RepRap back on track

After about 17 months of absence I decided to get this project back on track.

This was inspired partly by the recognition that I have been spending way too much time working and way too little time on my hobbies, and partly by a revival of interest due to the recent launch of the Raspberry PI. This device is right up my street, having cut my teeth on a ZX Spectrum back in the 80's. I immediately thought that this might tie in with the RepRap, and so did others as I saw RepRap mentioned a number of times in the news articles and forums.

Well, back to the RepRap. As those of you who have been following (or have read my older posts) will know, I have been building a Mendel using Techzone Remix Gen 3 electronics. The failure to get these electronics working properly being the subject of my last post and part of the reason the project stalled.

On re-investigating and knowing that I wanted a heated bed, I contacted "Think3dPrint3D" on eMakerShop (ironically, Jean-Marc of eMakerShop has previously bought some stuff from me) about his heat bed PCB last weekend as I wanted to buy within the UK. He said he was getting some in, and during the ensuing conversation I mentioned that I needed better electronics. This resulted in me purchasing a Sanguinololu v1.3a kit from him (assembled and tested). I figured, there was no point in wasting time trying to figure it out when he already has.

In the interim I decided to also look out for the other bits still giving me grief, namely the nozzle and Hobbed bolt. I ended up ordering both these from "ParCan".

Next steps are to figure out where I am at and start moving things forward. I will post these are separate blogs in order to not have too much in.

Final note for today is that I started by removing the TechZone electronics from my Mendel frame. I will keep them and still try to get them working sometime as I thought it would be a good donation to my brother down in South Africa who I would like to get setup to print as well.

Opto Issues

The issues with the optos are ongoing.  I replaced the connection pins with wires on all three my opto circuits, but it appears the one I damaged last time is fubar.

As for the other two:

• The TechZone optos have the LED enabled until the opto is blocked then it switches off
• On mine, they're never turn off, no matter what I block them with.

Help!!

Mendel Mayhem: Completing the bot

Having gotten the X-axis running last time, the job tonight was to finish off the job.

I started by wiring up the Y & Z stepper motors. Luckily with the Zapp Automation stepper motors and the Azdle mounting for my TechZone electronics, I was able to wire the steppers directly, no extending of cables. (The extruder stepper will be another matter).

I then starting playing with moving the axes around using the RepRap host software. This reminded me that I had tweaked the config for the ScrapStrap (which had a belt drive for the Z-axis), so I set about trying to remember how to reset the config. I decided that the best was to get the latest from Sourceforge (now at 20100806 - I had previously installed 201000702).

Upgrading RepRap Host
As I wanted to reset my config, I upgraded as follows:

• Extracted the latest software 20100806 to a temp folder.
• Replaced the raprap.bat with the one I modified last time (to make it work in a different sub-folder)
• Copied in my RepRap.ico file I had created
• Deleted the contents of my install folder (having backed it up)
• Copied in the new installation (and deleted the temp folder)

This means that I reverted by firmware config as well, so I had to reprogram the firmware. This was achieved as follows (any folder locations refer to sub-folders off Reprap\mendel\firmware\FiveD_GCode):

• Copied configuration.h.dist to configuration.h in the FiveD_GCode_Interpreter and Extruder folders (I compared to my old config and was reminded that I commented my changed with my initials - glad I followed a guideline I insist all my coders at work follow)
• Load the FiveD_GCode_Interpreter/FiveD_GCode_Interpreter.pde sketchbook
• Modified the configuration.h tab to match my setup (guessed most of it as I don't know what applies yet - it seems to be pretty much setup for the v3 electronics which the TechZone stuff is - For the hardware, I left it as standard for now, as it should be) and saved.
• Selected the Tools->Board->Sanguino board and then Sketch->Verify/Compile
• Connected the board to the PC.
• Selected Upload to I/O Board and done!!

For the Extruder controller:

• Copied the configuration.h.dist to configuration.h in the Extruder folder
• Moved the USB board to the extruder controller, remembered to invert it (ground is on the opposite side). Mine is now marked with a black marker.
• Loaded the Extruder/Extruder.pde sketchbook.
• Modified the configuration.h tab to match my setup (left it all standard as I didn't see anything relevant to change) and saved.
• Checked the temperature.h tab as I am running a thermistor. I wasn't sure is the default table is correct or not, so I left it be for now.
• Selected the Tools->Board->Arduino Diecimila, Duemilanove or Nano w/ ATmega 168 board and then Sketch->Verify/Compile
• Connected the USB cable to the PC
• Selected Upload to I/O Board and done!!!
• Disconnected the USB and moved it back the main board

Next step, testing the config. I reloaded the RepRap host software and it all worked fine.

