Building a reprap incrementally

I'm excited about building my first reprap, but I'm afraid I don't have the budget to buy all the vitamins together now. Instead of saving up, I'm trying to build a prusa incrementally. Here's my plan:

1. Microcontroller & Power supply- $30
There are lots of cool electronics projects to do with just an Arduino. Of course, later on I'll have to build some reprap electronics which work with an Arduino (the Polulu electronics, for instance), but I should have enough experience with the Mega by then to overcome any challenges posed by DIY electronics as opposed to buying a Sangrolulu or Gen6 pre-assembled.

2. Stepper motors/drivers - $110
There should be some cool robotics projects to do with 5 NEMA 17s. Maybe a robotic car of some type?

3. Electronics - $30?
I'm currently planning on wiring up a RAMPS or Polulu electronics on a protoboard. Then I can scavenge components to save money.

4. Prusa Frame - $200
With just the frame I can test out the electronics and learn the firmware. I can tape a sharpie to the x-carriage and have a CNC plotter.

5. Extruder - $50 + filament
Finished! A few test pieces, a set of spare printed parts, and then I'm browsing thingiverse for 3D models!

6. Heated Bed - $40
To improve print quality

7. Bonus!
A second extruder, better electronics (maybe etched myself), etc.


Does this plan sound hopelessly naive? I'm sure my price estimates are pretty bad (although I can cite sources for most of them). I'd be grateful for any advice from experienced reprappers. Is there anything I should try to buy all together, rather than trying to spread the cost out? Am I cutting any corners that will come back to haunt me later? Am I forgetting anything?

Thanks!
Spencer Bliven

It's pretty much the same as my plan. About a month ago I first read about RepRap. I had a Teensy microcontroller and a couple thrift-shop scanner steppers laying around, so I half-baked ported Teacup to the Teensy, then spent about $50 on a couple Pololu driver boards and a beefy NEMA17 stepper to see some motion.

Then I was headed down the slippery slope. I saw that Wallace would work with the $16 20-oz-in NEMA 14s from Pololu, also that the 20oz met the Mendel requirements at wiki/Stepper_motor#Holding_Torque so I bought the $64+26 worth of steppers and stepper drivers & starter sourcing parts for the Wallace.

I've liked the idea of getting the multi-purpose steppers, stepper drivers, and breadboarding stuff before committing to some single-purpose plastic bits and electronics.

Of course I can't reassure you too much, since I'm not yet done, and am still waiting on a few bits. I figure my mistakes won't be terribly painful, and I'll at least have some fun steppers to play with.

I want to do the same thing, but I have access to some dead laser printers at work, and I'm pulling the steppers from them. I'm just not sure what to get controller wise, I don't want to risk burning out my Arduino.

I may have access to an old HP plotter soon.

Splated Wrote:
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> I want to do the same thing, but I have access to
> some dead laser printers at work, and I'm pulling
> the steppers from them. I'm just not sure what to
> get controller wise, I don't want to risk burning
> out my Arduino.
>

Many of the RepRap boards, (RAMPS, Sanguinololu, and the other [reprap.org] ) use the Pololu or stepstick stepper drivers. These stepper drivers would protect your Arduino logic outputs and amp them up to cover 28V by 2A, which would likely drive any stepper you might from equipment.

> I may have access to an old HP plotter soon.

One issue you might run into with found steppers is that their shaft sizes might not match, requiring corresponding mismatched shaft couplers and pulleys.

Good choice on getting some experience with arduino first. I did the same thing, and it makes uploading firmware and poking around in the code a breeze.

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-Nudel
Blog with RepRap Comic