Sunday, 1 December 2013


My Ramps-fd arrived from geeetech

Previous stuff Ive ordered from here was quite good, but I'm not impressed with this board that much.

I was expecting the polyfuses, as has already been discussed in the forum, other people from now on should be getting real fuses.  But some of the edge connectors are rather twisted not aligned with the board edge at all.They also look far to small to handle 11amp for the HBP. The HB IN also looks very small, though larger than the the output connector.
Some jumpers are badly bent over (see jp1 VIN). Lot of flux residue is also viable. Boards not cleaned at all.
The bottom side is similar, very grotty, not cleaned and pins bent.
The Pins on the left hand have obviously been pushed in by someones figures!
Some of the pins are quite bent over. Its obvious this happened at the factory as the 4th pin from the right is far to low and has been soldered in like that!

Also no jumpers where supplied. So your going to need to find 22 jumpers.

This arrived very very well packed, about 10 layers of bubble rap, so none of the damage could have been caused by shipping.

But basically you get what you pay for. If you get one of these expect to change the fuses, and most of the connectors and it needs a few things straightened out.

Tuesday, 29 October 2013

Distracted by firmware

I've been distracted a lot by various firmware things of late.

Although some time back I've had formal training at programming at a university level, I've never used it. I've never done any firmware before, other than compiling existing stuff and simple mods, so it been an experience

The first project is A serial interface for a WS2812 LED strip (and others)  This was the first step, next is to add the ability to talk to this into marlin reprap firmware so the reprap can control the LED strip. This is minimalistic for now, but working.

I've also gotten interested in the Smoothie project In particular the porting of Smoothieware to the Arduino Due. With this in mind I've created in the hope that a group effort can get this achieved. I'm well out of my depth here...  but will plod along slowly. Help would really be appreciated here. Especially related to porting mbed to Due


Sunday, 15 September 2013

24volt ramps

I've been planning to upgrade to 24volts for some time. gathering info and parts.

I was going to do a big writeup of what I had found was needed etc, only to find its been done very nicely here

So I've gone for a Taurino power as it takes a 24v supply, including from a ramps.

The caps on my ramps are all 35v rated, so that's a good start.
The 11Amp fuse is as expected only rated to 16v, so that has to go.

I have a 24volt Kapton heater, rated at 8.5amp, so I needed to find a replacement fuse in that range.

I found this at a local auto part shop.  10-32volts 10amps,  and auto resetting.
Its about 2mm taller that the original fuse. Seems ideal.

This is designed to fit into a socket, that that would have made it much taller.
So I just drilled some 2mm holes in the tabs and soldered in the thickest solid copper  I could find. (off of a coil in a dead power supply) The centre of each of the fuses tabs lines up very nicely with the original fuse wire spacing, which was a plus. 

The fuse looks a little odd, I'm so used to them being yellow squares. But fits nicely.

So I setup my test workbench (kitchen table!)

Using a 24volt 16.5 amp power supply, I tested a bare ramps on the  Taurino power
It didn’t go bang, that is a good start!.  Then I plugged in a thermistor into the extruder thermistor port to stop marlin complaining, that read fine also. Next I added in one Pololu driver and tested that. Worked as expected so I populated and tested the rest of the Pololu drivers. All worked.
Next the big one, I plugged in the 24 volt Heated bead and its thermistor.
I turned it on, and it all worked! I can now get my HBP to 115C in 15 minutes, that’s with very poor insulation.

I did replace my HBP FET with a IRLB8743. I know that the FETs that came with the this board aren’t up to the normal 12volt 11amp load, let alone 24volt. Better safe than sorry.  

NB all plugging in was done with everything off!

Now all I have left is the hot end (which is a 12v makergear) and 12v fans to work out.

I'm tempted to try this, to create a 12 supply. 

Then I can just use the hotend and fans as normal, using 12v as their supply and GND threw the appropriate FETS.

I can just set an upper limit to the PWM for the hotend and run it directly, but what happens if the controller crashes with it on?, instant melt down that's what.

I might also just runs the fans from a 7812, as they are low power... 

Saturday, 14 September 2013

Ramps for Arduino Due!

I been watching the forums of late and I came across this thread,244284

So a Reprap running on a Due is imminent!

For me this is exciting news, so I just wanted to make sure everyone knows about it.

I think this is probably going to be the next set of standard electronics.

We should all get in and support this where we can.

Sunday, 4 August 2013

I3 Finished

Its been a couple of months since my last post.

Caught a nasty case of the winter blues, not wanting to do anything.


The I3 is complete!!

This is my sheet fame style Prusa I3

The back view, as you can see I use a 12v, 30A power suply vs a ATX. It is much cleaner without all the extra cables and voltages.