Next step was to get on with mounting the end-stops and checking that it can home itself. This is when I discovered one of the issues with the TechZone electronics. In their efforts to reduce the size of the components, they gave no consideration to the retention of the standard mounting locations and as such I managed to damage one of the circuits while trying to make this work. This caused me to suspend work for the evening as I now need to get into some soldering etc, which is a change of focus so will be done on another day...

Mendel Mayhem: Frame continued

I got bored inside, so here I am again. My wife popped out to the shed to see what was happening, and got a guided tour of the assembly to date.

Installing the Y-axis
It took very little time to get the Y-axis installed, completed with belt. I then quickly installed the X-axis belt while I thought I knew what I was doing. As said before, the bed is going in later.


Fitting the electronics
Having a moving cartesian frame and a seperate set of mounted electronics will only drive one insane, so the next step was...

And it works!!!! Well ok, I only connect the X-axis, but at least I'll be able to sleep tonight (sort of).

Tech Zone Techniques - Part 4

Step 10: Wiring the steppers

Not much to go wrong here really, as I had wired the stepper sup to my CNC stepper boards before, I kind of knew what I was doing. I also made up a power lead which I have wired up to my variable bench supply for now. (This will be replaced with a PC based ATX supply for the final version).

Step 11: Testing Times

Next up was testing the electronics. I tracked down the Testing RepRap Electronics page on the wiki and started following that through.

I ran into some trouble with the motherboard not returning any temperature results and not looping, so I asked on the forum. In summary, note the following when using the hardware:

• If you don't get the temperature readings looping, then your USB cable may not be autoresetting the hardware
• Plug in the the USB
• Hit the rest button
• Start up the host software

So, I managed to get the desired results for the motherboard and the extruder controller (sans stepper driving), so I decided to move onto to testing the stepper boards and opto's.

For the steppers I followed these steps (for each axis - results further down) (BTW: follow these steps at your own risk, the wiki steps are more detailed and isolate issues, I already knew my steppers work):

1. Wired the stepper to the controller
2. Ensured the stepper was in the middle of the axis (as I wouldn't know which way it would travel)
3. Wired the power to the stepper board
4. Wired the stepper board to the motherboard
5. Connected the USB
6. Reset the motherboard
7. Opened the RepRap Host
8. Changed to the XYZ tab, and set nudge to 10mm and feedrate to 300mm/min
9. Switched on the power
10. Clicked the right arrow (>)
11. Clicked the left arrow (<)
12. Moved on to testing the Opto's

Y-Axis results

• I did the Y-Axis first as it made sense in my wiring config
• > caused a small movement (and was repeatable)
• <>
• Off to the forum to figure out what's wrong (read about this before somewhere)
• Ah... Seems I got the Opto connected the wrong way around. The picture wasn't very clear (that's my story and I'm sticking with it).
• While fiddling with this I noticed that the opto LED (which on the TechZone boards is normally on) was not switching off when blocked.
• I swapped out the other opto's and found that 2 of my three boards had the same problem.
• I've been trying to stay out of the TechZone flaming that's been happening on the forum (I won't post any links, searching for TechZone will find many), but I do think the quality of the soldering leaves something to be desired. I spent a lot of my spare cash with them (it's the single biggest purchase in my project) and wasn't too impressed. I reckon could do it neater and I only tend to solder copper pipes for plumbing and automotive wiring.
• Anyway, off to figure out how to fix my opto's (given I know next to nothing about electronics, this will be interesting).

Following on from the Y-axis, I had mixed results with the others. I eventually figured out that I had to tweak the pot on the stepper boards to get the steppers running properly. I turned them anti-clockwise a bit at a time until they didn't work and then back a bit till they did again.

I then found that my Z-axis motor would run great when the belt was freed off, but wouldn't run the axis. I have just located a more powerful motor on my scrapheap as my Z-axis doesn't even have the extruder mounted yet. (May have the go the bowden route).

Current state of play is X & Y axes work. Z-axis being fiddled with....

Tech Zone Techniques - Part 3

Following on from Part 2, I'm still trying to get my electronics moving in the right direction.

Step 9: Loading the firmware (still....)

During the last post I was trying to load the firmware and got an error not in sync...

I searched the forum and found this post. Reading through it I saw the following line "Wrong serial port in use for USB connection", and thought "I didn't set the serial port, so how will it know?", obviously it didn't. The Arduino IDE was set to COM1, not COM5 as it needs to be on my system.

I changed that and hit the upload button. Done in seconds. Boy was that dumb... 3 days of wondering what I did wrong (ok, I didn't come back and work on it for the 3 days as I was doing other stuff, but it still bugged me).

