Sunday, 19 March 2017

Original Prusa i3 MK2 upgrade kit to full printer - progress thus far

The Y axis is assembled

And the X and Z
No X belt yet as I ran out of time.

A note on the provided belts: They are really nice and solid. Comparing it with stuff Ive had from china, their stuff is soft and lacking material (its almost like they use a filler vs what ever the belt is meant to made from) "Prusa" belts also have steel (at a guess) cores    

The extruder im still missing a few parts, the idler bearing and springs are the main hold up at the moment.

Also it would seem that m3x18 is a non standard size. Not available from my local supplier. Looks like another order from china is needed. Either that or ill have to make 17 odd of them from m2x20's

My Z axis was quite problematic. The lower plastics the holes in my alu frame are sloppy and I have lock nuts on the back side. The issue is you need to make sure the stepper rods are straight up and down, but the bolts are behind the steppers... So you cant loosen and adjust them when the stepper are in place and you need the steppers in pace to align the position of the lower plastics. Got there in the end. Wouldn't be an issue if I had a higher quality plate

Wednesday, 15 March 2017

Original Prusa i3 MK2 upgrade kit to full printer - checking Y plate

I checked that the old Y plate I have will fit on a new mk42 heated bed

Yes it will, once in the correct orientation all 6 holes line up nicely. (4 corners + 2 on Belt clamp)

Sunday, 12 March 2017

Original Prusa i3 MK2 upgrade kit to full printer - planning

I'm going to build a printer based on the MK2 upgrade kit

It will be as close as I can make it to the "Original Prusa I3 MK2"

I’m not going to worry about the colour of parts, ie threaded rods nuts and washers will not be black. Mostly because I can't find any source for such things at a reasonable cost or locally. Even M8 half height nuts seem to be rare here. So ill be using standard size M8 and M10 nuts

So far its all theoretical, but this is BOM so far.

Everything with a red background in the spreadsheet needs to be acquired.

This will be updated as I complete each section.

The provided spares bag with the upgrade kits has been a lucky inclusion,containing just enough of a lot of the required hardware.

If anyone wants to send me 10 of these "spares" bags, ill convert the nuts and washers to black. :)

Saturday, 4 March 2017

Core XY update 2.8, first print

I've leveled the bed close enough, and enabled mesh leveling to compensate for the remainder (its as close as I could get it without using a dial gauge)

I’ve also set the nozzle distance from the probe so Z0 is correct for the hot end.

First print!

Just a few seconds of a test cube (still on slow ADSL here, so uploads are painful!)

The bed is still cold aluminium, here I am attempting to print on glue stick with PLA. Seems to work for this small object

Finished first print looks great.

Now I have it working I have a few comments about the hypercube.

It is very much a build in place design. If you expect to change things later there may be lots of dissembling involved.

Not all tslot is equal, the tslot nuts in my extrusion are tight, as is will not turn freely to get into correct position. I find I need to force the nuts into the correct orientation with some long nose pliers then screw them down. Another person I know whom is building a hypercube his tslot is so loose in comparison that they work as designed, ie they self orientate on tightening.

The Z build height is only about 145 with current parts. (Z tslot 350mm)
This could be increased 15mm ish by dropping the bed onto the alu extrusion and letting auto be leveling take care of any offsets. (ie remove the springs), Make sure your bed is still electrically insulated from the alu if you try this)
Secondly the Y lm8uu holders could be modified so the bed is at the bottom of the part, this would also add about 20mm to Z (others have done this on thingiverse)

The current Y smooth rod mounts, the mounting screws end up behind the smooth rod (slightly offset) these are not fun to tighten.

Lots of parts stick out the sides...  making it very hard to stick any sides on the machine.

I’m now going to diverge from the standard machine.
Make some of the changes mentioned above and put the re-arm on this machine.

Tuesday, 28 February 2017

Core XY update 2.7

All assembled, cables made tidy. Only the heated bed is still to be wired and I need to mount the power supply somehow. The standard mount is not sized the same as my supply and no cad files to re size...

