I have a large quantity of 3/8- 16tpi threaded rod w/ a major diameter of about 0.355 inches. 0.355 inches = 9.01700 millimeters I've got the standard mendel parts on the way. Does anyone foresee any issues with drilling out the parts to just over 9 mm and using my rod? I have not ordered washers and nuts yet.by pica - General
Are there any reprap PCBs up at batchpcb.com besides Brief: Breakout board for 4 SparkFun EasyDriver boards, with RepRap & MakerBot compatible connectors I'd try to u/l the Makebot open source boards if someone could nudge me in the right direction. I'm running Ubuntu and have not tried any PCB software yet.by pica - General
I'd try putting it in a vise, with the gear on top of the jaws and the vise NOT clamped tight to the shaft. You want close, but not touching the shaft. You want the edge of the vise on the metal insert, not on the plastic. Now take a punch and hammer and tap downward on the stepper shaft. You should be able to get it off and save both parts for re-useby pica - Mechanics
Bad topic title, I usually skip over these types. But a very good question. I've picked up complete, ready to use, P-III computers up off the curb on trash day. I'd be happy to commit one to running a bunch of steppers, running the PC headless and sending commands via the ethernet port built into the mobo. Your power usage would be more, but the cost of power in the developed world means that tby pica - General
>I can do it myself without much cost or equipment. I've seen the price on Brownells cheap kit. You could by a lot of stainless smooth rod with that. Maybe you mean "rust bluing"? Maybe you plan to farm it out? Maybe you already have all the gear, and you mean "not much more cost or equipment beyond what I've already sunk"?by pica - General
well, that's obviously not the picture of the device on sale. But I'm guessing that this is allowed usage of the photo under the license? I can't read the text to know if the seller is claiming that you get what's in the photo. For all I know it says "monitor not included" ;-)by pica - General
> I don't really see the need for two identical > extruder heads... How about printing two objects that are exactly alike at the same time? How much are those Medel kits going for on ebay? What would it mean to make parts twice as fast? Or twice as likely to have a successful print?by pica - Mechanics
no idea with your specific issue, but I use to test push-rods for straightness by rolling them on a piece of float glass (ordinary window glass, a mirror will work too). Float glass is supposed to be flat to a few thousands of an inch.by pica - General Mendel Topics
I was surprised to see those MDF triangle pieces. They are very close to my sketches for my repstrap. By using the triangles you remove 6 printed parts from the build with two parts that should be able to be fabbed without anything anywhere near as complex as a laser cutter. My sketches left more "meat" on the triangles by only cutting out a rectangle for the hole. I also plan on making the holby pica - General
I was thinking along the same lines today, but actually I found a supplier of Zytel in granule form (bookmarked on laptop, I don't have it handy) Here's an interesting link: ..because the supplier and Dupont are both touting "low-warp Zytel" (which seems like just the ticket for printable plastic.) The worst issue I see is the high melt point (which can be significantly higher than ABSby pica - General
great job! I myself am planning a mini-Mendel inspired repstrap, and as I have to do a bit more work than just bolting things together. A document that explains all the approaches taken (like the section on different designs of extruder) is enormously helpful to keep from either reinventing the wheel or reading through elevendy thousand threads and blog posts I originally was going to go withby pica - General
mccoyn Thanks for checking my math. I see size is not an issue. krafter Agree , "Bright mild steel rod" seems very close to the "drill rod" you found at mcmaster-carr. I'll probably go that route when I try for a mini-mendel inspired repstrap. Quite a cost savings. I was thinking of cutting a part of an automobile shock (stainless steel, hardened, ground smooth) to use for the z-axis, but Iby pica - General
Quote krafter 8888K41 - 5/16" bar, 3 feet length, A2 tool steel, $8.37 each On the last item I am evaluating to see if the 5/16" bar works as a substitute for the 8mm stuff. Its pretty close 0.0625 inch smaller than 8 mm 0.0625 inch = 1.5875 millimeters The substitute is not hardened, in fact it says it's annealed. I don't know if that will make a difference in the long run with bearings,by pica - General
BTW, you can put the details behind the part number, and it will still paste in fine: 1 90576A102 mcmaster.com, m3-nylock.par 100 pack 2 91166A210 mcmaster.com, m3-washer.par 100 pack 1 90591A141 mcmaster.com, m4-nut.par 100 pack 2 90576A103 mcmaster.com, m4-nylock.par 100 pack ... no need to use "#" or anything, everything past the part number is ignored.by pica - General
