Heh, I stop paying attention to the reprap project for a bit and come back to find a whole new generation of electronics. I am very pleased with the choice of RS485, I always thought something like that would be the right way to go. I just have one suggestion that I think will help us out in the long run and can be implemented in a fully backwards compatable way with the gen 3 boards that are alby John Meacham - Controllers
Yes. You don't even need another arduino. Although it isn't in the pick-n-place video I made, there was also an LCD attached displaying status. You can get standardized one or two line lcd modules for $2-3 each. they require 6 IO lines, but a 74X595 or two gives us all the IO lines we want. A full interface could be done for ~$15 I think.by John Meacham - Controllers
an SD card would probably be simplest, note that all SD cards actually speak the fully open MMC protocol which is just plain old SPI! Far easier to speak than USB. The arduino even has built in hardware to speak it. I actually had something of the same plan and am modifying my electronics some appropriately, namely I am adding a couple cheap port expanders to give me 16 extra general IO lines. Noby John Meacham - Controllers
A big advantage of the reprap model for FDM machines I think is the inertia of the object you are creating itself. if it only has to move in the Z direction while printing, then it only needs to handle upward and downward forces, which it was already constrained to do because of gravity. if the whole table moved then the object will have to withstand lateral forces due to acceleration of the wholby John Meacham - Mechanics
Just because it is opaque in the visible wavelengths, it still can be transparent in the UV. for instance glass vs lexan in UV is quite dramatic. A cool effect is looking at someone holding a big pane of glass in an IR heat vision scope, the glass acts as an IR mirror, so you will see their IR reflection in it just as if it were a visible light mirror. likewise you can get by those tricky IR secby John Meacham - Plastic Extruder Working Group
Ah, excellent ideas. A nice thing about copper tape I was thinking is that the same process can be used for a variety of metals as copper becomes more expensive, and a roller-press could perhaps just be fed recycled copper wire to get nice flat copper tape. I have no idea if that is feasable on a small scale though, but on a large scale, I imagine metal foil isn't hard to come by and a simple choby John Meacham - Mechanics
Thanks for the feedback. I think I am gonna start work on beta 2 pretty soon, with any luck, beta 3 will be made with nice repraped parts The only non-reprapable parts in there are the servos and I gather that repraping parts for a servo is something that will be actively worked on by others. Yeah, the Wii accesories are great, there are 4 wires coming off of them, connect them to +5, GND, andby John Meacham - Mechanics
While waiting for the parts for an actual reprap, I decided to play with some parts I had around and some shapelock and try to make a picker placer head type thing. The idea is using a vaccum, it can arbitrarily place objects in 3 dimensions. The thing is real rough, but I was wondering if anyone had any comments on the basic design. I am mainly a programmer and have very little experience buildby John Meacham - Mechanics
Just thougth I'd share this, I got my boardruino built and while I am waiting for the rest of my reprap electronics I decided to play around a bit. I am really impressed. other than a bit of minor PIC programming I have not done much embedded (on this tiny scale) programming and within a day of getting my bag of parts I had the following working: that is interfacing to a nintendo wii nunchuckby John Meacham - Controllers
But then you lose almost 60% of the power to heat with a linear regulator. it seems like you might be better off with a single efficient switching supply for 5V if you are powering it from a battery or solar. Though, whether it is worth it or not will depend on how much power the lower voltage stuff is pulling, if we run all the logic at 3.3V and have an efficient switcher, that could cut down onby John Meacham - Controllers
I would think the inertia of the head assembly would trounce the inertia of the rotor, and would be equally an issue for steppers or servos. is this not the case? Forrest: do you use magnetic encoders to encode an absolute position or just how far the motor moved? as in, do you still need to zero out your location occasionally? Hmm.. did you try to do any gradual speedup/slowdown to combat the iby John Meacham - Mechanics
this is what I ordered. I'll post more when I get it in the mail. 36 yards for $10 doesn't seem that bad. Another idea is to spray the board with adhesive and just roll out copper strips, which might be easier to dispense and fabricate as we can perhaps just roll some heated thin copper wire through a press to get it... Not sure how easy copper is to work like that though.by John Meacham - General
I recently shopped around for copper tape and found out that some are labeled as having conductive adhesive. I ordered some and am going to test it out, but I read a review online that said it conducts well so I am hopeful.by John Meacham - General
Hi, I noticed in a few places that the plan was to move from stepper motors to servos. I was curious what the advantages of doing so were and why? And by servos do you mean like are used in hobby RC craft or something else? is a repraped geartrain needed for such a switch?by John Meacham - Mechanics
Is there a way to list all items at the store? it appears that items are for sale that I can't actually get to from any of the categories. for instance, skate bearings appear nowhere other than the 'recently added items' list where they will soon fall off the bottom. and there are references to items in links that don't seem to lead anywhere.by John Meacham - General
I have some shapelock, I was wondering if anyone had any ideas for turning it into a very fine powder? I wanted to do an experiment where I mixed powdered polymorph with laser toner and measure the resulting conductivity. here is the inspiration for the idea:by John Meacham - Plastic Extruder Working Group
I have wondered whether it conducts through the adhesive side too and whether the adhesive holds up to high temperatures. if so, it seems like it might be a quick and easy way to solder connections onto metals that are tricky to do so otherwise.by John Meacham - General
Most Excellent. This project has progressed a lot since I last looked! I ordered some adrino electronics to start prototyping and working with the electronics design. I have lots of random steppers and whatnot I can play with to familierize myself with the brains and interfaces of the reprap until I can aquire the parts and free up the time to build the body.by John Meacham - General
Oh, it isn't actually a pyramid scheme at all. Sorry, I thought that was clear. it is actually exactly the inverse of a pyramid scheme. in a pyramid scheme, the wealth flows to the top of the pyramid, this is exactly the opposite, it distributes value down the pyramid to the most people, rather than concentrating it. The use of the list is actually almost the same algorithm as the canonical clasby John Meacham - General
Here is an idea to help spread reprap further/faster as well as help jumpstart those that are financially strapped. The idea is based on those good ol make money fast schemes. We create a waiting list of people needing reprap parts and what they need to complete their machine. People that wish to donate parts send them to the person at the top of the list for free. When someone completes theirby John Meacham - General