Re: Multiple syncronized spindle question.

[Dncnorthwest1-at-aol.com]

I see I need to explain the concept on the synched spindles a bit better.  Years ago. (1980s, Fanuc 6MB days) I ran a a Matsuura 760 twin spindle. In order to make two parts you had to have two of each tools of identical diameters, (simple enough) and identical lengths (getting more difficult), the fixtures had to be exactly the height or the tool lengths needed to be adjusted during the setup, (adding more things now). and finally, the spindles which were joined in a common casting, would grow as they ran due to different temps and expansion.  The idea I had concerning this would be to take a pair or more of the fairly common Bridgeport CNC heads and see if the individual heads could have offsets for each tool change, allowing a less precise tool length adjustment or allow for changing tools and offsets during the run. This would also make it easier to make offline tool length settings. If each head/quill has its own !
settings, but the group of heads/quills move through their z travel in unison, creating multiple parts with different length tooling. 

In a message dated 9/27/2002 10:29:17 AM Pacific Daylight Time, elson-at-pico-systems.com writes:


> I'm not exactly clear on the terminology.  But, what it sounds like is rigidly
> mounted
> heads, and Z motion is on the knee (or the quills are all tied together,
> somehow).
>
> As far as I know, EMC, and most other controls that have tool length
> compensation and
> G54,G55, G56 etc. up to G59.3 work offsets would be able to do this.  Instead of
> using
> G54, etc. to produce the offsets between multiple workpieces, it would perform
> the
> offset between the heads.


The real reason why you probably don't want to do this is that hydraulic
controls
are VERY inefficient, power hungry, LOUD, and dangerous.  If something
electrical
on a DC motor drive shorts out, it causes an E-stop or a blown fuse.  If
something
goes wrong on a hydraulic drive, a hose can blow off under 1500 PSI, and kill
anyone standing too close.  Even if noone is hurt, the mess of having a gallon
or
5 of hydraulic fluid sprayed all OVER the shop would be a mess that you could
literally
NEVER clean up!  You'd be buying kitty litter by the truckload, and still
falling down
on the slippery spots.

Jon


I also spent time running tracer mills as well as up to 1000 ton, (yes 1000 ton) hydroforming presses. Leaks and noise are an issue, I have never seen a line burst without months of warning. I agree about the kitty litter. but tracer mills and the like have such small volume pumps vs the line size, that the likelyhood of death from a line blow off is probably only about three to five times that of a garden hose. The fact that machines of relatively large, as well as basic Bridgeport size can be had for a mere pittance is a plus. Valve failure is an issue, the rest of the machines are usually quite good. 

Fred