406+330=736 buy a 800 mm 6112K15 instead at $20.41 (save $12.27) 406+330=736 buy a 800 mm 6112K15 instead at $20.41 (save $12.27) 475+475=950 buy the 1200 total $24.54 in savingsby pica - General
Quotesircastor I like this idea. Are you considering a genuine signature from the core members, or simply a copied signature. The latter would certainly be a lot easier to do. Now there's an idea. Get a Mendal, except replace the steppers with rotary encoders. Replace the extruder with a pen. While watching and recording the encoders, grasp the pen and sign your name. replace the steppers and plby pica - General
To follow up on a positive note, here are a few ideas I'm tossing around to cut the cost on my Mendel construct the frame out of angle iron which I keep finding near dumpsters (as bed frame) and carting home. (Mend-angle anyone?) use part of a used shock absorber for the Z-axis rod. It's stainless steel, ground smooth, and dimensionally stable. The only issue is that it's thick and short. Direcby pica - Mechanics
100 608ZZ for $34.95 plus shipping (US based) M8x1.25 cap screws 25mm long, 50@$8.85 plus shipping (US based) The specs say 624 bearings for most of the machine, so these aren't exact fit, but it sounds like you are deviating from the plans anyway. At these prices, unless you need it now, I think you are crazy to go to the hardware store for supplies. Doubly so since you talk of drilling oby pica - Mechanics
You'll really want to beg, borrow, buy or steal a DMM, ohm meter or the like. I picked up two of the cheapest DMMs at Harbor Freight a few days ago (US store for all things tool related specializing in cheap Chinese copycat tools, many of them are quite good for the money) They were on sale for US $4 each. I assume it should be sufficent to built all the electronics and test the random unmarkedby pica - General
pretty much answers my original question. (sorry for the bump, but in the interest of completeness...)by pica - Mechanics
From reading only, I've seen a few projects that need to be paused at some point and a captive nut inserted. Anyone else?by pica - Controllers
>you've skipped a carry or something, (200 * .1) / 3.14 = 6.37 mm diameter. Yes you found my mistake. Maybe i'm missing a link to all the Mendel parts shown as isometric drawings and measurements. That way I could look at the parts myself and grok any gear ratios. My question was actually "how does Mendel get the .1 mm positioning accuracy? Is it micro-stepping? or maybe there's a gear somby pica - Mechanics
How does cleaning the nozzle work? Is this just a place to squirt extra plastic or is there an add-on somewhat like a precisely placed upturned pin that Mendel can move over to and clean out the extruder under automatic control?by pica - Mechanics
(big picture of Mendel) There's a notch in the bed table, like it was a clearance cut for a stepper or something, but I can't see why it's there. Sorry for all the questions, but I'll be attempting a RepStrap and I'll have to translate the design decisions over to wise choices in my material of choice. I'm probably going to go with a scaled up version of Mendel, using angle iron as the strucby pica - Mechanics
The x axis seems to be a gear mounted on a stepper with several idlers and directly driving the extruder. Assuming 200 steps per revolution of the stepper, you would get a tenth of a millimeter per step by sizing the gear on the stepper to have a circumference of .1 x 200 mm or a diameter of 20/3.14 = 63.7 mm (which seems reasonable from what I can see) Am I on target here or are you doing half-by pica - Mechanics
>glossy magazine paper is far more available and has pretty much the same effect. Yes, we're on the same page :-) glossy slick magazine paper is almost always "clay coated" I used to be a short-run digital press operator. Look up the "pica" in the dictionary and you'll see my points. All 12 of them :-) (for the record, I also like spicy food :-) >toner transfer works by melting the tonby pica - RepRap Host
sorry, Thanks jbayless, looks good.by pica - RepRap Host
Looks good, Triffid_Hunter. This could be such a boon to repstrappers. Why hasn't this been done yet and put on the wiki? I wonder if I could print this out on clay coated paper and iron the toner right onto say some white cutting boards for drilling and stock removal? I prefer letter, being in the US.by pica - RepRap Host
I'm in the planning stages of a repstrap. I've been checking the surplus sources available to me and I note a glut of cheap steppers with only one issue, the stock voltage is either 24 or 36 volts. I was looking at the controller boards, and I was thinking I could lift a trace that's used to feed the steppers 12 volts and then just bolt a 24 volt power supply right next to the ATX, I could makeby pica - Controllers