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Another DIY repstrap analysis after one year observation

Posted by sheep 
Another DIY repstrap analysis after one year observation
February 15, 2010 01:50PM
Rather than clutter up some of the other threads with more off topic analysis, I decided to create yet another thread.

I was amused by the CNC MILL wiki page. Is this sarcastic tone really the image that should be presented to interested parties?

If so, I have more to add in the same spirit.

I liked the comment of knocking up a Bridgeport to work as a repstrap controller in a week. While repstrapping my 20 year old RobotMart converted Prazi mill lathe CNC is still in progress after a year. Perhaps I am not dedicated enough. My desktop mill is quite a bit smaller, but the motors on it are large enough. These motors make good hand warmers while I test the software installation.

At first it looked like a Darwin could be done in a month or two. I have a bunch of old steppers, some threaded rods and other materials.

It quickly became apparent that there was more imagination than practical progress. What progress by others has been made seems to be in the form of resume padding, requiring the latest versions of software tools that run on expensive hardware.

I posted criticism on some of these thought on this subject and was met with the usual attitude. Since I had no opinion at the time, it was easy to adapt this attitude for myself. That this is a Do It Yourself project and nothing else is important. So what does it really matter what others think, as long as it runs on the latest version of Linux built from the unstable branches.

My experience has been with firmware, I have a lot of AVR development tools. Recently I had the epiphany, that the electronics are no different that the MIDI file players I have made and have parts left over from. I have written much in the last few weeks on this subject.

I even spent a week(which could have been used for code development or board layout) and managed to open my own repository for yet another firmware path. I still have yet to make the time to update my blogs at delectra.com. Perhaps this will inspire me.

Of course I am re-inventing a wheel, but the wheel does turn the way I want it to. This seems to be the main focus here. Do something then say something about it. I tend to do things, then say a little about them. Or to say a lot, then do something else.

First on the firmware, I got rid of that pesky C compiler. This way I do not have to worry about incompatible build libraries. NC code is 60+ year old technology (from the paper tape days) which was made digital by the industrial complex of the 1960s, perfected in the 1970s.

There are tons of websites, a search click away that explain, In simple terms how to do someone else's homework and make a stepper motors draw pictures. The micro-controller forums are full of this information. Especially if one wants to convert the coefficients of temperature sensors to ASCII codes.

Drawing pictures, is much simpler than playing music. All those pesky notes and measures get in the way. One one gets rid of the music, there is plenty of room in my code left to draw pictures. In theory, not much more than 8K of code space is needed. Ideally one needs at least 1K of S-Ram, so slightly larger chips can be used.

What controller need is there, for a powerful vector processing computer? If the program is going to slam the axis into the framework anyway? This can be done with 8 bits as easy as with 64 bits. So we can do without the supervision of the master computer and give freedom to the slave. Like management some sort of high end processor is needed for the slicing and dicing. But this is just the sausage making side of the process. Now that is an extruder!

Of course no one does meat slaughtering with C, So Java or Python is used instead. Not that these are platform independent, but they do leave one with a good buzz and a warm and fuzzy feeling inside. The rodent might object, to that squishy sweaty feel. Most of the practical contributors here like to point out this is the way nature works. The only revision needed is the source code revision.

So after a year, I have not made as much progress as I would have liked. The CNC has better commercial crippleware software on it. My extruder still lacks a practical source of plastic. The v1.2 stepper controllers are still unpopulated. At least I made some progress making a more portable(between small processors) asm version of the firmware.

There is much to still criticize as to the usability of the reprap project. On the other hand, Brutus, there is much to praise. Hopefully we can continue to discuss this. I have made my own peeves regarding platform dependency (Linux on the latest vector processor) clear. I have also worked to make the solution that I want.

Even so, I am dependent on the work of others, especially the reports of nophead, as to what directions I want to take. I was pleasantly surprised with the professionalism and packaging of the parts I ordered from makerbot many months ago. More recently I have been looking the different firmwares out there. Choosing which parts I like which I do not.

This is what makes reprap special. That I can rant and rave about what I do not like then find the parts to steal that I do like. More like the spirit of the early days of computing, before the distinction of source and object code. The pooling of ideas.

So keep those ideas coming and the threads here active, because that is what will keep reprap from being a dream and a lie, to something practical and real.

-julie
Re: Another DIY repstrap analysis after one year observation
February 15, 2010 03:33PM
I was amused by the CNC MILL wiki page. Is this sarcastic tone really the image that should be presented to interested parties?

Probably not. I typed it, so I should clean it up. smiling smiley

Also, this thread wil get moved to the MillStrap Forum as soon as I create said forum.
Re: Another DIY repstrap analysis after one year observation
February 15, 2010 03:48PM
Personally, I loved the D&D references at the end smiling smiley
Re: Another DIY repstrap analysis after one year observation
February 25, 2010 02:14PM
I would love to see a steampunk reprap. that would be cool.


Necessity hopefully becomes the absentee parent of successfully invented children.
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