
I'm currently testing the setup.
The hotend is staying at 235°C for an hour and I'm touching the upper part to feel for any warmth every now and then.
I already know that the "L" shaped heat spreader does get warm to the touch during long running print jobs before friction due to expanding filament above the hot zone ruins the print as even the strongest extruder cannot push hard enough to overcome this.
results:
The "L" shape stays cool while the threaded part and the M4 nut at the top of the threaded part of the Makibox hotend is too hot to touch.
The TEST PRINT FAILED AGAIN with the same filament stalls as all the others.
Either this isn't the issue at all or I need a way to cool the threaded filament tube above the hot zone.


>>> Part II