Parallel port capability?
May 25, 2007 11:25PM
How about adding parallel port support for some of the "hobby" CNC boards? The price comparison to buying all of the components required is less than building all the electronics yourself, not even taking into consideration the time investment of putting everything together. Yes I realize this is a sidestep from the RepRap spirit of self replication, however I might also add the questions of waste, chemical disposal, and the fact that the PCBs (microchips even!) cannot yet be made with RepRap. How many people have poured a gallon or two of Ferro Chloride or Sodium Metasilicate solution down the drain? :+(

I hate to be such a weenie right off. Short of having an army of RepRap machines which CAN fabricate the electronics, cross compatibility seems a good solution. If someone can point me to the files which would need overhauling I'll look into it. The thermostatic control will have to be made to work independently or controlled by other means.

The idea of building this device has me quite enthralled. The idea of building a rapid fabricator, or other robotics, has crossed my mind quite a few times however finding a data store and direction to help achieve the goal hasn't been as easily available as here. I look forward to contributing to this project... and picking a few brains. :+)

~Seth
smileys with beer
Re: Parallel port capability?
May 26, 2007 03:50PM
Hi Seth,
You could do any of that. I'm sure there are lots of people with access to CNC and that might prove worthwhile for them. The key piece would be providing an interface to the cnc machine that used the reprap software. If you are concerned about the extrusion, just add that piece and integrate normally. As for the CNC control, I'm not sure what they use. You could opt to use reprap to control the CNC steppers. Othewise, you would have to reroute the commands to the parallel port and do appropriate semantic (reprap meaning to cnc meaning) translation. That might be an interesting side project if you can find enough people with the skills to make it work. That would not enable you to do subractive work except in special circumstances so maintain the original capabilities in some sort of quick change adapter(s) or connectors.
Anonymous User
Re: Parallel port capability?
May 26, 2007 06:04PM
The other advanatge would be for those of us who own PCs that don't have serial ports on the back! grinning smiley
Re: Parallel port capability?
May 27, 2007 07:13PM
That would be a different and probably simpler project (not that I'm signing up to do it). Parallel to serial adapter and software driver to make parallel port pins look like serial port. Might even be something like that out there.
Re: Parallel port capability?
May 27, 2007 09:08PM
With USB-to-RS232 adapters (like those at [www.newegg.com] ) selling for maybe US$8 to US$15 or so, and PCI USB cards (like those at [www.newegg.com] ) for US$6 to US$12 or so), is such a parallel-to-serial converter sub-project really appropriate? Anyone with a PC that lacks PCI slots and also lacks USB ports is, I submit, almost certainly trying to use a PC that is too old (or too otherwise unusual!) to meet other [reprap.org] requirements anyway.

Jonathan
Re: Parallel port capability?
May 27, 2007 10:14PM
I didn't say anything about adding parallel to serial support. What I'm saying is there are stepper controllers selling for around $150 to $300 which use parallel cables natively.
Re: Parallel port capability?
May 28, 2007 12:10AM
net3d Wrote:
-------------------------------------------------------
> I didn't say anything about adding parallel to
> serial support.

True. However, in this thread, Bozz wrote:
-------------------------------------------------------
> The other advanatge would be for those of us who own
> PCs that don't have serial ports on the back!

This is the idea being responded to in the last couple of posts.
Consider that a sub-thread, if you like.

> What I'm saying is there are
> stepper controllers selling for around $150 to
> $300 which use parallel cables natively.

We may have a terminology mismatch here? The "stepper controller" boards that are part of RepRap Darwin are not anywhere near that expensive. [reprap.org] and [reprap.org] . Maybe US$16 of components, plus the PCB itself. Call it US$25. One for each axis, and we're still under US$75.

Could you please provide a URL or two to web pages describing the devices you are talking about that you refer to as "stepper controllers"? Are they what RepRap calls a "3D Cartesian robot" plus the related control electronics?

If you can really buy what would amount to "a complete RepRap equivalent excluding the extruder" for US$150 to US$300, that would be really spectacular... links please!

Jonathan
Re: Parallel port capability?
May 28, 2007 01:03AM
I think I have found my answer here: [forums.reprap.org] Using a standard CNC board is not possible, the output from reprap software is not compatible.

I don't believe making the stepper controlers is possible for $16. Especially when you take into consideration the time needed, tools and everything. This statement isn't logical. For comparison, I have a broken window in my house which I could replace for next to nothing using sand from my back yard...

Ah, I didn't say anything about a complete RepRep equivalent. The closest thing I've seen is the Fab@home stuff (which looks like cool, but seems to have little function). I'm just looking for an out of the box electronics package replacement.

Some of the things I've been looking at are:

4 Axis 4 Amp Unipolar Stepper Motor Driver
[www.stepper3.com]

XS-3525/8S-4 Stepper Motor Driver Board
[www.xylotex.com]

MC433 4-Axis Unipolar Stepper Motor Controller
[www.soc-machines.com]
Re: Parallel port capability?
May 28, 2007 02:17AM
net3d Wrote:
-------------------------------------------------------
> I don't believe making the stepper controlers is
> possible for $16. Especially when you take into
> consideration the time needed, tools and
> everything. This statement isn't logical.

It is rare (though not totally unknown) for me to make illogical statements! For someone who already knows how to solder and owns basic soldering tools, the statement that "a RepRap stepper controller board can be built using about US$16 of components and a PCB" most certainly is a both rational and valid statement.

I personally checked all the parts prices (from the BoM at [reprap.org] ) at [www.mouser.com] -- did you? Such basic soldering skills and tool ownership are fairly common in this community. Factoring in "time needed" seems out of place on a research project being constructed by hobbyists, don't you think?

This is a research project. Expecting commercial boards to be a drop in replacement, and wanting major software mods to talk to those boards, just to avoid a little soldering, is the irrational expectation, it seems to me.

> For comparison, I have a broken window in my house
> which I could replace for next to nothing using
> sand from my back yard...

Right! For someone with a glass-making and cutting factory in their garage, this could be entirely valid :-) Fortunately for our project, more people own soldering irons than have glass factories in their garage. If you have *way* more money than time for rapid protoyping... just buy a StrataSys :-)

For RepRap hobbyists who can solder and have an iron, diagonal cutters, and so forth, the US$25 total price per board I used is entirely valid. Starting out with no tools (and being very cheap!) ..., well, I could buy a dirt cheap soldering iron, solder, and a pair of diagonal cutters and a multimeter (US$5 + US$2 + US$2 + US$6 = US$15, from somewhere like [www.circuitspecialists.com] ) and still come out ahead. We'd then be looking a a parts cost for 3 stepper controller boards of perhaps US$90 total, (so US$30/board) and I'd have the (admittedly low quality and very minimalist!) tools too,

> I'm just looking for an out of the box electronics package replacement.

OK. That's now clear. For that, you can just wait for complete Reprap electronics kits to become available at the store: [parts.rrrf.org] . Then, you can ask a friend who can solder to populate the boards for you (or, ask Zach if the store plans to carry pre-built and tested boards... maybe it will, I don't know!). Even if you pay your friend US$50 to solder up the boards for you, you'll probably *still* come out cheaper than the US$150 to US$300 you mentioned!

Jonathan
Re: Parallel port capability?
June 07, 2007 10:28PM
I get it, it's the journey as much as the destination. I say it many times myself that nothing worthwhile is easy, yet I thought it might be worth at least asking to make it easier... No harm is asking?

I've already learned quite a lot. And already received clad PCB and electronics for the v1.0 COM board... and some weak motors...

~Seth
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