Author: Quentin Harley

I have been looking for a hackerspace ever since I started tinkering on Morgan, and I finally found one, right on my doorstep!

House 4 Hack is a local Centurion hackerspace, with members participating in Arduino, Reprap, and other Open projects.  They have a couple of bots – perhaps I can get some of the tricky parts for Morgan 0 made this way.

Centurion is turning out to be a very nice place to live it you like to tinker!

Something that is very noticeable with all the current reprap and open source 3D prototypers, is that they look very steam-punk.  There are open wires, switches, boards, gears etc. all over the show, with little or no attempts made to conceal the sensitive bits. DIY 3D machines are, for lack of a better analogy, stark naked.  Inside out insects.  Starwars intergalactic fighters with special safe entrances for getting to the power core (to blow it up, and get out unscathed of course)

RepRap, and other “low cost” 3D suppliers can take a lot of pointers from the big players. Make your functional bits in such a way that it protects the sensitive bits.  Sure, it will now make your precious (and complicated) 3D printer look boring, and not anything as complicated as you would like people to think it is.  Just maybe it will now be a little less daunting to use.

We need to make our RepRaps easy to make, easy to use and affordable.  Only then can we even hope that it will take off like it should.

On my way to get some more small pieces and plugs for the testing of the board something awful happened.  I left RAMPS on my car roof and drove almost a kilometer before it finally came off with a screech and a slap.  Onto the road.

I only realized what it was a couple minutes later…  I dreaded what I would find.  My precious RAMPS probably run over by a Gautrain Bus.

When I got there it was lying on the line between the two lanes – and still intact save a few bent pins, a broken pololu header and a destroyed 11A resetable fuse.

Repairing the damage now.  It is very fortunate that I decided to leave the Arduino Mega and the Pololu drivers at home!

Checked basic RAMPS function today.

Loaded latest Marlin firmware, and connected using latest pronterface (Kliment’s Printrun) .  Managed to read temperatures from thermistors connected to the board.  Boots on 12V to Ramps 5A input.

Next step: testing Stepper motors, and heating circuits.

3D printing Filament is one of the largest concerns determining your running costs.  Of course many of the efficient designs are fueled by the extreme cost of filament, but why the extremes?

It seems that there is finally some light in the tunnel.  Somehow the good people at Cad-house managed to bring down filament prices by 50% since I last looked!

http://3d-printer.co.za/3D_Printers/Personal/RepRap_Kits/reprap_kits.html#.UEA74IogdUw

A step in the right direction, although I still believe that we should work together in finding a cheaper solution.  The raw extrusion quality ABS costs only about R6/kg

It is common knowledge that there are many ways to achive a goal.

Not so well known is that for every successful technique there are just about 50 ways to get it wrong…  There is not one reputable blog or DIY SMT reflow guide that recommends using a heat-gun as a way to reflow your freshly pick and placed SMT PC board.  I tried it early this Saturday.  It was surprisingly successful right up to the point where the Electrolytic capacitors started going off like popcorn, leaving little trails of smoke as it whizzed past my face… Quite entertaining…

After I had my thrills, I went to look for my trusty reflow skillet.  The electric frying pan method always worked for me, and this time – it still did.  Heat guns are for stripping paint, and other DESTRUCTIVE tasks!

I applied the solder paste using a hobby knife blade, and the mask.  Worked well.

I think my solder paste is a bit old. It did not go completely shiny like it once did.  May be a good time to order a new tube.  (Mine has a sell by date of Oct 2007.  Go figure…)

So, in stead of building a couple of RAMPS, I built one, and it still needs to be tested.  At least the LEDs seems to behave in a predictable way – A good sign!

RAMPS sourcing complete.  The last step is to put everything together.  In the picture you see my bare RAMPS board, the pick sheet I made with all the components attached, and the soldermask I hand cut out of 0.15mm thick mylar sheet.

RAMPS 1.4 uses larger SMT components, so hand cutting the solder mask to an acceptable tolerance is not hard.  I have contacted a local laser cutting service to potentially make the mask for the stepstick though.  It is just too fine, especially around the IC.

The previous time I tried to build RAMPS I was way too eager, and used a syringe to apply the solder paste.  The effect was that the components lifted and drifted on the large blobs of solder, causing problems in the denser areas.  I also did not have the right 100uF caps, causing the headers for the pololu / stepstick drivers headers not to fit.

More on Saturday…

 

Never take anything written on the web as gospel.  A lesson I just had to relearn when sourcing parts for RAMPS.

The BOM on the REPRAP wiki for Ramps 1.4 is not quite correct in all instances, for instance the package information of some of the capacitors, notably the 100uF electrolytics.  The package indicated is 0605, where it should have been Type D aluminium electrolytic.  No wonder nobody wanted (or could) help me with those caps.  To add insult, when I finally got some caps, I was supplied Type E, which is about 2mm too large, and the headers will not fit on my Ramps board with these fitted.

New caps ordered today.  Communica has stock, but once again I have to take a reel of 1000 pieces at close to R3000.  RS got the deal, again.  Should arrive next week Monday.  Besides, that same reel would be less expensive at RS!  Talk about warped perspectives.

I will document the RAMPS build with a proper BOM for South Africa, and photos of the process.

Life has once again interrupted fast progress, but this does not mean everything has ground to a halt!  I finally found a company in Gauteng that can supply us with the hard to find PTFE (Teflon) tubing needed to fashion the Bowden couplings required to reduce weight on the hot-end even more.

Chemical & Industrial Plastics http://www.ptfeplastics.com/  in Benoni specialises in Teflon, and can do almost anything teflon you can think of… including the elusive Teflon tubing.  They do small quantities, and they are affordable too!

 

I have a couple of extra RAMPS 1.4 boards on my hands.  I decided to make a couple more in order to bring unit cost down, and I can share with anyone interested for about R150 each.

These are very well made double sided surface mount boards, and will save you the tooling cost normally associated with a small board run.

I only have a few to share, so if interested leave a comment here.  You do not have to leave your email address in the massage body (think spammers…) I can get it from the email address you enter in its own field when you post.

Hope this helps somebody getting started as well!

NB: These are the BARE boards, nothing component wise on it yet.  I am waiting for a couple of caps from RS for the build. and it it goes well I may have a couple built up that I could sell as well.  Just need to fill my needs first 😉