Hi guys, Sadly I can't make it tonight - hope you have an interesting discussion. Regarding slicers: I have used slic3r almost exclusively, and it's worked well for me. Having said that, and after reading the article in the Magazine, I am interested in trying Cura and would be interested in hearing about anyone's experiences with it. Have a good night!by Lsutehall - Beds/Herts/Cambs RepRap Usergroup
I realise that I'm a bit late getting on the ball with this, but I'm in south cambs with a (mostly) working prusa, and can make it tomorrow night - is the meetup still going ahead?by Lsutehall - Beds/Herts/Cambs RepRap Usergroup
I'm also having trouble with this. I am using a home-made nozzle on my prusa, and cannot bridge at all - the edges of the bridge barely touch the walls (and often don't touch at all) resulting in extrusion into thin air. I'd love the ability to tweak the spacing, such that bridges overlap the layer below more.by Lsutehall - Slic3r
I have an acrylic bed, but it has never been good enough to print directly on. Once I got it level, I discovered that it dipped in the middle. I have subsequently switched to using a sheet of glass, which works well cold with tape. The few times that I have managed to stick pla to the acrylic, it has become almost impossible to remove, and generally the acrylic has been distorted as well. What sby Lsutehall - Printing
I've finally got my prusa printing, but am having some trouble with the first layer. The linked pictures show the problem - some of the corners get laid down correctly, and stick to the bed, whilst others don't stick properly at all, and lead to either warping or the object being pulled free of the bed. Has anyone else encountered the same? Anyone got any ideas on how to fix it? Machine config -by Lsutehall - Printing
I am running my prusa from a server power supply. You'll have to do a little work to ensure it powers up correctly (just like you would for an ATX supply). Mine runs very well, if a little noisily - the fan could do with a speed-dropping resistor. Some details here: forums.reprap.org/read.php?2,111066by Lsutehall - Controllers
I had a load of trouble burning mine too. I also used an avrispmkii. I am on my phone at the mo so can't say a lot, but here is where I blogged about how I managed it. hope there is something helpful in here: foraysinto3d.blogspot.com/2011/09/chapter-17-in-which-i-finally-burn.html?m=1by Lsutehall - Sanguino(lolu)
That's an interesting point about the z axis, as I was considering counter-weighting the other day. Presumably this prevents the entire weight of the z carriage from being held only by the pinion's grub screw?by Lsutehall - General
Thanks for the suggestions. I'll try the free-air extrusion again once I get back up and running. How slow should I go? Somewhere in the region of 10mm/s, or less?by Lsutehall - General
Towards the end if last year I designed and built my hot-end. The nozzle is formed from a 0.6mm MIG tip. Following a tip I saw here on the forums, I used a hammer to reduce the aperture size. (The build details and report can be found on my blog here: foraysinto3d.blogspot.com/2012/01/chapter-24-in-which-i-design-and-build.html ) When my prusa comes back from its Christmas holiday to the garageby Lsutehall - General
My Prusa is currently using an old (and I think slowly dying) ATX PSU. I had a rummage around work's WEEE skip the other day and came away with an HP ESP113 series server power supply (specifically a PS-3381-1C1). It is rated to 32A at 12V and so ought to provide enough juice for the future heated bed and then some. I followed a guide I found on an R/C forum to make it work (link here). Puttingby Lsutehall - Developers
I used the 12v screw terminal on my build. I cut the plug off of my ATX12 and screwed the cables into the connector. The 12v plugs near the motors are outputs. I am using one of mine to drive a 40mm fan to cool the hotend.by Lsutehall - Sanguino(lolu)
I'm very interested in trying slic3r when my prusa is up and running. Does it use volumetric eSteps in the FW ala SF40+?by Lsutehall - Printing
I had this too, but mostly on my extruder motor. Turns out I had breaks in my wires - check all the wiriing really carefully, especially where it runs into the plugs on the board and at any terminal blocks.by Lsutehall - Sanguino(lolu)
My firmware uploaded ok first time without any pressing of the reset button, so not everyone has trouble with it (not sure why though?). Have you got the baud rate set correctly? IIRC the setting for sprinter is around the 11 thousand mark. ReplicatorG calls it "klimentokip" or something similar. I actually had trouble with both the host software and RepG, but Pronterface works perfectly - youby Lsutehall - Sanguino(lolu)
