Sunday, April 10, 2011


Sourcing a 3d Printer

It's amazing to see how much the RepRap community has grown in the 6 years since it started, and little over 3 since RepRap 1.0 Darwin was released.  We have gone from only being able to get the parts for a Darwin from commercial prototyping services that made the total build cost $3000+ to today where you can put a Mendel together for $400.  This blog post is going to try to help a person figure out the easy ways to get into this hobby.

There are 2 main ways to get a RepRap or RepRap alike (Or Repstrap).  You can buy a kit or you can self source.  I am a very large fan of self sourcing because the difference between the cheapest kit I can personally recommend and the self sourced machine is $425, or TWICE as much.

Self Source Open Source (The Cheap Skate Route)

A RepRap is made up of 4 categories of parts.  Motors, electronics, RP (Plastic Parts), and Hardware: These parts are not hard to find, and no matter where you are in the world you can have them shipped to you.  Below I will give a bit of a guide on how to find these parts outside of a kit vender.

RP (Plastic Parts)

The availably of plastic parts has seen a real dramatic shift in availably in the last year.  24 months ago there was literally almost NO parts available for less that then commercial Prototyped price ($1300ish),  18 months ago the parts where going for $700ish on Ebay, 6 months ago they settled on an average of $250-$300, and now there is such a glut of parts that they are going for $100 and cast $50.  This is part of the magic of the $400ish RepRap.  I find these to be the best places to find the RP Parts.

Print them yourself:  I know, how do you print the parts for your 1st 3d printer when you don't have a 3d printer?  Well believe it or not there are 3d printers all over the world, and most Metropolitan areas of the world now have at least 1 RepRap or RepStrap operator, if not dozens.  Before you go buy a kit, or buy parts off the internet search your local area to see if someone has a Makerbot, RepRap, or other 3d printer.  You would be amazed at how friendly our community is.  The best places I have found to find Local 3d printer operators are:

The RepRap User Groups:  Even if you don't find anyone in there, post that your trying to get the parts, there is a very good chance that the 3d printing bug has infested someone else in your area.
The RepRap Map:  This will let you know if someone is in your area, most the time people don't put links for people to contact them here, but 90% of the time there is enough info in the link to hunt the person down
The Makerbot Map: Same thing but for Makerbots.  There is a LOT of people who have bought Makerbots,
The Makerbot User Groups:  Makerbot has compiled a nice list local MB user groups.

Buy the RP parts: This is the most common way for people to build their 1st RepRap.  There are plenty of different places on the internet to get the parts.  The most quality dependent part of the print is the gears, so when you buy the parts, insist on a good photo of the gears, you are looking for very well defined teeth on the gear.  Here is where I suggest you get the parts:

RepRap IRC:  Our community's IRC channel is a hopping place.  The reason I say go here 1st is because by buying your parts in this channel your also helping out the people who are most likely going to help you get it running.
Emakershop  Jeanmarc from the IRC runs this webshop.  The great thing about it is that it has a varitey of venders (you can literally self souce JUST out of his shop for $550ish (if everyone is in stock, which they are not now).  Lots of us like this vender because he does not charge a transaction fee.  Only thing you have to pay is Paypal fees.
Ebay This is likely going to be the most expensive way to get the parts, because with Ebay there is no way to get around the doubt hit of Paypal and Ebay fees.  Unless you just have to don't buy parts here.
RepRap Forum Parts go up for sell in the Forum all the time (less than you will find at any of the other choices), but people do sell there.  1 note it is VERY easy for people to "Puppet" in our forums, so you never know if the reviews listed there are real or someone being dishonest.  Most the Ebay sellers also sell here, so buying in the forum allows you to skip the Ebay fee.
Metrix Clonedel These are the cheapest parts, and I have personally reviewed their products, they are good enough replacements for the printed parts.  They do require processing with a drill press.


