Millrite MV1 Vertical Mill Spindle Lubrication

I have a acquired a U.S. Burke Machine Tool Co. Millrite MV1 Vertical Mill that hasn't been assembled in 25 years or so. I found a PDF version of the manual online (http://www.neme-s.org/Shaper%20Books/millrite-manual1.pdf) and it says to lubricate the spindle by removing the plug on the rear of the quill. The problem is there appears to be something in the center of the plug that is preventing a 5/16" hex wrench from getting a good grip on the head of the plug. I have tried a few different hex wrenches and none of them will insert deep enough into the hex on the plug. My concern is the head of the plug is also starting to strip.

I have used penetrating oil and let it sit for a few days as well, but so far nothing I have tried to remove this plug seems to be working. I was wondering if anyone had any other suggestions short of drilling it out?

My next course of action was to try a left handed drill bit to see if it would get enough bite on it to back it out, but I hesitate on this as I am not sure how thick the plug is and not sure how deep I can drill into it before hitting something that should not be drilled into. And I would like to avoid getting chips in the spindle itself if I can avoid it. I also want to locate a replacement before I go this route as well.

Here is a picture of the plug I am referring to:



Thanks for the help,
-Mike

Spindle lube

Mike,
What did you figure out about that set screw/plug?
Dave

The plug from my millrite is only .465” long. If you drill it there is not much left to work on. I’d try to heat it and maybe drive a larger hex (ground for super tight fit in the socket) or maybe a torx bit that will get a grip. It seems mine stops on a shoulder in the hole. If the above fails, you might slot it with a small cut off wheel in a grinder. Something like a Dremel is good for this. You may get into the ram a bit but it won’t keep it from functioning.

What I wonder about is exactly how greasing the spindle works. Directly behind the screw is the spindle adjustment collar and screw. Does the grease just sit there and somehow make its way down to the bearings by gravity? Or do you pack it tight and full with a grease gun?

You don't pack it tight! Simply drop in the specified amount (the manual says how much) periodically and you're good to go. You do need to use a grease that's not overly stiff or it won't drop to the bearing. Its a total-loss system, grease goes in, grease slowly comes out around the spindle nose. High-speed (hot) running speeds the process up. It seems crazy simple and hardly reliable, but there are a lot of them out there running just fine 50yrs later.

I have one of these, and did get the plug out without difficulty.

From the manual (p/n MV-1361), it is a 3/8" S H pipe plug with a grease fitting built in. It is a right-hand thread.

Most likely nobody has budged that plug in 50 years, and the grease has become varnish. A tight-fitting hex wrench plus some heat should break it free. Once free, clean with acetone to remove the hardened residue. Such as to get the grease fitting to work again.

What may help is to use methylene-chloride based paint stripper to soften that old varnish.

For grease, I use Mobil 1 synthetic grease (the red stuff) from the auto parts store.

There are at least 2 designs out there. One has the screw on the side and I think it is a pipe plug. The other has the screw on the side of the ram and uses a standard allen type plug. I think the older original Millrite uses the side plug and the later Powermatic uses the back plug.

Gordon Heaton said:

You don't pack it tight! Simply drop in the specified amount (the manual says how much) periodically and you're good to go. You do need to use a grease that's not overly stiff or it won't drop to the bearing. Its a total-loss system, grease goes in, grease slowly comes out around the spindle nose. High-speed (hot) running speeds the process up. It seems crazy simple and hardly reliable, but there are a lot of them out there running just fine 50yrs later.

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Thanks for this Gordon. It looks like mine had white lithium grease that is now butterscotch colored. The manuals I have seen don’t really tell how much or how. I’ll just push some grease in the hole and call it good.

henrya said:

Thanks for this Gordon. It looks like mine had white lithium grease that is now butterscotch colored. The manuals I have seen don’t really tell how much or how. I’ll just push some grease in the hole and call it good.

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White lithium is not one of the better ones for that warming and slithering is it?

Old "#2 cup grease" was a butterscotch colour when fresh, sort of orangey-brown as it aged, but ran like 3-in-1 oil when hot.

Amusing when a schoolmate tried it for an Elvis Presley "ducktail" hair poumade and lubed himself clear to his socks with "eau d' John Deere combine" as it warmed up!

henrya said:

. . .The manuals I have seen don’t really tell how much or how. . .

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I've got the info somewhere.... I'll post in this thread if I can find it. In the past, I've used black moly EP grease and most recently, the Sta-Lube Red Premium grease. Both have worked fine.

I found the manual with the lube info.

"Lubricate the Timken bearings in the quill every 200 hours of operation. To accomplish this, first lower the quill until the pipe plug is exposed. Then remove the pipe plug and pack the area with Sohio Sactram No. 2 or equivalent. DO NOT OVERFILL as this may cause excessive heating in the spindle."

"Specifically, the best grease to use for this purpose is a short fibre, medium sponge grease, with sodium soap base. This is not a critical requirement, however, the main concern is not to lubricate these bearings too often or too heavily"

I thought I had read in official literature that the grease quantity was 2 oz. I cannot find that reference at the moment but as time permits I'll keep looking.

Another tip to try on getting the pipe plug out is to run the spindle in high speed for about ten-fifteen minutes, long enough to get the spindle quill warm, not blazing hot. Then attempt to back out the pipe plug. Put a cheater on the end of your Allen wrench if needed. I notice the pipe plug looks like a vented one to prevent any pressure build up in the quill housing. I remember the Millrite mill dad had, he had a pipe fitting with a grease zerk in it that we would install hand tight. Two pumps on the grease gun and that was it. Pulled the fitting and replaced the pipe plug, gently tighten. I remember the grease having a white color to it. That was over 45 years ago.

Good idea but keep in mind that the OP’s mill has a set screw on the rear of the ram and not a pipe plug on the side.

henrya said:

Good idea but keep in mind that the OP’s mill has a set screw on the rear of the ram and not a pipe plug on the side.

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Earlier one's were definitely a pipe plug.

But a person could have changed it out to a 5/8-18 UNF set screw! I work with a product line where we thread mill a flat bottom hole to 5/8-18 UNF and install a 3/8-18 NPT pipe plug in the hole. It's a totally non-traditional application where a standard socket set screw will not work.