BeagleFury Wrote: ------------------------------------------------------- > Triffid_Hunter Wrote: > -------------------------------------------------- > ----- > > problem with screws is that harder plastics > (ABS?) > > will crack under the force that a self tapper > > exerts > > Wear gloves, and heat the screw in a candle before > screwing it in. That wouby jgilmore - Mechanics
Have you considered refiting your McWire with belts drive? That would solve your speed issue. And it would also be easier than redesigning the mendel to use all off-the-shelf parts. This is a McWire modification that I'm seriously looking at.by jgilmore - General
Part of the point of and endstop is electronics level crash protection. I.E. if the min endstop is hit, the electronics won't allow the motor to turn anymore in that direction, even if the firmware says "keep going". Also the firmware level stuff is MUCH simpler to write with safety in mind that way. Since the only real point in having a max endstop is safety, there's not much point in combiningby jgilmore - Controllers
Personally, I think almost all of the nuts/bolts need to be switched out for screws. Drywall screws as spec'd for the McWire would work great, and I think are available cheap worldwide? Since the diameter and length don't have to be exact, and the threads are self-cutting, I'd think any approximately correct wood screw would work. But again, you'd need to modify the STL's and print modified partby jgilmore - Mechanics
Forrest, I thought you'd given it up because the pinch wheel thing was working so well, not technical difficulties. My first thought right after "it's getting dull" would have been "Let's heat-treat it."by jgilmore - General
Good question. I'd like to know that one myself. I think, though, that most of us Americans are just ordering the (more expensive) metric parts. No real reason to though. Except that nobody's figured it out and posted it yet.by jgilmore - Mechanics
For the gen5 they seem to be looking at some pretty hefty processors - the one they said they liked the best had 64MB RAM! IMHO, nothing like that strong a processor is needed, and it'll just add cost. Personally, I think we'll end up with something like the Xduino. The chips range from around $5 to around $15, so it's about the same pricepoint has the atmel's we're using. It has plenty of I/Oby jgilmore - Next Wave Electronics Working Group
Forrest Higgs was looking at 1/2" diameter nuts. Doing essentially the same thing, but with a large nut instead of a small threaded insert. As I recall, one of the issues he had with it was twisting the filament. This was also something of an issue with the threaded-rod based extruders. There was even mention of getting a nut with a left-hand thread and using both to avoid twisting the filament.by jgilmore - General
You can order insulators and heater barrels from reifsnyderb but he's in the US. That doesn't cover the RP parts for the extruder, of course.by jgilmore - Plastic Extruder Working Group
For $200 you may not be able to get what you need. It may help to think of the reprap as four systems: Electronics Motors Cartesian Robot Extruder You CAN probably get the electronics and motors for that price - makerbot and www.alltronics.com. Pololu's stepper driver is a good price and liable to be more available, though it does require heatsinking. The parts for a McWire cartesian bot, whicby jgilmore - Wanted
spacexula Wrote: ------------------------------------------------------- > Andros1200 Wrote: > -------------------------------------------------- > ----- > > I thought it was by tradition that you would > print > > off atleast 2 more sets when you finished your > > Mendal. > > That's the promise that is rarely delivered upon. > > 60-80 hours is a lot ofby jgilmore - Wanted
I second the suggestion to build a McWire. It's a much easier cartesian robot to build from locally sourced parts than the mendel design. Note that the firmware, electronics, and stepper motors should be mendel's. That way you can swap out the robot frame for mendel's later if needed.by jgilmore - Reprappers
I think those "optional" files really are optional. Usually a filename ending in "rc" is a configuration file - i.e. where you put your personal configuration preferences. Having said that, it DOES seem to be insisting on finding "gafrc". You might try "apt-cache search gafrc" which will search in all software modules that your system knows are available for automatic install. Doesn't show anythby jgilmore - Reprappers
Linux is always better. On a more serious note, I haven't used windows for years and years, but I hear the reprap software, skienforge, replicatorG, arduino compile etc. works fine under windows. So in theory there's really nothing much to choose between them, and you should pick whatever you're most comfortable using. Asking such a question is somewhat akin to "which is better, vim or emacs?"by jgilmore - General
goinreverse Wrote: ------------------------------------------------------- > Anything regarding the reprap software is a > complete waste of time in my opinion. It is one of > the worst pieces of software I have ever seen and > the documentation takes you in 500 different > directions. Use replicatorG, it auto-updates > firmware for both the sanguino and extruder > controllerby jgilmore - General
Presumably the SVN version of the STL files was updated - after all, how else could a change have been made? That being the case, the instructions for using that particular part should have been changed. Perhaps each part in SVN should have a "instructions for this part" with it in SVN? It would then be blindingly obvious that when you change the STL, you should update the instructions with it,by jgilmore - Administration, Announcements, Policy
