A complete-ish RepRap sold

Posted on April 8, 2010 by Maker Block

A few days ago I posted about a RepRap Mendel for sale on eBay with all electronics, motors, belts, etc fully assembled. 1 The auction (for a set sold in Ireland) settled at 760.00 Euros or about $1,017.18 USD.

Frankly, I would have thought it would have sold for more. Printed parts are still selling in the $300-$450 range, electronics clocking in at $250 or so, bearings at $50, and all the other bits probably costing another $100 for belts, rods, nuts, bolts. This means just the materials would cost $700 – $800. Then there’s the delay and extra expense of sourcing all of the parts for yourself.

Interestingly, I had thought the bottom had fallen out of the RepRap printed parts eBay market. However, a set of printed Mendel parts just sold on eBay for $455 on April 5. I suspect the difference is that these parts are being generated and sold in the US which makes for an easier and slightly cheaper transaction

To be fair, the seller mentioned it would require some adjustment to start printing. [↩]

Have we reached the bottom already?

Posted on April 5, 2010 by Maker Block

Having reached the bottom of a market can actually be a very good thing. It means anyone who wants a set of RepRap parts can have them for as little as the market will bear. Right now there are lots of options for someone who wants to get involved in building a RepRap/RepStrap. You can get a MakerBot, RapMan, ShaperCube, Profound Devices, Isaac Mendel, or pick up a large selection of parts on eBay.

As an owner of a MakerBot, I’m far more likely to want to print up my own RepRap parts than buy them. However, each of Spacexula‘s Mendel print sets would probably take me 2-3 hours of print time plus about 15 minutes of human intervention/monitoring.1 I would of course also print up parts for any friends/family who wanted parts. 2 I’d be willing to do this to create my own Mendel, but the idea of spending three weeks3 , say $30 in plastic4 , and about six broken up over that three weeks fiddling with stuff5 makes me wonder if there’s a better way to make $300.00.

Setting that aside, I wonder where the bottom of the RepRap parts market is heading? Spacexula has suggested around $250 or so based upon the price for lasercut parts. I suspect the price of printed parts will always be higher than the price for lasercut or molded parts – because of the time involved. Lasercut parts can be cranked out as quickly as a lasercan cut. 6 Molded parts can be churned out as quickly as the poured material can be dried. Plus, no matter how nice lasercut/molded parts are – you still have a RepStrap, not a true RepRap. Assuming identical quality, I’m probably always going to be more interested in printed parts over alternatives.

Such as setting up, warming up, untangling plastic, checking, peeling off, etc. [↩]
At this point, this is purely theoretical/hypothetical since none of my family/friends are interested in their own RepRap. Hmm… Maybe I should talk about RepRap MORE??? [↩]
A little over one sheet a day [↩]
I haven’t weighed a sheet of Mendel parts, so this is pure conjecture. [↩]
Assuming no extruder clogs, blocks, PTFE bulging, oozing down the threads, and problem free printing… [↩]
How many phasers could a laser slice if a laser could slice phasers? [↩]

A RepRap business model

Posted on April 4, 2010 by Maker Block

So, here’s an idea – much like the distributed manufacturing system for printed pulleys, why doesn’t someone set up a website business for RepRap parts? Here’s the outline of the business plan:

A price could be set for a particular RepRap plastic part, depending upon size, complexity, scarcity, how many more are needed to make a full set, etc.
People with RepRaps/Straps can register for an account and send in RepRap parts, and get their account credited for those parts.
- Ideally, the website would also have an area where you can print out a table of contents – with bar codes. That way the receiver could just scan the parts into their inventory – and verify the contents/quality later.
People who send in parts are paid on a regular basis electronically.
The site also contains a store where you can purchase an entire set of printed/molded RepRap parts – or perhaps just those ones you need.
It would be quite handy if such a site also sold the various other parts needed for a RepRap – bearings, metal rods, electronics, fasteners, etc.
I suppose the sets could be sold on a bid-style basis – and the parts paid for pro-rata. 1

This idea isn’t without it’s problems:

How do you ensure a minimum quality in crowdsourced parts?
1. Perhaps you could use a seller/rating system like BrickLink does for lego vendors?
Why would someone buy/sell from a website like this rather than eBay?
1. Well, eBay and Etsy each take about 3.5% with PayPal snagging another 3% or so. Assuming sales are handled through PayPal2 , you’re talking about basically 6.5% out of the seller’s end.
2. Assuming you go with PayPal (3%) and you charge less than the 3.5% for eBay, you can probably attract buyers and sellers. The problem is once you’ve gotten this far, you’ve basically re-created eBay buy-it-now or an Etsy store. To succeed you’ll need to serve the market better or cheaper.
As soon as RepRaps in the wild increase or demand for parts is met, won’t the bottom drop out?
1. Quite possibly. A week ago Mendel plastic parts were selling for $450. 3 Today it looks like parts are going for about $300 or so. Then again, a set didn’t sell with a $200 reserve just a few days ago.
2. How many sets have been sold on eBay anyhow? A dozen? Let’s say it was 20 sets at $450 each. 20 * $450 * 3.5% is $315.00. If 100 sets are sold at $300 with a 3.5% cut, that’s $1050. Neither of these amounts would not have been enough to entice me to code a RepRap sales site – but I’m a slow coder.

