by makeme

Posts Tagged ‘emaker’

How Low Can You Go

In Uncategorized on 20, Nov, 2011 at 14:34

When it comes to 3D printing, the most expensive part of the system is the electronics.

Makerbot wants $370 for their Gen4 electronics. With their Gen6 stepper extruder (and the driver for it) costing $165, and a set of X-Y-Z motors costing $105, that puts the complete cost of electronics at around $640. I figure this is a good upper bound on what 3D printer electronics should cost since Makerbot’s electronics are probably the most professional and full-featured. I’m not going to include a heated bed in this comparison because it’s not strictly necessary to get started, it’s just a performance upgrade.

Obviously, when there are complete 3D printer kits starting at $500, $640 for just the electronics is unacceptable for my purposes.

The confounding thing is that when you move away from Makerbot (and complete kits in general) you start to have to source from multiple vendors. There is not, as yet, a clearing house for open-source 3D printer components. Sellers tend to focus on one or two options. Additionally, they tend to be located in Europe, so that whole “You want HOW MUCH for shipping?!?” thing gets reversed.

RAMPS and Gen6 are mid-range in terms of performance flexibility and cost. So, you know, whatever. All the electronics kits I know of use pretty much (if not exactly) the same stepper drivers, and they all use USB, and these days they all have an SD-card option, so unless one of them tends to spit out errors more often they all have the same 3D printing performance. 

Sanguinololu seems to be the strongest attempt to whittle the electronics down to just the bare necessities. eMakerShop sells the whole thing (including drivers & firmware tested) for about $170 shipped, they want $95 for the motors (shipped) and $75 for the extruder (shipped). That all comes to around $340. Solidoodle sells the whole thing (without drivers) for $105 (shipped), but doesn’t sell anything else. LulzBot can make up the difference with four Pololus for $65, four motors for $75, and a 12V 25A 300W power supply for $35. They have a hot end that they want $75 for. That all comes to around $350.

There are rumors of people pushing the electronics cost even lower. For example, something called GenL offloads most of the computation to the host computer by using more USB bandwidth. Another example is Repic by Mark Feldman, but I can’t find much information about it.

As you can see, the electronics is the most expensive part of the printer and the stepper motor/driver combination is the most expensive part of the electronics. The need for four bi-polar steppers and four microstepping drivers demands $120 minimum. You might be able to get that down under $100 if you get really lucky on sales or start salvaging parts. The biggest barrier is that these particular parts can’t be made much cheaper. The Sanguinololu board can be brought down to around $60 if you buy the bare PCB, then the components, then burn the bootloader with something you already had (or maybe you can find a chip that’s already burned). But the motors and driver prices aren’t going anywhere.

Some blue-sky ideas for lowering the cost even further involve basically starting from scratch and creating a new family of electronics. The primary reason steppers are so popular is that they don’t require any feedback for accurate positioning. It’s possible that coupling a feedback mechanism (linear resistor, optical encoder, whatever) with a standard DC motor to create a servo would be cheaper. It would also be possible to simulate the entire electronics board on an FPGA for a one-chip solution; just a PCB with the FPGA, its interface, and a bunch of transistors for amplification. Maybe the motors, and their complicated drivers, could be replaced with solenoids and some clockwork. Running all the high-power functions off of AC (out of the wall) might eliminate the need for a power supply (get logic power from the USB).


Practical Payback Period

In Uncategorized on 12, Jun, 2011 at 20:29

The payback period of an investment is the amount of time it takes for that investment to produce as much money as it originally cost. The assumption is that any money made/saved AFTER the end of the payback period is what you invested for in the first place. The payback period, then, is how long you have to wait to start seeing a return on your investment.

A 3d printer is, obviously, an investment. For the people who are interested in 3d printers themselves the payback period isn’t really an issue, but for the people who are only interested in what 3d printers can do for them it’s a different story. A common question is, “What can you do with a 3d printer?” People like me are usually quick to skirt the question with a passionate description of the future of 3d printing…but it’s a good question.

What CAN you do with a 3d printer?

