yes, probably. RGB is for emissive CMY for absorbative. Mixing plastercene seemed (when I was a lad) to result in : Brown. You could produce models in a fetching range of brownsby Lampbus - Reprappers
With three extruders feeding into a single in-line mixer and nozzle, you could print the full spectrum !by Lampbus - Reprappers
As I understand it (subject to UK/US differenses too & I am not an expert, just an inventor) a Patent is totally different to copyright. Simply put, a patent is for an Idea. If Pratt&Whitney scan or do their own drawings or just make somthing that has the features of GE's blade, then they are only in trouble if P&W have a patent over some novel aspect of that blade. So for a knob, yby Lampbus - General
LEDs have short/long legs - short is usually to the negative. They often have a flat on the body beside the short/negative leg. If you look into the side of the body, the legs get larger and close together, but the negative one is usually larger and cup shaped.by Lampbus - Controllers
Through plated PCBs are tricky when removing multi-pin things. I have been known to chop the component off first so the pins can be removed individually. Overheating the board and damaging tracks and vias is tooooo easy and often the components are cheaper then rebuilding or bodging the board.by Lampbus - Controllers
THe pausing in Gcode systems could be solved my running the maths in the forground, queueing the output and running the stepping drives on an interrupt. Of course this is nowhere as simple but I always prefer using a neat software design over just adding more CPU hardware. I went along to a local user group type thing last week (www.supermondays.org) and they were all keen on these new languagesby Lampbus - RepRap Host
Ok, I re-read this and now realise the layout. My coments were based on 'conventinal' stuff. This system certainly appeals - no need for a precision optical path between light source and sensor. The larger area available for light transmision would allow cheaper sensors and/or less signal conditioning too i suppose.by Lampbus - Controllers
Im not clear - how do you offset one sesnor ? what is it offset from? Quadrature requires two sensing channels anyway, at 90 degrees phase shift - how you get the 90 degrees is either from two rings of markings with one shifted and both sensors at 0 degree shift OR one ring with one of the sensors shifted. If you require a zero position then a third sesnor/marking may be required. or you could geby Lampbus - Controllers
Quadrature output dosnt need two offset gratings - just offset one of the sensors by half the grating pitch.by Lampbus - Controllers
I have added details of my brain transplant design on my blogspace here : Unfortunately, I need to get enough interest to go ahead with boards. Remember, this replaces 40 dollars of sanguano AND USB>TTL cable. I intend to supply with the Processor surface mounted and bootstrapped but the 0.1" headers loose so users can fit whatever connectors they like.by Lampbus - Controllers
Steel is a wonderfully versatile and laser cuttable material... powdercoated? Aluminium - annodised in cool colours would be good. How about using reprapped plastic parts ? or has that been thought of??! I suppose the aim of laser cut parts is to build a repstrap and replace components to create a durable reprap, but it does seem a waste when you could be using the 'replacement' parts to buildby Lampbus - Mechanics
For sugar : boiling water - heat + water solvent + ajitation = quick clean modelby Lampbus - Mechanics
I have laid out a PCB that has a DIL array to plug into an Arduino's CPU socket, a surface mounted Atmega644p, a header for the extra I/O and a header for ICP. The idea is that I can upgrade Arduino descimilla etc to the bigger brain just by plugging it in. Problem is I need to make 50 of them to bring the unit cost down below ten pounds. Anyone want to share?by Lampbus - Controllers
How about glass? I have an old flatbed scanner with an nice flat glass plate in (& a stepper motor + slidey bits).by Lampbus - Mechanics
Maplin in the UK do a kit of gears : I dont have it so I cant say if the quality is any good - from the website photo the teeth dont look so good. And a fiver for that? not cheap.by Lampbus - Reprappers
I have carried out some basic limited heat & feed tests - got leaks and the PTFE was visibly swelling. I have made up a replacement with machinable ceramic but I havn't run it yet. I gotta build my repstrap bot next and experiment with my roller nut feeder.by Lampbus - Plastic Extruder Working Group
The kit I got from BitsFromBytes had a similar problem - it had been squished in transit/storage and arrived as a solid lump - I bought a tub at B&Q for aboutby Lampbus - Plastic Extruder Working Group