That would be a fancy bit of coding… [↩]
it’s the easiest to write plugins for – heck I’ve written a few [↩]
Adrian Bowyer’s set sold for $620. But, I suspect that was an anomoly. [↩]

Full RepRap for sale

Posted on April 1, 2010 by Maker Block

A complete 1 Mendel for sale? That’s incredible!

There has been a truly amazing progression2 in RepRap parts lately. While I’m not crazy about eBay as a way of selling3 , it’s a very democratic4 way of disseminating RepRap parts. The first few parts and sets of parts were all printed, then molded, now MOLDS are for sale?!

Yes, the Platonic ideal of RepRap is that a machine makes the components of the next machine. But, is it not also part of the RepRap ideal that these machines be disseminated as far and as widely as possible? It’s really great you can use a RepRap to build another – but that doesn’t mean it’s the best/most economical way.

These RepRap mold are advertised to be good for roughly 50 pourings. It is advertised to create 9 vertexes at once, but they all appear to be 1/2 vertexes. The posting also suggests it takes 12 vertexes for a full RepRap. So:

12 vertexes per RepRap / 0.5 vertexes halves = 24 vertex halves required
24 vertex halves required /9 vertex halves per sheet = 2.67 sheet uses per RepRap
50 uses per sheet / 2.67 uses per sheet = 18.75 sets of RepRap vertexes

Admittedly, this is only a set of molds for the frame vertexes, not the entire set of parts. However, it’s really only a matter of time before a set is up for grabs.

This makes me wonder – is there a different market value to printed parts rather than molded parts?

ish [↩]
transmission?? [↩]
having sold things on eBay myself [↩]
fair? capitalistic? [↩]

Fair wages for Robots!

Posted on March 22, 2010 by Maker Block

Several hours ago I posted about two eBay auctions for full sets of Mendel printed parts. I just checked on them to check out where the two auctions ended. One ended at $446 (actually, at 330 Euros, for a seller located in Ireland) and the other at $455 (seller located in Ohio).

Why, then, would an auction just two days ago go for $630 (rather, 420 pounds)? A sale at 420 pounds implies someone else was willing to bid 415 pounds. I’m guessing it’s a combination of factors that went into a $600+ sale – perhaps because the English really want RepRaps, people wanted to support Adrian Bowyer, anyone who bought RepRap parts from Adrian himself can basically be assured they’re getting quality parts.

This tells me $450 seems to be the going rate for a set of Mendel parts (for now). This raises an interesting conundrum. Will the prices go up as more people become interested in RepRap? Will the prices go down as people start printing and making available more RepRap parts?

Either way, suppose the going rate is $450 for 60 ‘bot hours. That’s $7.50 an hour. This is less than the minimum wage in California!1 This means if human help is required at all in the production of RepRap parts, the entire process is taking longer than 60 hours and the hourly rate is even lower than $7.50/hour!

I’m not saying RepRap parts should cost more. I’m just saying I was really getting used to the idea of a gnome sitting in my living room earning above minimum wage while I slept.

Oh well, I guess I’ll just have to take solace in running a robot sweat shop.

$8/hour right now [↩]

My own plastic gnome

Posted on March 21, 2010 by Maker Block

1. …or Minimum Wage Rights for Robots!

MakerBot posted a screenshot of a RepRap Printed Mendel Parts auction that sold for 420 pounds – roughly $630.84. 1 2 Others have been posting RepRap Mendel auctions as well. One just sold for roughly $453, another for about $270, with two more auctions around $450 each with at least 3 more hours to go.

Using Spacexula’s Mendel production files, 24 STL sheets of parts, averaging 2-3 hours a print, we’re talking roughly 60 MakerBot print hours. 3 Assuming I only have the patience to print up one STL sheet a weekday and two sheets on the weekends, starting on a sunny Sunday like today, I could finish in 19 days.

Assuming very little human intervention, $600 for 60 hours of MakerBot operation is a pretty good deal. It’s like having a fussy gnome who eats electricity and plastic living in your home and earning just above minimum wage for you. 4

According to Google and at the time of this post. [↩]
I couldn’t find a link to the actual auction at first, but then figured it must be a private auction. It turns out this was the RepRap eBay auction posted by Adrian Bowyer a little while ago. You might need to be logged into eBay to visit that link. [↩]
This assumes no failed prints. [↩]
You know, like those shoe gnomes that made shoes for the cobbler in that children’s fairy tale. [↩]

Replicating without a RepRap

Posted on March 18, 2010 by Maker Block

I’ve read others writing about creating molds for pulleys and molded RepRap parts. Is this something you do? Several of the Mendel sets on ebay appear to be parts cast from molds. This would seem to be a very cost effective and relatively quick way to replicate parts.

At the same time, I’m not sure just how useful it is. The best thing about a RepRap/RepStrap is you can tell the robot to build you something while you go out for a beer or take a nap. Casting molds (from the reprap.org link above) seems to be a more involved and detailed process require a fair bit of human intervention.

Given that a set of printed or molded parts are selling for upwards of $400, I have to wonder why no one has stepped up to create a huge mold with all the parts and just start stamping them out.

I also wonder – if everyone had all the plastic/reprap’ed parts they needed – what would the next bottleneck be? Electronics?

MakerBlock

And I, for one, welcome our new robotic overlords

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