Monday, 11 September 2017

Core XY update 3.2

Winter is passing and I have awoken from hibernation.

This is my second attempt to get 200 mm in the Z axis on my hyper cube.

I have lowered the aluminum cross bars as far as possible, and moved the 90 degree brackets to the inside.

This of course caused an issue where smooth rods and Z stepper motor now sits below lowest point of the printer.

I created new legs for the printer to raise it up again.


I have put the model for these legs on thingiverse and the openscad. Its parameterized so if you want to change anything you just have to edit the variables.

The printer now looks like this.

With a ruler and eye balling it, It looks like I may now have 200 In Z. I wont know for sure till I re install the electronics.

With all this space under the printer I am also looking at mounting the power supply and electronics under the printer. There should be about 60mm under the bed when its fully down.

Monday, 26 June 2017

Original Prusa i3 MK2 to MK2S upgrade kit - contents

I got this kit to make my machine even closer to a factory MK2s. In particular the smooth rods I used for my machine I borrowed from another machine with the intention of replacing them, then they released this kit and I thought problem solved.

So what exactly is in this kit, lets see







You will note there are no replacement printed parts, instead they give you filament and your meant to print your own!  They do provides models and even pre-sliced gcode for the main parts http://www.prusa3d.com/prusa-i3-printable-parts/

In some ways I like this idea, but not in others, what if you have a power cut or some other failure? You can't get this filament, you cant just try again. This color "Safety orange" is made special for Prusa. Also the pre sliced only replaces the main parts, the extruder mainly. But if you look at the mk2s parts nearly every single part has been modified. Notably absent are new X ends, where the nut traps have been strengthened.

Also just how are you meant to print from an unspooled roll without making a mess? 

At this stage I have not printed these upgrades. 

Wednesday, 3 May 2017

Core XY update 3.1

I upgraded my Z rod holders on the hyper cube

The way my rods are mounted the smooth rod covers the t-slot screw head, making it very difficult to tighten the screw or align the rods. So I created my own part with two offset screws for much easier access.

This can be found on thing:2167139

This also gave me an idea, the current lower Z rod clamps are not at the end of my Z rods.
So I could extend the mount downwards to hold it lower. Like this.
This should give me a little move Z travel? Yes it did, but there is a issue.
The lm8uu holder on Z hits the middle nuts. It used to hit the old part also. My solution, remove that screw. Now it moves as far as it can until it now hits... The Z stepper mount

So ultimately having the lower Z mount achieved nothing as you can't move down that far, but swapping the original mount for my new mount did enable me to remove that screw and give me full Z movement. Untill the Stepper mount is hit.

I'm now wondering about mounting the the Z stepper motor back at the top with the lcd screen elsewhere so it is not blocked by the stepper motor. 




Wednesday, 26 April 2017

Core XY update 3.0

I've  Printed a few replacement parts for my Hypercube

Some parts you may recognize.
On the left are standard Hypercube e3d mounts and fan duct, but now in ABS.
In the middle, these parts are replacement bed mounts that are much lower, giving me 15mm more Z axis. Files can be found @ thing:2272127  (These are adjustable in scad)
The last part is a very simple mount for my power supply. I'm not sure I am happy with it, so no files at this time.
 E3D mount installed

New lower bed mounts installed

Power supply mount installed. Really need to tidy up those wires sometime...


Sunday, 23 April 2017

Original Prusa i3 MK2 upgrade kit to full printer - Power supply and test prints

I've temporarily (Will probably never be changed) attached my power supply to the frame.

Since there are no power supply mounting holes on my frame, and I'm not 100% sure where it is meant to have holes I opted for a more make shift solution

Yip, good old zip ties. Two of them to form a crude box shape so they sit flat on the front so as to not catch the X axis. There is also some strong double sided sticky tape between the power supply and the frame.

The MK2 is complete (well close enough) :)

Now for some test prints.

I grabbed the pre sliced examples from the mk2 site.


All printed fine. There are two "PRUSA" as one is ABS and the other PLA, the simple color changing eg (Prusa bottle opener) worked well, but I ran out of red PLA so ended up doing two filament swaps.



As a final stress test, I printed one of the 6 hours examples. NB it really took over 7!

It a little stringy in places, but nothing that couldn't be picked off later.

Over all very satisfied with this printers performance.

Sunday, 9 April 2017

Original Prusa i3 MK2 upgrade kit to full printer - extruder, LCD and electronics

I finally got my 625 bearings as was able to proceed with the build.


The extruder was a little fiddly but no real issues. Since the blower fan was self sourced the cables needed to be extended. I just made it the same length cables as the 30x30 fan cables. This needs a standard non locking 2 pin 2.54mm connector. The extruder needs a 5x16 shaft for inside the 625 bearing, this seems to be printed, probably in PET. I found a replacement.


I went to the local hardware store looking for something I could cut into a shaft, I sadly found almost nothing. In desperation I spotted some shelf pins with metal pins.

