Could someone please scale the image to 8.5 x 11 paper and post it to the y-axis wiki page, please? I've been trying to do the scaling myself and getting more and more frustrated! ARRRRRGGGHHHH!by Buback - General Mendel Topics
Perhaps a homemade rotary encoder below the idler wheel of the extruder? if the filament jams in the hot end it wouldn't spin the encoder, and if it doesn't match the movement of the stepper it could trigger a shutdown. not really a simple solution, though.by Buback - General
yes, thank you, i have, but i didn't think the software worked in this way. I was actually going to post about this in that topic but didn't want to distract from Reece's software. It seems like Reece's software determines a silhouette in software, and from your example picture, it needs some refining before it's generally usable. using an actually silhouette might be more accurate? I'm also thby Buback - 3D Scanners, Book Scanners, and Optics
well here's something i just found myself: Generating NURBS Surfaces through 3D Silhouette Scanningby Buback - 3D Scanners, Book Scanners, and Optics
are there any projects out there that use the silhouette of an object to form a 3d model? it would not capture concave details like an open mouth or hole, but it would capture both sides of an object 180 degrees opposed. you would then have more data points with which to combine meshes (i.e. this method would create a base model on which you could lay laser scanned meshes. i've attached a simplby Buback - 3D Scanners, Book Scanners, and Optics
Why does the plastic stick to a heated bed and not at cold bed? (like nophead's experiments with glass beds) Another critical property is ease of release. Has anybody tried a coated bed? I'm envisioning a spray on coating that adheres to the bed and plastic (perhaps with different forces), forming a strong, thin layer between the two, but can then be washed away to remove the parts.by Buback - Polymer Working Group
As i understand it, if you run the extruder faster than nomal, the filament will swell after exiting the nozzle orifice. So, a .5 mm filament can swell to .7 mm. it's not a lot of room to play with, but taking advantage of the swell for infill should give a couple percentage points decrease in build time.by Buback - General
I'm still waiting on some parts, but I got the CF tubes in yesterday. wow they are light! (I got 2 48 " lengths of tubing, so i had to cut the axies a couple mm short each. weight is for length listed) x axis - 493 mm - 16 g y axis - 404 mm - 13 g z axis - 328 mm - 10 g I have a length of chromed steel i got out of a printer that is 435 mm (so between x and y) and it is 171 g! The main concerby Buback - General Mendel Topics
What forces make an extruded plastic stick to a build surface? I'm guessing it's different factors for different plastics, but it would be good to spell out, for each plastic, what makes it stick to the best current build surface. I'm sure there are polymer experts in the forums that can answer the question.by Buback - Polymer Working Group
One thing you could do is print rough blanks. They would be in the general shape of the figure, but you (or the user) would have to carve out the details. the plastic is easy to cut; if you are a good whittler it would be easy. (actually, it would be a lot of work, but at least the user has the option.)by Buback - General
I got the aerogel in today! I have to wait till I make an extruder before I can do any testing on the machine, but i will start playing with it. First impressions: it's hard to see! the picture below are played with a bit so it's easier to distinguish. It's also dusty; if i stick my finger into the bottle, it comes out with a fuzzy white sheen all over it. i'll have to get a dust mask (which i haby Buback - Plastic Extruder Working Group
It's not so much a question of resolution, but rather build method. you can get higher resolution by using a smaller orifice and higher gearing. anything hanging in air, like the scythe, is hard with thermoplastic extrusion. it would require lots of support structure. A powder bed machine would be much better at building these types of models.by Buback - General
ok i'm on my lunch break so no time to model. here's a napkin drawing. (edit: link works now) before, i was thinking taped holes to hold the block together, but with the compression fitting i would need a bolt and nut like Greg Frost has. If you have the tools, trapped nuts would be better. (edit: actually you could just tap the bottom layer, duh) I also decided to have the orifice screw intoby Buback - General