I managed to solder the wires onto the alu heated bed by putting the bed on a hotplate on the oven at the lowest possible temperature. I watched the temp with a IR probe, it never got over 150c (not accurate but good enough) I would expect the pcb bonding agent to fail if it was allowed to get much hotter. I soldered the wires while on the still on hot plate.. Soldering iron in one hand, oven mit on the other. It worked really well, but I can't recommend this, just a tad dangerous.

NB your responsible for you own actions if you attempt this. Don't complain to me when you burn yourself.

Another small change.
The provided extruder cable support is for 16mm diameter, my tube is only 8mm
So I modified the part.

Source and stl can be downloaded from

Everything else so far seems to work, all axis, endstops, thermistors, fans, probe and hotend 

Hotend heat up and first extrusion into open air.

Next I need to find a nice way to level the bed. Previously I have just used a dial gauge, but can't seem to find that.  But the machine has a probe. There must be a way to get the machine to tell me how far each probe point is out...  There are quite a few probe options in marlin... reading up on those.

Sunday, 26 February 2017

Original Prusa i3 Plus to MK2 upgrade kit unboxing

I ordered this kit, mostly just to get the heated bed and to see exactly what comes with it.

Friday, 10 February 2017

geeetech Reprap Smart controller LCD12864 on re-arm controller

I finally got my re-arm! in case you some how missed it.

I set it up following the quick start guides on
Installed the latest firmware, no issues, used the eg config.txt and basic commands worked as expected. (just the controller powered over usb at this stage)

Then I went to plug in my GLCD, which I gave up on on using atmega based machines a long time ago as being too resource hungry.

Problem..   The re-arm supports the reprap discount GLCD, I have a geeetech GLCD, close, but not identical.

The documentation show this following image

And they provide the special cable with the separated 5v line.

If you look at this image you notice you cannot see the key on the lcd adaptor sockets. They are are the back side from this view.

Now if we take a look at the geeetech one
You can clearly see that the key on the ramps lcd adaptor is on the opposite side.  So we cannot use the provided special cable as the key makes us plug it in backwards breaking out the wrong pin.

I checked out the circuit and it looks compatible apart from the socket keys.

I wired it in using some prototyping wires

You only need 7 cables.
Lets define Top left on the adepter and the GLCD pictured as pin 1, and bottom right is pin 10.
Its simply wired pin 1 to pin 1 and pin2 to pin 2 up to and up including pin 5.
Then skip to pin 9 (black, gnd), which also goes to pin 9
On the GLCD pin 10 (red) is the 5v supply and needs to be wired to the 5v line of the re-arm as pictured in the guide.

And setup the firmware, as documented.

# Panel See
panel.enable                                 true            # set to true to enable the panel code
# Example reprap_discount_glcd
panel.lcd                                    reprap_discount_glcd             # set type of panel
panel.spi_channel                            0                 # set spi channel to use P0_18,P0_15 MOSI,SCLK
panel.spi_cs_pin                             0.16              # set spi chip select
panel.encoder_a_pin                          3.25!^            # encoder pin
panel.encoder_b_pin                          3.26!^            # encoder pin
panel.click_button_pin                       2.11!^            # click button
panel.encoder_resolution                     4                 # override number of clicks to move 1 item (default is 4)
#panel.button_pause_pin                      1.22^             # kill/pause set one of these for the auxilliary button on viki2
#panel.back_button_pin                       1.22!^            # back button recommended to use this on EXP1
panel.buzz_pin                               1.30              # pin for buzzer on EXP2

This mostly works! (yea I haven’t remove the protective plastic yet)
But the encoder is backwards.

To fix this you just need to tweak the provided config a little.

Just swap the encoder pins over

panel.encoder_a_pin                          3.25!^            # encoder pin
panel.encoder_b_pin                          3.26!^            # encoder pin


panel.encoder_a_pin                          3.26!^            # encoder pin
panel.encoder_b_pin                          3.25!^            # encoder pin

The GLCD and encoder work as expected now.

NB I have not tested the SD card at this time.