The electronics are the heart of your machine, and the part of the machine that most effects your overall experience with the machine.  I have experience with RAMPS, Gen6, Gen3, and Gen4.  All have worked well for me.  The big difference between these electronics is the cost / firmware support you get with them.

RAMPS Is currently my favorite electronics.  Mostly because it's both "single board" & modular, has provision for controlling a heated build plate, has the most active development (3 separate teams competing and working together on firmware for it), and it's about the cheapest electronics I can suggest ($140 if you do it yourself $200 if you get it preassembled. It's sold by Ultimachine, or you can etch it yourself.

Gen6 Is my second favorite choice.  It does not have provision for a heated build plate, and it has the least active development team as far as new firmware.  It's not etch-able, and is only available from 1 vender,  But is the simplest set of electronics to install, and it does work.  It's $200 with optos.

Gen4 is my 3rd favorite electornics.  This is the official Makerbot electronics, but you could use it on a RepRap.  The up side of Gen4 is that it will out of the box use ReplicatorG, which I think is one of the easiest RepRap control programs, the down side is that Makerbot sells it for $370.  That's twice as much as it costs to put together RAMPS, and 4 times as much as a Sanguinololu.

Gen3 and the multiple derivatives thereof.  There are many companies out there that sell a version of these electronics, but in the end they are 2 years old, and it shows.  Gen3 was problematic, but at the same point LIGHT YEARS ahead of what we had before.  Zach and the guys over at Makerbot did a wonderful job on these, but they are just old now.  If you can pick up a set of these electronics cheap, great, but just remember even at their best they where fussy, and no one is writting firmware for them anymore.  They can be had for as cheap as $165.  The Real Gen3 are no longer sold or supported by Makerbot.

The Self Source options.  If you have the ability to create your own boards, there are some truely cheap and nice options out there for you like Adrian's Ramps, Gen7Sanguinololu, or even self etched Arduino_Mega_Pololu_Shield.

Electronics can be as cheap as $100ish all the way up to nearly $400 depending on which set you go with.  It's up to you.

Your also going to need a power supply.  If you plan to not run a Heated build plate, you only need 60W for all these electronics.  The power supplies are usually avialable where you buy your electronics, and are either ATX power supplies (Desk top Computer supplies), or Laptop Supplies (Solid state but smaller).

If your going to run a heated build plate your going to need a high amp power supply, so an ATX or Laptop supply is not going to cut it.  You will need something like this:

Just search "12v 20a universal power supply" in ebay and you will see tons on them, just buy the cheapest one.


Motors can be the easiest or the hardest parts to source.  All that really matters is that they are NEMA 17 (I know it's "possible" to run a RepRap on Nema 14, but don't even try, it's way more trouble than it's worth) they must be bipolar (4 wire), and have a holding strength of  40 N-cm at an aperage lower than your driver .  Remember if you get 3 amp steppers most of our electronics only push max 2amp, so your not going to get the rated strength, but if you get a 1amp motor (that has the right strength), you can run it on a 2amp driver, just remember not to max the pot on your stepper driver!  When in doubt buy a stronger stepper than you need, because there is no way to make a stepper have more torque than it's rated for.  I use 53.1 N-cm motors just beause the last thing I want to deal with is a skippping extruder steper motor.  Here are some links to motors that look about right, or I have used to give you an idea what you want.

Any of those would work, but you can buy what ever you want, just remember 1-2amp 40ncm (Good converter if they play games with different numbers), Bipolar, 4 wire.


Hardware will depend on which machine you choose to build.  I have built a Makerbot, Thingomatic, Huxley, 3 Sells Mendels, and well over 5 Prusa Mendels at this point.  You can see videos of all the builds over at my Youtube Channel.  The newest and in most active development RepRap is the Prusa_Mendel.  The advantage of the Prusa is that the hardware costs are a fraction of the Sells Mendel, and it's much easier to calibrate/assemble.  Here is a video showing the two machines side by side.

