Frame assembly

The top part of the frame was measured out previously.  To start assembling, the holes need to be drilled, and the bottom part of the frame measured and drilled.  The frame is made of wood (chipboard).

The first hiccup I experienced was when one of the captive nuts dislodged inside a pipe while assembling the frame.  Luckily it was one of the ported caps, so I could access the nut and managed to fasten the bolt as designed.  With the frame holes drilled as per the dxf file in github, the PVC pipes are slightly bent around each other, but the frame is nice and stable.

Other snags:  the hole in the top platform, through which the drive shaft passes, can  be at least 1 inch diameter.  I originally made it only slightly larger than 22mm, but the outer pipe touched the wood once assembled, making the one arm difficult to turn.  Disassembling, fixing and reassembling took a good portion of the afternoon.

Another thing:  the printed parts break easily.  I'm sure the second assembly will go much easier, but I have broken some parts.  Nothing that I could not fix with a bit of glue, though.

The progress so far:

Frame pipes

Next up, the pipes for the frame.  These have been cut to length already, so I only needed to fit the printed end caps.

The ported end caps go on the long pipes, and they are mounted at the front (on the bottom of the frame).  I started by drilling the holes out to 4mm, and pulling the M4 nuts into the captive holes from outside (leaving the bolt in for the moment).

The end cap surfaces need to be parallel, so the ports point in opposite directions.  I aligned these by eye and fastened the caps with a liberal helping of PVC Weld.  To get the end caps in more easily, I beveled the inside of the PVC pipe with a Stanley knife.  This worked well.

The only thing I forgot was a piece of string through the long pipes to pull the wiring through.  This should not be too difficult to get through, though.

Drive shaft assembly

Assembly of the printer has started with the drive shaft.  Having done a mock assembly of the drive shaft earlier, I decided this would be where I started.  The first step would be to prepare the drive wheels.  I quickly realised that all openings/holes on the printed parts are slightly smaller than they need to be, so I drilled out the rod-mounted wheel's centre hole to 8.5mm, in order to get an M8 bolt through to pull the nut into its captive hole.  It is a tight fit but using a bolt as puller (28mm washer on the bolt head on the other side of the wheel) makes it easy.

It is only possible to do one side like this, and the other side was more difficult.  I ended up pulling out the nut already placed, pulling in the other side nut, and then replacing the first nut (which now fitted much easier once having been in there).

I reamed the pipe mounted wheel hole with a 22 mm  drill bit, and mounted the pipe using two 3mm self tapper screws.  Enough space was left at the bottom for the flanged bearing.  It is important that the self-tapping screws need to be very short (or grind/file off the tips) as the 15mm copper pipe fits inside the 22mm pipe.

Quite predictably, I mounted the rod-mounted (bottom) wheel upside down, i.e. with the flat side towards the bottom.  A lot of unnecessary screwing and unscrewing was the result!

Printed parts are here

On my way back from a work function in Johannesburg this morning, I stopped in Centurion at the house4hack open day / Robobeast launch, met Quentin Harley (designer of the RepRap Morgan 3D printer), and collected the printed parts for my build.

The next week or two is going to be busy, with lots of progress!

Stepper drivers are here!

Yes, after a week the mail is starting to trickle in.  The postal worker strike was called off on Monday, agreement signed on Wednesday, and first mail in the post box today.  There are still three international parcels in the pipeline (amongst others Kapton tape and small thermistors) but at least something is happening.

The drivers are Stepsticks supplied complete with small heat sinks and adhesive tape to attach the heat sink to the surface mount driver chip.

Testing will start this weekend - I will post the test procedure and results.  I will be using the RAMPS 1.4 testing software.

Autodesk 123D Design fail

Still suffering of postal non-delivery (and resultant non-progress on the Morgan), I have been looking at 3D design software to introduce mainly the kids to 3D making.  I have downloaded and installed OpenSCAD, but for the rest of the family that is not going to work that well.  I have previously used Google Sketchup, and from what I could see the Autodesk 123D Design software might be easy enough to use to introduce the rest of the family to making.

At 282 MB download, I waited till after midnight to save some bandwidth (we have a lot of "Night Owl" data available), and in the small hours of the morning I battled to get 123D Design to work.

The software starts up, with splash screen, and simply closes down directly after the splash screen.  No error messages, no event log entries, just a fail.  I scrutinised the system requirements, and although the laptop is a few years old, should easily fulfill the requirements.  Searching the web and forums on the Autodesk site was no help, and I was in no mood to go to extreme lengths to search or contact tech support, so I just deleted it from the PC.

I did try an install on the newer Windows 8 laptop, but that is a 64bit machine, so I need to do ANOTHER 300MB download, no thanks...

Update on Noteworthy thing #2

Just a few days after I posted the bit about the 3D models for Space:1999, the Eagle Transporter has landed on Thingiverse.  Still not printable, created in Sketchup, and not as detailed as the models in the original post, but better (a little more detailed) than the previous one!

On another note, it seems as if I have fallen victim to the postal worker strike here in South Africa.  I have some four parcels inbound, and I visit the post box every second day.  Nothing (not even a bill) for well over a week now.