RepRap: Blog

The folks at Ponoko are being very patient with me and have run off a second attempt at getting the RepRap printed out on their laser cutting service. I'm not as good at this as Toby Borland who did the original lasercut conversion. Ponoko did their job fine; I goofed again, hence a few nibbled edges in the photo where parts almost fit together.

But this run also produced parts that DO fit together. We also managed to include 2 x 9mm MDF baseplates with cutouts for the wiping mechanism (no mechanism bits yet though) instead of just one in acrylic. I used the cutout space to print some test parts in that normally would require laminating. If they work, that'll save money and effort as you pay per cut and we can get the kit cost down further. I think we shaved US$40-50 off the previous run, and I hope to do the same again.



Most of the parts now have helpful little labels etched onto them, letting you know which tab fits in what slot. One of the more interesting set of goofs is that I accidentally told the laser to cut some lettering right through (and vice versa where some cut lines are only etched). So if you see lettering on the reverse of the cut sheets, you know it's a bad sign (marked in red on this photo, dropped sweet wrapper marked in blue). Maybe they parts will work if the 'D' and 'O' gaps are loaded with epoxy...

The ball-chain gears look like they'll work for 90 degrees of drive - just. I'll tweak them a bit more, and thicken the base of the gear teeth where the laser cut more than I thought it would. All being well, I'll be talking to the awfully nice Ponoko people in a week or so to run my third - and hopefully final - prototyping run. Meanwhile, I have what feels like a 1,000 piece 3D jigsaw to assemble and I have to correct the bits that don't fit!

Vik :v)

PS Missed the Y carriage out altogether Garrr!

Labels: ponoko, reprap

I have something to do while my RepRap is out of action. Toby Borland has done a wonderful design of the RepRap which is meant to be cut on 4mm plywood. He has kindly released the
source, and I've converted an early version of it to the EPS format used by Ponoko on their laser cutting and vending service. We're putting the files up there for free use; we're not taking a cut. Ahah.

I've put up the plywood parts separately to the thick acrylic bed; I'll experiment with a 9mm MDF base but it might be too thin. Toby has since sent me some fixes for the plywood parts - already in EPS format - which I'll work in and scale according to how well the first batch of Ponoko parts fit. The files need optimising to reduce the cutting cost (mostly removing double-cut lines) too. Until that's done, the design should be regarded as pre-alpha and non-functional. As it stands, the ply seems to be slightly thicker than 4mm, so a lot of parts don't fit together properly. Oh yeah, I did muck up the scaling in a few places too - mostly ones that matter!

Prepare for strike two, and props to Ponoko for their support.

Vik :v)

Labels: laser, plywood, ponoko, reprap

Being allowed to present RepRap at LinuxConf 2008 was wonderful, and thanks to all for the encouragement I got that really belongs with the RepRap team. So many new ideas, and very little time spent on repairs all considering.

One that stood out was the idea of using RepRap to print braille, and to make relief maps with textured surfaces to assist the blind.

I contacted the OLPC project to see if they would cooperate on ensuring an OLPC can drive the RepRap. Currently our software won't fit, and the OLPC is essentially python-driven so a re-write or novel way of printing the CAD files might well be necessary as things stand.

Finally, I've been porting Toby Borland's plywood RepRap files to Ponoko's upload format and I think I've got something that should print. Whether one can actually assemble what comes out remains to be seen. The parts cost for RP'd parts, gears & base is in the region of USD$350 and you can download the source. I say again, it's not quite perfected yet.

My Darwin has been chugging along while I work, having a little difficulty with the Z axis after its return from Oz. Perhaps I was just lucky before, but now the Z axis rubs on parts of the base. Being me, I've bashed holes to allow clearance for the nuts.

Here are three Y bearing housings, recently printed. One is marked with a break and is dud, the other two were printed after Adrian's recent accidental sqrt() bugfix. I now have 3 of them, and have manufactured bearings. Bearings look a little short on infill - OK, very short - but seem functional. I've just done another corner bracket (3 to go) and the next part is: Replacement Y axis flag.

Vik :v)

Labels: braille, lca, linuxconf, olpc, ponoko, reprap