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Harig 612 automatic grinder - peculiar power cabinet setup?

specfab

Titanium
Joined
May 28, 2005
Location
AZ
I acquired a Harig 612 automatic a while back at auction. It was outfitted with two axis DRO (Sony Magnescale) and specialized vacuum fixturing held down on a permanent mag chuck. This was a couple of years ago. I'm just now getting around to trying to get it operational, now that I've found a spot for it in the shop.

This machine was bought online, no chance to inspect, and I opened up the power cabinet today and saw a Dayton AC inverter (VFD?) mounted inside. I think this was a user retrofit, but I'd like to know if anyone has any observations about that. I don't see any mention of that in the (skimpy) manual. This machine was apparently used at some point in a healthcare hardware manufacturing setting (division of Siemens according to some notes with documentation).

I have not yet tried to ferret out what the VFD may be talking to, but I did apply power, and nothing happened, so there will be some sleuthing needed.
 

CarbideBob

Diamond
Joined
Jan 14, 2007
Location
Flushing/Flint, Michigan
I have never seen a Harig with a factory VFD but mine have them added on.
In case of power fail some of mine need the VFD to get it's button pushed on the VFD to bring it back to life.
Depends on how the reset is wired and drive parameters set.
Bob
 

specfab

Titanium
Joined
May 28, 2005
Location
AZ
Very interesting. To ask a stoopid noob question, is the use of a VFD to allow for better control of various diameter grinding wheel speeds?
 

CarbideBob

Diamond
Joined
Jan 14, 2007
Location
Flushing/Flint, Michigan
Very interesting. To ask a stoopid noob question, is the use of a VFD to allow for better control of various diameter grinding wheel speeds?
That is one use.
More for me is that I can change the hardness or cutting characteristics of a given wheel for a specific job.
Added plus is that you do not have to wait forever for the wheel to stop plus the soft start.
Bob
 

jmkasunich

Aluminum
Joined
Mar 3, 2007
Location
Cleveland Ohio
Very interesting. To ask a stoopid noob question, is the use of a VFD to allow for better control of various diameter grinding wheel speeds?

That's certainly possible. Another possibility is that the VFD let's the machine run on single phase power while still keeping the smooth three-phase balanced motor.
 

CarbideBob

Diamond
Joined
Jan 14, 2007
Location
Flushing/Flint, Michigan
If the VFD is set to act as a brake, make sure it's not too aggressive. You don't want wheels spinning in the adapter.
No but if a need to stop for whatever reason a 20-30 second stop is so much better than a coast.
How many have "helped" a grinding wheel/spindle to stop as it seems to go on for a long time with a good spindle.
I've seen and I have done bad things because the darn thing just wants to spin forever.
VFD great here if nothing else used.
Bob
 

metalmagpie

Titanium
Joined
May 22, 2006
Location
Seattle
Diagnose the VFD non-starting first. "Dayton" didn't make that VFD. First step is to call or email Grainger parts and get them to email you a PDF of the manual and find out from them who actually manufactured it. Worst case you need to replace a VFD for a small 3 phase motor, not a huge dollar consideration.

Once you get the VFD back to life, if it still isn't working, there is often a method to reset it. On a TECO recently I found I just had to put a 1 into a certain parameter and that did it.

Lots of help online from guys with VFDs.

metalmagpie
 








 
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