Removable Indexer on a PRT

[br928]

I finally got around to mounting my indexer on my PRT. I could not permanently mount the indexer so I had to make it removable. The Z axis for the router is set up so I can use the overhang at the end of the table to reach the indexer. The indexer platform hangs from the C rails. There are bolts on either side to adjust the platform to square it up with the Y carriage. Once that is done the platform is clamped to the table legs.


5283

I read over a year ago where more documentation was forthcoming on this accessory. I have not been able to find much. I missed the Austin SB camp and understand there was some discussion there about using the indexer. Has anyone come up with some good software yet? (maybe ought to ask Vetric for a post!) I know some of you other botters are using these. So share some of the wealth of knowledge!

[myxpykalix]

Stan, that was my post:
http://www.talkshopbot.com/forum/messages/312/19760.html
and the short answer is that since that time, almost a year ago, nothing has been forthcoming.

[br928]

I guess if you keep someones "feet to the fire" long enough they get used to it! Ted?

[mrdovey]

As with open-source SB_CUT code, I think the expression is "RSN".

[br928]

Morris, how about another hint. RSN?

Where are all the indexer experts? I need to put this accessory to a challange.

[scottcox]

Stan,

That's a tough one, but the indexer is also one of the main reasons that I bought a shopbot.

I've done work on it a couple of different ways.

1) Wrote my own programs for simple spirals using windows notepad. See the wiki for details...

2) Converted "flat" 3d files into "round" files by converting the M3 commands to M5 commands and changing the Y moves to B moves. Email for more info on that. I'll try to find it.

3) Using Vectric's Cut3D for 4-sided files and rotated the indexer 90 degrees between sides.

[Brady Watson]

Stan,
What is it that you want to produce? The indexer can be suprisingly simple (and productive) for simple parts, and require heavy duty software and lots of brain power for more complex parts like 3D etc. There is quite a bit of room between 2D and 3D parts in terms of complexity. It ain't rocket science, but it does often require good planning and clear thinking to pull it off. Not all 2D parts are easy, and not all 3D parts are hard to setup either...It often comes down to the shape and machining strategy.

-B

[mrdovey]

Stan...

"RSN" is short for "Real Soon Now" - an expression so overused and underintended that it has a strict tongue-in-cheek context.

My indexer has never (six years and counting) come out of the box. It's still waiting for me to have enough leisure time to "play".

I have a fondness for analytic geometry and would probably have taken Scott's route (written my own SBP programs) if I'd had a pressing need.

...Morris

[dana_swift]

Morris- what is SB_CUT? I wrote my own SBP generator for my own parts, I presume I must not be the only one to have done so..

Has anybody else taken that route?

[Brady Watson]

"what is SB_CUT?" - The DOS version of the control software v2.39 or earlier. It can only be used on a PRT Standard or earlier.

-B

[mrdovey]

Dana...

SB_CUT.EXE is (or was, I'm still using v2 and that's the program I use) the ShopBot program that interprets SBP text files (ShopBot programs) and communicates with the ShopBot controller box so as to appropriately drive the stepper motors, sense switch closures, and switch the outputs.

A fair number of 'Bot owners (myself included) have written their own SBP code generators. Most of these are are special-purpose and parameter-driven. I wrote one to facilitate in-house solar panel production and I'm aware of a general-purpose cabinet code generator that the author generously makes (or did make) available to 'Botters just for the asking.

...Morris

[dana_swift]

Thanks. Cutting from DOS is clearly before my getting involved with a SB. Unfortunately I was involved with computers many years before that. (showing my age!) Windows is about the worst possible real-time OS, so I can see why DOS would look attractive.

D

[mrdovey]

Dana...

Yup - me too. My non-preparation for CNC woodworking is detailed at http://www.iedu.com/mrd/mrd_res1.html - and I absolutely hate that the upper limit of my machine's reliability is determined by MS.

...Morris

[Brady Watson]

Dana,
The Windows/PC clock doesn't create the timing for the tool. The outboard processor, or the 'brain' sticking up from the control board does on a ShopBot.

-B

[jamesgilliam]

Morris, I am so glad to see there is at least one more person using the DOS software. I had been thinking about upgrading my PRT and the software, and do use the newer version to preview my files, but if it isn't broke you don't need to fix it.

James

[mrdovey]

My problem is that if I did upgrade to v3, nearly all of my existing code would break because of gratuituous incompatabilities between v2 and v3 control programs.

Eventually, I will upgrade - but not until I have time to rework all of my production part programs. I may end up just writing an SBP to G/M-code converter in order to have a standard code base.


I don't like DOS any better than Windows. I've wanted from the beginning to migrate the whole works to a more reliable POSIX environment so I could safely network the entire shop. <sigh>

...Morris

[dana_swift]

Brady- I understand that, its an I8051 or derivative as I recollect from looking at it. But the PC is famous for task-preemption even when the task priority is set to "real time". That is why all the problems with screen savers, virus detectors etc. They SHOULD NOT BE A PROBLEM! We have become accustomed to thinking that there is something good about having such a poor operating system to work with.

When the OS starves the data stream we get a lot of posts in the forum. It "outta just work" in my opinion. There should be no need for special USB cards and black magic.

Using Windows for anything critical like machine control is somewhat like watching a dog walk on its hind legs, its awkward, but amazing it can be done at all.

The bot depends on having the 8051 act as the real time interpreter, but the chain is only as strong as the weakest link.

D