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Re: LOM RepRap? - 14 years ago

SebastienBailard Wrote: ------------------------------------------------------- > > My idea is using high speed dentist drill motors > (350K - 500K rpm at about $30-$40 per motor). > > What's your source for those? Is that a turn-key > bolt in spindle? They are a turn-key item, Chinese sellers on ebay offer them for about USD 30-50 each, like these, . They're available in li

Re: LOM RepRap? - 14 years ago

SebastienBailard Wrote: ------------------------------------------------------- > > cyanoacrylate can be dribbled through the burrs' > slots to consolidate afterwards > > Madness. > > Try a glue swabbing thing or inkjet down > cyranoacyrlate. > Aside from that, it may work rather well, although > you might wear out your bits faster than you'd > think. >

Re: LOM RepRap? - 14 years ago

I've been hacking a Mendel variation with a thought to the mcor Matrix, that does LOM with paper. My idea is using high speed dentist drill motors (350K - 500K rpm at about $30-$40 per motor) and burrs to rout the paper rather than cutting it with a blade. I'm also thinking that multiple heads could reduce the need for x travel to 50mm - 100mm and speed up the processing. Support material with

Re: MIT 3dp patent expiration and Desktop Factory flop - 14 years ago

Desktop Factory didn't go bust, unlike a lot of speculative ventures. They ran out of venture capital, but wound down their operation without outspending what they had available (and returned the deposits they'd attracted). The technology, assets, and key people have been taken up by 3DSystems, who are continuing development and intend to get a mcachine using that technology to market. The for

Re: McWire Successor - 14 years ago

If you've two pulleys and a belt, you could use the back of the belt as the tyre. Both pulleys pinching the table would be even better.

Re: Mold and pour mendel parts - 14 years ago

I had better success today. Woohoo, I can put some bits together! The mold design works well to align the studding holes, but polystyrene sheet was the wrong choice to use with polyester resin, which dissolves it. I designed it as a grandpa's axe mold, so that deteriorating parts can be replaced, so I'll replace them with polyethylene sheet (milk bottles!), which doesn't react with the solvent

Re: Mold and pour mendel parts - 14 years ago

It's polyester car body filler. I didn't put enough hardener in the mix in two of the three mixes that I filled the mold with, it was a cool day and the end result is that only one of the pieces has fully hardened today! Maybe they'll set overnight with a bit of warmth from a light bulb, if not I'll have to do it again. At least the mold's reusable... I'll probably use food wrap as you suggest

Re: Mold and pour mendel parts - 14 years ago

I think the idea of using kitchen foil as a release foil was inspired. The inserts slid out without any resistance at all. A good enough result to be going on with.

Re: Certificate of Replication - 14 years ago

sircastor Wrote: ------------------------------------------------------- > Also, another idea that occurred to me would be to > add your name to one of the printed objects in a > set that you send off to someone else. Either your > name, or your printer's name right on the piece. I think a part identification would be useful too. Thingiverse adds QR codes to the part pages, which ca

Re: Reprapped Mendel parts for sale - 14 years ago

The image has a copyright claim on it, but doesn't say who to. Is a copyright claim valid if it doesn't identify the copyright holder? It's a nice irony because of the open source aims of the project.

Re: Mold and pour mendel parts - 14 years ago

So, I got down to it and built the mold I proposed. Built from 1.5mm styrene sheet, all the faces are sheathed with vinyl duct tape as a release agent. The removable cores are the barrels of cheap fibre tipped pens, because they're very close to 8mm diameter and they're slightly tapered, I assume because that's the draft for injection molding. I wrapped them in aluminium kitchen foil as a barr

Re: Automatic Teardrop Holes - 14 years ago

Consider that each g-code polyline segment would have to be referred back to the facet normal that it's derived from, then the g-code production needs feature recognition from the .stl, which also needs the feature recognition from the originating model to reference holes-at-other-than-z-coaxial-angles, there are two degrees of separation from the design intent. Non-trivial, yeah.

Re: Automatic Teardrop Holes - 14 years ago

That would require the g-code application to also be the design application. If you take the hole in isolation, ie as a hole in a block, orienting it vertically to write the g-code, it's visually recognisable as a hole, swing it through 90 degrees, it's going to have to be a teardrop. That's ok to think about with holes, but how's that application going to reshape a filleted external edge, for

Re: Automatic Teardrop Holes - 14 years ago

You'll need to do it yourself, since the teardrop shape isn't needed if the hole's vertical, ie, the necessity for it depends on the orientation of the hole while the part's being built. Orient the object build to minimise overhangs, and the hole might not need the teardrop, or if you've got multiple holes with differing orientation, some will need it but not others.

