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Discuss any sort of mechanical stuff here: positioning systems, gears, extruding methods, etc.
First 3D printer build, hoping to use my stash of OpenBeam - 1 year ago
After a long hiatus, it’s time to get my feet wet with a 3D printer. I bought more than enough openbeam to build one back when openbeam was new, but it never quite came together. I really like the looks of both corexy and h-bot, but it seems like there’s a lot to consider when it comes to the kinematics and construction. I think I’d prefer the corexy. My printer will live in my garage, which isby Annirak - Extruded Aluminum Frames
Re: Grounded Experimental Delta Printer - 11 years ago
QuoteA2 @nicholas.seward Simpson 3d printer calibration: What does calibration involve, after thinking about it I don't have a clue If I were to guess calibration would entail some of the following: Accurately measure the center to center distance of pivots (arm lengths). Temperature control of hot end and platen. End stop firing. Stepper motor voltage, amps. Platen leveling. The amount of noby Annirak - Delta Machines
Re: design firing circuit for thyristor - 11 years ago
A more conventional approach to this problem is to rectify the AC at high voltage, then use a DC-DC converter. For larger loads, you may want to use a PFC circuit instead of the normal rectifier-filter pair. If you're set on doing this with an SCR, here's how you do it: (@bobc, he's talking about firing at 80-deg on the cosine wave, which DOES put it around 80V) Approaching this as a cosineby Annirak - Controllers
Re: The Remoter - 11 years ago
Yes, if you wanted to run two chains in parallel, tensioned against eachother, you could elmininate the backlash AND keep a torque multiplier in the system, just like with my gearbox.by Annirak - Mechanics
Re: The Remoter - 11 years ago
QuoteGuizmo EDIT: SPAL patent was re-examined in 1999, so it's still enforced. Anyway, it's good to learn and improve existing technology. Let's make it better! As near as I can tell, re-examination does not reset the clock on patents. The 1988 patent has expired. Anything claimed in it should be fair game now.by Annirak - Mechanics
Re: The Remoter - 11 years ago
Is there any reason we can't run a plain old cross-link chain through a bowden tube? I know that beaded chains are out due to some of the patents quoted above, but what about plain cross-link chains? We can still keep them in tension. As long as the link size is reasonably precise, we should be pretty well set.by Annirak - Mechanics
Re: The Remoter - 11 years ago
I want to do a 6-DOF GUS with this. Not sure if it's manageable or not.by Annirak - Mechanics
Re: Thermocouple - 11 years ago
I prefer the MAX31855 series. They give you an SPI interface.by Annirak - Plastic Extruder Working Group
Re: Pro's and Con's of Delta printers? - 11 years ago
Delta printers as a class only have one advantage: symmetry. This means that the toolhead can move much faster since it's not hauling the weight of more motors around with it. The disadvantage is more complicated math, but software, as the saying goes, is cheap. Certain delta printers have additional advantages. For instance, some delta printers do not require linear bearings or linear rods. Thiby Annirak - Delta Machines
Re: The Remoter - 11 years ago
@Guizmo, you've got the idea exactly! @Nicholas.Seward, I hadn't realised that the compression spring was the preferred alternative, but now that I think about it, it would be much easier to mount!by Annirak - Mechanics
Re: The Remoter - 11 years ago
As promised, I have been working on a zero-backlash torque multiplier for the remoter. Nicholas.seward was kind enough to draw it up for me, since he's a lot better with solid CAD than me. A quick explanation of what we're looking at: The two gears on the left are attached to cable pulleys, much like Guizmo's original design. Here's where things differ. The two pulleys are not directly connby Annirak - Mechanics
Re: The Remoter - 11 years ago
Patents protect from all use, not just commercial.Quotehttp://en.m.wikipedia.org/wiki/Patent a patent provides the right to exclude others[17] from making, using, selling, offering for sale, or importing the patented invention for the term of the patent, which is usually 20 years from the filing date[4] subject to the payment of maintenance feesby Annirak - Mechanics
Re: The Remoter - 11 years ago
I would recommend rotating one of the cables 180 degrees. That will reduce the load on your bearing significantly. I have another idea which is a modification of this one; I just need to find since time to sketch it.by Annirak - Mechanics
Re: New arm design for Simpson style printer. - 11 years ago
Haha, yeah, I do. For one, you can remove a lot of force from the bearings on the drive side by making the apertures of the Bowden cables point towards each other. I've got to say, I'm really liking the remote drive approach. I had played around with the idea of pneumatics or hydraulics, but I couldn't work out how to get the price of the actuators down low enough to be usable. Why didn't I thiby Annirak - Delta Machines
Re: Grounded Experimental Delta Printer - 11 years ago
