Bridgeport Mill Notes

EMS has the use of a Bridgeport V2XT CNC mill, and this page is here to document useful info to keep it running.

• Type: Bridgeport Series I V2XT retrofitted for CNC by Bridgeport.
• Specs: http://inv.machyintl.com/q/nlist/=,008611,20264290
  • Spindle Taper: #30 QC (Erickson Quick Change) will work with NMTB#30
  • Search terms: ("NMTB 30" OR "erickson quick change" OR "quick change 30")
• Motor:
  • Phase 3
  • HP: 2 but can run at 3HP for 30 minutes
  • 6.5 A at 208V
  • 6.3 A at 220V
  • 6.2 A at 230V
• Servo Motors:
  • Model: MTE4237-157CF
  • 90VDC
  • Nominal current 11.4 A
  • Max power 90V at 60A

Since we only have split or two phase power, It Needs a split phase to three phase converter. Before the move it was set up to run off of a rotary converter.

Previous converter:

• Make: American Rotary
• https://www.americanrotary.com/products/view/adx-smart-converter
• Model: ADX07
  • This converter was sized to run two mills like this at the same time.
  • Split phase input current: 20A (I think)
  • Max load single motor: 4HP
  • Max load total: 7.5HP
  • Rotary component
    • Gentec Induction Generator
      Model: 36M440T56G1
      5.5KW / 7.5HP
      230V
      1800 RPM

VFD Option:

The latest thinking is to run everything but the spindle motor on 240V split phase, and run the 3-Phase spindle motor off of a VFD. Some desierable features for a VFD might be:

• To be rated at least to 3HP since the spindle can do 3HP for 30 minutes.
• To not buzz too much when it's powered up. Heard some of them are noisy.
• To have some serial control link for future integration with the CNC SW.

Misc:

Good places to get electrical wire and parts:

• Greybar:
• Eoff:
• Jerrys:
• Home Depot:

Links:

• http://www.practicalmachinist.com/vb/transformers-phase-converters-and-vfd/how-do-rotary-converters-work-101159/
• Rotary or Static converters? http://www.kayind.com/basics/types.htm
• Complete converter: http://www.ebay.com/itm/American-Rotary-Phase-Converter-AR5-5-HP-1-to-3-Three-PH-Heavy-Duty-HD-CNC-USA-/281095520874
  • $374
• Control Box only: http://www.ebay.com/itm/5-HP-ROTARY-PHASE-CONVERTER-CONTROL-PANEL-make-your-own-true-3-phase-power-/300553550607
  • $139.18
• http://www.brazilmotorsandcontrols.com
  • Don't have any used Converters but they have some motors that we might build one out of.
  • Three phase GE motor 3HP 1800RPM $150
  • Three phase Baldor motor 5HP 1800RPM $195
• https://stcloud.craigslist.org/bfs/5294690130.html
  • Three phase motor 5HP $100
  • In Glenwood
  • Check to see if RPM is in the 1700 to 1800 range.

Notes:

The three phase breakers for the two machines at the old shop were 15A for each phase. The fair has a converter that they no longer use but I believe it's quite a bit larger than we need. This means it's expensive, and they may be shy to loan it to us.

Talked to a guy who sells control panels as above, and he said that a 5HP converter would probably work but a 7.5HP would work for sure. Not sure if his concern was genuine or it was an oversell.

Might want a keyed lockout on the mill so unauthorized users can't run it before they are checked out.

Not all NMTB 30 will fit the quick change spindle. The "Lyndex" brand will, as will Bison, Erickson and some others. Some say "Erickson qualified", this means they fit the quick change system. As said, you can modify the other holders to fit, but why bother when they can be had so cheaply?

Stranded power cord can have different classes of jackets and insulation, coded with letters that have special meanings. Some common codes roughly from ok to best are: SJOW, SOW, SEOW, SOOW, SEOOW.

-- Main.ClifCox - 09 Nov 2015