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+--- Thread: Harrison Milling Machine (/thread-3554.html)
RE: Harrison Milling Machine - Zoot Suit - 06-11-2017
Thanks hermetic I did know that all of the nipples are for oil. According to the manual only the motor bearings need grease and I would add that modern bearings should be maintenance free.
John
RE: Harrison Milling Machine - Zoot Suit - 06-19-2017
Here is a small update but one that may be of interest to others on here trying to rescue old machines.
The motor rewind guy called today to say that my motor was ready, I only sent it to him a week ago. (this is the small motor that drives the table). He told me that the job turned out easier than he thought and so the cost is less. The cost is still a bit more than a new Chinese motor but overall significantly better value than buying a new motor and then having to make adapters to mount a new face mount motor on this old machine.
The motor has gone from 415v Three Phase to 230v Three Phase. This means I can now add a VFD and instead of having to change gears to alter the table feed I should be able to leave the gearing alone and change the feed rate using the VFD.
For anyone tinkering with these old machines it might be worth getting an opinion on rewinding the motor before buying a new one as I am sure in some cases it might be worth doing.
John
RE: Harrison Milling Machine - awemawson - 06-19-2017
Was your re-winder aware that you intend to drive it from a VFD?
The reason I ask is that apparently 'inverter spec' motors have a higher class of insulation to cope with the fast rising edges of the drive signal. Also don't overlook cooling if it relies on a fan - running at the slower speeds the fans don't shift enough air in certain circumstances.
(Sorry to be a harbinger of doom, I'm sure it'll be fine :) )
RE: Harrison Milling Machine - Zoot Suit - 06-19-2017
He was aware although the cooling thing is food for thought.
There is no fan but it does have a heavy steel casing that I assume will act as a heat sink. There are no cooling fins either just a cylindrical casing. I assume that a non fan motor has to rely on something like a heat sink although I hadn’t given it any thought until now.
I guess I will need to see how it goes when I start using it. Does a motor running at lower than original design speed through a VFD generate more heat than one running at original design speed?
John
RE: Harrison Milling Machine - f350ca - 06-19-2017
I wouldn't expect heating to be a problem with that motor, The housing is huge for its rating so there should be ample area to cool it. My Hardinge lathe uses a DC motor for carriage power, it has no fan either and works fine.
RE: Harrison Milling Machine - mlalonde - 07-23-2018
(06-11-2017, 03:03 AM)malben Wrote: I have a Harrison mill manual pdf I can forward to you or anyone who wants one.
I sure would love a copy of that!!! I Just got the same Mill today!! Its in mint condition. BIG downfall is that the Arbor support was not to be found!!!!! I bought the mill anyways. Hoping to find one. Any help would be awesome!!!!!!
Thanks Marc
RE: Harrison Milling Machine - Vinny - 07-24-2018
Welcome to the forum, Marc!!!