This is my 4pi board, thanks to Kliment from designing this nice ARM based reprap controller.  The wiring is still a little messy.

I went with a MGS extruder. Its wonderful! And since its all well defined gears, the e-steps is spot on. I also used a makergear hotend. Old school, tried and reliable.   

This is the very first print!  (blue on blue was not the smartest of choices though when you want to watch the first few layers being printed!) This is a continuous Z print.

There are still a few little things with my Y axis that I want to look into.

And a bit more tuning to do, bridging and such. But it basically done.

Sunday, 26 May 2013

MGS update

The link on the main reprap forum page clearly point to for MGS plastic parts.

This is in error!

It should be

This also has the source and is for 30mm holes, perfect for I3

I have updated the link on the wiki

I now need to reprint... 

Tuesday, 14 May 2013

I3 Metal Gear System Extruder

I've been wondering for a while what extruder to put on my I3

I decided to try the Metal Gear System Extruder

I ordered a kit online from 

The web site put a scary amount of shipping cost to New Zealand, so I contacted the site owner on #reprap and he was happy to send it via normal post (3.45 EUR) , with the understanding there was no insurance or tracking. I went with this option.

This arrived!

Here are all the parts, as pictured on the site.

Plus some plastics I prepared earlier

And assembled.

It is reasonably easy to assemble but also the main shaft is a bit fiddly

Now the issues:

The mount is for a X carriage with 24mm hole spacing, the standard Prusa I3 has hole spacings of 30mm. They do provide stl files for their own X carriage, but the two lm8uu's and single lm8uu where swapped over. I didn't want to completely rebuild my X axis just to move one lm8uu.

So I made a bigger mount.
This is still listed as experimental, as I haven’t actually mounted it on the I3 yet.
The new hole isn't on the extruder, I used the mount as a drill guide and drilled a new hole. 

If I have assembled it correctly. I am one m3 nut short and one m3 bolt short.

I'm also left with four left over parts, which I can't find a use for.

This is probably for a different extruder mounting system

I'm fairly sure I have it assembled correctly, now I'm going to pull it apart again,
The main drive gear on the stepper only over laps the large gear by about 1 mm, I think it should have more contact, so I am going to move it a fraction.

Saturday, 4 May 2013

4pi mount for I3

I've been slowly building up my own Prusa I3 Single Sheet Frame

The first challenge for me was that I wished to use my 4pi controller. This is not one of boards that there are mount holes for. In fact its to wide to mount flat on the X axis on the Aluminium directly without large overhangs.

The first step I needed the measurements from the 4pi board.  I started by just measuring the main PCB, While doing this I noticed that the various connectors are somewhat unevenly spaced, so I was going to have to measure this too. I quickly came to the conclusion that this was going to be a lot of work to measure everything.

I then had an Idea. The Eagle brd file is available, and the X and Y position data should be in the file somewhere.  I took a look at the .brd file, it seems to be well structured XML I have no experience with programming and XML, but a friend "Finch" Showed me how to process XML files in Python. The resulting components file was edited by hand to add Z axis data. The resulting Board file was modified slightly to move one component and remove a 6pin connector that isn't on he board.

The result is the following, very accurate 4pi model

This can be found here

So now I have a nice model to work from. I started to work on a way to mount this on my I3.  I wanted a protective box, but not enclosed so I can watch the LED's. With the model it was very easy to make a box for the 4pi and cut out all the required connecter holes.

I added a small Lip to the box so the box wouldn’t rotate when mounted on the mount arms.

The mount proved to be trickery to make that the box, mostly because I was being fancy and added rounded corners.

The mount is "RAMPS" sized, as it is attached to the ramps holes in the plate.

The final parts mounted on the machine

Files are available here
Currently its still "Experimental" as I need to tweak the sizes of the m2 nut traps.

Wednesday, 3 April 2013

I3's update

Partial I3 kit going on sale on soonNow (

My personal I3, desperately waiting for smooth rods! (yes the Z threads is in the wrong place, it was just a convenient place to put them for the photo)

Saturday, 9 March 2013

One of the issues with the internet is its to annoymous when something breaks

Case in point. is currently broken with the following error.

I would like to fix it, but can find no one who even knows who looks after it..

I’m hoping this post will grab the attention of someone who can help.


Phorum Database Error

Sorry, a Phorum database error occurred.
Please try again later!


