RE: [CAD_CAM_EDM_DRO] Re: Power draw bar

There are plenty of commercial machines that use a power draw bar driven
from an air impact wrench, no spindle lock, you hold the spindle and tool
with one hand whilst pushing the button with the other.

The designs for DIY ones use 3/8 butterfly wrenches which are also easy to
hold.

I think the biggest issue is that in mid program you have to stop the
spindle and then put a hand in there, which tends to be against most safety
training.

Jon is looking at an electrical impact wrench, I have such a thing at it
also is easy to hold, it does have a lot of torque, it just knocks in the
direction required.

On my machine I have a full spindle brake, spindle motor is stopped, brake
applied, then you put your hand in, and the break defeats the spindle Estop
relay. I am also not intending to put my hand in, but to chuck a tray of
tools on one end of the bed so the machine can do a full auto tool change.



Regs Mark



_____

From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of HTCLKI@...
Sent: 28 December 2006 19:46
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO] Re: Power draw bar



which hand will hold the tool

it also sounds quite dangerous to me . you could rip your hand off

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