I realise it's a bit more manual than the punchtape method, but how about if each layer were to be milled/routed by hand, at say 10 times the size, in MDF/ hardwood/floorboards etc. You could then use a pantograph arrangement to plot the extruder around the bed. Use a foot-pedel to turn the extruder feed (spinnng/pottery wheel style), and maybe let air out of a set of bellows to drop the bed awayby Lsutehall - Developers
Yup this was windows xp, although the process should be similar on other windows systems. The sequence of operations should work for all o/'s though.by Lsutehall - Sanguino(lolu)
Just a quick suggestion, but did you write the unlock bit successfully?by Lsutehall - Sanguino(lolu)
I programmed my chip in the order I gave above, thus setting the fuses in the middle of the sequence. I did however encounter the "incorrect device signature" error, hence the "-B 8" switch on the first line. I also suppressed avrdude's default behaviour of checking the fuses 3 times before doing anything. I have been testing the axis motors today, and they all work ok. the order I set the fusesby Lsutehall - Sanguino(lolu)
I finally managed to burn the bootloader. I used a different set of instructions to that above, mainly because it wouldn't all fit into the command line. Here is what I used: avrdude -c avrispmkii -p m644p -P usb48 -B 8 -u -e -U lock:w:0x3F:m -v avrdude -c avrispmkii -p m644p -P usb48 -v (used to check if chip signature is now correct) avrdude -c avrispmkii -p m644p -P usb48 -u -U efuse:w:0xFby Lsutehall - Sanguino(lolu)
jtribe, did you try ebay? I picked up a twin pack of M3 taps for a very reasonable price (although I don't remember how much now, it was way less than £6 each)by Lsutehall - Reprappers
I'm thinking about how to mount the hot end to my prusa. It is my own design, but based on seemingly the most common design of hot end out there at the moment. It has a PTFE barrier joined to a nozzle via a PEEK part. The assembly is held together by bolts running through the PEEK, and then up through the x-carriage and then the extruder mounting holes (see attached render) I am slightly worrieby Lsutehall - General Mendel Topics
So I've finally gotten my computer to talk to the programmer I'm using, but only via avrdude directly - the arduino software still can't find it. I've used the examples at the bottom of this page as an example of the order in which to write each byte and have posted below what I will send to avrdude via the command line. Can anyone cast their eye over it, and see if I have made any mistakes pleby Lsutehall - Sanguino(lolu)
The caps next to the resonator are not for the load capacitance - they are caps C13 and 14, and are between pins 30 & 10 and ground. They're next to the processor on the schematic, and are 0.1uF.by Lsutehall - Sanguino(lolu)
I don't believe any of the caps are in backwards. Correct, I don't have access to one. I ought to have access to an AVRISPMKII next week though, if I can't get things working with the parallel cable. Photo of board without IC fitted. Other information: the board is rev 1.1, I'm using Aruduino 18 and sanguinio 18 on XP SP2.by Lsutehall - Sanguino(lolu)
The USB is plugged in, and the power LED is on. Interestingly, the avrdude error is the same as when I try to program the board without the programmer connected, so it sounds like something is not talking/connected correctly. I'm sure the parallel programmer I made is correct, and I buzzed it several times while building to check the connections.by Lsutehall - Sanguino(lolu)
I have been attempting to program with the chip mounted in the board. In this config there is already a resonator connected across these pins - do I still need to add another?by Lsutehall - Sanguino(lolu)
I tried programming the bootloader today, and was met by failure. I tried both with and without the 12v side of my sanguniololu powered, and got the same message each time: avrdude: AVR device not responding avrdude: initialization failed, rc=-1 avrdude: Yikes! Invalid device signature. avrdude: Expected signature for ATMEGA644P is 1E 96 0A avrdude: AVR device not responding ***failed; avrby Lsutehall - Sanguino(lolu)
So I made my parallel port programmer today and will be attempting to burn the bootloader later in the week. I made it from a whole parallel cable - I didn't cut it down. If anyone else wants to take this approach (note - currently untested!) the pins are as follows: PC end Printer end Pin # 1 1 2 2by Lsutehall - Sanguino(lolu)