Friday, October 21, 2011

Cost Breakdown

Instead of this post showing what I believe the costs are expected to be, I will be posting my actual costs. Hopefully that will help you all out even more since I believe my actual costs are much more meaningful. That being said, though these costs are literally what I have spent they are somewhat dated, considering I ordered everything more than 6 months ago. Hopefully if you decide to build a Prusa your actual costs will be less.

My Prusa: mostly put together.
As for my final costs? I spent less than $600 total (so far) and do not expect to spend any more (except for upgrades)! Keep reading to find out how.

The Breakdown

In order to really optimize cost I broke down the project into a few categories which I called part groups. These are the categories I have chosen, keep reading for a quick explanation of each category.
  • Printed Materials - The printed plastic parts.
  • Vitamins - All the non-printed hardware.
  • Stepper Motors - The five stepper motors needed.
  • Hot End - All the parts needed for making the hot-end
  • Electronics DigiKey - The electronic parts I needed to order from DigiKey.
  • Electronics Mouser - The electronic parts I ordered from Mouser.
  • Gen6 PCB - The cost of the bare PCB
  • Filament - The plastic filament needed for a few prints and initial tests
  • Print Plates - The wooden plates on which things are printed on.
I will be going over each section individually, but here is a summary of each category and how much it cost.

Printed Materials - $120.55
Vitamins - $171.55
Stepper - $105.70
Hot Tip - $70.29
Electronics DigiKey - $33.20
Electronics Mouser - $34.92
Gen6 PCB - $35.78
Filament - $20.50
Print Plate - $0.00
Total - $592.49

The printed materials were purchased on eBay as I mentioned in this previous post. The overall cost including shipping was $120.55. The vitamins cost me $171.55 total including shipping as I also mentioned in a previous post. This was a bit more than I would have liked, and if I ever build a second Prusa I will be buying the parts individually from McMaster Carr. For first timers, I would recommend just buying a kit as it is easier and much less of a headache. I believe that kits which include the printed parts and vitamins should cost about $200 total; though it is possible to save upwards of $50 if you ordered the parts separately and shopped around.

I actually made a mistake in the post where I talked about the stepper motors. Even though I said that I bought the motors from SparkFun, I ended up buying the motors from Pololu. The reason? SparkFun's stepper motors were out of stock and I did not want to wait for them to come in. I ended up cancelling my SparkFun order and put in a new order at Pololu. The total cost was $105.70 including shipping. In hindsight, I should have ordered these from Ultimachine because the motor shafts come with a nice flat edge on them.

The first two parts of my hot end.
The hot tip, or hot end, was a bit more complicated than the other categories. This is the part of the Prusa with the least documentation and it seems like everyone does it somewhat differently. Using McMaster Carr the total cost for parts came out to $70.29. This is a bit high because of the minimum quantities, but I have enough material for more than 4 hot ends (if I decide to machine that many). The cost should be closer to $20 per hot end if I do not need any extra material and exclude labor. I will discuss how I built this and the parts needed in a future post.

A blurry picture of my soldered custom electronics.
I broke the electronics into three separate categories; the first two are for the components and the third is the cost of the PCB. Not all the parts were available at Mouser (my supplier of choice) so I ended up buying some parts from DigiKey also. Mouser and DigiKey came out to a combined total of $68.12. Keep in mind, I bought extra parts for almost every component (enough to populate two full PCBs) and I received many of the parts through free sample programs.

I ended up getting three copies of the circuit board. The service I use to get PCBs made, gives you three copies of your board at $5 a square inch. The PCB came out to about 3.6 x 2 inches, so I spent a total of $35.78 for three boards (that is a little less than $12 a board). I will post much better pictures when I discuss my design in a separate blog post.

PLA Filament from Ultimachine
Back when I bought my filament, I considered using either Ultimachine or eBay and ended up deciding on using both! I spent $20.50 on 1 pound of filament including shipping on eBay. The cost for 1 pound of filament from Ultimachine was closer to $25 including shipping. From everything I have read, the quality of Ultimachines filament is superb. I haven't had a chance to try filament from other stores yet, but when I do I will write a post about it.

The last cost group is the print plates. As I was trying to spent as little money as possible during my initial built, I decided to use MDF print plates instead of aluminum or acrylic (or any of the other materials people use). My decision was made easy because my brother had some scraps of MDF around that he cut for me. The cost? Free.


All in all, I think I did a great job of keeping it cheap. Keep in mind, all the prices mentioned in this post include shipping. Sure, there were some areas where I cut costs where others might not be able to, but that's the nature of RepRap. What should you take from this blog post? It is indeed possible to get a fully functioning RepRap with less than $600 and a lot of free time. I'm not saying that there aren't millions of upgrades I would like to buy for my printer (e.g. heated print bed), but this post shows what it takes to get started with a "bare-bones" Prusa.

You can expect to see a separate blog post for most of these categories, where I will show you what exactly makes up each category while I discuss how my build went.

Do you see anywhere I could have spent less? Let me know!