Reprap 3d printer

Does anyone have any experience with one? I really like the Mendel90 design but was worried it might be an ambitious first build, since there are no kits available I would have to source everything myself piecemeal. I’m now considering a Prusa i3 kit from eBay or Amazon. There seems to be many available for $180-300. Any advice on brand/seller?

A note on popularity of platform. I started learning hobby machining on a high end machine. Novice material and support were way hard to come by. The 7x10 platform had so much information, it was like drinking from a fire hose. (Not to mention learning on a three hundred dollar platform is less risking than an antique made of expensive unobtainium.) So, don’t underestimate the power of popularity. Next, something slash anything is better than nothing. Even if the kit is not perfect, the learning transfers. If you really hate, or outgrow the kit, then odds are the controllers and steppers still can transfer. Or you keep that one and buy another. Lathe’s are like potato chips… you can’t just have one. I imagine printers are also.

Best question though is for the 3d printer guru’s “What kit is top of your list, and why?”

If I were building a kit printer, I would stay away from the cheap i3 knockoffs… you’ll be hunting problems down constantly and fighting out of tolerance issues for ever. (They also tend to be very weak structures, especially the acrylic ones.) You’ll be luck to get a few months out of the Chinese knockoff extruders and electronics.

I’d go right to the source, splurge, and get the actual Prusa i3. You absolutely will not find a better kit machine out there, period. It has features that no other printer does, as well as optional upgrades that allow easy multiple color support, etc. If you want to go cheaper, build his machine… print all the parts, and source all the other components… but use EXACTLY what he has listed, don’t by the cheap Chinese version… you will not go wrong that way.


I agree with Bill 110%

Before I ramble about theory and social implications, I first started messing with 3D printers in 2008/2009 and knew nothing. I was part of a group that did fabrication, design, and prototyping and there was a guy who obsessively built repraps at an alarming rate. We also had a Zcorp powder printer, but the reprap seemed like a hell of a lot more fun because it was challenging and interactive (and also because the material wasn’t expensive). Those were mendel-esque machines that Kenji made, and they really really really really sucked. So did the actual mendel later on.


That’s not the point, though. I am LOVING 3D printing for a similar reason I love electronics, it’s damn hard, slow and frustrating. Frustration is an important component of learning, and I encourage you to do this project regardless of budget or scope or practicality. Get really frustrated. It is now possible (it wasn’t in 2008) to get unfrustrated and then make a pretty decent machine. However, the experience making the machine is the primary gift at first. Whether it’s a Prusa or a Mendel or hot glue gun attached to a typewriter carriage, it will be great.

That said, I see good results in the end with the Prusa, and with Delta repraps, although I would discourage a delta as a 1st build (I do see them working much better in hands of experts than mendel). I recommend Bill’s option #2 – build it right, use best components, don’t get a kit, and print parts, laser, machine, and use hive to DIY.

I am bringing back the Ultimaker within a few days – I still need to do a couple things. However, it is printing great, other than lacking a 0.4 nozzle right now (I have 0.25, 0.6, 0.8). I can train you on it, and we can use it to build a reprap. I’m willing to help as I can. I am even thinking about having some folks in my Media Lab class at UC do a reprap at hive as a project next semester.

Also, your cost will be absorbed slowly if you do it this way. You can do it spool by spool, rod by rod, etc and it works out well. The kits are dissapointing unless they are the top-notch ones. That said, the whole point of reprap was that you can do as well as a kit version with just the resources we have.

Also, a few of us, including me, own our own machines which do not break down as often. I’d be happy to print something for people at Hive on my home machine if our hive machines are being wonky.

Here comes a bit of a digression into theoretical less practical land:

One of the interesting ideas with 3d printing is related to complexity. As the complexity of an object increases the “cost” decreases. Cost is not just money, but raw materials, processing, shipping, carbon emmisions, and well, in complexity theory, thermodynamics and entropy. Here’s an evolving theory: a simple 3D design print results in greater entropy than a complex design print. It doesn’t make sense until you think about the fact that 3D printers do something exceedingly well: they print void, or nothing very efficiently. In my own designs, for instance, I am always making a much better object when I integrate void space as a design component. Result: less material, less time, less frustration*, better object.

*If other factors, such as calibration, ringing, etc are not considered, the complexity of a good design does not inherently increase failure rate of the machine.

This is a primary reason that 3D printers are actually considered indispensable in two professional communities: design (industrial design, arcitecture, art), and mold making. Professionally, we prototype and test IDEAS with 3d printers. In fact, I’m about to print some mechanical prototypes now. If they fit and do what they are supposed to, I will use purchased metal gears in place of the 3D print prototype gears. However, note that I no longer end up with a pile of gears and pulleys that were ordered and did not fit the design as often now.

Sorry, I got philisophical. In summation. Do it. I will help. You can use Ultimaker now to make parts. I recommend prusa over mendel as well, and warn against kit problem bill spoke of. Heck, with the PCB fab that we’ll have with the electronics upgrade, you can even make a heat bed yourself :slight_smile:


I have a half-finished mendel90 sitting in my basement :slight_smile: I think Mendel90 is a much nicer design than the older Mendels,but sourcing your own parts takes effort. My personal recommendation for your situation would be to go with a Prusa i3 kit. I’m not as down on the Chinese knock-offs as Bill–my Flashforge makerbot knockoff is a workhorse. Whatever the nationality, look for a brand with reasonably large volume of business and decent reviews.

Or you can start from scratch as Lorin described, with help from other members! You will learn more and potentially end up with a great machine, although it is likely to take longer.


One more note–if keeping the price as low as possible is a priority, consider buying in an auction. Here’s one going on now:

3D printers and kits on this site usually end up going for about 50% of the amazon price. You do run some risk of parts missing if it’s an “open box”.


Awesome, thanks for all the advice everyone. I am now leaning toward the official Prusa i3 kit, unless I can find a decent kit for $500. I was trying to keep the budget to $500, but the more I think about it I would rather spend a few extra bucks and get a success under my belt.

Lorin, I absolutely agree with your advice and theory, but right now I think I need a quick ‘win’ and not let this drag out. I have ambitions to build a ceramic 3d printer, I will certainly take you up on your offer to help.