mccoyn, The board looks really good, nice tight design and logically laid out. I would still recommend a bigger chip (and possibly 20Mhz crystal) to have enough extra pins to handle a bed heater, and maybe a second extruder head. Look at Mouser ATMega1284-PU . This is a 128Kbyte flash, 16Kbyte RAM, 20Mhz in a 40 pin DIP that still has 32 pins open plus a total of 4 counter/timers to set a diffeby rocket_scientist - Controllers
That would also work well with the steel wire cable I was thinking of using for a new McWire design I am trying to call Mike Wire. I had already though of using a tension spring to close the loop in the drive cable. This would take up less room that could not go around any pulleys. Speaking of which, where did you find the plastic pulley you are using there? And what of the drive pulley attachedby rocket_scientist - General
I also bought an Arduino Mega to use controlling a McWire, all four stepper motorts and the extruder heater. Will it be easier to adapted existing code for this single micro approach to controlling everything, or would I be better off just starting from scratch? Mikeby rocket_scientist - Controllers
You are farther along then I am. I may decide to jump on _your_ bandwagon rather then re-invent the wheel again myself. I am on a different listserver for the gEDA open source schematic capture and PCB layout software. Some just asked where is the best place to get prototypes done, and BatchPCB is one of the ones mentioned. Once you get the bugs worked out, there are also Chinese companies withby rocket_scientist - Controllers
I have been posting all over the place, but I have some newcomer questions, too What 3D CAD drawing program are we using? Is there any prefered one, or does everyone scrape up what they can as long as it output DXF files? Once we have a 3D model, how does it get converted from DXF to something that a reprap can use? I hear a lot about g-code, and I am guessing that g-code runs on the microcontrby rocket_scientist - General
EDIT: replaced MOSFETS with Allegro A3977 stepper drivers mccoyn, to save money, I am planning on starting with a raw ATMega128 instead of an Adruino, and also A3977 stepper controller modules. That means 1 A3977 per motor for a bipolar stepper motor, 2 MOSFETS for the extreuder heater, and possibly one for a bead heater. But from Mouser or Digikey, the ATMega is about $3, the MSOFETs aboutby rocket_scientist - General
Stoffel, Your English is FAR FAR better than I can speak any other language. And that is after studying spanish in grade school and 3 years of russian in college! You have absolutely nothing to apologize for. I just need to figure out how to get google to translate the page for me, cause the extruder graphic looks good! Mike Stoffel15 Wrote: ------------------------------------------------by rocket_scientist - General
Sebastian, clear and focused thinking, once again. How about suggestions on where to air the dirty laundry? With such a diverse group of self-motivated(to varying degrees) and quite creative minds, it is inevitable that arguments from the best screw size to use at location X of to who should be leading this group and what they should be doing. The small stuff is not a problem int he frequentlyby rocket_scientist - Administration, Announcements, Policy
Lengertoes, I agree with you completely. Even though I have not yet had time to start building mine, I am coming to understand the bits and pieces and way it operates better, and I am now confident that I can not only build it, but improve the documentation and performance. MDF sounds like a good idea, but one advantage of the pipe or welded square tubing is leaving the front and sides openby rocket_scientist - General
I threw in a few things while someone else was editing too. I like the Wikipedia diagram, it makes it seem at little more possible to build one. Mikeby rocket_scientist - General
Sebastien, In my inflated ego, I am thinking of calling my revision of the McWire with wire cable drive instead of threaded rod the "MikeWire". It should speed it up to what ever speed the extruder can handle, and should make it about as fast as a Mendel. I still have a Regional Robotics Competition to mentor this weekend, then I will work on building and documenting my version of the McWire. Iby rocket_scientist - General
I have often heard of heat treated aluminum, but was never taught the secrets. Here is what I found with a little Googling: Racing Pistons T6 They talk of a two phase process. Phase one is heat to 920F (493C) for 9 hours to allow the copper in the alloy to fuse with the aluminum. The water quench down to room temp. The second phase is to 'age' the alloy at 350F (177C) for 10 hours to allow the Aby rocket_scientist - General
Well, there is aluminum, and then there is aluminum. Heat treated aluminum, know in the states as 6061 T6 aluminum is heat treated to be very strong and stiff. Even in thickness of 3mm or less, it is very hard to bend, and forcing a 90 degree bend may cause it to crack. If you can find some 6061 T6 in 6mm thickness, I think you will never have a bent plate again! Mikeby rocket_scientist - General
I am just about to start building my McWire. I think I have all the parts in house. I have heard the complaints about the design being slow, and I will experiment with using inexpensive steel wire cable instead of 1/4-20 threaded rod/studding. The earlier comments are correct. The basic NEMA 17 stepper motors (there are variations, including the depth of the motor, so watch carefully when yoby rocket_scientist - Stepper Motors, Servo Motors, DC Motors
Speaking of alternative methods, I believe that one of the ways wires inside a, IC package are connected from pins to silicon is to press the wire against the pad and then vibrate it at ultrasonic speeds. The rubbing motion then melts and fuses the wire to the pad. This is for extremely thin wires, so I am not sure how well it will scale up to wire sizes safely used by reprap machines, but it wouby rocket_scientist - Wire and Thread Embedded Extrusion