Assuming you go with the Prusa, you can get most the hardware locally.  The Threaded Rod will be at your local hardware store, the screws you need (SAE if your in the US, Metric anywhere else), will be at the hardware store also (you might have to search in google maps for a thing called a "Fastener Supply" in your area to get the right sizes.  Also your going to need Smooth Rod.  If your self sourcing I am assuming your not rich, so just get "Tool Rod", or "Drill core".  This can be also sourced locally from a machine shop, the Fastener supply, or even from old junk printers, that almost always use 8mm or 5/16 smooth rod.  The only bearing a Prusa uses is the 608 bearing or "Skate board bearing".  Before I started doing support in the RepRap IRC I never knew that every country in the world had Skaters, but they do.  They don't need to be fancy, the cheapest 608 you can find will do (I have even used 2nd hand bearings from the skate shop).

Some Hardware is harder to find locally, such as the belt, you will need .2" or t5 (t5 is the spec belt, but .2" will work)

In the US I have found these suppliers to work great and be cheap:

Your also going to need hardware for your extruder.  This is the part that handles to molten plastic (hot end), and the part that pinches the plastic (cold end), so it's very important that it's done right.  You can make these yourself, but unless you are a machinest I really suggest you just buy the parts (at least for the hot end).  These are a few vender's I know work well. 

Hobbed Bolt's are what is used to pinch the plastic.  You can use a gear to do this, but the hobbed bolt seems to work much better.  They can be found from a variety of vender's on ebay, and only take about 10 minutes to make yourself with stuff you likely already have sitting around your shop.  You can search eBay for them here.

The only other hardware you will need is bushings if you chose not to go with PLA sliders (which a lot of people love).  I have used both of these:

This should get you a good way though self sourceing a Mendel, but if you have any questions go to the Prusa Mendel in the Wiki, or go into RepRap IRC off freenode.

The Kits:

I would say that purchasing a kit has always been the most common way to start in this hobby.  That's changing now because untill recently is was almost impossible to source the plastic parts, and the RepRaps where much more challenging to get running than the kits.  This is not the case any more.  But non the less, a kit is an option that is perfectly reasonable if your time is worth more than a few hundred dollars.  Again this is not a complete list of Kits, but only the ones that I would recommend to a friend.

Makergear Prusa Mendel Kit $825

There are cheaper kits, but I have seen enough issues with them that I can't suggest them.  This kit comes with all the bells and whistles you could ask for on a RepRap.  Heated build plate, big power supply, bowden extruder, geared stepper, stainless steel, etc etc.  It's around $300 more than self sourcing, but only about $150 more than if you where to try to buy all the components individually (good luck on them being in stock).  This kit does have the advantage of being the same as a Self source Mendel, so you can get direct support for it though both Makergear IRC and RepRap IRC.  Build area is 200x200.

Makerbot Thing-O-Matic $1300

I love to hate on the Makerbot because they went up $500 on their kits cost in the last year, but the Thingomatic, which is the follow on the the Makerbot Cupcake is a much improved unit.  Their Mk6 stepper extruder is much improved over the Mk4 Extruder that I got with my $750 cupcake.  Build area is the smallest of the available kits at 110x110.

Rapman 3.1 $1300

The Rapman 3.1 is based off the Darwin platform, but has evolved steadily over the 4 years it's been around into a very solid machine.  It's the 1st machine I will mention here that is not fully open source.  The Rapman 3.0 designs where released, but 3.1 never was.  And the Electronics where never released at all..  It also Uses a closed source Program call Nettfab to drive the machine, but every person I have ever talked to that used it loves it.  Nettfab has a free version and a pay version that is $400+ dollars.  It does have the 200x200 typical RepRap Build area.

Ultimaker $1725

The Ultimaker by Erik has not been released yet, and to my knowledge no one outisde of people associated with Erik own one.  But at the same time Erik has a GREAT name, and the machine looks to print very well in the videos.  The Ultimaker uses a bowden caple extruder to get extremely fast x/y motion (300mm/s).  200x200 build area.

