It's also important to keep in mind such things as "what happens if it's unplugged or my pet rabbit chews through the cable?" I.E. design it such that when it's unplugged, it registers as "at the end" rather than "keep going"by jgilmore - Controllers
I was editing the Glossary on the wikik, and noticed that the extgruders aren't arranged very well. Right now, there isn't a clear definition of "extruder" There's "Wade's extruder" and "mendel extruder" etc. Then there's the syringe-based extruders, the paste extruder (operates by air pressure) and the wire extruder, amount others. It might make more sense to split it up (and link it together)by jgilmore - Administration, Announcements, Policy
Ohms on steppers don't matter, as long as it's low enough. Unless you're using the H-bridge chips on the older-style extruder controller to drive a stepper. That hack works, as long as you don't turn the potentiometer up too high. Then it overheats the H-bridge chips and burns them up. On the stepper drivers (pololu or otherwise) the driver limits the *current* and so doesn't get overloaded. Alsby jgilmore - Stepper Motors, Servo Motors, DC Motors
You might like to take a look at chylld's replacement repman corner blocks These parts use clamping, replacing a two nuts and two washers on each with a smaller bolt/nut combo. Notice that they also "cradle" the rod, and extend down it a bit for extra stability. I think that the smaller bolt/nut combo could/should be replaced with a single screw. Make one hole larger to put the screw through, anby jgilmore - Reprappers
Appliance repair. I had a washing machine where a medium sized plastic part broke. It was an older machine, and the part would have been $60+, so it was cheaper to pick up a replacment than to repair the old one. With a 3D scanner and 3D printer I could have scanned it (it still fit together OK, just wasn't water tight) and printed a replacment. Again, 3d scanner and printer combo. I've heard oby jgilmore - General
It may be just me, but your first drawing looks like you have the belt driving the X axis in a large loop, pinned to the axis (to drag it along when the belt moves) at two points. But the belt will be moving in opposite directions, and would just pull the axis askew when it tries to move. You could pin it in two places, but you'd need an extra loop of belt, and isn't belt expensive? I supposeby jgilmore - Reprappers
So what I'm hearing here is 1. Third person probably should be encouraged, not certainly should not be required. 2. Editing to change to third person is fine, except in cases where it's obviously a person build blog. 3. When we finally have official blog support in the wiki (Sebastian, when is that going to be?) then rule 2 will change to "except in somebody else's blog" Correct?by jgilmore - Administration, Announcements, Policy
steveo290 Wrote: ------------------------------------------------------- > G1 F30.0 > G1 X-7.75 Y8.92 Z0.6 F30.0 > > Even though my z raise command has the correct > feed rate, I have to 'declare' it right before the > command or it just make a quick vrrpt noise and > doesn't raise. That sounds like a firmware bug then - the g-code interpreter in your adruino should handleby jgilmore - Skeinforge
I didn't mean "I" -> "we". I meant avoid "we" as well. I meant "I" -> "he/she/it", and "we" -> "they". as: Quote Adrian Bowyer wanted to design a single extruder driver that could 1. Be bolted to the X carriage of Mendel and run as a normal extruder, 2. Be mounted somewhere at the side and drive a Bowden extruder (as invented by eD and developed by Erik), and 3. Be mounted someby jgilmore - Administration, Announcements, Policy
I think it should be policy to never use the pronouns "I" or even "We" but instead use a proper name, and "he" "she" etc. It may feel odd to talk of oneself in the third person, but the better documentation is worth it. I was looking at Adrian's Extruder Design on the wiki, and the phrase "I wanted to design a single extruder driver that could" caught my eye. For anyone who didn't know that Adrby jgilmore - Administration, Announcements, Policy
I'd suggest following their suggestion, and using a temperature controlled vat. You can buy a "deep fat fryer" which has a thermostat controlled heater in it, allowing you to control the temperature of your molten wax fairly precisely. You encounter the same sort of problems when doing deep fat frying, as fat/oil/wax is all pretty much the same stuff. Which is why people use thermostat-controlleby jgilmore - General New Machines Topics
This is, I think, the strangest problem I've heard of. Congrats. Since the machine follows the lines correctly when jogging, it would seem to indicate that the mechanics and the g-code interpreter (i.e. the firmware) are fine. What PC software are you using to generate the G-Code from the STL? Maybe the software you're using to send the g-code to the reprap is helpfully massaging it somehow?by jgilmore - General
Demented Chihuahua Wrote: > perhaps something like > this? > > > if (bit_is_set(ADCSRA, ADSC)){ > raw.bytes.low = ADCL; > raw.bytes.high = ADCH; > old_low = ADCL; > old_high = ADCH; > } else { > raw.bytes.low = old_low; > raw.bytes.high = old_high; > } > > in place of this > > while (bit_is_set(ADCSRA, ADSC));by jgilmore - Firmware - experimental, borrowed, and future
I'm on my laptop, so here is the code. Note that though this code compiles, it's not been tested. It's mostly copied from more standard sources and glued into triffid's code, so it should in theory work fine. It DOES block while waiting for the A/D conversion to complete though. look for a "TODO" in the code marking that spot. This is temp.c from an earlier version of triffid's code, modifed fby jgilmore - Firmware - experimental, borrowed, and future
The cheapest 3D pictures I ever saw involved using a regular camera, and a mirror. Position the camera and the subject such that about half the camera's field consists of the subject, and the other half the subjects reflection. (For the real tightwads, this would be "stand next to your bathroom mirror, and have your buddy take the picture from the other side of the bathroom.) Reflect the refleby jgilmore - 3D Scanners, Book Scanners, and Optics