Re: McWire Successor - 14 years ago

I'm busy playing with hardware at the moment, and I had something different in the kitty: a board that I bought off ebay before I found reprap from a Canadian company called SOC machines . It's called MC433G and it has similar features to the reprap electronics. Onboard g-code processing, four stepper drivers and provision for other add-ons like relays, joystick, USB interface and what not. Dr

Re: Belt Versus Screw Drive - 14 years ago

I've used small turnbuckles available from radio control hobby shops, used for tensioning of cable runs from servos to control surfaces. The figure eight arrangement is possibly more useful as a slave linkage to maintain alignment, although it occurs to me that opposed blocks-and-tackles winding on and winding off could be used to eliminate length variation through angularity and as gearing at t

Re: Belt Versus Screw Drive - 14 years ago

Re: McWire Successor - 14 years ago

sircastor Wrote: ------------------------------------------------------- > bjbsquared Wrote: > -------------------------------------------------- > I'm not big on the DIY leadscrew, I think because > it feels like a bit of a project itself. On the > other hand, it's a solution to a problem we've all > been tossing around, which is more than I can say > I've offered. There'

Re: Confusing the isuue - 14 years ago

rocket_scientist Wrote: ------------------------------------------------------- > Another approach is to replace the belts with > aircraft cable (braided wire cable, not sure what > it is called in Europe). This has the advantage > that it can bend in several directions, allowing > the wire to wrap (possibly multiple times) around > a pulley, then down one edge of the stage righ

Re: Certificate of Replication - 14 years ago

Rather than certificates, why not a family tree? Reprap genealogy might be easier and less expensive, and could let you see where your work is going as well as where it's come from, show where the developments kicked in, too.

Re: Meta-Molds - molds that make molds. - 14 years ago

Good idea. There's an acrylic modified plaster that's used for body molds and architectural work called Forton MG (modified gypsum). It's stronger, lighter (cheaper freight costs) and holds finer detail than common ol' plaster of paris, not very much more expensive (the cost difference could be saved in post or shipping costs), and it's waterproof. Gauze fabric reinforcement can make a shell m

Re: RepRap future and leader (the need for) - 14 years ago

I don't think that's quite what I wrote. But what the hey... Now that consensus has been achieved, when's the ticker tape parade?

Re: RepRap future and leader (the need for) - 14 years ago

Bureaucracy is the stultifying reactionary evolution of any social population. Its advocates believe that their own activities are the real purpose of any endeavour, that consensus can be dictated, and that in a democracy, their ideological despotism is justified, because they serve the community by leading it.

Re: Tools for creating non printable parts - 14 years ago

Carburettor jets are common. Easy to file or grind away the surrounding material.

Re: Plastic recycler - 14 years ago

Lionel Wrote: ------------------------------------------------------- > The blog presents quite a good work! the author > also says that he managed to make a machine work > the first time (19 dec 2008), but that a problem > arised when the machine cools down because the > plastic gets stuck in the machine from the > previous extrusion. > > Well, I think there is a solutio

low powered lasers - 14 years ago

I don't know anything practical about lasers, except that I would be worried about trying to do something with an invisible thing that could hurt badly! But I've seen reference to the low powered lasers that're used to burn CDs and DVDs. I know that they are too low powered to do much as a single unit. But, the Americans have a fusion energy project being built that involves plasma deuterium i

Re: cheap CAD offer - 14 years ago

sweaving Wrote: ------------------------------------------------------- > To be honest are there any CAD packages that can > import, and then manipulate and edit STL files > easily? ive been looking for some months now and > havnt found one.Alibre has the largerest file > import solution i found, and although the STL it > exports are not Binery, they can be opened in > Meshla

Re: rack and pinion versus belt? - 14 years ago

rhmorrison Wrote: I particularly like the use of > plain paper, adhesive and a cutter that creates > wood-like objects at a very low cost - the main > cost being the special adhesive required. Others > use a roll of plastic, adhesive and a cutter which > makes even stronger parts but at a significantly > higher cost (plastic vs plain 80/160 g paper). I agree. I admire the m

Re: roller pinion seems very printable... - 14 years ago

Since I'm speculating, and you're not, why don't you think a length of bicycle chain with a cog rolling along it is essentially the same device as you're proposing, non-speculatively?

Re: roller pinion seems very printable... - 14 years ago

The rack's tooth profile is cycloidal, so unlike an involute gear on a rack, the pins/bearings' contact point slides over the tooth form rather than rolls on it. Without bearings, the rack teeth will wear down to something like a bike cog shape, losing the design's biggest selling point, the opposing two-point-contact, introducing prominent lash and only getting contact when the pins are at the