I chose to use the clear ones, as you can see the shaft doesn't have any ridges or other defects. I cut off the plastic with side cutters. The rod is a perfect 5mm x 16mm. The only down side is as its metal, this will make the extruder fractionally heavier. But fits well.

The LCD is an unknown as to what LCD electronics they use.  I used a geeetech 20x4. It fits well. The screen is in the correct place, the SD is in the correct place, the Knob and button are in the correct place, but somewhat short. The mounting screw holes are also in the correct place (about .25mm out, but not an issue)
I designed some small printed parts to make the MK2 lcd case work with my electronics.
thing:2237167
You also need longer LCD cables, I made my own. These are 70cm long.

The heated bed went on without any issues, since I had tested the fit earlier.

The printer now looks quite good.
At least from the front. The back, needs work.
Lots of cables

I added the electronics enclosure, installed the electronics. Since everything has correct connectors and lengths, it really was just a case of plugging it all in and zip tie-ing it in place.


 The more observant of you will notice there is no power supply yet.




Saturday, 1 April 2017

Original Prusa i3 MK2 upgrade kit to full printer - electronics, firmware and LCD testing

I’ve tested out my Mini rambo with Prusa's latest firmware binary.



The first "got you" is the Mini rambo needs external power to power the atmega2560. So although when you plug the USB cable in this will power the usb/serial chip so your computer will see it. Without the 2560 you can't upload firmware.

I used the avrdude method to upload the binaries, the binary was downloaded from the normal place, at this time 3_0_10 is the current version  http://prusa3d.com/downloads/firmware/prusa3d_fw_3_0_10.zip

After numerous attempts avrdude eventually worked.  Best way I got it to work was power off the rambo and remove USB cable.. Power it back on, plug in the USB, as soon as you computer sets up a serial port give the avrdude command.

Second "got you" when the MK2 firmware first turns on the printer hasn’t been configured, you can not talk to it with pronterface or any control program.
 
Press the LCD knob button a few times till the following display is shown. After this point you can use pronterface. This wont be an issue after its been calibrated.

  


The avrdude command I used to upload the MK2 firmware binary and full log of output. On Ubuntu linux 16.04:

(your paths will probably differ) 

~/arduino-1.6.13/hardware/tools/avr/bin$ ./avrdude -C ~/arduino-1.6.13/hardware/tools/avr/etc/avrdude.conf -c stk500v2 -b 115200 -p Atmega2560 -v -P /dev/ttyACM0 -D -Uflash:w:/tmp/1_75mm_MK2-RAMBo13a-E3Dv6full.hex:i

avrdude: Version 6.3, compiled on Sep 12 2016 at 15:21:49
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch

System wide configuration file is "~/arduino-1.6.13/hardware/tools/avr/etc/avrdude.conf"
User configuration file is "~/.avrduderc"
User configuration file does not exist or is not a regular file, skipping

Using Port : /dev/ttyACM0
Using Programmer : stk500v2
Overriding Baud Rate : 115200
AVR Part : ATmega2560
Chip Erase delay : 9000 us
PAGEL : PD7
BS2 : PA0
RESET disposition : dedicated
RETRY pulse : SCK
serial program mode : yes
parallel program mode : yes
Timeout : 200
StabDelay : 100
CmdexeDelay : 25
SyncLoops : 32
ByteDelay : 0
PollIndex : 3
PollValue : 0x53
Memory Detail :

Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
eeprom 65 10 8 0 no 4096 8 0 9000 9000 0x00 0x00
flash 65 10 256 0 yes 262144 256 1024 4500 4500 0x00 0x00
lfuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
hfuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
efuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
lock 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
calibration 0 0 0 0 no 1 0 0 0 0 0x00 0x00
signature 0 0 0 0 no 3 0 0 0 0 0x00 0x00

Programmer Type : STK500V2
Description : Atmel STK500 Version 2.x firmware
Programmer Model: AVRISP
Hardware Version: 15
Firmware Version Master : 2.10
Vtarget : 0.0 V
SCK period : 0.1 us

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude: Device signature = 0x1e9801 (probably m2560)
avrdude: safemode: hfuse reads as D0
avrdude: safemode: efuse reads as FD
avrdude: reading input file "/tmp/1_75mm_MK2-RAMBo13a-E3Dv6full.hex"
avrdude: writing flash (201814 bytes):

Writing | ################################################## | 100% 32.32s

avrdude: 201814 bytes of flash written
avrdude: verifying flash memory against /tmp/1_75mm_MK2-RAMBo13a-E3Dv6full.hex:
avrdude: load data flash data from input file /tmp/1_75mm_MK2-RAMBo13a-E3Dv6full.hex:
avrdude: input file /tmp/1_75mm_MK2-RAMBo13a-E3Dv6full.hex contains 201814 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 25.85s

avrdude: verifying ...
avrdude: 201814 bytes of flash verified

avrdude: safemode: hfuse reads as D0
avrdude: safemode: efuse reads as FD
avrdude: safemode: Fuses OK (E:FD, H:D0, L:FF)

avrdude done. Thank you.