I agree with the topic here. It makes more sense to do path planning and acceleration/deceleration management host side, where there's larger memory, no real-time requirement, cheap floating point math, etc. The "reprap" acceleration method in teacup should allow all calcs to be done host-side, and it shouldn't be hard to write a post-processor (in python) to read g-code and output modified g-coby jgilmore - Firmware - experimental, borrowed, and future
I thought that too for a sec. But it doesn't mention anything specific except their site. It feels like generic flattery, just enough to say "maybe it's genuine" while still being able to send many people the exact message. I thought I'd post it here and see of anyone else received the same message. Doesn't seem so though, so maybe you're right.by jgilmore - Administration, Announcements, Policy
I've copied the message here, looks like spam to me. Anybody else get this? I'd Iove your help From: zekebird3 To: jgilmore Date: 11/27/2011 06:40PM Hi John, I have read many of your posts on the RepRap forum. Your post quality and enthusiasm is awesome! I am very impressed with your ideas and would like to personally invite you to become one of the first beta testers for our new 3D printing plby jgilmore - Administration, Announcements, Policy
It should also be fairly trivial to reroute the belt so it goes the other direction around the pulleys on the X carriage. It would be more difficult to anchor the ends of the belt, as the ends would be on the inside. Since the belts would bend only one direction (inward) it should eliminate the breaking issue. ____________ / ___ ___ \ | \ / | \____/ \____/by jgilmore - Developers
jv4779 Wrote: ------------------------------------------------------- > My big issue was that send.py displayed the line > as read from the input file, but sent something > different. > > Jeremy Yes, that would be an unexpected behavior, now wouldn't it? I expect the original intention there was to make the displayed information more human-friendly while still getting the 20% spby jgilmore - Firmware - experimental, borrowed, and future
The basic tools for lensmaking have been around for hundreds of years, so the patents are all expired (or non-existant in the first place) so you could look for designs. As far as I know nobody has done it though. It's rather like a potter's wheel with a turning telescope attached IIRC.by jgilmore - General
SebastienBailard Wrote: ------------------------------------------------------- > Relegation of "Adult" and "Weapons" discussions > without models attached *may* be > a potentially acceptable middle ground where the > forum can have limitations markings > applied to such discussion sections of the forum? > > So, we play host to a 'let's design a plastic > derringer (no kiby jgilmore - Administration, Announcements, Policy
Nope! I hate and despise Java, and refuse to have anything to do with the reprap host software as a result. The best I can suggest is send your config files & probably some java-specific machine information to the maintainers. Since this g-code has G92 E0 on some layers and not on others, it's most definitely a bug in the g-code generation software, in this case the reprap host software. Thby jgilmore - General
jcabrer Wrote: ------------------------------------------------------- > The problem with using screw terminals for this is > that it defeats the purpose, which is to have a > quick disconnect for everything on the extruder. Have you looked at pluggable terminal blocks? All the benefits of a screw terminal, and quick disconnect/exchange etc as well.by jgilmore - Plastic Extruder Working Group
This problem is probably caused by a mismatch between the expected E values. For various reasons, mostly firmware limitations with tracking the total number of steps that the E axis (the extruder stepper) takes over the course of a print, the E axis's virtual "position" has historically been periodically reset to zero. There where two approaches to doing that. One approach was to use "relativeby jgilmore - General
I think that's almost the canonical way to embed hex nuts. Certainly I've seen Adrian endorse it, though I can't remember where. In the instructions to something, I'm sure. Works in ABS too, but it's easier with PLA b/c of the lower temp.by jgilmore - General
Right, there's the pressure buildup, ooze, etc. I don't have a mathematical model of the process, though it is predictable. The real question is: If we had such a model, and could tune it to exactly predict how much plastic is actually coming out of the end of the nozzle at any given time, could we then use that to adjust the E values to match acceleration to actual extrusion? My inclination is tby jgilmore - Firmware - experimental, borrowed, and future
I agree. I've been thinking about such a beast. Using basically G-code, but with the numbers in hexadecimal (for easy conversion) and all distances in steps (for axises) or pre-calculated times (for distances) or 14.2 fixed point notation for temps. Require some things (timing information) and it's basically done. It could be saved just like a g-code file - "corner_bracket.pgcode" For pre-digesteby jgilmore - Firmware - experimental, borrowed, and future
Accuracy? I suppose that's one test. Teacup is known to do "some small geometric distortion" this is due to the internal representation of floats - it's all fixed point rather than true floating point. This should make it much faster, (and smaller, fits on a atmega168) and was part of the reason for writing it. The standard firmware does true floating point math - some of it in interrupt contexby jgilmore - Firmware - experimental, borrowed, and future
