Bowden also gives you a lower head weight, which improves print speed and quality.
If you're not printing with flexible filaments Bowden works quite well.
You can also convert a direct drive extruder to a bowden relatively easily with $5 worth of push to fit connectors and a PTFE tube. The E3D Lite6 has an embedded Bowden coupling which goes all the way to the nozzle as well, so the filament can pass quite smoothly from the extruder to the hotend.
I have also had no issues dialing in filament extrusion settings. I used the Printrbot aluminum direct drive extruder I had for my Bowden setup and there is still plenty of torque.
How big of a stepper do you need for a 1.75mm extruder? I have an old scanner (like a REALLY old one, its beige and made for Windows 98) and I think it has a stepper motor, so I was gonna use that.
Also, I took apart a CD drive yesterday and I can totally use the stepper out of that for an axis, but its range of motion is a little small. Does anyone know a way to like link multiple DVD drive worm gear assemblies together? Or could I use the head motion assembly from a laser disc player since they're bigger? I've never owned a laser disc player so I don't even know if they have a head assembly that's salvageable lol. For all I know the laser discs could be being read by a tiny little leprechaun :P can anyone shed some light on this? I can grab 2 laser disc players for $16 on EBay, and I might be able to get some for free locally if y'all think they're usable for that.
And, I have one more idea. Can you drive 2 stepper motors with one stepper controller and just have them both do exactly the same thing (assuming they're the same number of steps per revolution, of course)? Because if that will work, I can stack a DVD drive carriage on top of a DVD drive carriage, and as ghetto as it is I'd get double the 2in print area, giving me 4in of printable area in whatever axis that is. If that will work then I'm going to do that, but if there's some fatal flaw in that design I don't know what I'll decide on. I know this isn't the most effective way of doing things, but I can get IDE DVD drives easily from old junk PCs, and 4in would be a perfect print area.
Also, what electronics would everyone recommend? I like the Melzi but is there some other AIO solution that's around the same price that's better? And what power supply do I need? The Melzi says it needs a 12v 25a PSU, but if I'm using tiny steppers from DVD drives does it still need that much? Just wondering. Thanks!
You're willing to spend 16$ and destroy a pair of old laser disc players, but not the 12$ for a proper NEMA17 or NEMA14 size motor... No matter what, you're going to need at least one "beefier" motor to drive the extruder. Check the steppers' voltage and current ratings too, ideally you want something between 3-5V and 1-2A. And yes, you can run two motors off a single driver, this is how most repraps are set up on the Z axis.
Melzi, Printrboard, Sanguinololu, RAMPS - these are all good designs, if built to spec. Melzi and Sanguinololu are practically the same thing since they use the same ATMEGA1284p 16Mhz microcontroller. Sanguino has more header pins for expansion but the stepper drivers are attached separately and may need heatsinks. Melzi's are soldered right on the board so the heat dissipation is better. Also, Melzi comes with a built-in SD card reader which is very handy. Printrboard offers better communication with a PC because the microcontroller has a built-in USB interface and connects directly, whereas most others use a "serial over USB" interface with a fixed baud rate. RAMPS offers a bigger microcontroller cache (256kb) so it leaves room for a lot of extra features like LCD control panels. You can have LCD support with a 128kb board but it uses up most of the memory (Marlin firmware is ~95kb with LCD enabled). Also, RAMPS is the most common electronics board used in the world, you will find a lot of neat expansions for it that work out of the box.
Most setups use about 5A with just one hotend and no heatbed. But you should always leave some overhead, so a 10A supply will work if you're not using a heatbed. But if you do want to use one, you need 25A or more. 30A should be great. To quote the wiki:
The motors plus single hotend take up to 5A or so, a heated bed typically takes 5A-15A. So for a standard setup with heated bed, look to about 18-30A total which is about 220-360W at 12V. For some setups you might be able to use less power.
Well I think I'm going to take your advice on the motors. I ripped up an old inkjet AIO and got the carriage sliding system out of it, and I can easily replace the DC motor with a stepper just with a simple wooden bracket. I also took apart the old scanner, and it can pretty much be used as is for the bed motor. So I've really just got to figure out the Z axis. I was thinking of using linear actuator steppers where the motors move with the head carriage, but is there an easier way? Also, I might be getting another broken scanner from a friend, so I might not even need to figure this out if it has the right kind of stuff in it.
If I do have to buy the motors, where can I get them cheapest? Just eBay?
And what about the Melzi, and the hot end? And are the Geeetech extruders really that bad, or is it just their Melzi boards that suck? I want to use a Melzi and a Bowden extruder, and I really don't care about what hot end as long as it works well enough. Suggestions?
I got my motors from RepRapWorld since i'm in europe, but eBay and even Geetech is probably going to be fine. Most commonly used steppers are made by Wantai, the 42BYGHW811 is present on just about every printer. It's hard to picture exactly what you're trying to do with these scrap scanner parts so i can't help with the design of it.
For electronics, if i were in your position, whatever i pick is likely going to have some sort of quality control issues as a side-effect of being so cheap. So considering this, i'd get a RAMPS 1.4 kit. Since everything is split into modules (shield, arduino, drivers), it should be easier to troubleshoot and repair in the event that something goes wrong.
Yeah, that's probably as cheap as it gets with these chinese RAMPS knockoffs. Just don't leave it unsupervised and hope it doesn't blow up :P It's better to keep an eye on the temperature for the MOSFETs and stepper drivers. Putting a 30mm fan (or any PC fan) over it for cooling is recommended.
I was going to use a spare 80mm fan that I've got off a broken CPU heatsink.
What would you use for the Z axis? I might be able to use some stuff from another old scanner, but I may end up having to buy motors and start from scratch for the Z axis if that plan falls through. I looked at ball screws but unless someone has mad coupon skillz those are out of my budget.