Perhaps I should have been more clear. The nonlinearity resulting from incomplete loops of the drive string is an arccos. The nonlinearity inherent in the Solidus Labs design is an arccos. They're just both arccos with different argumentsby Annirak - Delta Machines
Re: Grounded Experimental Delta Printer - 11 years ago
@A2, The Solidus Labs code cannot fix the nonlinearity because the nonlinearity is an artifact of the drive mechanism, which is not present in the solidus labs design.by Annirak - Delta Machines
Re: How many extruders do you need? - 11 years ago
bobc Wrote: ------------------------------------------------------- > Annirak Wrote: > -------------------------------------------------- > > 2) I've looked for I2C or SPI PWM controllers > for > > years. They don't exist. That's because it's > > cheaper to just use a microcontroller with a > lot > > of PWM instead. If you need more PWM channels, > >by Annirak - Controllers
Re: Water cooled all metal hotend - 11 years ago
The reason for using antifreeze is that it is a corrosion inhibitor. The hot end described in this thread uses mixed metals. And that is without any mention of the radiator. While it is possible to get brass radiators, most are aluminium, which will make things even worse. The long and the short of it is that if you're using mixed metals in a water cooling loop, you need a corrosion inhibitor, aby Annirak - General
Re: Firmware and acceleration - 11 years ago
How much would it help to have firmware that actively handled both Cartesian and non-Cartesian limits? I know this requires much more processing power. The controller I have in mind has plenty.by Annirak - Delta Machines
Re: Electronics to run three extruders without addon board or funky firmware mods? - 11 years ago
Okay, so there are a few. Then I don't know why no one replied earlier.by Annirak - Controllers
Re: where to start building a custom printer - 11 years ago
@cozmicray, their project appears, to me anyway, to be primarily mechanically oriented. They haven't told us the parameters of the course. They have explained that only one of them has programming experience, hence the focus on what's available. Why not give ythem the benefit of the doubt and assume that their profs are aware of the state of the art in hobby 3d printing and are asking for somethby Annirak - Developers
Re: where to start building a custom printer - 11 years ago
Honestly? You guys are in for a tough 6 months. I won't say it's not doable, but it won't be easy with the direction you're currently headed. I think one key point is that RepRap is not your ideal start point. RepRap is designed for self-replication, which means that the focus is on printing plastics. No other materials get much attention (compared to plastics) on these forums. Given that yby Annirak - Developers
Re: Tri-Polar Bot Concept -- Meet Wally - 11 years ago
A2 Wrote: ------------------------------------------------------- > I was envisioning adding 2 more steppers at the > shoulder joint, that's in addition to the 2 > steppers that you have driving the elbows. > DexTAR steppers are located at the shoulder joint, > your steppers are also presently located at the > shoulder joints. The point of Wally and Simpson is that they are simby Annirak - Polar Machines, SCARA, Robot Arms
Re: Electronics to run three extruders without addon board or funky firmware mods? - 11 years ago
The reason no one has answered this so far is that there really aren't any good options. Your best bet is probably to build your own RAMPS with extra space for stepper controllers. Otherwise, you're going to have to use add-on boards. Either way, you'll have to mod the firmware.by Annirak - Controllers
Re: Print speed limits? - 11 years ago
AFAIK, the limitations are the extruder itself. Here's the thread I started to ask about the problem.by Annirak - General
Re: Grounded Experimental Delta Printer - 11 years ago
Guizmo Wrote: ------------------------------------------------------- > My proposal: > > Completely Rail Absent > Bot I like it!by Annirak - Delta Machines
Re: A new line of investigation, Radial+Z - 11 years ago
I just have to be pedantic for a moment. A string in tension is not straight. It follows a catenary curve. I understand what you're trying to achieve, but I think you may have missed something with the linear actuators. The problem with linear actuators is that they require linear bearings. Linear bearings and linear rails have a lot of problems. 1) Linear rails aren't linear under load. 2)by Annirak - Delta Machines
Re: Precision Movement at a Distance - 11 years ago
I'm referring to retracting the filament. I don't know what is "enough." You'll need to determine what your maximum desired print speed is and work backwards from that.by Annirak - Mechanics
Re: Sextupteron - 11 years ago
I'm... not all that awed... They're using a conventional stewart platform, but inverted, which means that the frame will have rigidity problems. They're using (expensive) linear rails and pillow block. I'm not sure if they're loading them correctly to get precision. Their whole setup moves really slowly... What's new here? A printer on a stewart platform? Sextupteron is, at least, a novel aby Annirak - Delta Machines
Re: Grounded Experimental Delta Printer - 11 years ago
Six-arm Simpson is definitely a repcrab.by Annirak - Delta Machines