interesting possibilities, found a used system.

reece.arnott Wrote:
-------------------------------------------------------
> Zach, I'd be willing to help with the cost of the
> Stratasys.


Me too. A very rough calculation shows that if this machine can print a set of all the RP parts for under $500 or so (which appears doable), even with an initial investment on my part of $100-$150 this'll still be a cheaper way to RepStrap than, say, the Sherline route that EricM has taken.

Let me know if I can help.

Kyle

Sorry guys, I hadnt realized you were looking at that stratasys system. I contacted Stratasys and the software for that model is no longer sold. Meaning that we would first have to locate a source for the software before purchasing the system would make sense.

Thats very common since the 3d printer manufactures want to prevent the sale of used systems.

Something else I have been considering was contacting local career centers to see if any of the wood/metalworking programs might be interested in an arrangement. For those of you outside of the States, career centers are alternative secondary schools for older kids that know they are unlikley to attend college and wish to work on technical skills rather than academic ones. Its not uncommon for them to have close relationships of this sort with area businesses.

Mike

The thoughts and ideas expressed in this post do not reflect those of my employer and are intended only as communications between individuals. Any attempts at implement are at your own risk

Edited 1 time(s). Last edit at 09/12/2007 09:14PM by ohiomike.

I had actually already contacted the guy (Art) about the stratasys software for the 1650 auction and he replied that he has the software and it is included but no manuals.

"Hi Tim,

We are running 3.4.1. We have disks for that version and 2.1 and 4.4 which
will be included. I cannot find the manual.

Thanks for looking,

Art"

Still at $1000, keep your fingers crossed...

Thats great to hear, when I contacted them they had not been able to locate them.

Mike

Hi all,

I haven't posted here before, but I have been working on a reprap machine for a couple of months now.

I am an inventor (aren't we all?) and have been developing a new sensing technology for the last 18 months. I have built a number of prototype devices and last year discovered the FDM process - wow. The last few models have been so easy to build! Along the way I've had to learn 3-d CAD (I use Alibre design, which I've found super-easy and very affordable) and have had a number of FDM parts produced (usually at RedEye RPM - expensive, but really great quality compared to Alpha.) I really want an FDM machine in my lab, but the cheapest one I've found which looks decent is the 200mc, which is $65K - ouch! That's one of the reasons I've been so interested in the reprap project.

I have two patents-pending for my sensing technology and am in negotiations with several groups who may wish to purchase the IP. If this happens, I should be able to afford the 200mc. This should happen within the next 3 months, if patent attorneys and IP marketers can be believed (yeah, I know...)

I spotted the 1650 on eBay the other night and placed a bid, before I knew that you guys were considering it. I could really use the 1650 in the short term for reprapping as well as my other projects.

So, here's my offer: as I am very interested in the project, I would be willing to print parts for other reprappers at material cost if I am successful in acquiring the 1650. If things go right and I'm able to get the 200mc, at that point I would donate the 1650 to the RepRap project. By making this offer I'm hoping to a) avoid a bidding contest which will raise the cost needlessly (since we share the common goal of a working reprap machine), and b) acquire a piece of equipment which would help my business a great deal.

Thanks for your consideration and good luck!
Pat

Pat,

That was a much better post than my first post, way to burst onto the scene. I think I can speak for everyone when I say that your generous offer is much appreciated. I was going to suggest a similar proposal but I just don't really have the space at my house to store the machine properly.

If this works out I nominate you for RepRap sainthood.

How far along is your machine?

I have the extruder working and am designing the Cartesian robot. I'm not sure which way to go on that; I was going to use steppers until I found out how expensive they are, so I have some 12- and 24-volt DC gearhead motors on order which should drive a reprap machine very nicely. They were only about $15.00 each and produce about 70 oz/in at 200 or 300 RPM (12/24V). I have been following Forrest's progress with great interest and hope to build a similar system. I like the basic design of Darwin, but am not such a fan of steppers. Anyway, I'll get the motors in a few days and if I get the FDM machine it should really accelerate the process.

Do the motors have position feedback like a two phase optical encoder? Steppers allow non feedback positioning that is accurate and predicable. DC motor speed can be control by voltage, but position can't. I have a rep strap 3D stepper robot, but no extruder yet. How did you make the extruder? I sure could use some of your talents! You got a brand new pair of roller skates and I got a brand new key!! Do you live near Ohio?

No, the motors themselves do not have position feedback, but there is an easy solution: mount a small magnet on the end of the leadscrew and use an AS5040 encoder chip - 1024 quadrature steps per revolution, way more resolution than we need.

I cut my extruder parts out of 1/2" white plastic sheet I got at the hardware store (I think it's Polyethylene - it's sold as "cutting board" material) using my bandsaw. It cuts and machines great.

