I pulled an old 40-50 year old drill press out of storage. I cleaned it up and drilled 4 holes. When I went to drill more, the motor would just hum. I tried to turn it manually with power on, but would not go. It spins freely. Is the motor toast or could it be starter/capacitor?
I may look for a used motor if toast. Drill press probably isn’t worth new motor when a new Delta piece of drill press (benchtop) can be had for $100.
Thanks,
Replies
If it's a capacitor start motor, my guess would be the start/run switch got stuck on run. Give it a gentle all over massage with a rubber hammer. If that works, then you have to decide whether or not to invest the time to find the switch and clean/fix/replace it.
1. assume the motor is bell end and thru bolts, not an old appliance motor used with epoxied (commen in the late 60s) end bells - see #2. Also assuming single phase.
2. If it is epoxied, then a common fault is that it will turn freely with no power, but the end bell epoxy has failed over the years and the housing moves when power applied and the rotor magnetically 'attaches' to the stator and don't turn. Same thing if the end bell bolts are loose and end bells misaligned.
3. Best first guess is to disassemble and clean/align the start cnetrifigal contacts and try again. You sound like you know that if the start switch is open, you can usually get it to spin in either direction with a quick hand twist in either direction (unloaded)
4. If it wo'nt turn at all with power applied by hand torque, in addition to #2 the bearings could be so bad the rotor/commutator touch and lock.
let us know what other symptoms are specifically - e.g. "will not go" -- does that mean it wont run after you spin it a few turns or that you cannot spin it a few turns by hand with power on???
I was hoping that you would respond. I figured that you'd know the answer. I think it may be starter capacitor. It is a bell end through bolt motor. I haven't disconnected the belt yet to check no load. With the belt on, I can spin freely by hand but cannot get motor to take off on its own. I'll check this evening.
Thanks,John
J.R. Lazaro Builders, Inc.
Indianapolis, In.
http://www.lazarobuilders.com
Looks like you are on the right track, probably is an open start circuit - maybe as easy as just a broken wire, but file any pips off the start contacts and check the capacitor while you have the motor open.
If the motor pulley is same size as or larger than the load pulley, it is hard to start a motor with just a bad start switch or open capacitor due to the load stalling the motor (e.g. almost no torque until a few hundred RPM - with only the main winding connected, a single phase motor main winding only has about 10% of the normal starting torque at 15% of the running speed). On the other hand, if the load has a much bigger pulley, it is relatively easy to start such a motor by hand by a flick of the load pulley.
With the belt off and decent bearings, almost any movement of the shaft by hand in either direction will start a motor that has the starting circuit open.
I have not fixed the motor on my cement mixer since the switch went belly up about 25 years ago due to cement encased motor, etc. It always gets started by a good pull on the rim of the 12" dia pulley that whips the 2" motor pulley up to a few hundred rpm real easy.
John, if the drill press is heavy cast iron and otherwise works well you should put a motor on it rather than trash it. New Delta bench tops like you describe are probably not nearly as good as the old one. I have an old Craftsmen ( at least 40 years old) that I like better than the new Delta I own. I use the Delta for woodworking and the old machine for metalworking and anything where I need to use the quill lock and fine adjustment screw.The Delta I have has no quill lock, the depth stop is unreliable.
When the motor went on the old drill press I bought a new 1/2 hp from Grizzly. About $89.00 if I recall correctly. I did look for a used motor , couldn't find a decent motor in a reasonable amount of time.
mike
If you decide not to fix up the drill press, have a look at the Old Woodworking Machines web site. You may find somebody there who will give you a few bucks and haul it away for you.
-- J.S.
If it's just humming, maybe it doesn't know the words ???
Sorry - Couldn't resist.
My rather old table saw did something similar a while back. Dad looked it over and got it running again.
He said there was one circuit that got the motor going, then another one kicked in once it got up to speed. (Or something like that) He took the end off the motor, cleaned something, and it's worked fine ever since.
Unfortunately, I wasn't there when he looked at it, and don't know exactly what he did. But it sounds roughly like what Junkhound is describing.
If I were not a physicist, I would probably be a musician. I often think in music. I live my daydreams in music. I see my life in terms of music. [Albert Einstein]
Thanks, guys!
Looks like I won't have time to tear it apart but you guys gave me a shove in the right direction.John
J.R. Lazaro Builders, Inc.
Indianapolis, In.
http://www.lazarobuilders.com