Table './forum/dev_messages' is marked as crashed and last (automatic?) repair failed (144): SELECT count(*) FROM dev_messages WHERE forum_id IN (236, 168, 191, 187, 186, 193, 182, 36, 57, 149, 51, 130, 173, 157, 145, 140, 93, 19, 257) AND status = -1


Function phorum_database_error called at
{path to Phorum}/include/db/mysql/mysql.php:203
Function phorum_db_interact called at
{path to Phorum}/include/db/mysql.php:838
Function phorum_db_get_unapproved_list called at
{path to Phorum}/common.php:795
Function include_once called at
{path to Phorum}/list.php:21

Friday, 8 March 2013

I3 Single Sheet Frame

A limited number of these will be available soon

Still at the manufacturers for now, just arranging to get them to me.

Further details will be available when I work them out. 

Only planning to sell to New Zealand customers for now.

Wednesday, 27 February 2013

Taurino Power

I'm considering upgrading my Mendelmax to 24 volts threw out.

One of the issues with that is the standard mega2560 is limited to 12v, so you need to arrange 12volt power, or maybe you could power it from USB (haven’t looked into that)

I needed another RAMPS for annother project anyways so I decided to get the Taurino Power and swap some boards about. The Taurino power is a mega 2560 that is designed to run fine with power up to 35 volts, designed to be powered from a 24volt RAMPS board.

I ordered this 02/19/13 and it arrived in my hands 02/25/13, it actually arrived on 02/22/13, but needed a signature and I wasn’t around so it got delayed over a weekend.  So 3-4 days to New Zealand!

It arrived in a standard FedEx Bag
Wrapped nicely in a bubble wrap bag. I don’t know what they stuck this down with, but the glue they used refused to come off, it preferred to rip the bubble wrap than separate.
Inside that is a nice plastic box.
Inside the case, the board in more bubble wrap, and a nice looking USB cable.

I like the USB cables that you can see the sheilding threw the plastic.
The main board.

The board looks very very nice.

The board comes with a test firmware installed so shortly after turning on the tx led is on solid. It is spitting out a simple test pattern in gcode,

Unfortunately I found that I could not upload new firmware to the board.
After a bit of a think I decided to reflash the boot loader on the 2560. This fixed this issue. I can now upload fine.

I also found I couldn’t talk to this board at 250000 baud, but I suspect this is related to my machine.  The more standard baud rates work fine.

Monday, 25 February 2013

SL upload issues

I had a SL board that wouldn’t upload new firmware, so I decided to diagnose what was going on.

All I could could get was sync errors.

I had no idea as to the state of this SL so I started from the beginning. 

First some background

The SL is meant to have a boot loader on it. When the MPU is reset the boot loader is run, it is at this stage that you can upload new firmware from the arduino IDE.

The MPU reset line is tied to the DTR serial line on the FT232RL chip. Pin 2, this gives software the ability to reset the MPU using a simple serial port command.

The first thing was to check the boot loader was running.

The Standard boot loader toggles an IO line during boot up, unfortunately on the SL this is connected to E-DIR. So we cant see what is going on.

I did not want to remove my E Pololu so I went for a software fix.

I changed the port in the bootloader to one of the spare ports on the IO header. I changed it to D4.
NB this is incorrectly labeled on the SL board as D12

I compiled and uploaded the new boot loader.
I connected a resistor and led between pins  D4 and GND. NB LED's have polarity, if you need help with this see

I reset the board and it flashed as expected. So the boot loader does run. So the boot loader is fine and the fuses are probably ok.

I started up Arduino, set everything correctly, and hit upload. Nothing.
Including no flashing led!, so the software controlled reset was not happening.

I decided I didn’t want to have to load up Arduino every time I wanted to try and test the reset so I wrote (ok cut and paste bits from the internet) into a quick python script to toggle the DTR line.


import serial
from time import sleep

conn = serial.Serial('/dev/ttyUSB0',

Next I checked the hardware.

The DTR line is pin 2 of the small surface mount chip on the back.
I tested it with a multimeter and under a 10x magnifying glass. Looked fine.

I checked Jumper "auto reset" had continuity, yip.
I checked Pin 9 of the MPU, Reset, had continuity to the jumper, yip.
I re-soldered cap C7, no change
I re-soldered the jumper and MPU pins, no change.

Getting frustrated, I re-soldered pin 2 on the FT232RL, Success!!!

The board now resets when I run and flashes its little LED as it should.

I can only surmise that the underside of pin 2 was dry, and when I tested it with the multimeter the probe pushed the pin onto the PCB making a connection that wasn’t actually there, and I need better than 10x magnification to see this.

I then used Arduino, set it up, hit upload and after compiling the code, the board resets, the LED flashes and the code uploaded!


Tuesday, 29 January 2013

Rostock arms and bearings upgrade

Well the Rostock isn’t even finished and I’ve begun upgrading parts of it.

The printed arms to me aren't the best, even in a tinted PLA (one of the more rigid colours) it is still quite flexible, I also didn't like the idea of PLA bearings, these will wear out quickly.