Regarding the analog temperature reading, I did that already. On an older version of triffid's code anyway. I can't remember if I correctly started and used the old number, or if I wrote blocking code. It'd still be a leg up. Can't find it right now. Hrm... because it's on my laptop. PM me with a reminder to post it if you care, I'll reply when next I use my laptop (Monday night or so)by jgilmore - Firmware - experimental, borrowed, and future
The problem of excluding the air is solved in commercial extruders by a simple heated auger. The molten plastic has a more difficult time escaping (especially past all the non-molten granules) thus forcing the air back out the hopper end, and leaving only plastic on the business end. The auger also pressurizes the plastic for extrusion. This has been done, with varying degrees of success, by varby jgilmore - Kartik M. Gada Humanitarian Innovation Prize
The Sanguino needs a usb->TTL cable to talk to it, right? So to use a sanguino, you need a usb->TTL cable. The usb-TTL cable can be used in "bit-banging mode" to program the raw chip, set the fuses correctly, etc. Given that, wouldn't an additional bit of hardware just to program it be redundant?by jgilmore - Controllers
I've got a model that has the top of the heater barrel drilled out to match the O.D. of the piece of PTFE tubing that goes through the insulator. The PTFE tubing's I.D. is 1/8", the same as the I.D of the brass barrel. I haven't tested it yet.by jgilmore - General
NSFW. Thanks. My 7-year old walked up at JUST the wrong moment there. Out of a ~3-min video there's maybe a 1/2-second scene. You'd think that sort of content wouldn't stay up on youtube. Also, I can't stand Java. Hilarious, though. Stupid stuff.by jgilmore - General
Let me see if I understand you correctly: You're increasing the printing area of your reprap by putting longer (and possibly thicker) bars in it. It is otherwise the same. In particular, the size of the gears mounted on your stepper motors shafts is the same. If that is correct, you don't need to modify the firmware at all. There is no software enforced maximum bed size. OK, well there is a intby jgilmore - Experimental
so one of the atmel 644's, with plenty of code space, and the 5D firmware from where? There are several versions of the 5D firmware. regardless, what you'll want to do is find where it starts on a new movement command, and add a temperature test - in a loop, so it loops forever if the temperature isn't right. It'll get better results to find some way for the microcontroller to turn the heater uby jgilmore - Controllers
So you want the microcontroler to pause when the tempurature falls to low? OK, you'll probably want to finish your current line, and back up the extruder motor (if you're doing that) and wait in place for the temperature to come back up. What microcontroler and firmware are you using?by jgilmore - Controllers
Actually it is a small business. Turnover != profit. assuming that they're parts costs are $500, that's $250 per, which works out to 333K/year, which is enough to pay a two or three employees and the space rental. Since they have about 5 employees, their parts costs must be lower than $500. And that's still not leaving much room for any real profit. Employees are expensive. Overhead will eat upby jgilmore - General
1: Depends on the specific setup 2: Fairly simple to do, write to the interrupt register to stop the timer interrupt associated with the stepper stepping. There may be some problems with it: What happens to the serial input? You MUST keep accepting serial input, or somehow communicate to the computer to not send anything anymore. What happens to the extruder? Stopping the XYZE steppers isn't eby jgilmore - Controllers
A pin vise? Seems risky. The vise in small, but much more massive than the drill bit. I'd be concerned about breaking the bit when (not if) the bit binds in the hole. Seems like the mass of the pin vise would be too much for the drill bit to start spinning, and the sudden torque would snap the bit. Nevermind those nicely knurled surfaces you'd be gripping, you could really transmit some torque thby jgilmore - For Sale
I mean that it's easier and quicker to get an accurate value for steps per mm. The value isn't affected by backlash etc. It'll be the same value regardless, your final position will be less accurate, but the number of steps to move 1 mm will be the same. Backlash can to some extent be compensated for in software. Compensating for skipping would of course require closed-loop control, which the repby jgilmore - Reprappers
If the nozzle sizes are larger due to the drillbit being held off-center, that would imply that the nozzles I drilled are accurate. Or more accurate anyway. I held the drillbit between my fingers, with the nozzle in my drill, touching the face to be drilled such that the bit holds still against the rotating face. It should be exactly in the center. I did it that way to avoid breaking the bit, aby jgilmore - For Sale
Nobody has tried it to my knowledge. Somebody did suggest rotating the whole machine to address "sag" issues. It's also been suggested to add a couple of degrees of freedom to the toolhead to allow prints on the side of existing parts. The main drawbacks that I've heard of for such a scheme are: 1. MUCH more complex software to control the toolhead/platform without running into existing parts ofby jgilmore - Plastic Extruder Working Group
If you're using any of the G-code firmwares, the feedrate is controlled by a steps-per-mm definition in a header file somewhere. Adjust this to match your motor steps-per-rev and your pulley size. It's better to calculate the steps-per-mm value from the motors steps-per-rev and the pulley size, rather than trying to measure and adjust it. Assuming that you know the spacing of the holes on eitherby jgilmore - Reprappers