I had a terrible time trying to make the 'smooth' parts of the threaded rod, so instead I got a piece of 1/8" stainless-steel shafting (Small Parts Inc. sells this pretty cheap) and cut two pieces of brass threaded rod (one short for the bottom and one longer for the main drive section), center-drilled them, and JB-Weld'd them onto the shaft at the right positions. That gives me a stainless-steel polished surface to bear against. I do actually have a lathe, but it was still easier to build it this way and I'm very pleased with the result.

I made the shaft long enough that I didn't have to do the flex coupling to the motor, which as far as I can tell was just so the motor would be out of the way of the filament, but if you mount the motor a bit higher (with a longer shaft) the filament can flex just a bit and enter the channel just fine.

Otherwise, the design's pretty stock.

Alas, I'm in Oregon, but am happy to help any way I can. I do analog/digital circuit design, PCB layout, chip design (Verilog) primarily targeting FPGAs, embedded processing, DSP, assembly, C, communications, and Windows GUI programming (Delphi and Java). I could probably hack another extruder head together pretty quickly (I got enough materials for several) if you want one. The only thing I'd need to know is if you have specific spacing/size requirements for the mounting holes to secure the extruder to the moving stage. The materials cost is probably < $20.00 for the whole thing.

I am using a dremel drill press with two circular straps. I have to measure the diameter and the spacing. Do you take paypal? I have some excess electronics parts, I even sent some to Evan in Ireland. Let me know what you need? The magnetic encoder sound great, 1024 PPR is accurate as hell!

ohiomike Wrote:
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> My next thought was that based on conversations
> and websearches I have located a manual 3d
> printing system, RapidPro, that takes a STL cross
> sections it and plots it on a vinyl cutting
> machine. RapidPro costs $900 and a basic automatic
> vinyl cutter costs $400. Assuming 50% usage of
> materials bulk vinyl would cost $1.50/in^3 so
> thats about $75 per set of parts. But you have to
> strip and stack the layers yourself (it uses
> locator pins to line up the layers).

What about the Desktop Factory 3D printer? It's $5,000, but material is only $1 in^3. It can read STL files directly.

Their website is here: [www.desktopfactory.com]

owad Wrote:
-------------------------------------------------------
> What about the Desktop Factory 3D printer? It's
> $5,000, but material is only $1 in^3. It can read
> STL files directly.
>
> Their website is here:
> [www.desktopfactory.com]


The Desktop Factory is only slightly further along in development than we are, they recently sent out a newsletter proclaiming their first beta customer (an art school). Waiting for them might take as long as it would to develop the project without them.

Kyle

If I recall correctly, Bill Gates is bankrolling them.

There was a story in the Oklahoman recently, about a non-accredited private school that had gotten funding from the Gates Foundation.
It seems the founder put his school down for foreign exchange students...someone accepted.

Now, it seems the DHS should have shut them down, had it been in their power to do so. The founder of the school is STILL behind on rent for the school and teachers salaries, (he'd been in trouble with the law for floating checks before.) One of the faculty, who hosted a kid, had cockroaches, which freaked out the foreign exchange student, but that student kept quiet because he'd been told at home to honor local customs and ways. The founder told his own charges he was gay, and asked if that was a problem. The two german boys thought that meant "happy", not having a real good grasp on americanisms. They got freaked out about it later.

Oh, and there is or was going to be a shakeup with the NPO that handled the foreign exchange program.

Just because Bill Gates throws money at something, doesn't make it a success.

Oh. I forgot to mention the best part.
The germans saw that the school had received money from the Gates Foundation, and took that a a good sign of the quality of the school.
Also, a slight edit to clarify. The student who was freaked out by the cockroaches was living with them at the time.

One last edit, and I'll stop.
[newsok.com]

Edited 3 time(s). Last edit at 08/01/2007 07:08PM by Sean Roach.

Roach_S Wrote:
-------------------------------------------------------

> One last edit, and I'll stop.

Thanks!

So the stratasys auction ended at $2550 which seems really reasonable to me since it had software and everything. Was it anyone from here that picked it up? If not guess the search will continue...

It wasn't I. My top bid was $2500. I based this partially on a conversation I had with a Stratasys rep. She said three things which limited its potential value to me:

1. People generally buy such a machine for spare parts; the extrusion head has no modular components, so when something goes wrong it's pretty much a new head or fix it yourself (most people here could probably do that anyway.)
2. It's s-l-o-w.
3. You can't buy materials for it unless you have a site license for their software, which they're happy to sell you for $1,500. I think this is a LAME policy, but there you go.

Man, these grapes are sour...

Sadly, that is just one of many policies that Stratasys has that makes a considerable number of their clients absolutely loathe them. ><