My Makibox status

I have 2 Makiboxes.
1 stock Makibox A6 HT and
1 Makibox A6 HT  with an Airtripper V3 BSP extruder and E3D V5 hotend but missing a working mount for the E3D.

I have given up on the Makibox and am willing to sell both.
That Makible is in trouble with it's investors doesn't help the case.
An Ultimaker 2 is already ordered.
Nonetheless I'm sitting in the GPN Karlsruhe at the moment trying to get both to work reliably.

I upgraded the stock Makibox to the new firmware v42 with PID autotuning.
(You use PID autotuning with the M303 command described here.)
I'm using it to print this E3D v5+LM4UU mount for the other Makibox.



PID results of stock Makibox:
< 02:45:13:  Clasic PID --  PID settings:
< 02:45:13:   M301 P7627 I57 D630
< 02:45:25: ** PID Autotune Cycle: 5 **
< 02:45:25:  bias: 39 d: 39 min: 199.00000 max: 201.00000
< 02:45:25:  Ku: 49.65638 Tu: 12.33100
< 02:45:25:  Clasic PID --  PID settings:
< 02:45:25:   M301 P7627 I61 D587
< 02:45:25: PID Autotune finished !
< 02:45:25: Place the above command in console to change the PID settings.

Result: IT WORKS. Pretty rough movement, so low in detail but it works now!
Printing more replacement parts while it still works.

Makibox: E3D hotend installed

The modification

I gave up waiting for the experimental Makibox hotend upgrade.
So as planned, I finally got my new E3d hotend.
Last weekend, during Easterhegg someone 3d printed me a mount for it.
I pretty much followed these instructions.
Except that I made a different modification to the Z endstop, that can be seen below.
I wanted my endstop to be adjustable. (See the photo below)

Endstops

 If you have the PrintRboard (first generation Makibox machines), you need to swap some cables after the firmware update:

From the top down the end-stops are:
* e-stop (move Y endstop cable here on the PrintRboard)
* z endstop
* y endstop (remove this cable)
* x endstop

Results

The E3D version 5 bowden 1.75mm hotend works great!
The Airtripper versioon 3 BSP extruder works great!
The hotend mounting has about 2mm of play in Y.
I'll replace it with a modified version that uses LM4UU linear ball bearings as soon as the bearings get here.
The final line is: I CAN 3D PRINT AGAIN!!!!! :)

#

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 .

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

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

Makibox issues

After I assembled my Makibox last night, I ran into a number of software issues.

Firmware: current 2.11
OS: MacOS
Host:

1 Lockups

Makible 5D Print in Google Chrome

In layer 5 of a test shotglass it just stopped and locked up. Wouldn't resume after power-cycling the printer and using the pause+resume function.
No error messages.

No manual jog controls for the extruder or Z axis => can't quickly move the head to a safe height and retract the filament after a failure.

Pronterface

Stock Pronterface/Printrun with Makibox settings.
I can jog each axis but loading any gcode and executing it, nothing happens.
It stays in line 0 (line 0 is a comment), doesn't heat up, doesn't home, nothing.

Update: gave Pronterface another try. This time it started printing but locked up just like 5D print did. So clearly this is a firmware issue or an issue in the common codebase (5D print started with a fork of Pronterface or so I've reat.)

Pronterface is incabable of stopping a print.
Pause, Reset, Stop, even Disconnect doesnt work. On Disconnect it executes the last 2 lines of g-code over and over again.This means the firmware has a bug and doesn't forget about already executed commands. At most it should finish the current command and then stop!


RepetierHost

I tried RepetierHost with these settings.
I cannot navigate to any but the first page in the preferences window. ("Host", "Slicer", "3D visualisation", "Colors")
It seems to not update the graph or textual output of the current temperatures.
Do NOT check the "( ) printer sends OK even after error" box for the Makibox to work.

....it just locks up like all the others.

Temporary solution: I switch from a Macbook Pro to a desktop iMac and a different USB cable.

Findings:

• On the MacBook Pro with MacOS 10.9 "Maverick" the printer just randomly locks up independent of the host-software used.
• On the iMac with MacOS 10.8.5 this doesn't happen.
• It seems to happen less on the iMac when I move the mouse every few minuted to prevent any kind of light sleep mode.