Up! 3d printer $2700

I am likely going to catch heck for suggesting it because it is ZERO open source, but so is Rapman 3.1 at this point so who cares?  The Up! has wonderful build quality, and is the only sub $5000 printer that you can literally take out of the box, set up in less than an hour and print with.  Build area 150x150


I hope this helps.  I am sure I missed some very good suppliers that I just don't know about, so if I missed you please comment below.  The above is just 1 man's opinion, and not official RepRap policy, because RepRap does not do official.  Like always if you have question please go search the Wiki, and ask questions in the IRC.  

excellent summary!
Neil, do you have any additional thoughts on the differences between the two types of bushings? Are the ball bearing bushings significantly better?

Nice write up, by the way. And I really like the weekly "state of the wiki" posts you've been doing.
Thank you. :)

I am using brass on all my machines. It's also what Makergear, Makerbot, & Ultimachine use. Brass is great at the speeds we print because we move just fast enough for it to "float", but are light enough that you will never ever wear it out.

I find the ball bearings to actually have more resistance than the brass (which is counter intuitive). But everyone want's ball bearings so I include it. :)
Very nice! Thanks Neil!
Great post man, this would have been really useful when I was making my machines (this was back in the days when you bought a BfB kit but got no electronics). Now for the shameless plug...

I'm not a supplier big enough to have my own website, but I sell machines either as completed kits or completed and tested machines. Right now I'm only selling to australia to save on shipping costs in case something goes wrong.

My prices are listed in the forum post,80230 I've realized I should have added photos which I'll do today with some of my produced prusas

and shameless plug over...
So this may be a dumb question, but why are those hot end kits ~$95 US when Techzone is $14.00?

I'm currently working my way through building the Techzone lasercut Mendel, but once I get it up and running, I'm going to print off parts for a prusa mendel and probably sell the techzone.
Teckzone has a horribe name in the comunity. Hot ends and electronics are not a smart place to go cheap.
LD: Compare what you get in those two kits... A chunk of wood with a whole drilled in it, compared to precision machined brass and engineered plastics. It shouldn't take long to figure out which is going to be the most reliable. Seriously, if it wasn't so far past the 1st, I would guess that hot end kit was a bad April Fools joke.

Remember, the hot end is the single most critical part of the printer. If it is unreliable, then everything else is as well. It may seem like a simple bit, but it is actually one of the most finnicky bits of the machine, so skimping there will be an exercise in frustration.
Can this blog entry be "stuck" somehow?
I find it very explicative.

Things that I think need more explanation (for the newcomers):
(1) Plastics: What plastics do I need? (differences) Where can I buy plastic? Can plastic be recycled from bottles? How much plastic does the Mendel parts cost?(i.e. amount of $/€ for the whole set of plastic parts)
(2) Electronics. All the wiki pages need to mention what an Arduino is and why is required. And why we can't instead request a free PIC from Microchip (yes, they give them away for students), buy some parts from the local electronic store and put all together.
David, a lot of this stuff is covered all throughout the wiki, but I mentioned the IRC several times for a reason dude :)

Crap in Crap out. "Virgin" plastic (1st use) is what is used with most products out there for a reason, and even the recycled stuff uses a pretty high virgin to recycled content. FDM printing (which is what RepRap does) requires the finest grade plastic for it to stick well and not be brittle. Sorry dude we are likely never going to use recycled plastic. :(

As far as the electronics, a vast majority of RepRap users just want a 3d printer, so we try to make the entry level on electronics very low.

Now if your just dying to do some soldering and use your free chips is your baby.

Have fun and good luck!
Thanks alot for thing, I know want I need for my printer now.
Botmill has a fully assembled Mendel for about $1400, and a kit for $1065. I don't know anything more about it than what's on their web site.
Hope it can recycle old plastic that are in a house. That will be great for the environment.
I hate to be nit-picky but you have GOT to proofread your blog so you're not mixing homonyms.
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