On Monday 19 November 2018 07:31:09 Les Newell wrote: > Hi Gene, > > > I have taken to using an impact screwdriver tool on the > > drawbar, and means to rack it up and down must be devised just to > > engage it with the drawbar. > This drawbar has a 5/16 square tip, so its driven by an 8 point socket. Rather than band it at the same time as the air cylinder pushes, I think I'd like to run the spindle at 15 or 20 rpm which would engage the socket with much less shockload. The wrench has enough power its splitting that 8 point socket slowly so I've bought spares.
The next problem is in getting it to spin slow enough the pin can drop into the spindle lock without breaking the pin or wallering out the hole. Maybe I can do a spindle home, then drop the socket. I don't imagine the plastic gears in the head could take that wrenches beating for long. It can pull the bar tight enough I can't loosen it again with the supplied wrench, so I don't let it hammer for any more than I can get my finger off the trigger. > I have a commercially made drawbar that works like this. The impact > driver is simply pushed down by a pneumatic ram which is driven at the > same time the driver is energized. The motor starts spinning as it > drops, allowing the drive spline to line up with a spline the drawbar. I've seen something similar, bring about $1000 to own it. Made for bigger mills than my GO704 though. > > A 5i25 simply doesn't have enough pins. And the 7i76D has lots more output power than a 5i25. I think it can drive the relays to run the wrench, or turn on the vacuum by way of another ice cube without any extra buffering, just a diode across the relay coil. Same relays can run the chain drive to change the tool. > Do you already have a 5i25? AFAIK you can have multiple cards so you > could simply add another. I don't have any spares that are 100% functional. I blew the probe input on one while doing EDM on that machine, and a loose ground on the frame of the G0704 did the probe input on another. > Les > Thanks Les. -- Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
