DIYbanter - View Single Post - Burke Millrite Spindle Bearings Access Plug

In article ,
wrote:

On Thu, 22 Jul 2004 22:50:35 -0400, Ned Simmons
wrote:

In article dvandam-2207040953520001@sdn-ap-
010tnnashp0277.dialsprint.net,
says...
In article , Ned Simmons
wrote:

Do you have any way of measuring how hot does the spindle
actually gets?

Actually I do. After I sorted out the business with the plug and got
some oil to the bearings (the manual describes obscure type of grease but
my guy at DC Morrison says "straight 30 weight oil") I attached a nice
little magnetic surface temp thermometer to the quill and turned it on at
full spindle speed (3400 rpm).

Within 30 seconds I could feel the quill starting to warm. Within 2
minutes it was acutely warm and at between 4 or 5 minutes the thermometer
was indicating and stable at 130 degrees. The way this thermometer works
it measures temp just above the surface it's attached to. That means the
quill is actually hotter and the bearings hotter still.

If 200 degrees is within allowable operating parameters maybe this is
perfectly normal (normal enough) and I just have to get used to it when
ever running at full spindle rpm.

Other wise the next thing to fiddle with is bearing preload or possibly
consider replacing the bearings.

First Ned and then Gunner advised;

Keep it oiled and I think it'll be fine. The limiting
factor will be lubrication, and just about any grease or
oil will operate at 200-250F. If there's old grease in the
spindle that may be part of the reason it gets as hot as it
does. If that's the case, I wouldn't be surprised to see
it improve as you continue to run oil thru it. Even SAE30
is pretty heavy at 3400 RPM - the oil for a Bridgeport
spindle is approx SAE10, for example.

Ned Simmons

Indeed. Scounge up a gallon of DTE Light, and run it in as much as it
will take for the next 4-5 times you use it. It will help flush out
the mange and is a good high speed spindle oil in its own right.

Gunner

Now that you fellows mention it, while I was running my quill temperature
test after having given the bearings a healthy dose of oil (SouthBend
Light Medium Saybolt Universal Viscosity 150-240 seconds is what I
actually had on hand) large clods of old grease, more the consistancy of
sludge, started seeping out the bottom of the quill. It stopped after
several minutes running at high rpm after the quill temp stabilized at 130
degrees, so I assume I cleared most of the old lube. Per Gunner I'll
continue to flush to see what further comes out.

I don't anticipate running at 3400 rpm very often, in fact after getting
the spindle oiled I completed the (non-critical) job I started at 3400rpm
at 725rpm and the mill bit cut-finished the material just fine.

McMaster-Carr shows a gallon of Mobil machine/turbine DTE light for $11.98
which sounds reasonable to me. The next item down is Mobil spindle
bearing oil. I assume either in a comparable viscosity will serve? If I
can't find one or the other here in town I'll phone in an order.

Thanks to you both for the help,

Dennis van Dam