Bridgeport Mk1 2HP Milling Machine re-commissioning

[Slooby]

Following on from the brief mention in my own introduction the other day I thought I would share, and seek advice, on the re-commissioning of my mill.

A purchase made from ebay between Covid lock-downs which has sat in my workshop ever since. Now, with a bit of time being freed up I looking to get it running.

Pics of it from the eBay auction:

And a couple of bits of tooling that came with it:

The fun and games of getting it home:

Where it sat outside my metalshop (we kinda have a woodshop here too), under the tractor shed with my Harrison Lathe (which will get its own thread), for a month or so while I cleared out all the stuff that had been dumped in it so that I could a) recalaim my space to b) get on with my own stuff:

Before getting placed, all be it temporarily for now, roughly where I aim to set it up:

With things taking place on the Harrison I've started to think about what will be required on the Bridgeport, and yesterday took a look inside the electrical enclosure...

Ahh...hmmm...what on earth is going on in there!?! From the fact that it has powered drives on each bed axis, and a factory option DRO fitted, I'm guessing the MGE Isolating Transformer at the top is providing their 110V supply, but there are dead legs everywhere and that black box floating around at the bottom :/ Hum this might not be so straight forward. Anyone recognise anything????

Supply wise I don't have 3 phase and was thinking of going down a Digital Phase Converter route to supply 415V to it and drive everything through the cabinet as one...now having looked in there...Help!

 

[Spectric]

I don't have 3 phase and was thinking of going down a Digital Phase Converter route

That is the most logical route to get a supply but that wiring is in a bit of a mess, If I were you I would try to draw a layout of the interconnections to work out what is what and then go from there.

 

[Sideways]

We need photos with more resolution and more angles as there are wires obscuring important details. Esp the voltage label on the transformer tap hiding behind the red wire.

It's old enough !
Brown things top right are a pair of 3 phase contactors each with a thermal overload relay on the output. So they will be for driving 3 phase induction motors. Not enough detail in the photo for us to read what current the overloads are set to.
Single brown thing in the middle is another contactor, this time without the thermal overload

Just checking BTW, it only has 2 motors, yes ?
Spindle motor and power feed on one axis, the traverse.

Rise and fall is manual.
Table forward and back is manual.

You have a light which may be 240, 110 or low voltage.

You have a coolant pump which might be 110 or 250V. That is controlled from the front panel so may be the 3rd contactor. Pumps are quite low power and in principle, unless they sieze or get blocked, the load on them is constant so that might well be connected to the contactor in the middle without the thermal overload.

The black box down below - take more photos, find a label, more detail of the connection area.

Same for the gizmos with the three round whatevers

In industrial control, it is common for 12v or more often 24v to be used to go through switches and operate the coils of contactors switching the 415v. It doesn't need to be DC for this. Low voltage AC is fine.
This is a safety thing.
It's not always done that way but if you are aware of it, it's easier to spot.

 

[porker]

I have one similar but a little simpler than yours as it didn't have any electronics as such and with the simpler J head. I put in two vfds from Direct Drives to power the existing 3 phase motors. Had to change the main spindle motor to delta and if I remember, the X drive was already 230v.

I think with the existing electronics on this machine I would agree a digital phase converter feeding the whole machine would be a better approach. Looks like a nice machine

 

[Spectric]

Same for the gizmos with the three round whatevers

I think they are fuses, I do recall seeing something similar in a very old bakelite control box many moons ago.

 

[ChaiLatte]

At vintagemachinery.org, they have extensive archives of many Bridgeport manuals, so they are worth looking at to see factory wiring diagrams.