Re: [CAD_CAM_EDM_DRO] Auto tool changers

Hi John:
I'm the guy with the Haas.
The air blast that you are hearing is to blow the chips and coolant out of
the spindle taper before the next tool is clamped.
The machine also consumes air continuously for the air/oil spindle
lubrication.
This is a real pain in the rear for a bunch of reasons.
First, it's NOISY.
Second, it pisses tramp oil into the coolant which makes for coolant stink,
and a $450.00 skimmer, and coolant disposal and anti stink tablets, and skin
rash and...you get the idea.
Third, I'm often consuming more power for the air supply, than I am to drive
the cutter and the tables.

I have another machine; a Defiance that has a really dirt-simple spindle
arrangement, that is good for 10,000 RPM and is rugged as hell.
It is a glorified router spindle with nothing more than a couple of angular
contact bearings pressed into an aluminum housing with a wave spring to
preload the system.
The spindle is tiny and lightweight; it carries an R8 collet into which the
toolholders are inserted.
It has pneumatic unclamp.
Perfect for a homebrew rig, in my opinion.

One of the things that I think this discussion brings out, is that a whole
order of different problems arises when you "go commercial"
It is important not to forget that, when you are drooling over that VMC on
Ebay for 3 grand.
It will often cost you another 3 grand to get it running, and the compressor
hammering away will piss off the neighbours something awful.

Don't get me wrong, I really like my Haas, but I sure got a rude surprise
when I added up the tab.
(Of course, the salesman never told me about any of this!!!)

Cheers

Marcus

PS: With the lathe...think of ways you can gang tool for your jobs.
It's way more accurate, way cheaper, and way less hassle than toolchanges.

----- Original Message -----
From: "John H." <johnhe-uk@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Thursday, February 21, 2002 10:09 PM
Subject: [CAD_CAM_EDM_DRO] Auto tool changers


> Hello list,
>
> I downloaded two small videos of a Sirrus machining centre. Apart from
> the truely terrifying speed the table moves at I noticed it made some
> serious noise when it changed tools. I suspected it to be an air powered
> tool changer. It may or may not be but why do so many new machines use air
> powered tool changers and spindles? I remember one guy on here who owns a
> ?Haas? machining centre, is it Sven?, who said the noise of the compressor
> almost drove him nuts.
>
> How much are simple cheap and nasty tool changers for lathes? The
lathe
> in question is a 5" swing, 1/2hp deal and I'm thinking of three of four
> tools. I've looked but not found any prices on the internet. It's school
> this Monday and I'm hoping the DT technician has some good news for me
about
> a certain CNC lathe. It's getting very hard to sit still and be patient
now.
>
> John H.