Ball screws are on the very far side of that spectrum - they are used in very high-precision CNC mills. Just one of the cheapest type will set you back at least 55$, and you need two. They're a waste of money and make no significant difference compared to cheaper solutions. For the Z-axis you have two choices:
Standard threaded rods from the hardware store. It's basically like a very long bolt with a standard nut on it. They're used in repraps a lot, especially in those "low cost eBay kits". They're cheap but suffer from major backlash (the nut wiggles just a tiny bit while on the thread, making things imprecise). The rods and nut also have to be either stainless steel or chrome plated because regular zinc-plated ones tend to bind up. Threaded rods like these aren't perfectly straight either - they will get your Z axis up and running for next to nothing, but expect layer wobble issues in your prints, as shown here: http://blog.lincomatic.com/wp-content/uploads/2012/06/leadscrewwobble.jpg
Real trapezoidal leadscrews, which come in two international standards- metric (ex: TR10X2), or ACME (ex: 3⁄8inch). You can probably guess which one is the confusing american standard. ;) These are more precise, and require a special trapezoidal nut that's usually made of acetal (Delrin), or some other low-friction polymer. Igus specialize in all sorts of precision linear motion tech like leadscrews, smooth rods, linear bearings etc. but expect to pay more.
Since you're on a budget, your only option are the regular threaded rods. You can always upgrade them with trapezoidal screws later if you need to.
I got to thinking last night, and I'm wondering...what if I used pulleys for the Z axis? I know I'd have to figure out a sliding rod system, but I think I can pirate those from one of several old contraptions we have sitting at home. If I used pulleys I'd only need one stepper motor, and if I played my cards right there would be an anti-sag system. The only issue I see with this is gravity...do stepper motors lock in one position when they're off, or will they just move pretty freely?
A couple of years ago, I made a 3D printer from scratch, using pretty good parts. The time it took to get the thing calibrated and working precisely was just insane, it was totally the most expensive thing I've ever built just because of the huge amount of time invested, and the time invested was silly, it took two days to build the printer, but it must have taken over 7 days to get it working right afterwards.
Over here, the Velleman kits are pretty popular. They cost 500 EUR all-in, and they have pretty well documented and easy and cheap to execute fixes for some problems they have. The advantages they have are great though: open source design, very big community, very solid frame, and a design that is a very good compromise between speed and precision. These are comparable to the Ultimaker designs, which is a Dutch manufacturer that uses the same open source designs, and these printers are very well regarded. You can turn a Velleman into an Ultimaker on a budget as you upgrade in the future basically. If 20x20x20 cm (6"x6"x6") prints are enough for you, I would strongly suggest taking a look at the Velleman kits. If you're not a technical person, the Velleman kits, just like any other 3D printer kit, are not for you, it's paramount to have a basic understanding of how to make reliable connections both of hardware and electronics to build the kit to such a specification that it doesn't crap out lolz
I'd love to try a kit, and I had been looking at the metal ones from Printrbot (Printrbot Plus metal looks awesome) but they're just too much money for me to spend at the moment. Thanks though!
You can use a pulley system for Z but it's probably not going to be practical. Not only are you going to lose resolution but you'd also be spending more on pulleys and belts than the 12$ you'd be saving on a stepper. It would be harder to maintain too. There is a nice single-leadscrew design by RepRapPro called the Ormerod, have you considered building one of those? A kit isn't too cheap but you could probably make some sort of ghetto spin on it after careful study. What's your budget exactly?
A couple of years ago, I made a 3D printer from scratch, using pretty good parts. The time it took to get the thing calibrated and working precisely was just insane, it was totally the most expensive thing I've ever built just because of the huge amount of time invested, and the time invested was silly, it took two days to build the printer, but it must have taken over 7 days to get it working right afterwards.
7 days is nothing for a serious DIY project. With these sort of things you either shell out the cash for an "out of the box" experience or you spend the time and effort to build it. If you ask me, doing the research and planning is part of the fun - you get to learn new things and meet interesting people on the way. If i had just bought a kit i wouldn't have been able to give any sort of useful advice about the pros and cons of various components here. Some people just want an expensive toy though, and that's fine too.
I'll probably just buy some threaded rods from a hw store. Those will work okay right? I know it won't match the quality of a $5000 3D printer, but I don't want to buy them if they're going to be useless to the point that prints straight up don't work...
I wouldn't worry about it much, threaded rods were used for the longest time on all the old first-iteration Prusa Mendels and you could get good quality prints out of them with a few tricks. Main criteria here is that you get stainless steel or chrome-plated instead of regular zinc-plated ones. M8 is the most commonly used size. They can get bent easily so try to pick ones that are as straight as possible.
Speaking of Prusas, if you have some woodworking skills, you can make a Prusa i3 or a Mendel 90 frame out of plain old wooden boards and a set of printed parts.
Okay. How would I mount the threaded rods to a stepper? I know there are those aluminum coupling things but is there a problem with those, or a specific type I need? And where to buy them/how to make them? (I saw on PrintrBots that theirs are wooden...would that work if I did some really careful stuff with a drill press?)
Printrbot's wooden couplings are mainly there to reduce costs. There's no problem in using wooden or printed plastic couplings, as long as they're tight and don't slip. The aluminium ones are called beam couplings and they're great. They are machined from a solid piece and the spiral shape in the middle allows them to flex which dampens small misalignments between the stepper and leadscrew. There's also jaw couplings which are the same as beam couplings, but use a polymer piece in the middle instead of a helix. They're more suited for high-RPM applications where vibration is a concern. I personally use beam couplings, they're only a couple of bucks on eBay.