With some of my laser cut parts, I specify exactly where I want the cut to start/stop. There is always a blip there and there are parts where it would be a problem if it occured randomly. In FFF it would also be nice to be able to specify where the seam is. Random by layer may work for some parts, but would make a pimply mess of a beautiful flat part. I dont think it will ever be fully solved, bby Lampbus - General
baster.89 - dont apologise for your english - its far far better than my ukrainian. (I assume that is what your 'native' language is - mine in UK english.)by Lampbus - RepRap Host
The advantage of a ball valve is it dosnt displace material axially as it opens/closes. It just rotates a plug of material through 90 degrees shearing of the flow. 3mm (1/8") would be big, but not massive. So long as the nozzle is screwed directly into the lower thread it could be worth a try. Polymer below the closed valve could still leak though. They tend to be fairly stiff to operate too (butby Lampbus - Mechanics
I like the reverse thinking idea - but you would still need to record the motion on the stepper. Also the force would be an indirect derived measurement which with steppers would be tricky = change in supply current. Stepper deflection - use a long sticky stick stuck to the pulley. Measure angle. This would include total system stiffness IF the tool tip is clamped to the bed.by Lampbus - Reprappers
hmm. can we get some stiffness data? newton milimeter numbers? I suppose a dial gauge would be required and a bit of string, pulley (to check horizontal loadings)and bag of flour/beans/2l bottle of coke to apply the force. What is the SG of coke? Probably better to dump the coke and fill with water at 20 deg C. Could make a gauge using a ruler & an 'amplifier' arm say 10:1 ratio. I assume wby Lampbus - Reprappers
When I was about 12, or perhaps 15, I purchased a book 'interfacing projects for the BBC micro' (or similar) and I got stuck in with many of those. THe real driver to get the book was the final project - an X-Y plotter (dot matrix printers just couldnt do the line quality I wanted for the CAD program I was writing). I never did build the plotter - thwarted by the vagueness of the plans - based oby Lampbus - General
I like surface Mount It is very fiddly until you get the hang of it (but you need good lighting, tidy workspace and good eyes) and I use two soldering irons to get both ends of small parts in one hit - no toombstoning. Another fringe benefit is you end up working on one side of the board - which lays flat and there isnt any legs to cut. No flipping the board over and holding parts in place 'tiby Lampbus - Controllers
Yep, its all down to how much stiffness you need. I had a kit of parcel strapping with plastic blocks just like Demented has described. The strapping was very strong with very little elongation, so I feel it may do a good job. It may be a bit fiddly to set the tension balance between alternate braces to keep it square. Wheel spokes in a bicycle are actually all in tension all the time. (ok theby Lampbus - General
Forrest, you got me confused there. I am a PICuser and I have never played with Atmel stupp before I got my Arduino (which I may bodge into being a Sanguino using the USB>serial IC ) PIC and AVR are similar but different. Which compilers do you use on the PICs - I use PBP and assembler. Looks like I need to get into C, but it does seem to be a resource hog on this weeny little hardware.by Lampbus - Controllers
My Dad & i were discussing ways to reduce FFF warping. he came up with the idea of welding lots of little spheres together by surface melt, not total melt. This means the thermal expansion is limited to the skin, not the volume. We couldnt think of a good way to heat just the skins though, especially in 0.2mm size grains. Microwaves?by Lampbus - Plastic Extruder Working Group
Sid, i havnt got around to doing hte maths on it yet - thanks. I knew I should have gone and checked the thread pitch before postingby Lampbus - Mechanics
Sid, if the pulleys are moved up, move the little stays up too - they are designed to resist that inward pull from the belt. OR put the tops of the M8 threads into the upper corner blocks and not all the way through the bottom ones and dump the fiddly brackets. As you say- gravity is our friend. My repstrap Z axis is going to use 2 toothed belts in a figure 8 on each side of the build platform.by Lampbus - Mechanics
The bitsfrombytes design uses a small axial screw to hold their drive gear on. You could check their partlist? When fitting grubscrews onto the shaft radially, it is good to file a flat. As mentioned above, this helps grip, but also helps you when you want to remoce the pulley/coupler. The tip of a grubscrew raises a burr on the shaft. Without a flat this burr will snag in the bore of the precisby Lampbus - Mechanics