Resources

So while I'm not making much progress I thought I would write a bit about the resources I have been using. The main one which helped a lot during the build phase was

• http://reprap.org/wiki/Mendel 

There you can find information on what you need to build a reprap, how to build it and how to test it. You can also find links to most of the firmware needed for the electronics and the arduino software needed to edit the firmware and upload it.

The only thing that I found hard to find was the details of the particular type of electronics I had. I bought a complete set, the TechZone Remix which is a 3rd generation set. The two wiki links I have been using are:

• http://reprap.org/wiki/Generation_3_Electronics/Tech_Zone_Remix

• http://reprap.org/wiki/Generation_3_Electronics/Tech_Zone_Remix/How_to

Neither are particularly complete but they were very helpful when assembling/testing the electronics and in particular when flashing the firmware.

Other than that the arduino site (http://www.arduino.cc/) was probably the only other place I turned to for information.

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First play with electronics

So I had time for a quick play today, I managed to upload the firmware to the motherboard and ran a test using the Reprap software to talk to it. It wasn't, however, a pain free experience. The instructions were poor at best, stable versions of bits of code weren't easily available and it didn't play nicely with windows 7 (didn't really expect it to though).

Anyway after fiddling around on my xp netbook I got it working... sort of. It seems that the motherboard firmware I uploaded, when asked for the the extruder temperature (M105), reported the extruder temp AND the heated bed temp. Well the Reprap software didn't like that, not one bit. There were NullPointerExceptions and IntegerExceptions everywhere as it clearly tried to parse "0 B:0" as an int. Luckily being open source, and having the source at hand, I removed the offending code from the firmware, reuploaded and - tada all was well. I was going to test more of the electronics but, that requires making up some cables to the right length, so that will be a job for monday.

The usb/serial adapter and motherboard with the happy yellow light of workingness.

Look it works, g-code commands being sent and replies being received, hurrah!

Electronics are here!

So finally the electronics are here! Everything seems to be intact, despite the box looking like it had been driven over. Time to resume work I on the reprap I think!

Obligatory pictures:

Mechanical construction finished

It's finished! Well sort of, I've not fitted the bed and I don't have any electronics yet but it's getting there. The electronics (or at least some of them) should be arriving soon, I got some of them from ebay so here's hoping they all turn up ok.  All that's left to do while waiting for more parts is add some thread locker in a few places.

I will try and post a video later so I can show how the various axis move.

Frame and a few fixes

Quite a long post today, as I had a fair bit of fixing to do. A few people pointed out that my x-axis wasn't quite right, it turned out I had put the carriage on upside-down. Luckily it was just a case of loosening a few bolts, taking off one end and the carriage and putting them back on the right way round! Here is how it looks now, carriage on the top and x-axis stepper pointing down. 

I also tightened the belt, I had left it loose when test fitting it and forgot to tighten it! Once that was done it was on to fix number 2 or 3 or 4 or something. One of the RP parts that holds one of the bearings for the z-axis was missing some holes, here is the part.

No idea why the holes are missing, it doesn't look like it failed print the holes properly just like it never tried, so never mind. Simple to fix though, pop it into a vice with the other RP clamp part as a guide.

20 seconds of drilling later, and its all fixed.


Now that's done, I can get cracking with the frame. All the nuts are finger tight at the moment as I will check distances/measurements once the frame is in one piece.

Here is the other half of the frame complete, just need to bolt them together now. I did have a bit of trouble getting the threaded rods through some of RP parts, but again it wasn't a big deal I just cleaned up the insides of the holes a bit with a file.

Bolting the two halves together was relatively pain free, the bearing assemblies for the y-axis belt are just loose fitted in the picture below as I hadn't broken out the ruler yet.

Just enough time to finish the frame off by adding the last two threaded rods. And all done, still need to check measurements, but that's for another day.

Here is my jig-stick :) made from a few bits of steel stuck together. I turned the ends down on a lathe to within about 1/10th of a mm of the jig lengths on the reprap wiki so it should be ok.

Finally a shot of my work-area (my carpet), as you can see I'm a tidy person.

And there you have it, I'm getting close to the end of the mechanical build. Now I need to fit the y-axis, attach the x-axis and z-axis, thread belts on and I should be very close to being done.

X-axis

Now the building starts, the wiki recommended starting with the extruder, but I'm missing a few bits (nichrome wire etc) so I decided to start with the x-axis.  I started with the Z-axis bearing (the Z-axis guide bar runs through the two washers in the photo, while one of the threaded drive rods runs through a trapped nut).

I then moved on to the extruder carriage, you can see the extruder stepper mounted here (the black box).

Time for the other Z-bearing assembly, here you can see the top set of 3 bearings that trap the z-axis. The x-axis stepper and drive belt were next to be added.

Et voila! One X-axis fully assembled, the action is very smooth and it's a lot more rigid than I was expecting.

Here you can see the extruder carriage, and how it sits on the supporting rails.

A box appears

It's always nice when a parcel turns up, however I don't remember ordering any bananas...

But what's this? The box is completely lacking in bananas, instead someone has filled it with reprap parts, which is much better!

So many packets and bags, all neatly labeled.  Everything is there and in perfect condition which is impressive considering it came all the way from Hungary.

So now that it's all here time to start building, I'd just like to say thank you to Laszlo again for getting everything printed and shipped to me and for putting up with my constant stream of emails!

Hello!

Welcome to AberRap, yet another reprap blog! This blog will follow the construction, operation and hopefully tweaking and improving of a reprap Mendel. 

So what is a reprap Mendel? Well wikipedia says:

"The RepRap Project is an initiative aimed at creating a largely self-replicating machine which can be used for rapid prototyping and manufacturing. A rapid prototyper is a 3D printer that is able to fabricate three dimensional artifacts from a computer-based model.".

The Mendel is the second generation or "new and improved" version of the original Darwin reprap machine, it is less prone to jams and is basically "better, faster and stronger"! I got the mechanical parts (printed parts, studding, bars, nuts/bolts,belts and stepper motors) from Laszlo at http://blog.arcol.hu. If you are interested in making one yourself definitely drop him an email, he's a great guy and really helpful. 

Now that the obligatory introduction is done, on with the build!