Ok, onwards and upwards, lets program that extruder, here are the steps followed:

1. I had already copied the configuration.h.dist to configuration.h in the Extruder folder
2. Moved the USB board to the extruder controller, remembered to invert it (ground is on the opposite side.
3. Loaded the Extruder/Extruder.pde sketchbook.
4. Modified the configuration.h tab to match my setup (left it all standard as I didn't see anything relevant to change) and saved.
5. Checked the temperature.h tab as I am running a thermistor. I wasn't sure is the default table is correct or not, so I left it be for now.
6. Selected the Tools->Board->Arduino Diecimila, Duemilanove or Nano w/ ATmega 168 board and then Sketch->Verify/Compile
7. My board was still connected to the PC from 2 above
8. Selected Upload to I/O Board and it worked!!!
9. Disconnected the USB and moved it back the main board

At this point I'd had enough for the day and decided to call it quits. Part 4 will start with wiring up the steppers, connecting some power and some ground lines as mentioned above.

Tech Zone Techniques - Part 2

Following on from Part 1, I'm continuing to try to get my electronics moving in the right direction.

Step 5: Upload Firmware (or more accurately, installing the Arduino/Sanguino software on my PC)

According to the HowTo page, the boards come with the Makerbot firmware installed. This means that a boot-loader doesn't have to be installed, but the firmware must be updated. This is a new area for me. I am a software developer by trade, but for Windows, not embedded so haven't had to do this before.

I found the Microcontroller firmware installation page on the wiki, so started by following those steps and installed:

1. the Arduino software (release 0018);
   • Download the zip;
   • Extract and move to your desired location;
   • Create shortcut (if you want) - I'm waiting till I figure out how to run it.
2. followed by Zach's Sanguino extensions.
   • Download the zip;
   • Extract and move the Sanguino folder into the Arduino/hardware folder.

Before actually programming the boards, you also need to download the latest stable release of the firmware. This is located in the reprap-mendel-yyyymmdd.zip that is installed when installing the Reprap Host software. Guess that means a quick side track. Don't go away.

Step 6: Install Reprap Host Software

Following the instructions on the 'installing the Reprap Host software' wiki page, I did the following (bear in mind that I am starting with a relatively fresh XP installation on the machine I am using for this):

1. Installed Java 6 from http://java.com/
2. Installed the RepRap Host software from sourceforge (reprap-mendel-20100702.zip)
   • Quite easy really, unpack the zip to a suitable location and run the reprap.bat to run the software.
   • As I decided not to install in Program Files, I had to edit the batch file. The instructions don't mention this, even though they word it as if installing in Program Files is optional. (I might go edit the wiki if I can figure out how).
3. Check out which other Useful Software Packages you need.
   • I installed netfabb Studio Basic;
   • I already had Sketchup;
   • and OpenSCAD.

Note, there are alternate host applications, two keys ones appear to be the Skeinforge/ReplicatorG duo and RepSnapper. I will be trying these in the future to see which suits me best.

Ok, that means I now have the firmware needed to continue with setting up the electronics.

Step 7: Wiring wonders & woes

This forum post by rhmorrison refers to faulty soldering almost blowing his electronics, but more importantly, he describes that moving the stepper motors before powering the electronics will like up the corresponding LED (kind of like the electric motor light bulb generator we all made as kids).

Because of this I decided to do the inter board wiring before hooking up any power to the boards. There seems to be no one clear description and image of this all working. I referenced the following:

1. Nudel's ground pin image. (Shows the stepper to main board connections).
2. The Tech Zone Official Electronics Installation Page. (Shows the extruder controller to main board connections)
3. The Tech Zone HowTo page.

For what it's worth my LED's all lit up when tested by moving the stepper back and forth.

For what's it worth, I will be changing the I2C wiring (one of the 2 wire connectors between the main board and extruder controller) to include a ground wire following Mdbaughman2's experiences.

Step 8: Getting connected

The Ho

wTo page says if you have 2 pins next to the serial connector you can put a jumper on them for the board to be powered from the USB connection. (In the recent versions of Techzone remix electronics sets sold from Ebay - May 2010).

On my board, there is what would appear to be two pins that have been permanently shorted/bridged, there are also no connectors for external power, so I figured the board is permanently configured to be USB powered (don't know what this means for using the SD card slot then). Anyway, I figured the best was to give it a go.

Having kept the Arduino Getting Started w/ Arduino on Windows page open since installing the software, I followed the steps on there. Basically the following:

1. Plug in the USB connector to your PC;
2. When prompted for drivers point to your Arduino/drivers folder (or check the FTDI site for newer ones);
3. Open the Arduino application, and revert to the Microcontroller firmware installation instructions (see next step).