The smallest test tubes I can find are 10mm diameter. Way too large. I'm not sure the rim on a test tube is large enough anyway. I would like something with a 3-5 mm flange to give a large mating area for a gasket. I can't seem to find anything that fits the bill. If rocket_scientist or someone with borosilicate would be kind enough to send me a tube with a flange as described, I would build anby Buback - General
yeah i agree Craig. I've been building computers since the 386 days. Back then (1988) installing a hard drive took all day, if not a weekend. That was with help from my uncle, who worked at NCR (so was a pro). I'd say the reprap project is at a similar stage. I think if you can't build and fix your own computer you probably shouldn't attempt to build a reprap. there are lots of similar skills,by Buback - General
yeah you are probably right. there would need to be some sort of gasket material to prevent leakage. Would high temp solder work?by Buback - General
Greg Frost could not source a block of aluminum for a block heater, so made one from a stack of 3mm aluminum rectangles. Here's a picture he posted of his heater. This got me thinking. here is what i came up with: The nozzle would be drilled directly into the bottom plate using a countersink bit, so no need for a lathe! (in fact there's a perfect dremel bit for this) A flange would be easieby Buback - General
I've been ripping apart old printers for parts, and they have lots of rubber grippers to pull paper through the machine. many of them are on 5mm shafts. If you can get your hands on an old printer or two I'm sure you would find something to experiment with. I'd be interested in the results.by Buback - General
I'd assume it's top and bottom, so elongating the slots slightly is the easiest solution. my RP parts needed extensive filing. It's a little painful on the fingers and it's slow, but you can use the a M4x40mm as the perfect size file. You probably only need to extend the slots a couple tenths of a mm.by Buback - General Mendel Topics
currently, the documentation is no worse than any lego kit i got as a kid. those instructions only had pictures, if any of you remember. the mechanical construction is pretty straightforward so far. i expect the software and electronics are a bit harder. I've been taking pictures as i go when i figure out something that isn't documented. I'll go through those when I'm done and post them to the wby Buback - General
I'm going to try extruded CF tubes, instead of rods. they have a 2 mm wall thickness, so i hope they'll be strong enough. I'll post an update once my mendel is up and working.by Buback - General Mendel Topics
yeah i also just paid $200 for ABS parts (Inc wade's extruder). Approximately how much do parts weigh? I'm wondering how much raw plastic it takes to build a complete set. i'd weigh them, but i'm half assembled already. i'm thinking the price will settle at: cost of materials + print time + 10%? + shipping.by Buback - General
Do you have any of your experiments up online? i'd be interested to read about what you've done with it so far.by Buback - Plastic Extruder Working Group
How do they compare to aerogel as an insulator? I thought silica aerogel was the best besides a vacuum. a solid piece of aerogel formed to go around a block heater would be the ideal setup. if my experiment is promising i'll learn how to do this for the next step.by Buback - Plastic Extruder Working Group
I'm new here too, but all this stuff is covered in the wiki already. You will probably spend too much money and time going down wrong paths unless you spend at least a week reading the wiki.by Buback - General
I just ordered some aerogel granules from here. I'm going to try using it to insulate the hot end. my idea for how to attach the granules: 1- pour the granules onto some aluminum foil 2- put the hot end assembly onto the granules 3- wrap up the foil a bit, then cover the hot end with more granules. 4- finish wrapping up the pile of stuff so that there's a big ball on the end of the extruder shouby Buback - Plastic Extruder Working Group
We should get in touch with johnny lee of wiimote fame. we could mount some IR LEDs onto the x carriage or extruder and just use a spare wiimote (if you have a wii). a cheap webcam would be ideal, but the wiimote would be great for experimentation.by Buback - General
Great news! You can be our guinea pig, unless someone else beat you to the punch and is using them in a working machine. Are they solid rod or tubes?by Buback - General Mendel Topics
Has anybody tried this? I've found this store that has ~8mm tubing. it's lighter, which might mean we can use smaller motors or move the head faster with the existing ones. it might be cheaper for similar tolerances. There are two questions: 1) Is it rigid enough? 2) How long will it last? 1) This question can be easily answered. Someone with a machine needs to order some and replace theiby Buback - General Mendel Topics