Motors are funny things when it comes to Ohm's law. The current you derive from measuring the resistance of the coils is the "stall current" which is the maximum current the motor can ever draw. If the motor is held motionless, it will actually draw this current, and quickly burn up. When the motor spins freely, the situation is different - the induction in the coils causes the current to ramp upby jgilmore - Controllers
I wouldn't think you'd need a drill press - a hand drill and a table vise should do the trick. Mounting the tip in the drill and the drill bit in the vise would probably work best... If the sides of the tip are all slanted, the drill chuck may not get a good enough grip, I suppose.by jgilmore - Mechanics
Thank you, reading your post gives me warm fuzzy feelings... I do remember one reason NOT to attach it too firmly though. If the motor is driven beyond the endstops, the hose should be able to pull off, providing a harmless failure mode. If it is attached too firmly, you'd end up damaging something else - bending the motor mount, crushing the MDF/acrylic, ripping the trapped nut off, etc. So eiby jgilmore - Mechanics
The question of maximum build speed is an interesting one. I've been thinking of a large printer - one capable of printing, for instance, a full-sized rocking chair. Obviously, it would take a LONG TIME unless the extrudate was quite a bit thicker - 1mm minimum or something. Maybe even a full 3mm... a granule extruder might make much more sense for that beast than it does for our current size. Gby jgilmore - Mechanics
goinreverse Wrote: ------------------------------------------------------- > *Tolerances on the mcwire are huge, the design is > simple enough that you can butcher pretty much > everything and still get by. I way over-thought > the whole thing. HAH! You're not kidding! You should see the heap of complete trash that I got to work - and it functions just fine. I did take SOME effort toby jgilmore - General
To get a 6.35mm hole exactly in the center of your 10mm bolt, you need to put the 10mm bolt in your hand drill, the 6.35mm drill bit in a table vise, and drill into it that way. You can easily tell if it's precisely centered or not, as it will shake/vibrate if you try to drill off center. It will also auto-center to some degree when you try to hold it steady. If you don't have a table vise, youby jgilmore - General
I think the excellent support by the universally available gcc suite was a primary motivating factor. The sdcc compiler which was being used for the pic software didn't work too well. I suppose that the old forum stuff with complaints about it and discussion of the move are still around.by jgilmore - Controllers
You may be trying to drive the stepper too fast. There is also a MAX_X_SPEED or something, that is used for G0 moves. If this is set to high, and the steps per mm is also high, then the firmware will try to drive the steppers VERY FAST, resulting in no movement at all. The solution would be two-fold. First, reduce the max speed settings in the firmware. This takes care of G0 moves, but normal (Gby jgilmore - Controllers
I think that most people that set out to get a mendel go the repstrap route - build a McWire, or a extruder to mount on a traditional (or nontraditional) CNC machine, or buy a makerbot, or... Point being that it's a difficult thing to build without already having one, and the usual way around this is to built something that's not a darwin/mendel but can print the parts for a darwin/mendel. Commeby jgilmore - Reprappers
There's some very good reasons to use a flexible coupler like the aquarium tubing. If you use a connector that doesn't flex, you'll put a great deal of extra stress on the bearings and motor. I used fuel line tubing from the auto shop. It worked OK except for the Z stage, where it didn't grip well enough to hold the Z stage up. So I clamped it on both ends with a twist of bailing wire. Works finby jgilmore - Mechanics
I second BodgeIt's vote for the separation of firmware from software. I'd go even further and suggest separation of reprap host from EMC2 from Skeinforge from firmware. I have zero interest in the reprap host software - I dislike java, and since the skeinforge toolchain doesn't use it, I'm going to use that... Using a make file instead of the "arduino enviroment" to compile the firmware is a smaby jgilmore - RepRap Host
I'm going the McWire->mendel route (or trying to) myself. The reasons that I have for making a mendel even after I get the McWire working enough to print out all the parts for a mendel include but are not limited to the following: 1. Speed. The McWire uses threaded rod, and is slow. Unless I upgrade it to belt drive, which I'm seriously considering trying to do before my extruder is even workby jgilmore - General
If your motor needs a higher voltage, you can still use it, but will need to get a different power supply as a computer power supply doesn't do anything higher than 12 volts. Also, you'll have to change the controlling electronics to handle the higher voltage, which may mean getting a different driver board for them (like pololu.com's A4983 stepper driver breakout board). That may or may not bby jgilmore - Controllers
You also don't have to use acrylic. I used MDF for the large pieces and sections of aluminum bar for the small ones. It seems to work fine. I'll probably have to use something else as a build surface, but for the cartesian robot parts, MDF did the job.by jgilmore - General