Notes for building a RepStrap.

Looked at the various RepStrap's described at RepRap.org. RepStrap and Ponoko look good. Tommelise is poorly documented and USAnian. HydraRaptor^? is undescribed. Plywood RepStrap is superseeded by Ponoko.

The main difference between the v1.2 McWire^? RepStrap and the v1.1 Ponoko RepStrap seems to be that the McWire^? is described in USAnian measurements, making it mostly useless for this side of the Atlantic.

The RepMan^? looks like a RepRap, i.e. not very pretty or easy to access. I like the accessibility of the McWire^?, but it's not in metric. Bummer.

Forums has the following on McWire^?'s in metric: khiraly is the only one who seems to have done extensive metric work.

First step: Talking to the Arduino

Mac-related instructions here. Installed version 2.2.10.

Rxtx giving trouble. Following instructions, I added -arch parts to CFLAGS and three cc -bundle lines. Ran make and sudo make install (had also previously made /var/lock changes recommended, and removed rxtx things from the Java extensions folder). It now works! The LED is blinkin' on and off!

Patched SerialImp^?.[c] as per post. Probably fixes some crashes down the line.

Second step: Making driver boards

Making stepper motor drivers, dc motor drivers, PCM drivers, and optostops. The circuits will need to be handmade using this Instructables method with laser jet print on photo paper/label paper, ironing and ferrichloride. Note comment on adding washing soda to neutralize and have the copper fall out -- copper in the solution is nasty, without it the solution can be handled easily by the local recycling center. Plus, you get loose copper:) Maybe get Dalo pen for patching up, if a Sharpie doesn't cut it. This Instructables recommends Konica Minolta Photo Quailty Matte Paper.

2009-02-08: Tried making a sample board. Got FeCl^? and 20x30 board from Lavpris Elektronik. Feeding special paper from the manual feed works nicely, even does smaller formats. Using the backing of label paper doesn't work, it crunches up, both the A4 labels from Tiger and the standard labels we had. Using the cheap photo paper worked. Made printer setup (max DPI, "Thicker" paper, no scaling). Cut board with Dremel tool, not easy to get nice that way. Ironed and soaked. Paper came of off easily, most of it. A little stuck to the masked parts. Tape stickiness never came off, even after etching. Maybe try masking tape. 4 parts FeCl^? to 5 parts hot water. Shook for a long time in the cold, water got too cold to be fast. Dedicated stirring container and container for used FeCl^? downstairs. Result is nice, though there's some bits missing along the edge that worry me.

The scratch on top is from where the Dremel slipped and ran across the copper. The big splotch is due to stopping short (it started to snow).

18/2: Boards turn out to be double-sided. Got double-sided boards, and got traces together on 10x15 prints for easier transfer. Will cut boards after transfer, possibly at Huset.

Did some test transfers. Points to remember:

• Never, ever, get finger prints on the boards! Even after thorough rubbing with acetone the fingerprinted corner did not come on right.
• Use the edge of the iron to get extra pressure, edging across in both directions.
• Use masking tape to hold print to board, it's residue comes off easily.
• Cut print larger than board so that the tape can be on the board side only.
• To get the last bits of paper off, esp. on dense areas, don't use a metal object, it can scratch off the traces. Even the soft side of a sponge can be too muc, if used with force.

Things to make!

• Organizer for electronics stuff.
• Replacement parts for the RepStrap itself.
• A RepRap. Duh!

-- LarsClausen - 31 Jan 2009
to top