got my new control system , Level 2 BiFi-EMC running today. And to demo created a portable nc plasma system - a concept which I believe is also novel.
the hardware
EPSCO digital 44x33 inch plotter off us navy carrier. aquisition cost $40K. totally gutted. new nema 23 steppers placed which will handle 24 to 170 vdc. hypertherm 850 machine torch system. i burned out bottom of plotter--all aluminium.
the control
BiFi-EMC binary filtered electro-mechanical control. consists of encoder which is used as pulse generator. the pulse stream is transmitted unaltered to two binary filters made by US Digital. called an EDIVIDE. it reduces pulse stream by whole number up up to 2 to the 12-== 4096.--hence binary.
no computer is needed. no software needed. only a 5 volt power supply for encoder and each axis edivide. the edivide filters according to dip switch setting.
pictures
images demonstrate plotter, then bottom of housing cut out. then about 45 degree diagonal cut in 1/8" plate. then short burns from start point of binary increments of N+1.

what is next.
in a few days i will demo generating a variety of tool shank tapers on a guted hardinge cnc lathe. the pulse generator in these pics will be used. no computer, no software.

jh

Picasa Web Albums - jacksonholland - BIFI PLASMA

we need to know more!!

Circles? Arcs?

Or do you mean there'd still be a computer, but only upstream? So this is a simpler backend and motor driver?

Not sure I'm following this correctly, BUT;
If I am, for a long time I've envisioned a controller
that would do little more than take away the need to be
"physically" {at the lever} on very large manual
mills (floor-bars) / huge engine lathes / or Vertical boring mills.

Example, often on giant oneS'ies, on large CNC floor-bars
or ganrty / bridge-mills, I simply get into the only place I can
actually see what is happening, (no-where near where levers would be)
and walk thru (hand-wheel) simple surface-creating manuvers etc. etc.
rather than program a path that I still can't see.

Not that I'm shy-ing away from confident-blind machining,
been there for a long time. BUT why take the gamble
if a controller in the hand could elliminate the "unthinkable OOps".
m1m

I have been running system 2 years on BP mill. 1.5 years on 10 axis Walter tool grinder. Lathe only 4 months.


keithmech- I am giving away how to make this control--it is cheap and simple. Give me another couple of weeks for the fine details.

bryan_machine the control illustrated does not do arcs. Soon I will chat with US Digital about production of an interpolated "function generator" with scalable arcs, ellipses, etc. Basically what a cnc engraving machine would be doing. simple machine code should also be possible by loading with usb type memory stick and subsequent hand cracking of the pulse generator-encoder. This unit would look like a Texas Instrument calculator of 35 years ago. what I am now describing is BiFi level 3 which will require prom chips with library of thread pitches, scalable arcs, tapers, etc. actually, pretty simple stuff by today's capabilities. this product will also eliminate the e-divide dip switch units. It will send selective data to a given axis.

machine1medic

what you descrided is just what I have been doing with the Walter grinder. I removed the 300 pound pendant control and have two hand held boxes which allow me to get my nose within one inch of the diamond wheel. I sit inside machine as it operates. I will shoot footage of this tomorrow. this control will operate any sized tool as long as the drives accept binary data or use a digital to analog convertor.

jh

JH:
Thanks for responding to my questions.
Regrettably, I am all guesswork and assumtions about
the source of any controlling technology.
What I do have is a very good blend of both 100% manual
and all-longhand CNC milling practice.
I will follow your thread as closely as time permits.

Here in the midwest (USA) we have the same wheel being reinvented,
over an over and over, with companies spending into the millions
of dollars, on large CNC machinery, and pulling their hair out,
when they discover that large, low-quantity work is still the product
of the machinist's intellegence, resourcefullness and sweat.

The old bar-hands and VBM guys struggle to learn CNC.
The young can't "get practical" and "Effective" fast enough
simply because it's a product of time and experience.

A good deal of low-quanity high tonnage work is done best
by just the kind of thing I see you advocating here.
I'm excited, to say the least.
Thanks
Phil

When you patent that, stay away from the term M.P.G, because that’s all have invented there. Sorry, but how can you call that a control. Its an MPG driving two axis with ratio’s.

http://lh4.ggpht.com/_gMLbc6VJRUg/S29gAVU3kDI/AAAAAAAAApI/je-eAMdogM0/s640/100_1951.JPG

I’d probably also lose the “Heidenhain” label off that old EXA box. They won’t want to be associated with that.

Quote:

Originally Posted by JHOLLAND1 1.5 years on 10 axis Walter tool grinder

Of those 10 axe’s, how many where you driving with that gadget? Two? What’s the point

Regards Phil.

JH -

It sounds to me like you have just implemented electronic gearing.
This doesn't eliminate a computer and software unless you are only
interested in cutting straight lines at a small number of angles. I'm
afraid I don't see anything very revolutionary about this, although you
could perhaps continue development and end up with a nice CNC
plasma cutter system.

-- Ralph

yeah and lose emc out of the title too, unless you start running it on emc in linux. Heck its easyer than what your doing, you have all the hardware, just stick the parrelel port in place of your control pendant. Ohh i wouldnt sit in a machine, ever seen what happens when a drive loses its encoder feed back?

some more thoughts

is this electronic gearing? yes
here are 2 images of the companion electronic gearing unit unit to the Superior step/servo drive which I am using. a multitude of connectors and computer required to program
Picasa Web Albums - jacksonholland - BIFI PLASMA

cnc plasma--here is photo of one I built in 1991-- repeatable to +/- .002". this is because of the platform which is a DAC pc board drill which repeated to 2 tenths. problem is it would on occasion blow a dsp control board at cost of $700. that is why I parked it 10 years ago.

Picasa Web Albums - jacksonholland - BIFI PLASMA

I mentioned that the plasma unit demoed yesterday is portable. here ae pics today of it hanging. in a few weeks I will put oxy-fuel machine torch on and begin the next phase of scraping a terex 82-30

Picasa Web Albums - jacksonholland - BIFI PLASMA

any up dates?

keithmech

update
backlash on hardinge was due to loose nut on ball screw. tightened and loctited. lash now is proper one-tenth.
i noted on another post taper turning. this required only moving dip switches to desired ratio and turning pulse generator. this produced superb morse 2 taper- the first time out.

i am installing a 1700 ounce inch stepper motor to power spindle. it requires a hydraulic clamp down cylinder. i tried an air cylinder which did not have power to hold toothed belt tight. this will take another couple days. should be cutting threads this week though. this will be real test of system.
here is link to taper post

hardinge BIFI taper turning

jh