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Plastic Extruders, mostly - > http://objects.reprap.org/wiki/Extruder
Re: linear magnetic encoder - 16 years ago
I really like the idea! Somewhere in the dark ages, before cellphones became a commodity, I relied on an answering machine. I remember that thing had an endless tape with a total time of a few minutes. One problem could be to know where you where, in case you should miss a period or two on the 11900 signal. You could modulate a data stream on the tape (also used in the dark ages to store data atby mimarob - Mechanics
Re: Maybe fab ladder chain instead of toothed belt? - 16 years ago
1) can't you just use an extra idler wheel on an arm with a spring, keeping the wire tensed all the time? 2) I must be silly I thought "the actual screw itself" was a non-RP part?by mimarob - Mechanics
Re: No Computers Attached!!! - 16 years ago
hmm your saying the implementation is free, does that mean there is full source? Would be interesting to read, a friend of mine actually asked for help reading/writing SD's the other day. How large is the maximum of a FAT16 file system?by mimarob - Controllers
Re: SD Card > PIC24 > Route PCB - 16 years ago
Hum wonder if it would work to paint a thin coating of plastic paint on a pcb. Then use the repap mill to scratch away the paint with a fine needle or so. The toolhead would be much lighter, make less noise and less litter. Also the tool could rest on the surface, making it less sensitive to misalignment! Then one could just etch the thing and eliminate the expensive photo-resist of common tecby mimarob - General
Re: Fresnel-type solar collector [STLs included] - 16 years ago
How much would a stirling/heat engine weight? Suppose we get 1/10 of 1000W = 100W out of this thingy on a sunny day, directed towards the sun with 1 m^2 of area. We would like to have a 100 W stirling engine. Wonder if one could make an engine out of plastics without being bitten by the Carnot factor :-/by mimarob - Let's design something! (I've got an idea ...)
Re: No Computers Attached!!! - 16 years ago
I found it! It was even better than I thought. The Compact Flash cards (available everywhere) have a memory mapped mode. Here is a description of how to interface it to a pic There is an example in pic-assembeler how to access memory! Hmm 10+3+6 = 19 pins I guess the SD wins on the pincount :-)by mimarob - Controllers
Re: No Computers Attached!!! - 16 years ago
Actually you don't need an IDE interface for that one. You only need address lines and data lines. put the address lines out and then do an I/O strobe and read in the result. You would be done in like 20 lines of assembler, even when resorting to bit-banging. It must be easier than reading a flash through USB. I'll look around and see if I can that darn chip somewhereby mimarob - Controllers
Re: Suggestion: Construct Frame from Conduit - 16 years ago
Maybe we could stuff some of the ugly wiring inside the conduit, that would also make for a more profesional look :-)by mimarob - Mechanics
Re: We got digg/dugg...er digged...dugged...er... - 16 years ago
I found the digg comments quite funny, a little self irony is only healthy, maybe we should collect the humorist remarks already made in this forum somewhere :-) My contribution: Extrude! Extrude! Extrude! Obey the reprap or you will be Extruded!! I believe we also have a doctor :-)by mimarob - General
Re: Serial Connection To Computer - 16 years ago
There are also driver issues with many usb serial dongles. Have to make sure that it is actually working in the Ubuntu LiveCD I ended up using and old desktop computer with an old-fashioned serial running the ubuntu live CD. That worked, but I would really like something more portable to show reprap to my friends at the local geek-club ;-)by mimarob - General
Re: Single sided vs. double sided pcb boards - 16 years ago
Sorry to put my nose in again, but I think double sided boards are really not that difficult to produce. For the ink-pen approach, just mark and drill all holes first then use them to connect the lines on both sides, using a printout to help your way. If you go the photo etching way, you just need to tape the transparencies together making the holes match. Then just expose one side at a time inby mimarob - Controllers
Re: No Computers Attached!!! - 16 years ago
Its funny someone would actually mention the Rabbit and even more funny that I have overlooked it for 2 months+ There is not so much secrecy in the Rabbit world when it comes to the hardware, circuit diagrams can be downloaded from the site itself. I also know for a fact that you can buy these thingies one-at-time. What is a secret though, is the software. That is also the reason for the develby mimarob - Controllers
Re: Oil from algae - 16 years ago
Still.. Assuming the experimental data is correct, do you agree with my efficiency calculation of about 17% ? Does that mean that it is not photosynthesis itself that is the limiting factor but more if the "farm" is closed or open and how much you manage to circulate the algae? We got a few things working in our advantage: * Exponential growth * Future reprap technology to build ponds On theby mimarob - Plastic Extruder Working Group
Re: Oil from algae - 16 years ago
Oh I meant the volume for the total pond, 100 m^2 x 0.25 m is 25 m^3 or I'll have to go back to primary school... So anyway. Am I right to assume that people doing ponds that are 25 cm deep could expect to get 1.6g/liter/day which means that in "my" pond structure I could get 100 x 0.25 x 1000 x 1.6g = 40000 g = 40 kg of green goo a day? Assuming I would live near the equator take [40 kg/dby mimarob - Plastic Extruder Working Group
Re: PCB Production - 16 years ago
Hum I had a go at salt-water etching the other day. I didn't try to do anything useful but I managed to get a way a lot of the copper that way. I also got some brown powder into my salty water, obviously it was some kind of copper salt. It could be easily filtered out with a coffefilter. I used about 0.5 amps with the cathode in the saltwater. Any one knows enough chemistry to attempt a formuby mimarob - Mechanics
Re: Oil from algae - 16 years ago
