Bridgeport Series 1 MDI Conversion

[Chaz]

Lots of consideration to take into account.

My machine worked well with the original motors, (it was fully functional on 3 phase when purchased). As previously mentioned, I was also very conscious of electrical max demand of finished machine, as well as keeping running costs reasonable.

The 1.5KW version might have been a choice otherwise, as you could just pull the rotors out of the motors and machine the shaft ends down.
Or fit different pulleys, as mine are tapered collet type. Having said that, I could probably bore out originals and broach a key way in to fit those 19mm shafts. Extra length makes no difference on Z or Y on my Interact. Your MDI has a longer X axis cover for the manual handles, so it may make no issues there either.

Only things that may catch you out is the rotor inertia and the possible effect of having so much Torque. ( although you might find a 4NM version in 110ST.

I partly figured that if my 90st 4NM versions ended up being too small in the end, I could always use them on the next project ( cnc lathe).

Guess its all a gamble really. The only good thing ( in my view) is that as they are 220V AC, there is no need for huge power supplies and torriods. Time will tell

Mark.

Thanks. Good points. Torque can be limited. I'd rather have too little than too much - that said, is rotor inertia a real concern?

Thheir 0.8 KW is 2K RPM, the 1.2 has the same rotor inertia. The next one down is 0.6 KW, so too small in this frame size.

[Chaz]

In the end I was able to get some Panasonic stock from the supplier of my previous kit used on my other mill (Thor)

I will have 2 x 0.75KW and 1 x 1.0KW available. Ill likely install the 1.0KW setup on Thor and then have the same three for the Bridgeport.

[Chaz]

Managed to get two of these 800 x 600 x 300 enclosures for fairly cheap. Perfect for this (I was thinking to use the original box), but this will work too.

Testing a layout. Any thoughts / concerns with what I am proposing? The VFD will be placed externally.

Thanks

[routercnc]

Nice project Chaz.

I’m sure you know this stuff but when I did my box I followed a few guidelines and have not had any problems or false estops:
Power lines separate from logic lines
24V logic wherever possible (not 5V)
Star Earth point
Drivers in a row not column so heat went up and away
VFD tucked up in the top left corner so air came in through the left side of the panel and straight out the top (if your VFD fan draws from the left side)
DIN rail power supply not the generic ebay power supply (just for ease of mounting, not sure if there is any electrical principle difference)
Ferrules on each cable

Final tip is give your fingers room to get in to insert cables and space for the screwdriver.

[Chaz]

Making progress, wired up most of the controls, quick test run with some existing / included code. Axis are not calibration yet (distance etc), wanted to check movement. It sounds like the X belt is fouling, will need to sort.