Currently investigating the USB port power requirements as a possible reason.
(Original Printsboard allows for being powered by USB or internal regulators from it's stepper/heater power supply.)
If so, a powered USB hub should solve the lockups.


Solution: Raspberry Pi with Octoprint

2 Stalls and filament grinding

At random points in the print, the filament stops.
The drive gear has ground a hole into the filament.
The filament above that hole is nearly half ground away by the drive wheel.

1. Repeated the bed leveling and all the tuning steps on the Makibox support page
2. The hole for the axis of the plastic wheel in the extruder was too small. sanded it and the wheel now spins freely. (all injection molded parts where oversized on this Makibox.)
3. Raised the temperature of the supplied "makibox HT test cube v0.2 PLA" from 192 to 218°C.
4. Retract the filament after printing. Don't leave the filament to cool inside the hotend. Don't re-insert it before the hotend is <120 br="">

 Currently testing....

Possible next steps:

1. Sanding down the surface of that springly plastic wheel to reduce friction.
2. lubricating the rods and the axis in the extruder.
3. Designing a different extruder with multiple drive-gears to increase grip without increasing pressure on the filament.

3. Slanted prints

...still working on this issue.

1. Check your stepper voltages. Maybe go slightly above the recommed 1.45V reference volrage
2. Check that your axis and hotend aren't fastened too tight.
3. Check the motor coupling for breakage or being loose
4. Check the bed-leveling bolts.
5. ...TODO

• Makibox forum thread about lockups
• Makibox forum thread II about lockups
• Makibox forum thread about jamming 
• Pronterface settings
• Some Makibox firmware modifications that could be interesting in the future 
• unofficial FAQ 
• Makibox Google Group

Assembling my Makibox

I received my Makibox HT and am trying to assemble it as per the
assembly instructions.

General improvements

• Label the bags!
• Numerate and label the parts! 
• Slot and tap contructions are always tedious. Especially in soft materials. It would have helped to tapper the taps (or the short side of the slots) of the slots to make insertion easier without affecting final stiffness. I get the impression that nobody ever thought about tollerances and how the parts have to move during assembly. A 5mm peg does NOT fit a 5mm hole. You make a 4.99mm peg and a 5.01mm hole!
• Other kits often include 1 extra back with 1 instance of each bolt type used. So you have 1 spare in case one gets lots and don't get confused with having bolts left. (because they come in an extra bag)
• The direct drive extruder is extremely prone to  get stuck and grind into the filament. It cannot transfer enough force, so a leadscrew or at least 2 driven gears on either side would have been a better idea.

Step 1

• There is a vertical feature on one of the 170mm parts that is missing in the drawing. Thus being confusing.
• Makible should label the parts by having a number be part of the mold. So you can refer to them.
• Step C looks like there are 2 of the parts used in step B. Image isn't clear enough.
• Use larger allowances for shrinkage in their taps

Step 2a+b

• My kit was missing the M4 washers. 
• The only M4x8 bolts in the kit have a different head (round) then in the image (flat).
• ...and need a different size of hex key then in the video.
• You need a broad screwdriver to hold the part for step B because you can't hold these with your fingers. (Too tight thread). In the video this is done by hand using the larger hex key...impossible in my kit because the bolts needs the smaller hex key and the part is made out of a denser material. One way is to clamp the screwdriver between your legs, hold the plate with one hand and very carefully turn the hex key with the other hand.

• The round parts have no thread to hold the M4x8 bolts but these types of bolts are not ment to cut their own thread (That's why you need pliers. To force them).

Step 2c

• A limit switch on the Y plate collides with a motor mount of the X plate. They don't fit. It looks like the limit switch on the X+Z plate is 4mm too long for it's position.
• The M4x8 bolt thus can't reach the box on the other side that it is supposed to cut into. :/

• Solution: That small, rectangular tab at the base of the cylindrical motor mount should not be there.
  If blocks the end stop and thus prevents the plates from matching up.
• Problem: That M4x8 bolt is way too short! If you can, get a longer bolt to replace it!

Step 3

• If you have magnetic (metric) hex keys, that could help in the fiddling with these tiny M3 bolts.
• As always with steppers, check the orientation of the cable in the drawing to sew how to insert the stepper.
• The image is not showing where one of the end-stop cables has to go when attaching the Z stage. 
• The z axis in step C has no bolts securing it in place. It falls right of then you lift the assembly to continue with step 4.

