Ru Wrote: ------------------------------------------------------- > What makes you say that it is better? Given that > it is lower, lower res, etc etc. Well the original idea was to attach it to a high mechanical advantage gear train which is in turn attached to the motor, such that the encoder turns much faster than the motor, giving it more pulses per rotation of the motor shaft. The eby Joshua Merchant - Controllers
Hm... I wonder if I could just do it as a hobby until the patent expires, and then make it commercial. That's what I was planning to do anyway (since it would take a while to learn about all the stuff I need to learn about - probably a few years or more). And it's not like the parts I would make and use would be a major factor in the profitability... they don't even have to be precise, I just wby Joshua Merchant - General
Just listing options as they come to mind. Sometimes options that seem more complex can actually be more effective and sometimes simpler in practice (usually due to the effectiveness). For example, given proper geometry, you may not need parallel supporting rails on the stages. It also may be easier than one might initially think to have braking/locking mechanisms. But yes, at the moment, the idby Joshua Merchant - Mechanics
Note that I'm in the U.S. (patent laws seem to be a bit different here, but they follow the same WTO rules, as far as I know). Also note that I have only a basic understanding of law, and no personal experience. I'm interested in building a RepRap and using parts that I make as components in machines that I will use to manufacture products that I can sell for a profit. I understand that Stratasby Joshua Merchant - General
I received my Mouser shipment today, which included 101-5433-EV and 101-5437-EV. While I can't test them or anything yet (I still don't have all the components for my Arduino), I can say a few things about them. They both have 3 pins. In the middle of the shaft (for both) there is a hexagonal hole, into which I imagine can be placed a hexagonal rod. The diameter of the hole is about 2mm. I triby Joshua Merchant - Controllers
Interesting. And yes, that last part does make sense. The thing about moving the table about in 3 axes is that the table is generally much larger than the toolhead. Personally, I think it would be best to move only the toolhead as the toolhead should generally be much lighter than the build platform and build object (as far as I know). If we end up making a really heavy toolhead the reverse migby Joshua Merchant - Mechanics
This is a question that has been bugging me for a bit, and it should be simple to answer. Everywhere that I've seen discussion of cartbot options, the three listed all have at least one axis of movement for the build platform. Why? Is there something intrinsically wrong with moving the toolhead on three axes and leaving the build platform immobile?by Joshua Merchant - Mechanics
Forrest Higgs Wrote: ------------------------------------------------------- > Given that we really haven't been talking about > printing solid objects the leakiness of our prints > as to opposed to their tendency to absorb water > might be quite an issue for some applications. That's just a software/firmware problem though, right? Wouldn't it be simple enough to modify the code to eby Joshua Merchant - General
Another idea would be to have the linear and rotary controls for an axis on the same leadscrew. Essentially, you have the end of the screw rigidly attached to the stage (I'm using McWire terminology, as I haven't taken a good look at the Darwin cartbot in a while), and at the end of the screw you have a motor which can rotate the screw. Between the stage and the motor, you have a nut threaded onby Joshua Merchant - Mechanics
You might want to look into coating with some sort of water-resistant material for objects that need it. This would be analogous to painting (priming?) wood, but it doesn't necessarily have to be a paint. Just a thought.by Joshua Merchant - General
Ru Wrote: ------------------------------------------------------- > I made a comment about 4+ axis printing a little > while ago: > Ah, yes. You're that person I was referring to in the OP. > To summarise; the problem isn't a mechanical one, > its a software one. Calculating toolpaths when you > add extra axes is going to be very, very, very > hard. Just as I thought. But tby Joshua Merchant - Mechanics
Afghan lathe ? If you're going to thread the rod yourself anyway, you should probably get one that's already hollow, if possible (I think Nop said something to this effect, also related to a high temp extruder). A rod with a large enough OD and a small enough ID might not be available (note that the ID could be less than 3mm, and you could then more easily drill your 3mm hole in it, using the exby Joshua Merchant - Mechanics
I couldn't get to sleep, so I came up with an idea for a cartbot which can change the angle between the extruder and the build object to overcome the 45by Joshua Merchant - Mechanics
Kyle Corbitt Wrote: ------------------------------------------------------- > Haha, for the record I've never seen a milling > setup that didn't produce a certain amount of > dust/scrap, no matter how well set up the vacuum > is. I've never seen how professionals do it > though. You can still contain the entire thing with a really innovative contraption. I call it a "Bawcks 1.0".by Joshua Merchant - Plastic Extruder Working Group
Demented Chihuahua Wrote: ------------------------------------------------------- > @Joshua > > Actually, the differing diameters, pitches and > what not are there for good melt quality and > consistency in extrusion. Not for air removal. > That is a by-product of all that. Would it happen > otherwise...I don't know. Regardless, they do it > for some reason and we need aby Joshua Merchant - Mechanics