> Where did you get that number? One cubic meter is 1000 liters. You could produce > 25kg of biomass per day from one cubic meter of medium given the numbers > established in my earlier post. Your entire rooftop system of tubes, 100m2, > would > contain about 1500L total volume, or 1.5m3. It's not that much, but that's good, > since that keeps medium preparation costs low! sby mimarob - Plastic Extruder Working Group
Re: Oil from algae - 16 years ago
Interesting stuff. Sorry, when I said "glass" I meant something like plastic transparent sandwich wrap. Anyway if one could get a way with a material that thin, it might not be so much of a problem to replace it every season. So is it the photons in the sunlight that is the limiting factor to the photosynthesis or is it the limited amount of CO2? I read somewhere that they where going to tryby mimarob - Plastic Extruder Working Group
Re: Oil from algae - 16 years ago
25 g/m^2 and day.. So assuming good sunlight we could get around 9 kg of it per square meter and year. My rooftop example would then give about 900 kg of biomass for a year. Is that dry substance and oil or is it before we remove the water? Any guess on its energy content? I made some rough guesses and ended up about at about 10W assuming it could be burned as fuel (and the smell didn't kilby mimarob - Plastic Extruder Working Group
Re: Oil from algae - 16 years ago
Hmm, so I'd better lower my expectations one order of magnitude or so, damn I have to stop reading thoose news-from-a-startup-company texts... So we are down to a 10W/m^2 production rate and that is in a closed tank under optimal conditions... o well, back to the drawing board :-)by mimarob - Plastic Extruder Working Group
Oil from algae - 16 years ago
Hello! Woke up in a visionary state of mind today and thought I'd put my thoughts out for display! In order to achieve world dominance, or rather crush it, we need infinite supplys of raw material apart from the ultimate meta-fabber that makes itself on all levels. Obviously supporting dictatorships in oilproducing countries is not the solution. Most biofuels also suffer from the problem of eby mimarob - Plastic Extruder Working Group
Re: PCB Production - 16 years ago
After six months I found the link! Some modifications towards automation and this low-tech approach might be exactly what we need! The plastic paint could be bio-degradable since it is only used for a few hours.. Then I don't know what the by-products are, copper-chloride? or will the copper attach itself to one of the poles?by mimarob - Mechanics
Extruding - 16 years ago
Not the 9'oclock news but I thought I drop a line and said I extruded this weekend! Once I made the filament <=3 mm all went smoothly. I'm using something I think is CAPA. It's called "repair plastics" and I bought it at a local hardware chain. I made an approx 3mm guide hole that I test all rod before it goes into the extruder. It was quite fun to roll the plastic rods and I also managedby mimarob - Reprappers
Re: Controlling stepper duty cycle in PIC boards - 16 years ago
Hello Zach! Thank you for your suggestions! Humm, no power setting in the excersiser or I have gone blind (it has happened before ;-) Maybe the software on the Live CD I have is different than the installed software? I tried to install the Java on my Windooze box before but failed horribly.. guess I have to go at it again...by mimarob - RepRap Host
Controlling stepper duty cycle in PIC boards - 16 years ago
Hello! I have some steppers with a low coil resistance, right now I run them with some 12 ohm 50W series resistors, but it seems like a waste of energy. Is it possible to adjust the PWM duty cycle somewhere from software? I have roamed aroung the Live CD but couldn't find it in the reprap program menus... I searched the PIC code and found some variable called "CCPR1L" with a default value ofby mimarob - RepRap Host
El-cheapo in-circuit pic-programming to the masses!!! - 16 years ago
Hello guys, I thought I hadn't terrorised this forum for a while, so I will just dump some news on my latest findings. I got a cheap JDM programmer (http://www.nbglin.com/jdm.htm). It seems to me that the zero-force sockets are the only things that cost anything on that board, the rest is a bunch of discrete components. It is also very similar to the free JDM programmer seen on many reprap pagesby mimarob - Controllers
built the universal controller board - 16 years ago
Hello! Yesterday I got the UCB 1.2.1 working, actually I used a modifed version (kicad rules!!) of the board where I moved the vias to eliminate the need for plated-through holes. I also burned the X-motor driver with the JDM programmer and the crappy-but-free software that came with it. In order to use it you need to be able to unpack .rar files, (haven't seen those in a long time) and alsoby mimarob - Reprappers
Re: RepRap machine for UV-curable resins - 16 years ago
Ok, so the resin has a rather low viscosity that makes it stay on top of the previous layer? I was imagining something more like milk, floating out evenly everywhere...by mimarob - Polymer Working Group
Re: RepRap machine for UV-curable resins - 16 years ago
why do you need to move the syringe around? I though it would just act as a tap in a bath tub to fill more resin, then you would move around the laser/diode or whatever to harden the object where desired? /Erikby mimarob - Polymer Working Group
Re: RepRap machine for UV-curable resins - 16 years ago
This might be my most stupid question ever. Is it possible to pour a layer of this liquid into a bassin and then use a UV-source to harden only the parts that are to be solid, leaving everything else liquid? Then add another layer and put the UV-lamp on the places where you want solid. After doing this with the whole object, just pour the remaining (unexposed) liquid away? If I'm not alreadyby mimarob - Polymer Working Group
Re: Home-brewed plastic made from milk ... - 16 years ago
regarding ethanol, there should be a ton of ordinary chemicals containing ethanol, more or less pure, but with some additions to make it undrinkable, at least for anyone not a serious enthusiast :-P I have some 1/2 litre bottles to disolve ice-cloggings in the carburettor in our cold country, a lot cheaper than even cheap vodka... oh and also they are peddling ethanol at the gas stations now adby mimarob - Polymer Working Group