I didn't know it did that - That means that if there's noise in your thermistor readings that vary the temp by more than the hysteresis amount, then M109 will never ever return. Perhaps the default config should have a relatively high hysteresis setting? Like ±20° or so? Would that cause unneeded oscillation for those of us who don't have noisy thermistors?by jgilmore - Firmware - experimental, borrowed, and future
Is a DB9 connector rated for 2A? It may be better to have two plugs, with a separate one for the motor. We already more-or-less have a standard for the motor plugs, it's a .1" (2.54mm) spaced female plug designed to plug into the top of the pololu motor driver carrier, and this method is outlined in the RAMPS electronics specs. I think most (?) of the other electronics use something similar. Iby jgilmore - Plastic Extruder Working Group
Bertha just happens to be my laptop's name... I don't get it though, what was your favorite when you where four?by jgilmore - General
Bigman: I don't know that there's any advantage to that? You still need a microcontroller to interpret it, so you're not saving on hardware. And as long as you have a microcontroller, you may as well use the built-in serial interface, which gives you a lot more flexibility and control... It's true that there's a time delay on the serial link, but for temperature stuff that doesn't matter. goarby jgilmore - EMC2
You've got to enable the "dimension" plugin in skienforge. What's happening (if you check your g-code) is that every movement command specifies a relative amount to extrude. If your firmware isn't set up for that (it's expecting an explicit G92 (IIRC) to reset the value of the E axis to 0 again at the end of each layer) then you'll get the behavior you've described. Look at the "E" values giveby jgilmore - Controllers
What you're describing is what "Mach 3" (windows, closed source) and "EMC2" (linux, GPL) do. And there are some people who use EMC2 to control the reprap. I've never heard of using Mach 3 though. It's in the wiki somewhere, and there are a couple of people doing it. Like nophead noted, it just replaces the arduino, you still need the stepper drivers and so forth. And you actually still need theby jgilmore - Controllers
I've got one of these around somewhere. Had to re-jet my trailer's water heater for high altitude. Don't remember where I put the low-altitude jet though. That was over a year ago, and I don't remember if the hole went all the way through the same size or not. I suspect not, simply because it'd be easier to drill through a bigger hole on the back so the small drill bit doesn't have to go as deep.by jgilmore - Plastic Extruder Working Group
0.005" = 0.127mm. Since the *goal* of accuracy on this project is 0.1mm, and it's not that accurate yet, I'd say a .005" resolution would be fine. The Mendel uses a 8 tooth pulley and a 5 teeth per inch belt. Ok, the spec is for 5mm per tooth, but 5 teeth per inch is only a smidge off of that anyway. With a 200 step/rev stepper, that gives 1 full step = 0.008".by jgilmore - Reprappers
Sebastian, I've noticed that it happens most when I take a long time to compose a message, and if I leave it for a couple hours, it's practically certain to happen. Maybe something to do with timeouts or expiration times?by jgilmore - General
I know that we're using mediawiki, so I can probably find the syntax reference/demo pages type things. However. For convenience it would be nice to have an obvious and prominent link in the wiki (i.e. on the front page.) That way we can also put in something like "If you find this confusing, just dump what you have in plain text form on a page! That way it'll be there, and others can reformat iby jgilmore - Administration, Announcements, Policy
Greg, I see a brief discussion about your design here: Do you know if either you or pdf417 ever wrote more about it? If not, could you take a few pictures? rhmorrison, what are the pros/cons? How much did it cost? How hard was it to get to work?by jgilmore - General
Various designs for heating the beds (be the actual bed made of whatever) have been used. Some use uninsulated nichrome wire attached to the bottom of the bed with kapton tape. Some use aluminum clad resistors. Some use TO220 resistors. Some use etched PCBs. ($50) Some use "hot plates" normally used for cooking. Some use cheap (in every sense of that word) clothes irons. What else are people acby jgilmore - General
It's also easy to send pulses too fast. In that case the motor will just hum without moving. Try really slow movement too.by jgilmore - Reprappers
It's meant to run on 12V, so that works out to 2A. It's usually under PWM control though, so with 2A through it it will probably get a bit to hot. Incidentally, nichrome is a bit dated. It does work, but has a tendancy to be fragile, depending on what you use to attach it. What did you use? The newer thing is the ceramic wire-wound resistor - 6.8Ohms was chosen as it won't burn things up (too mby jgilmore - General
8mm aluminum would be perfect for a heated bed. Stick some nichrome to the bottom with kapton tape. Or some resistors! You'll probably want to drill a hole for the thermistor for better contact. Hook it up and away you go! Erm, what *is* the standard method of insulating the bottom so you don't melt your bearings anyway?by jgilmore - General
Generally, it's best to calculate the steps/mm for all axises except the extruder, which should be measured because it's hard or impossible to tell what the "effective diameter" of the pulley is due to differences in how much various plastics and pressures squish the filament into the pulley's teeth. With X, Y, and Z, it's much more accurate to calculate, because it's hard to measure precisely tby jgilmore - RepSnapper