Step 9: Loading the firmware (eventually)

I could eventually continue following the steps under the Programming the Motherboard heading on the Microcontroller firmware installation page.

I followed these steps (any folder locations refer to sub-folders off Reprap\mendel\firmware\FiveD_GCode):

1. Copied configuration.h.dist to configuration.h in the FiveD_GCode_Interpreter and Extruder folders
2. Load the FiveD_GCode_Interpreter/FiveD_GCode_Interpreter.pde sketchbook
3. Modified the configuration.h tab to match my setup (guessed most of it as I don't know what applies yet - it seems to be pretty much setup for the v3 electronics which the TechZone stuff is - For the hardware, I left it as standard for now, but will need to change when I figure out the steps, etc on the ScrapStrap) and saved.
4. Selected the Tools->Board->Sanguino board and then Sketch->Verify/Compile
5. My board was still connected to the PC from Step 8. (if your's isn't, reconnect now).
6. Selected Upload to I/O Board and ... It fails!!

Binary sketch size: 22514 bytes (of a 63488 byte maximum)
avrdude: stk500_getsync(): not in sync: resp=0x00
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

More in Part 3...

Plastic Phantastic

Just a quick note tonight. While trying to figure my way through the electronics I figured I needed to also get a move on with the extruder parts.

I decided to give in and do the sensible thing, so instead of trying to make an extruder manually I bought a set of RP parts for a Wade's extruder from NopHead of Hydraraptor fame. This is fitting as the heater portion will be based on his Plumbstruder design.

The parts arrived today and are fantastic. These are the first printed parts that i have seen and touched physically, and they definitely inspire me to continue on this quest. Having said that, progress is likely to slow over the next few weeks due to work commitments and holidays.

Here are some pictures of the bits and progress so far (more detailed descriptions will be included in a future post on the plumbstruder - you'll also see that I now have the proper stand-off's for my electronics):

Tech Zone Techniques - Part 1

Having completed the ScrapStrap hardware, I figured it was time to dig out the Tech Zone Remix electronics that I bought (I bought directly from Kimberly at Tech Zone, but you can now buy them from BotMill)

There is a HowTo page on the wiki which I hope to help update, but thought I should keep a record of what I do, as I do it so that I can be sure what works and doesn't. Hence this page. I will be including pictures as I go. This page does not intend to replace the HowTo page or other resources, but should rather be seen as a record of the steps I followed.

Step 1: Mounting plate

Choose and make a mounting plate. As per the HowTo page, these electronics are so much smaller that they don't need to use that original thick sheet. Choosing and making the plate at this point means that you can make the wire lengths to suit.

I chose to go with Azdle's Mounting Plate for Tech Zone Remix Electronics, although in my case it was manually made using my bandsaw and drill press. I installed Inkscape in order to be able to print the svg file out to scale.

The material was a piece of ABS plastic which had formed part of the cover of a plan printer which I stripped recently. I kept the plastic covers in case I could recycle the ABS at some time in the future.

Step 2: Unpack and mount

Unpack the the electronics (be careful of static). The first picture was taken removing the bubble wrap, but while still in the anti-static bags. Mount all the pcbs on your mounting plate. (I don't have enough stand-off's so will only complete assembly when I have bought some more. I mocked it up in the meantime)

Step 3: Ground points

Mark the ground pins on all the connectors (see this image). At this point a slight diversion happened as I noted that one of the 10 pin connectors was not in place on the main board. I emailed Tech Zone, but as I didn't feel like waiting to find out if there was a reason for it to be missing I went ahead and fitted one (before and after pics below). I salvaged the connector off an old PC motherboard I had lying around for just such a reason. When de-soldering these I find the best strategy is to remove the plastic bit first and then de-solder one pin at a time. The connector can be reassembled again afterwards.

Step 4: USB/TTL Board to Mainboard connection

Here I followed the lead of those who had gone before and decided to use The Jumper Technique. Instead of creating a cable for linking the USB board, simply use 6 jumpers. This needs the jumpers that have holes right through. I scrounges some of the old motherboards and bits that I have lying around. I'll probably change this to a wired connector in the future once I can print a USB mounting block in order to ensure a firm mounting.

Step 5: Upload Firmware

According to the HowTo page, the boards come with the Makerbot firmware installed. This means that a boot-loader doesn't have to be installed, but the firmware must be updated. This is a new area for me. I am a software developer by trade, but for Windows, not embedded so haven't had to do this before. I'll be continuing with a detailed breakdown in Part 2