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We have had good luck engraving pyrex with the Ostrich Eggbot engraving tool– a good example might be the Klein bottles that we wrote about recently. ( http://www.evilmadscientist.com/2013/eggbot-klein-bottle/ )
For each of those three adjustments, there are tradeoffs between intensity, speed, and precision:
1. With higher vibration strength (as you have seen) you make a bold mark more quickly, but the tip can bounce around more, making a wider line.2. With slower engraving (as you have seen), you make a bolder mark. With faster engraving, you cover more ground quickly, but weakly.3. Higher pressure will help to make a bold mark more quickly, but can lead to uneven depth, and a loss of precision in that way. (For thin glass, it can also lead to breakage more readily.) On the other hand, increased pressure can decrease the line width when the vibration strength is turned up all the way.The pressure can be adjusted in a couple of different ways. The primary variables are the type of hinge that you use and the “rest position” of the engraving tip. The latter can be controlled by moving the pen arm up and down (using the big brass thumbscrew on the proximal pen arm), and by the two position setpoints for the pen-lift servo motor.Using the thin (more flexible) hinge, and aligning the engraver tip such that it barely touches the surface, you can make it so that the engraver exerts nearly zero pressure on the glass, which will give the finest resolution and very good precision (but very light lines). Lowering the pen arm so that the “pen down” position would naturally rest below the level of the glass will begin to exert more pressure, and you can increase that further by using the stiffer hinge.Making multiple passes is another fine way to make the lines darker. To run the same job twice, either just start again after it finishes– if everything is setup well, it should go *exactly* over the old lines again –or (select all and then) duplicate all of your objects in Inkscape before plotting.The best way to fill the numbers will probably be to use the “Hatch Fill” extension, which you can find in the “Eggbot Contributed” menu under Extensions in Inkscape. Be sure and check the “crosshatch” button to get a solid-looking fill with the engraver. We used this with a very coarse fill on the Klein bottles, and it looked quite good. For your smaller numbers, you’ll want to use a finer fill, perhaps spacing of 5 steps to begin with, with cross hatching at 45 degrees.When setting up the Eggbot, you should definitely go through all three parts of the “Essential documentation” listed on the Wiki: http://wiki.evilmadscientist.com/The_Original_Egg-Bot_Kit
Part 3 of the instructions walks through the process of making your first plot and adjusting the motor current.And, if you do need it, the complete EBB documentation (including LED signals) is available here: http://www.schmalzhaus.com/EBB/
Hi Bob,
I’m afraid that I don’t understand the problem– can you please explain what it is that you think you’ve missed?(In general, my advice would be to ignore the LEDs, and proceed right to the next step, of testing it out and adjusting the motor current.)Let me add a bit to what Dan has said (which is all quite correct).
First, we use our laser in almost exactly the same way that you might use the Eggbot: We do all of our design work in Inkscape, and then open it up in Corel in order to use it as a “print driver” for our laser. If Corel is the flavor that you prefer, this certainly will work the other way for you.Second, if you can describe a good G-code workflow for us and provide some example output files, we can probably write a converter or driver (like Dan was describing) that takes G-code as input to drive the Eggbot directly, without using Inkscape. While we do use CNC tools extensively at our shop (CNC router, laser cutter, vinyl cutter, computer-controlled embroidery machines), none of them actually uses G-code, so we don’t presently have that workflow.Third, we are presently working on some new stand-alone software (that initially will just drive the WaterColorBot), that will work as a stand-alone driver for the Eggbot as well, starting from existing vector artwork.-WindellI am not sure exactly what the problem is, but it doesn’t sound like a chip kind of problem. If some LEDs were lighting up initially, it’s almost certain that it is not– it’s much more likely a power supply type of problem or an already weak connection somewhere that was coming loose. Do you have an alternate power supply that you can test? And, you might want to open up the case and look carefully through the PCB to find any possible loose or cracked solder connections that might be at fault. If you really get stuck, you might also consider sending it to us for diagnosis; we’re pretty quick at finding problems like these. :)
This sounds mostly correct, but I think that PA5 is mapped to Analog 5.
Those analog pins were left open specifically so that you can do projects like these; it sounds like a fine approach.A genuinely “new” chip is sometimes called a “bare” chip– you’ll need to install the Arduino bootloader on it (using a AVR ISP cable) in order to use it through the FTDI interface. If you have another Arduino handy, you can do that with the Arduino as ISP method, or you may want to just purchase a prepogrammed chip.
We do sell them at our store, here: http://shop.evilmadscientist.com/productsmenu/partsmenu/132Yes, it is not possible to reprogram the chip if it is missing its reset pin. If there’s still a stub of a pin there, I’d suggest soldering a wire to that stub, and wiring that to the circuit board.
Hi TimL,
It sounds like you’re mostly doing everything right– I say “mostly,” because obviously something is still amiss, or it would be working. :)It sounds like the auto-reset circuitry is working correctly, because it blinks for a bit when you try to program.So far as I know, there’s no driver issue with MacOS 10.8; I’m using 10.8.3 right now.One possible thing to check: If your Peggy has the Atmega328 chip, you probably need to select the “Arduinio Duemilanove with Atmega328” option in the boards menu.And finally, are you getting any kind of error messages in the Arduino window?The Eggbot is actually a bit overdesigned in terms of motor capacity and so forth. It can easily run all day, and we have used several units side by side, all day long, on many different occasions while giving demos or otherwise exhibiting the Eggbot. When we give demos like these, we normally don’t bring any spare parts (motors or otherwise) along.
The stepper motors are super reliable. They basically seem to last forever, with a couple of exceptions: on rare occasion one gets damaged in shipping or by dropping it on the floor such that it lands on the shaft. We’ve heard reports lately of people replacing the motors in their 3D printers with our steppers for improved performance.The servo motor is indeed a low-cost clone of the HS-55. It’s not the lowest-end clone, nor the highest, and yes, you can use a brand-name HS-55 as a drop-in replacement. Again, if dropped correctly, it is possible to break one easily. However, we do not know of any documented cases of one wearing out or breaking during the course of normal use, either from customer reports or on our heavily-used demo units. I suspect that our use of the servo motor is just very gentle compared to how they are used in RC cars and airplanes, where they do break very easily due to repeated impacts.
