Njones Wrote: ------------------------------------------------------- > Would Nema 23 motors all round be a better choice? Yes, I think that's what Forrest is using. Check you can get motors that the electronics can run if you're going to use the standard reprap electronics (RAMPS) - I think most reprap boards can only run motors of up to 2 amps at 12V.by droftarts - General
Now small, powerful stepper motors are being used as direct drive extruders (like the Makerbot stepstruder Mk6 and the new Mendelparts v9), extruder/hot end size is coming down. Though the motor is the weightiest part, it is clear that this is not an issue for most machines that use NEMA17 size motors for driving the axes. Having a Bowden cable reprap myself, due to limitations of my reprap frameby droftarts - General
Hi theodleif, I tried out the new bug-fixed version of dimension.py, and set the distance to 8mm. I had a little bit more stringing between parts that were close together as I was printing a plate of small Prusa parts, but as there were lots of small sections that didn't have retraction I think it saved a lot of print time, and stopped some of the blobbing on really small parts. So, success! As tby droftarts - Skeinforge
There are plenty of repraps that use a Bowden Extruder, like the Huxley, but it seems nearly impossible to overcome hysterisis, which causes oozing, and necessitates using retraction before non-printing moves of the hot end.by droftarts - General
Forrest Higgs is building a reprap that sounds similar to what you're after, including a dropping bed and the X and Y axes at the top like the original Darwin - read his blog here If you're using larger, heavier bars, the torque of the normally used NEMA17 motors may not be enough to rapidly change direction. I got my motors from Zapp Automation who I think can ship to you, and seem reliable anby droftarts - General
Good effort, and fine British bodging! Looks like you are making progress. You already have a couple of the parts that seem the hardest and most expensive source - the electronics and the motors. The frame seems to be one of the easier/cheaper parts to source or repstrap, and there generally seems to be a move away from repstraps as the cost of printed parts continues to fall as availability riseby droftarts - General New Machines Topics
owism8 Wrote: ------------------------------------------------------- > I'll ask him about how he got the bowden to work so well. I was thinking that. It would be great to know!by droftarts - Huxley
Try swapping a different motor, say the Y motor, into the same position. If it stutters, it's the electronics. If you've got pololu drivers, swap driver boards over and see if you can narrow down if it's a driver board or main board fault. Check for dry joints, burnt out components. Run through the diagnostics from the reprap wiki that relate to your board. If it doesn't stutter, it's the motor.by droftarts - Reprappers
Hi Nerfsmith, and welcome. Where are you based?by droftarts - Stepper Motors, Servo Motors, DC Motors
nophead Wrote: ------------------------------------------------------- > Don't you get strings over gaps less than 10mm then? Might do, but it's worth experimenting. It's a toss up between strings or blobs for Bowden cables. I'll be glad when I finish my Prusa and get rid of the thing!by droftarts - Huxley
How about ?! They have a facility in Dallas...by droftarts - Reprappers
Yes, I tried your Dimension.py and it works very well. Excellent job! There are still quite a lot of retractions, I think the distance could be pushed up a bit higher, perhaps to 10mm. Is this easy to do? Or could an option be added to allow the user to enter their own value in the GUI? I've never looked at a Python script. But good work! I also think Skeinforge could be smarter about optimisingby droftarts - Huxley
This large kit from B&Q is only £31.79 here But you don't really need anything that big. I bought a 10 piece B&Q kit for about £12, with M4, M5, M6 and M8 taps and dies, die holder and tap wrench. Most holes will be in this range, and you don't need anything too fancy to work brass. Steel might need a higher quality kit. You might also want a M3.5 tap to hob bolts for extruders, but you cby droftarts - General
This guy on ebay always has lots of stepper motors at reasonable prices, and is US-based:by droftarts - Reprappers
Sorry, posted in wrong thread!by droftarts - General
I think this tutorial should address your problems: I have found these links useful too. (has a list of tutorials and other very useful links at the bottom)by droftarts - General
I'm UK-based, but take a look at the world reprap map There seem to be a couple of people around Dallas, though I'm not sure how you go about contacting them. They may have the same name on the google maps as their username here. Don't be surprised by the deafening silence if you are asking for free parts. However, the printed parts are really not the most expensive part - the electronics and tby droftarts - Reprappers