xsainnz Wrote: ------------------------------------------------------- > Crackpot idea: > > long length of 'fishtank tube' one end positioned > close to the milling head other attached to a > vacuum cleaner That's not a crackpot idea; in fact, that's pretty much exactly what I had in mind. I suggest we come up with some way to discredit the milling option, though, so we can haveby Joshua Merchant - Plastic Extruder Working Group
Korndog Wrote: ------------------------------------------------------- > this is all nonconstructive criticism. I disagree; it made me think (and that stuff usually leads somewhere, eventually). > if you want to help, then put some of your > time into this community project. It looks like he might be trying to gauge whether the project is worth his time at the moment. I, for one, wouldn'by Joshua Merchant - General
Quick edit: I missed the first reply while I was posting, so I'm reading it now. Edit2: Hm. Ru, I found your post quite entertaining. It was a bit defensive though, and some of your response points were flawed (probably due to the emotions that controlled the reactions). No worries, though (it's apparent that your intentions were generally positive... plus, I'm human too ). In any case, I think tby Joshua Merchant - General
Demented Chihuahua Wrote: ------------------------------------------------------- > Doesn't need a membrane. The air is vented out the > hopper end. The pressure forces the air back up > the screw. You basically have a static air > situation. No air really goes in, and no air > really goes out. Just forces the beads together > and voila! extrudate! > > Actually, it's wayby Joshua Merchant - Mechanics
Kyle Corbitt Wrote: ------------------------------------------------------- > Interesting, just came across this story in Hack a > Day: > > rinted-circuit-boards/ > > While it is less than ideal, getting a laser diode > that can etch black spraypaint may be easier than > trying to get a working milling head. > > Both processes are messy - milling gets fine dust &gby Joshua Merchant - Plastic Extruder Working Group
Kyle Corbitt Wrote: ------------------------------------------------------- > You're ordering PTFE tape from McMaster? > > It ought to be available for cheap in most > hardware or plumbing stores, assuming you're in > the U.S. or some other western country. Sure, but is it "Super Slick"? The stuff from McMaster is $8.40 per 5yd roll because it's a 1" wide specialty tape. They doby Joshua Merchant - Mechanics
Andromodon Wrote: ------------------------------------------------------- > Demented Chihuahua Wrote: > > It just requires a > > shit ton of force to squeeze the air bubbles > out > > of stuff and the drive screw provides the > needed > > mechanical advantage. > > Where does the air go anyway, is there some sort > of membrane or gap that can pass air buby Joshua Merchant - Mechanics
Kyle Corbitt Wrote: ------------------------------------------------------- > By all means, try it and report back whether it > works. It has been a long time since I have used > PTFE tape - does it feel physically slippery? If > so, I think you've got a reasonable chance of > success. No idea. Up until today, my entire involvement with the RepRap project has been limited to theby Joshua Merchant - Mechanics
Lot's of interesting ideas. I've decided that I'm not going to order any special parts for the coupling (yet, but I don't think I will eventually either), as this is a bootstrap extruder and I'm trying to make it reasonably simple. I'll take a small piece of scrap (wood, probably) and cut it to a square cuboid (square prism). On one side I'll cut a rectangular slit for the GM3's output shaft,by Joshua Merchant - Mechanics
Demented Chihuahua Wrote: ------------------------------------------------------- > IMO the plywood would be flat/smooth enough if you > sanded it before installing and didn't torque > those bolts down too hard. Excellent. > Keep in mind, however, > that I'm only speaking to building a machine good > enough to print the parts for a Darwin. I've had > exactly zero problems witby Joshua Merchant - Mechanics
sid Wrote: ------------------------------------------------------- > $4 each? > > I got a set of 16 from ebay for about $12 (10 Eur > to be precise) > > 'sid Well, I found these for $0.59 each. 16 would cost $9.44 plus around $6 shipping. I doubt quality at such prices, although if RRRF is not an option, this would be my next choice.by Joshua Merchant - Reprappers
Using non-RP parts, what's the best way to attach a GM3 to a M6 drive screw? I'm not quite clear on the output shaft's shape, etc, and seems to be experiencing some technical difficulties. The five types of drive screws I'm considering are: 1) M6 studding, with no head (#93805A333) 2) M6 hex bolt (#93635A241 or #91287A346) 3) M6 machine screw, philips head (#92000A444) 4) M6 machine screw, slotby Joshua Merchant - Mechanics
A bit of a cool idea I came up with while refining my extruder parts list: Instead of bolting the PTFE strips onto the wood rails (with 0-80 flathead screws), perhaps I could use the "Super-Slick Tape Made with Teflonby Joshua Merchant - Mechanics
Yeah, but I liked the pricing and simplicity. I was already buying from RRRF so it would save me time and money (both in shipping and the fact that they bulk-ordered). I can just order from McMaster at $4.06 each (#5972K36) or buy from some specialty store for around $1 each (lower quality probably). ...I'd still like to know if/when RRRF is restocking them though.by Joshua Merchant - Reprappers
I'm buying the majority of my Seedling parts this weekend (the ones ordered online to be shipped on Monday, hopefully), and I noticed that the RRRF store is out of skate bearings. I need the 16 required for the McWire. Anyone know when/if they are going to get more in? Or should I try to find another supplier for them? Thanks!by Joshua Merchant - Reprappers