Anybody have a 3D model of that that we can print out?by rocket_scientist - Kartik M. Gada Humanitarian Innovation Prize
sircastor, I was thinking about modifying the wiki and/or pdf to have choices and subsections. Like for instance, the black iron pipe is easy to find anywhere, but all the pieces add up in cost. If you have access to tools, and know someone who can weld, it should be both cheaper and stronger to make the whole frame from one piece 1" square box tubing cut to lengths and welded together. Also soby rocket_scientist - General
At the bottom of each post, there is a tool bar with several buttons. Under your own messages, it should include an 'edit' button. Hover your mouse over the word edit, wait for the pointer to change to a link following finger, then click. You will get just that message on a new screen so that you can change any part of it. As a courtesy to others, if you make a major change in your post so thby rocket_scientist - Administration, Announcements, Policy
For us lazy folks, would it be possible to put a second copy of the back to forum and back list of forums buttons on the bottom of each thread? Some of the posts (mine especially) can get quite long, and by the time I have waded through all that text, I don't want to have to wade back up again to get back to the top to click on the forum name again to look for the next thread I want to read. I guby rocket_scientist - Administration, Announcements, Policy
Victor, fascinating idea, using Lasers or power LEDs to cut, solder, and/or fuse the wires. What type of wire are you working with right now? Steel/iron wire has a moderate thermal conductivity, so it pulls heat away from the point you are trying to cut rather slowly. But steel has a very high melting point. Copper as a melting point a little of half that of steel, but it has such a high therby rocket_scientist - Wire and Thread Embedded Extrusion
ybayless, If you look inside the box of a MIG or wire feed welder, you will find exactly the system you are talking about! They push 6 feet (2 meters) of wire down a narrow tube inside the welding cable AFTER it has gone through their pinch roller system! And they use only one driven wheel and one idler wheel. They do have channels cut in the idler wheel to max the diameter of the wire going ouby rocket_scientist - Wire and Thread Embedded Extrusion
Gene, The concept I am currently working with for my own next-gen entry in the Gada prize would have plastic beam trusses capped with metal strips to provide high tensile strength and low creep. They are: 1) So one thing to make right off the bat would be long thin strips of aluminum, possibly with built in pins or fasteners. 2) The next is that the moving stages, whether the bed or gantry,by rocket_scientist - Kartik M. Gada Humanitarian Innovation Prize
Anton, Thanks for the reassurance! In the week since I have joined, I have been fire-hosing the forums with ideas, none of which I have the time or equipment to test yet. I am collecting materials for a McWire, and have most of the non-RP parts for a Mendel to follow, but until the team I am mentoring finish their FIRST Robotics Challenge Regional Competition, there will be no time for reprapby rocket_scientist - General
EDIT: Ignore bottom of post. Late at night, missunderstoud Triffid's post. Yes, using a layer of ABS instead of toner to print directly onto the copper should work fine. It will be more water (acid) proof than the toner, but as you pointed out, probably not a finely detailed. The main advantage is it does part of the job on a reprap without requiring a special head. But if a reprap had a milby rocket_scientist - General
Thats good because the Kapton tape, expensive as it is, is still cheaper than Teflon tape with adhesive! OK, I give. First project will use Kapton sheet on the bed. If I ever get there! Still have to finish helping the High School team in First Robotics Challenge Regionals, then there is the under water robotics challenge in June . . . Mikeby rocket_scientist - General
nophead, quite true. I was thinking more of an enclosed machine, or like what I am planning for Open Air 1, a stationary table and moving gantry head. However, it is also possible to heat the outer most squares hotter than the inner ones to partially make up for the plastic there being more exposed. I was also thinking that using cheap, carbon resistors on each square of the heater, then plby rocket_scientist - General
Sounds like a call for _immediate_ testing! Pity I don't have a machine yet, just piles of boxes of parts! You might try this from Amazon.com to start with. Mikeby rocket_scientist - General
sircaster, you have the matter correct. Where I tend to think we should stick with the laser printer is two areas. The modern laser printers currently have about 600 dots per inch resolution and accuracy. That is about 1.6 mills per dot. The is right around the mechanical resolution of our reprap machines. If you only add toned where needed, it will be hard to get the powder to stay in such tby rocket_scientist - General
dissidence, I must disagree with you on that one. Cast Iron pots will always have worse hot spots than aluminum of the same thickness. If you look at modern cookware, the aluminum pots and pans are thick, but not quite as thick as the cast iron. And anyone who has rounded the corner of a piece of aluminum on a grinder or sander knows just how good a heat conductor, in _every_ direction, alumiby rocket_scientist - General
No, Wade, I was completely ignorant of the whole forum. I will switch to writing there. I have been pulling ideas out of my original GADA forum team submission posts to make less confusing, individual titled discussions on each idea. But I have only just found this forum last Thursday, and have not read all the sections yet. VDX, that looks like a fun expansion item to add! Mikeby rocket_scientist - Kartik M. Gada Humanitarian Innovation Prize