Step 4

• There are multiple parts that fit the drawing in 4a.
• The parts added in 4a will fall off during 4b-d all the time.
• 4d: You have to bend the thick wires to fit through the slots.
• In 4d the on-off switch is not shown in the drawing and it it completely unobvious where it has to go.
• Doing 4b before 4d makes fiddling the plug trough in 4d more tiresome then it needs to be.
• In 4c it is not obvious from the drawing what part to use. (2 parts fit,  4 parts look like the drawing. 1 part is correct)
• Seriously....Makible wants you to join about a dozen taps at once? In a tap&slot construction with no tapper and 0 allowances? Did they ever assembly any tap&slot or T-slot construction before? This is insane!
• Tools required: flat rasp and mallet!
• The bolts are too short to compress the parts together!

Step 5

• This step requires some force. It would actually be easier if the part was not pre-assembled because the rods block the way for the hex-key.
• For Step 5 B and C the flat part is one of the metal parts.

Step 6

• easy

Step 7

• 7b is tricky. The bolt has to cut it's own thread, yet there is not support form the other side. Why the plastic part had not been designed to fit is a mystery.
• Page 7 (like others) doesn't follow western reading traditions of left to right and then up to down. So make sure where steps A, B and C are and execute them in alphabetic order.
• The spring loaded platform is something I know from the old Repman. However this one is not good. The holes in the heated bed should be larger then the bolts! This way the plate tilts and then cants on the bolts and the springs have no effect anymore.
• The position of the bolts makes leveling the bed and adjusting extruder height a nightmare!

Step 8

• 8c : I'm not sure about their way of routing the cables. I usually try to keep cables away from heated metal plates. 
• Warning! The printed instructions forgets to tell you that the bowden tube has 2 DIFFERENT ends. Check this video to see what end goes where!(The end with the deeper support goes in the hotend)

Step 9

• I'm not sure that using bolts on acrylics without washers is a good idea.
• Attaching the edges is very difficult without using a thread-cutter first.
• Force the bolts into the edged first without the acrylivs, then remove them and then mount them. This requires enough force that the bolt actually gets hot (no powertools involved). Again this would be much simpler with another type of bolt that was designed to cut it's own thread.
• Do NOT put that cable through there like instucted. It's too short later!

Step 10

• Yes, you have to partly disassemble your preassembled extruder. That's correct.

Step 11

• If you mounted your Z stepper wrong...now you'll regret it.
• Also...what direction is X and what is Y? There is no imprinted hint! (Y is the longer axis)
• HE?
• HB? Maybe "Heated Bed" 
• The drawing shows 3 endstop-headers but the board has 4. 
• The video doesn't do the cabling in step 11 but aparently wires X and Y in some previous step. 

Step 13

• aparently as with any other hole nobody thought of allowances and tollerances for the hole for the power plug. Even though that hole could easily be 8mm bigger and still nobody would notice.
• I'm not exactly looking forward to installing Google Chrome just to run the damn printer software. A standalone Java program would have done exactly the same without installing such a thing on my Macbook. I don't see why I need to enter my Google account somewhere to use my local and offline 3D printer.

After Step 13 - Software

1. Power up the board with the power supply and plug in the micro-USB cable
2. Remove the jumper in the middle of the board at connector JP14

• Right after we are told how to screw the case shut above the board..
• I absolutely don't like that the host app is a Google Chrome app. Standalone Java already has a serial port API and doesn't require a new browser that auto updates without asking me, no knowledge of my Google Account and works!
• Installed the Google Chrome app.
• "Über die Chrome-App-Übersicht können Sie Ihre Lieblings-Apps direkt vom Desktop aus starten." Had to search a while to find that this damn thing has nested in my launcher WITHOUT ASKING FOR PERMISSION TO DO SO.
• 5D print says "no device". No hint how to tell it that my printer is already connected and running.
• bed leveling is a nigthmare.
• The PID control is not good. I tell the bed to go to 35°C...it goes to 35....then slowly to 36....37....38..stays at 38. 

Links

• official assembly instructions
• one inofficial assembly instruction