Doall G7 surface grinder

F

FinnCustomKnives

Member
Hey Guys,

I am new to the forum and thought I would share my latest machine tool acquisition. Its an old school Doall G7 6"x18" surface grinder. Everything works on it which is a godsend because aint no body got time to crank handles all day lol. Picked up for $1000 bucks from a local machinist who purchased it from his work when they got new machines. Whats even cooler is that the man I purchaded it from is the same guy who ran this grinder at his work, so he knows this machine well. It had been sitting in the corner of his shop for a few years so he just decided to let it go so someone else could use it as opposed to just collecting dust.

Here was what it was like mobing this god awful heavy thing. I believe it weighs in at 3,000 lbs.

Got it loaded on to a drop deck trailer with the use of hilman rollers a few comealongs and nerves of steel. These things are crazy top and rear heavy so please use extreme caution if moving one.

Here she is on the way down. We spun it around so it had the weight better suited for coming down the ramp. We used multiple straps and tied it all to a comealong. Lowered it a click at a time to be very careful.

And she's down!!

And into her resting place

Now I just need to grab a couple vfd's to power this badboy. One for the spindle for 3 phase conversion and to have variable speed. One for the hydraulic pump, strictly for 3 phase conversion. I will also be belt converting it from the get go so I will of course create a post when the time comes for that.

Let me know what you think guys
 
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Nice looking machine! That's a score, and you got what looks to be a good looking mag vise too.
 
Why wouldn't you just change the motors to single phase instead of getting the VFD's? Don't get me wrong, I love Freq drives, but I'm not going to spend the bucks unless I need the variable speed.
 
Nice score, especially knowing where it came from and who ran it. that's one big Christmas present right there!
 
J. Hoffman said:
Why wouldn't you just change the motors to single phase instead of getting the VFD's? Don't get me wrong, I love Freq drives, but I'm not going to spend the bucks unless I need the variable speed.
Click to expand...

Variable speed on the spindle will be key for me when grinding titanium and the likes. Also hopefully I will be able to use it for satin flats so variable speed is a must there and I will be using a kbac24d for that since it will be exposed. On the pump side, I can get a vfd for cheaper than an equivalent powered single phase motor. For that I am going with a regular vfd and either mounting it in the cabinet itself or in a small enclosure inside the cabinet (more likely). That way I can wire everything for the pump inside the machine where said pump is. Then run a wire to turn on the pump's vfd when I turn on my spindles vfd.

Also this is a direct drive system where the motor is directly coupled to the spindle. I believe, I may be wrong, that the motor is balanced to the spindle to minimize vibrations, so to find a single phase that would net the same kind of vibrations will probably be difficult.

Really though, if I wasnt concerned with speed control I would just go the RPC route so I could use it on future 3 phase machines.
 
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