Or, more specifically, WHY would the average person pick up a 3d printer at Sears on their way home from work?

I doubt that the proliferation of 3d printers will turn a lot of people into “makers.” Most people probably aren’t going to ever design a single printable object. Does that mean they’d never get their money’s worth out of a 3d printer? Well, I’d like to argue that the average person absolutely WOULD get their money’s worth out of investing in a 3d printer. The only thing holding back 3d printers from being a good investment RIGHT NOW is that they cost more than $500.

What I did was I went through thingiverse and kept track of all the things I could find that served a practical, but not overly specific, purpose (the table is included at the end of this post). After I found something that looked practical, but pedestrian, I shopped for it online. I found that most things could be had for about $1-2 dollars, which sounds about right for hunks of plastic. A few things, however, were more expensive. To make this a realistic test of the principle I made an effort to price out the cheapest thing I could find. Even holding the costs down, the estimate came out to more than $400 in savings.

This doesn’t include costs like the raw plastic, or electricity, but I can’t imagine those are greater than or equal to the costs of gasoline and shipping, which aren’t included either. Obviously, one could perform a more rigorous analysis, but I think the point stands. An average person COULD pay back the cost of their 3d printer $1-10 at a time…just as soon as the cost of the printer comes down below $500.

The cool thing is that we’re right on the edge of that price point. A 3d printer, the eMAKER Huxley, just recently got down to a promotional price of $500 each (for preorders).

So, if you picked up a $400 3d printer, and started using it to make things instead of buying them, how long would it take you to get past the payback period? Estimating 30 minutes per print, and estimating 70 items in that list, it would take you just over a month of printing 1 hour a day to have saved the total cost of the printer. Of course…handy people who like to do things for themselves will benefit more from this technology, but I think everyone else will start to get used to the convenience.

It’s not just a question of how much money you save, but also how much time and frustration. Pretty much everyone keeps a microwave around simply because it’s waaay easier and quicker to use than an oven or a trip to a store or restaurant. When 3d printers come down to $100 they’ll pay for themselves so quickly that apartments and hotels will keep them in rooms, right next to the microwave. The convenience factor will be overwhelming because the payback period will be functionally irrelevant.

estimated savings # project link

$2.00 each child deterrent device
$4.00 pair tire leveler
$1.00 each drink coaster
$1.00 each guitar pick holder
$20.00 each tripod mount
$7.00 each paper towel roll holder
$50.00 each lens gear for follow focus
$124.00 each peristaltic pump
$40.00 each solder fume fan mount
$3.00 each pillbox
$0.75 each bag clip
watch back replacement
$1.00 each small perf board
$2.00 each replacement table/chair foot
$1.00 each replacement drawer slider
$5.00 each capodastre
$5.00 each wall mount
$1.00 each headphone sorter
$1.00 each replacement knob
$7.00 each ukulele bridge
$1.00 each picture frame
mop/broom attachment
$2.00 each hex key holder
$1.00 pair jump rope handle
$1.00 pair toilet seat hinge
$0.50 each wire cube storage bracket
$1.00 each pencil holder
custom cookie cutter
wet food divider
$10.00 each cell phone stand
$2.00 each candle holder
$5.00 each emergency belt buckle
toilet seat holder
$0.10 each silverware
$1.00 each wall mount bottle opener
$3.00 each door latch
$20.00 each third hand PCB vice

stereoscopic camera mount
$30.00 each orange juice squeezer
$2.00 each lint roller
$2.00 each soap tray
$1.00 each sim card adapter

recycling bin key
$1.00 pack table cloth clamp
$12.00 each collapsible traffic cone

shower bar support
$1.00 each tweezers

$3.00 each pet brush

textile fastner
$5.00 each tie holder
$3.00 each sandpaper block
$1.00 each guitar string winder
$1.00 each whistle

curtain clip
$2.00 each protractor
$2.00 each component bins
$6.00 each coin holder
$10.00 each bird feeder
$1.00 each carabiner
$1.00 each file handle
$10.00 pack tarp clip

water bottle camera mount
$3.00 each door stop