Though I tend to be modelling things in Google Sketchup, I've just started my journey with Openscad. I find it a bit difficult to use, but appreciate it would be really good to learn it. The first thing I'm using it for is importing a number of stls to produce a plate of different parts to print, using the transform and import_stl commands. This is relatively easy - here's the sort of code: tranby droftarts - Reprappers
Wow, theodleif, the dimension change is just what I was hoping for! I'll try it this evening. I gave up using cool as I had ooze problems, and tend to just blow on a part to cool it if it's a small column building up (the peak of the hollow pyramid is a particular problem), but perhaps I'll give your cool.py a go as well. Have you sent them to the Skeinforge developer to roll in with the next veby droftarts - Huxley
Try a different font? Could be an issue with the one you are using.by droftarts - General
I built a model yesterday in Google Sketchup for the first time, and it Skeinforged fine despite not setting any model solidity. Check that all the faces and edges in your model coincide, there may be a small gap somewhere.by droftarts - General
Welcome! Sounds like you have all the relevant skills. You'll be fine. Sluark Wrote: ------------------------------------------------------- > What are the length limitations, and why? None, just a compromise between cost/time. There are a couple of repraps around that have larger build areas, but build time for really large models becomes an issue. > Why belt drives? Fast, cheap, accurby droftarts - General
The controller in the reprap/CNC machine doesn't care how big the file is, just what the next move is; they generally have a very small buffer, which is filled serially by the controlling computer. It is possible for the controlling computer to run out of space for a particularly complex gcode, but the current OSs have much greater file size limits than fat32 mentioned by james above. You are morby droftarts - General
Here's mine. Only recently moved into the flat, so it's a bit spartan. I'm building a Prusa, vertices come in handy for holding the homebuilt, cardboard spool.by droftarts - General
I think the Gen6 board is speed limited by the firmware. I have one, and played around with speeds in repsnapper, but it topped out - sorry, can't remember off-hand at what speed. Higher speeds didn't seem to make it skip steps, just go at max speed. As retractions are carried out as single commands, is it likely to skip steps? On mendel-parts, Camiel is experimenting with printing at 250mm/s witby droftarts - Skeinforge
Maybe you're running the heater too hot, making the filament too liquid? I've reduced the temperature on mine a bit, from a reported 205 degrees (for PLA) down to 190. Unscientifically, it seems to ooze slightly less, and pushes through the extruder with about the same pressure. I wish I had one of those laser thermometers to know exactly what the temperature is. I'm building a Prusa, so should bby droftarts - Skeinforge
I guess Nelson is using a Bowden cable. I have the same issue, but it's either strings or blobs with a Bowden, it seems. I think retraction moves are generated independently in Skeinforge, so always happen without movement, which could be part of the issue - though maybe this is due to being able to specify the retraction speed, which needs to be set differently to any other feed rate? Another isby droftarts - Skeinforge
Very nice, Greg. I see the new Prusa felt X-motor-ends, your new LM8UU linear bearing X carriage and linear bearing Y axes. That's pretty much what I'm building with my repstrap, though rather slowly due to hot end leaking problems. Are you using irons to heat the heated bed? Cunning idea. I still can't see why nobody has built an upside down Z axis Prusa, with the motors at the bottom. It wouldby droftarts - General
Not necessarily Bob, as it also depends on the INFILL width over thickness; if it is set incorrectly, say to 1 when it should be 1.5, a 60% infill will look like 100%, but it doesn't necessarily mean you are pushing too much filament, just that the infill paths will be spaced too close together, as the WOT ratio governs the spacing of the path the nozzle takes. Getting the width over thickness seby droftarts - Skeinforge
I think your Perimeter width ratio setting under carve is wrong. With it set to 1, you are saying that it is extruding a perfect 0.3mm diameter filament. In fact, each layer gets squashed onto the previous layer and spreads out. This may be why your part as fractionally bigger in the X and Y dimensions. By setting it to, for example, 1.5, the path of the nozzle will be inset, and the filament squby droftarts - Skeinforge