The following solution was suggested to me on the #reprap IRC  channel

These are a race car part. "Traxxas Rod Ends Large w/ Steel Hollow Balls 5347, Revo 3.3"  just search e-bay and you will find them.  Nicely they also come in packs of 12, which is just how many you need for a Rostock

The inside diameter of the Plastic part is 3.5mm and 10.5mm deep. The inside diameter of the Steel is 3mm (not documented but needed by us)

Assembling these together was a little tricky. One side of the plastic is bevelled (shiny circle around the hole) they go in that side. I held the bearing with some long nosed pliers just sitting on the bevelled side then snapped them in place using the plastic as a lever.  

Next is the arms between the ends. Some people are using m4 thread rod as their arms with these, but this is heavy and easy to bend.

I found a local supplier of 3.5mm solid carbon fibre rod.  Now this rod was not the best quality, ie it was a little bent, but when cut up into 6 * 236mm lengths I was able to discard the worst bits. (236mm is what is required to make the arms the same length as the originals)

I glued the arms into place, the fit was so snug I had to ensure there was no air trapped in the end (ie you would let the arm go and it would spring out due to compressed air being trapped). Also make sure that the two ends are on the same plain. Ie The flats are level.

The top original arm weighs 16g, the new carbon fibre arms weighs 6g, and is a lot stiffer and in my view a lot better looking.
That also a weight saving of 60g! (6 x 10g) (important when you considering putting an extruder directly onto the carriage vs a Bowden cable type system)

The arms fit where the old ones did.  There are new single lugged plastics if you want to reprint, but I didn't want to.

NB this was originally connected with 2 * 12mm m3 bolts. Here I am using one 20mm m3.  To be exact the order pictured here is M3 bolt head, 3m washer, Printed lug, embedded m3 nut,  Traxxas steel bearing, m3 lock nut. The second m3 nut is still embedded in the other side but the thread is just sitting indented in it, not threaded in.

NB this is still a work in progress, looking at its range of movement a second m3 nut before the bearing to move the arm towards the centre of the gap will be required.

Update: I’m not happy my with my attempts to attach these to the original plastics
So I am printing a set of

Wednesday, 9 January 2013

Sprinter, Arduino 1.0.3, Sanguino-0101r1 and Pololu USB AVR Programmer

I recently learned that Sprinter is Arduino 1.0.3 compatible (has been for a while)

So I had to give it a try on my Sanguinololu 1.3a.

As per usual download the Arduino software from here, to suit your OS
Then download and install the Sanguino-0101r1 files from here

Grap a copy of the latest Sprinter from github 'git clone'

Edit sprinter configuration.h to suit the board and any other changes you need.

One of the things I wanted to get working was installing a new boot loader via the Arduino GUI using my Pololu USB AVR Programmer vs cmd line as I have been doing.

After some debugging I found that there was no hardware settings for the Pololu USB AVR Programmer

So I added the following to programmers.txt (as documented here) ISP v2

Then set your programmer to AVR ISP v2, and your serial port to /dev/ttyACM0 (linux naming convention)

Then Burn Bootloader works, uploading the new boot loader and setting the fuses.

One thing to note is that the upload baud rate has changed to 57600 from 38400 in the new boot loader. This means if you have a older boot loader, you will not be able to use Arduino 1.0.3 to upload new firmware via the boot loader. (without changing settings, or using the new bootloader)

Now switch your serial port to /dev/ttyUSB0 and your board to Sanguino W/ ATmega644P and upload your new firmware via the new, faster, bootloader.
Sprinter compiled and uploads without issues.  

Tuesday, 8 January 2013

12v to 24v converter and mount

I wanted a way to mount the converter where I had my Soild state relay inside the frame. Firstly as there was a nice space there and secondly it holds the cover over the back of the mains plug in place.

I had to design my own thing again...  Getting quite good at simple scad things

I added a 50mm fan to the converter, as I've been told it runs warm. Attached with 3 bolts onto the other side of the heat sink. There should be 4 but as per usual I was one bolt short.

It is now mounted on the frame, and the input power and fan have been wired up.

I haven’t found any official documents on how its meant to be wired up.

But I did find this in the mendelmax google group .

  • Connect the Input lines of the step up to the PSU. 
  • Connect the the + line of the HBP to the + out on the step up.
  • Connect the - line on the HBP to the - pin on the D8 FET on the RAMPS board.
Also with a warning

"It's been discussed previously on this group that the step-up
converters can't handle full bed power. They're pre-set to 19v since
they don't burn up at that output voltage."

The concerns I have with this way of wiring it is there are no fuses between the power supply and the HBP, and its a 24volt kapton heater, how badly is 19v going to slow it down or cripple it?