VN VAN NORMAN no 24MLA-1512-259

Cal wrote, "...As for the transformer route, that's NOT a very good solution. The current inrush for a large transformer will trip the breaker unless you really oversize the circuit and the rotary phase converter. Much cheaper to swap out the motors (or have them rewired) if they aren't dual voltage." & also wrote, "...but have you looked at the data plates on the motors? What do they say?"

Yes, my motors are 3ph 240 or 480V compatible. To switch to 240V operation is easy for the motor connections as it is right there on the motor plates. That does require taking into account the Amp increase of the motor feed wiring (Is the wire large enough?). Then there are the motor contactors that I actually just discovered don't care which voltage once the internal transformer is configured (easily configurable actually) on the terminal board. The magnetic motor start coil is on the secondary side of the internal transformer. OK. I get it (only had to take time to look at the wiring diagram & wiring chart 30 minutes before the light bulb came on)!

In a sense, my desire to keep the machine stock as it has been it's whole 58 year life makes no sense - because the machine is designed to perform (with proper minimal wiring changes) on either voltage). I simply did not want to change that dynamic.

Correcting my original incorrectly ordered rotary phase converter mistake is best handled by returning the converter to have it reconfigured for 1ph 240V / 3ph 240V operation. From there in further getting all the right parts together the cheapest route would be to convert the mill to 3ph 240V as described above. The addition of a 3ph 240/480V transformer after the phase converter would be the middle price value (keeps the mill as is). I really only mentioned this on the CrankyOldMan's Thread to make him aware of more cost effective measures than the path I have taken. If I ever start a You Tube Channel: I'll be The Impractical Machinist. LOL. At least I would show & introduce more cost effective alternatives to my own old school stubborn ways!

Pic very soon.
 
Elaborating on the "Impractical Machinist" jest; I present the original reason for my investment in learning the machinist hobby...
A design exercise I'm working on using a Grizzly G0773 LATHE & MILL COMBO: It's brass, it's 3" wide. Needed more - mostly from a mill, so I stepped up. I'm only 4 months into 'now I have a real machine' & Keith Fenner takes a machine the size of my Grizzly & proves my Grizzly can be brought up to spec. Sorry, wrong topic. I'll skip below this pic to get back to the topic of Powering This Mill.

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Spindle Motor & Feed Motor:
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Sump motor - I don't have good pics of that nameplate yet.

But yes, Cal is absolutely correct in saying to me that I could have saved money up front & heartache along the way by simply switching the machine to 3ph 240V. I'll bring his point home in a minute. If you look at the 1st motor plate above, you will see that the lower voltage uses 9 amps while the higher voltage uses 4.5 amps. The machine will run cooler at the higher voltage.

Now once I get to a place that I can actually have a 3ph 277/480V service, my electric bill will be much more manageable.

Here at home, what runs through the meter really don't care how it gets converted or used on my side. Every part has losses. By keeping those losses to a minimum with a simple 3 phase converter & idler motor both properly sized to 240V (in the USA) both startup & running costs are minimized. I AM paying (once my 1 phase 240 to 480V transformer arrives) for the losses inherent in that with each use + the large cost of getting 1 specially built.

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Do you have any experience using a 240 to 480 transformer after a rotary phase converter? You're going to need oversized wiring, RPC and everything just to get the transformer powered up, due to the high current inrush. Anything you save on running cooler due to the higher voltage on the motors (which only run part of the time) will be more that lost in the heat generated by the transformer, which must stay powered on any time that you're in standby mode. And I hope you enjoy the wonderful 60 cycle hum of a large transformer.

The two motors add up to about 15 A on 240; that's nothing. A typical household circuit is 15A and is often wired with number 14 wire. I would wire it up with number 10 wire anyway, just because it's not that much more expensive, but that's just me.

Trust me, the transformer route is NOT the way to go.
 
Actually, one of the strangest sounds I've ever experienced is the silence of a dead power substation. Part of the reward for getting lights restored to a town is the 60 cycle hum. Cal is absolutely right, though, I have chosen the worst way to go about this. My 15KVA single phase 240 to 480V transformer should be here tomorrow. I'll have to do a temporary setup & test to determine the noise level. Hopefully a video of it can be shared.
 
I hurt my back right around my last post in this thread then tore / bulged a disc, pinched off a major nerve to my leg & fractured a vertebrae in January. Finally had surgery & feel much better. Still on restricted duty & only doing very little / light things for a few more weeks. But the doing part feels so wonderful! It's been too long.
 
The results of 'able to get out in the shop - but don't pick up anything.' This coolant drain on the table consists of a cover, screen & sponge filter. Measuring, planning, cutting, bending & shaping to fit are very time consuming ... at least until you figure it all out. Fab work is something I enjoy, but need practice to be any good at it. It's been therapeutic.

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The cover shape is designed to stay below the T slots. Only the 1 mount is potentially in the line of fire. The screw in the middle holds the screen to the cover & is also a handle for removal of the cover assembly. This is the cover showing the drain side. Drain holes are placed where needed.

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The sump pump is located in the bowels of the column. I found a spare from a no38 together with a hand wheel & decided to take a chance on them fitting my no24. Seller's pic:

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I cleaned up the wheel. Surprise, surprise! Fit's & looks good doing it too.

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Now I am turning my attention to the sump. The spare is the same make & model as is in my mill. This thing is heavy. Quick history, the sump in my mill was disconnected, so I expected there would be something wrong with it. Now, I have extra parts & a chance to learn how this thing works. Sure is nasty.

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Impeller needs a brazing. It is held to the shaft by a set screw.

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The upper weep hole in the column lined up with the 3rd shaft set screw, so I removed it only to find the pump housing would not separate from the motor. I had no idea that 3 more set screws were hiding with no access to them at all. Fortunately, the impeller let loose & allowed separation. Lotta cleanup ahead.

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I have been a mechanic - but not a machinist. I once saw a cast iron drum brake wheel cylinder that was rotten & soaked through n through with brake fluid. Now this sump housing that I'm cleaning up with a wire wheel on a side grinder for my mill is not rotten & the grain of the cast iron appears tight. But I'm starting to wonder if it isn't oil soaked. It seems each time I come back to clean it up more as I pass on to more pressing jobs that there is another layer of oil laying on the surface??? Sure, expected around threaded bolt holes, but this is on other areas.

So here is my question: What can I soak this old cast iron casting in that will leach all the oil out of it pores & all?

Before pic (cleaned up) now & after pic tomorrow.

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Sent the spare pump motor out to the motor shop. Have the housing ready though!

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So, this is my after pic & I should elaborate on my solution to the 'pickled' fear I had about these castings. I basted them in the sun for a while & they dried out over time.
 
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