Sunday 27 June 2010

Electronics Testing - Stepper Motors

I've moved on to testing the TechZone Remix stepper motor controllers. I've wired up the boards in a test bench set up. I was confused at first that the motors were only turning one way, clockwise, until I worked out it was because the end opto sensors were not plugged in so the software thought they were in the home position and hence would not allow them to turn the other way. I was surprised how straight forward everything was to put together. The ABCD wiring I was worried about earlier was not a problem, it was the correct ABCD same as the standard Makerbot electronics. The video below shows one of the first tests, this is the set up printing the minimug object. Note that the y and z axis only rotate clockwise as there are no opto sensors attached.


Monday 21 June 2010

TechZone Electronics First Play

My electronics package from TechZone finally arrived! I think it has been held up at UK customs for almost two weeks. For those of you not familiar with the TechZone Electronics Remix, they are an alternative to the Makerbot set, you can find out more here. There was some debate about the ethicacy of the electronics at first but I think that has all been resolved now. In my defence I was all set for buying the Makerbot set but they were out of stock.

Anyway, I thought I would post some pictures of the unboxing for anybody considering a purchase. My first impression is of how small they are, i knew they were smaller footprint than the Makerbot set but boy these are tiny!









Impatient to start testing the stuff out I decided to start with seeing if I could upload the firmware (the bootloader is already pre installed). This is done by connecting the motherboard to the USB TTL boad via the 6 pin ribbon cable. I can't say I managed it straight away, I had some problems getting decent connectins at the connectors. So switched to the jumper method described on the wiki page. After using jumpers it worked a treat just as per the reprap.org build instructions. The only thing I noted is that you have change the COM port in RepRap software preferences. I don't think this is mentioned in the build instructions, but is important for running the motherboard test.





Thursday 17 June 2010

Iconic

Just thought I’d share this. I’ve been playing with the RepRap software and thought I would brighten up the shortcut to the reprap.bat file by giving it a proper icon. See below for the icon file and what it looks like on the desktop. To get the icon to show, download the .ico file by following the link, right click on the shortcut on the desktop, click properties, click customize, change icon. When prompted just find the .ico file you downloaded.



Wednesday 16 June 2010

Power Up

I got my cheap power brick off ebay yesterday so I decided to adapt it to the Mendel standard XLR connector. The power brick was only £9 inc the lead and the seller even threw in a European power adapter, not bad, hope it lasts. The connector was a sinch to solder up even for me! Double checking the polarity with a multimeter I hooked up the positive (red) wire to pin 2 of the female connector. I've also received the male chassis connector so I've temporarily put it in place using a cable tie.









Monday 7 June 2010

Bearings here

I have taken delivery of the bearings. Ordered from a nice bloke off ebay all the way from the Netherlands - Gubbels Engineering. Actually worked out cheaper than getting from RS so I went for it. Quick delivery and no customs charges. One step closer, can't wait to start building.


Friday 4 June 2010

Stepper Motors Here




Stepper motors have arrived. I ordered 4 NEMA 17’s from Zapp Automation, 3 for the axes and 1 for the extruder. They look ok but I will have to wait until I have the electronics before I can test them.


They are of the 6 wire unipolar variety code SY42STH47-1206A. According to the datasheet the wire colours correspond as follows:

Coil 1 = Black & Green
Coil 2 = Red & Blue

Therefore for the RepRap setup I need to connect:

A = Black
B = Green
C = Red
D = Blue

The Yellow and White wires are the centre leads for each coil and so are ignored
I’m sure I have read that the ABCD on the TechZone Remix electronics may be wired differently so I will need to check the above set up.

Thursday 3 June 2010

Thick Sheet

I have been working on cutting out the thick sheet parts. The way I have chosen to do it is by printing out the templates from the original dxf. I used Paint Shop Pro to open the dxf files, though for some reason it didn't seem to preserve the scaling so I had to the then scale the pictures to get them to the correct size, (I hope I got it accurate enough!). I then glued the templates to the thick sheet so I could cut around them and drill the correct holes. I found I could also import the dxf files into SketchUp see below for the thick sheet models I have created from the dxfs and put into google's 3d warehouse.

I am making the thick sheet parts from 6mm thick MDF bought from B&Q for less than £4. I have cut them out using a jigsaw and junior hacksaw, finished using a Dremel and sand paper.



RepRap Mendel Thick Sheet Motherboard Plate:



3D model by James
RepRap Mendel Thick Sheet Motherboard Plate 6mm thick. Converted from the dxf drawing files provided @ http://objects.reprap.org/wiki/Mendel_materials_preparation To find out more about the reprap...



RepRap Mendel Thick Sheet Stepper Plate:



3D model by James
RepRap Mendel Thick Sheet Stepper Plate 6mm thick. Converted from the dxf drawing files provided @ http://objects.reprap.org/wiki/Mendel_materials_preparation To find out more about the reprap...


RepRap Mendel Thick Sheet Purge Plate: "




3D model by James
RepRap Mendel Thick Sheet Purge Plate 6mm thick. Converted from the dxf drawing files provided @ http://objects.reprap.org/wiki/Mendel_materials_preparation To find out more about the reprap project...



RepRap Mendel Thick Sheet Bed:




3D model by James
RepRap Mendel Thick Sheet Bed 6mm thick. Converted from the dxf drawing files provided @ http://objects.reprap.org/wiki/Mendel_materials_preparation To find out more about the reprap project...



RepRap Mendel Thick Sheet y-chasis squashed frog:


3D model by James
RepRap Mendel Thick Sheet y-chasis squashed frog 6mm thick. Converted from the dxf drawing files provided @ http://objects.reprap.org/wiki/Mendel_materials_preparation To find out more about the...