Re: [CAD_CAM_EDM_DRO] Newbie follow up

Vlocci wrote:

> Several months ago I posted my first message regarding a future conversion
> of a series I / II to PC control. Well as luch would have it, I just picked
> up a used series I, with a long gone Boss controller for a steal. Machine
> has been sitting for a good 2-3 years as it became to expensive to fix and
> too much trouble to haul out. Following an afternood of tugging, pushing
> and general cursing, it now rests in my shop.

> >From what I have read over the last few months EMC is the way to go for low
> cost CNC conversions. I'm open to this, but let me throw in a few
> hiccups....
>
> I have several high end software packages available at work, including IDEAS
> and Solidworks (and possible an old version of Pro E) . I'm more than
> skilled in the CAD side of things, but we have never compiled anything to be
> run on CNC. All our work stops on the modeling side of things, and is
> passed off to the next person in the chain. Are these packages a better
> solution to EMC for a user in my position?

EMC is not cad or solid modeling. It is a machine control, equivalent to
a BOSS control, Allen-Bradley, etc.

> Do they do what I'm after or is
> there an "middle man" program that goes from a IDEAS file to G-code? (for
> exmaple) I'm ready to pull the manuals off the shelf, but rather save myself
> the research if I'm barking up the wrong tree. If my current CAD
> applications are just "too good" (i.e. too complicated) for my pursuits, any
> suggestions on hobby CAD programs? How about the conversion from CAD file
> to a ready to run G-code file?

If your CAD software produces DXF files, you can import this to BobCAD/CAM
or a number of other programs to convert into RS-274D commands, alias
"G-code".

>
> Moving onto the Hardware side of the equation:
>
> -Again, its a low use series I with stepper motors. Its the control
> that died (from what I'm told) and the steppers should be fine. What
> exactly "the control is dead" means is beyond me, so I'm unsure what can be
> salvaged.

The BOSS controls contain a DEC LSI-11 CPU, and Bridgeport-made
power supplies, control panels and stepper drivers. The LSI-11 is pretty
hardy, but Bridgeport's astoundingly poor power supply and thermal design
can even kill this part. For something as expensive and "high-tech" at that
time, it is just amazing how bad a job Bridgeport did on this, to save about
$50 per machine!

> I'm inclined to start anew, as opposed to trying to keep a dying
> beast alive anyway.

After checking prices on the dwindling supply of spare parts, you will see this is
not only the wise decision, but the only one for hobby use. Unless you were
an electronics guru and fixed it yourself, you couldn't afford it.

> Without starting a huge flame war, what is the
> reccomended approach to interfacing what I have to PC. I've seen some
> glowing reviews of the Gecko drives a while back. Is this a modern approach
> which will work well? Posting seem to indicate this is also an inexpensive
> route to take. Additionally, I'm assuming I'm going to need some sort of
> power supplies for the motors. Are these the type of things someone handy
> with a soldering iron (but far from an EE) can handle, or is there a
> reasonable cost alternative?

Yes, there are outfits that have suitable parts available at reasonable cost.
Brigar Electronics, Mendelson and Marlin Jones often have these in their
catalog. Surplus Center sometimes also has larger transformers.
For the higher voltage ranges, a "step-down transformer" salvaged from
many pieces of industrial equipment can do, when used on 120 V input.
These may go over the 80 V limit for the Gecko, however. Hooking up
a rectifier and capacitor to this is no big deal.

> Finally, any suggested reading on the CAM side of things. I've never
> even seen a line of g-code and have virtually no experience on selecting
> toolpaths, plunge rates etc. Ran a part or two back in college (i'm a Mech
> Engr) but that was a few years back and there was a TA who held by hand
> along the way. Regular machining practices I'm OK with, as I've been turing
> handwheels for some time, it is the CAM oriented side than is blank right
> now.
>

Take a look at some of the info on
http://www.ktmarketing.com/faq.html
(The site seems to be down just at this moment, but should be back soon.)

>
> Sorry about getting so long winded. I'm sure I will plague you guys with
> more than a few questions in the coming weeks. If you prefer, I'll gladly
> take this off list if it is too off topic.

No, this couldn't be more dead ON topic than anything, so we probably should
stay on the list, so the good points get archived. I believe someone has just
done a Gecko upgrade, but I think that was a servo machine. We ought to
have a complete guide through the process. The Geckos are fairly new, and
a couple smaller machines have been done with them. The wiring is actually
pretty much the same in any case. I know a few people have successfully
upgraded BOSS machines using the existing Bridgeport stepper drivers with
EMC.

Jon