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Bridgeport Interact Series 1 Mk 2 conversion

Hi everyone,

UK based. I am converting/modernising a Bridgeport Interact Series 1 Mk2 to run using the Masso controller and wanted to post a diary of the build and a place where I can tap up the shared knowledge on this forum. This is a running machine that currently has a heidenhain 151B controller. I have stripped an old Haas CNC machine that was left to rot at a local farm and have pilfered some great parts to help this conversion including limit switches, automatic oilers, relay boards and the unbrella tool changer. I purchased a set of  Nema 34 12nM closed loop steppers with HSS86 drivers which is currently up and running on my bench using the Masso and have everything working including probing and tool offset automated. I have changed my mind and I intend to reuse the SEM MT30-R4 58 servos from the Bridgeport as they are in good condition and I was concerned that the steppers would be inferior (noisy/not powerfull enough for this sized machine etc). I have purchased 3 Machdrives servo drives to control the servos and I will reuse the servo power source from the original mill 135v dc. The mill arrives here on Thursday - I've already stripped off the top end/head so that it will fit thought my workshop garage door! Photos to follow.

Jobs to do

  1. General inspection and tidy up
  2. Replace the Heidenhain servo 'encoders/accelerometers' with encoders uk 2000ppr rotary encoders from the Haas servos
  3. Connect the Machdrives servo drives and tune using 'Tuna' software
  4. Connect servo drives to Masso and check for correct operation
  5. Install on mill and calibrate
  6. Fabricate new control panel with new operation buttons - will the original jog wheel/joystick work??
  7. Install flood coolant pump from the Haas
  8. Install mist coolant system
  9. Workout best post processor/program post processor using UPG
  10. Fabricate enclosure
  11. ?fit Haas umbrella tool changer system (I have all the original servos, limit switches, hardware)
  12. Install spindle encoder ready for G76 features (i'm sure you Masso guys are sick of being asked about this!!) as I really need to be able to machine tap in the near future

Quick question for you guys. This mill has a 7.5hp Spindle (Iirc it's actually 6.8hp from the motor plate) and I have a GPD503 3 phase VFD which came from the Haas. Either I get 3 phase installed at my workshop which I have had a quote of £830 for or I look for a single to 3 phase VFD which is suitable. The only one I can currently find is a Spedestar PC75 from the US. I have emailed the company and they assure me that this will run this spindle from 240v sp ac so this might be a better option as if I move I am not tied to having 3 phase. Does anyone have any thoughts on this? are there any other options out there?

Many thanks and looking forward to working with you guys!

Chris

I do believe that if you use single phase in a vfd for a three phase motor you need it to be about 1/3 higher capacity or so. I use 10 hp capacity to run 7.5 hp motors all the time

Guy

Chris,

The Spedestar PC1-75 should be suitable for a motor rated at 7.5hp.

The only thing that I couldn't find was the max input amps, because that will determine what your single phase input will require for wiring and CB. Over sizing the VFD could take you outside the load rating allowed for single phase.

Regards,

Arie.

Machine Arrived on Thursday and was moved into the workshop on Saturday. I've stripped out the servos and control panels and have started cleaning up the machine. I am in the process of fitting the encoders (2000ppr) from the Haas onto the SEM servos with new 3d printed encoder mounts and servo caps. I intend to reuse the existing wiring. I am using an Hitachi WJ200 110lf derated to run 3P from 240v SP for the spindle motor. Anybody derating a larger VFD for use with 5+hp motors? I am hoping for some advice re fuses and MCBs for my consumer unit. The manual recommends an 80A fuse??

A few pics of the conversion so far

Uploaded files:
  • 2020-01-30_12-15-47_760.jpg

@bobster75

That's a seriously heavy load of American Iron!  I've contemplated buying one of those many times but just don't have the room.  Let us know how you make out.

Cheers, Stephen Brown

Hi all,

I've nearly completed the re-wiring process and could use some advice. I will upload some pics later.

I am using Machdrives to control the servos and have a couple of questions.(I have a gen2 Masso)

  1. The manual for the drives requires the enable pin to be controlled (active low). Is there any way of wiring this via the Estop or do I need to wire this through a relay using relay pin 7?
  2. How to connect the drive error to the Masso via the input pins? This is an active low output from the servo drive. However, the error output is 5v normal and goes low on drive error. I cannot find any documentation specifying the minimum voltage trigger for the Masso inputs. I assume that 5V would not be enough so I think that I will need a pullup resistor between the input and the Masso +24v. If so could anyone recommend an appropriate resistor value to use here? Obviously I would need to invert the input in setup by wiring this way.

I attach a wiring schematic to help explain what Im on about!

Thanks Chris

Uploaded files:
  • drivewiring1.png

@bobster75

The manual for the drives requires the enable pin to be controlled (active low). Is there any way of wiring this via the Estop or do I need to wire this through a relay using relay pin 7?

Wire through a relay using Estop pin7

I assume that 5V would not be enough so I think that I will need a pullup resistor between the input and the Masso +24v.

No that is not required. The Machdrive outputs +5v and the MASSO inputs are opto-isolators so will operate on 5v.

The only time a pull up resistor is required on a MASSO input is with passive devices ie. switches.

From the Machdrive manual

 ERR: This error output is active low, and all drives should have this line connected together. The drive will pull this line low if an alarm condition occurs. While this is an output, drives can also detect if it is pulled low by another drive, and will also stop and raise an external error alarm. The ERR output can sink a maximum of 50mA and is short circuit protected.

0V: This is the control ground, and all drives should have this line connected together. This terminal should also be connected to the negative (return) of the 5V control power supply and the 0V (return) wire of the encoder

You will need to connect 0V to MASSO negative supply to complete the return circuit for the ERR signal.

Obviously I would need to invert the input in setup

Yes, because the Machdrive ERR output has built-in pull up resistor.

Regards,

Arie.

Great, makes sense. Presumably I can wire the 0v into the common DC ground bus rather than directly into the MASSO? and is there any reason not to wire each drive into the individual drive alarm inputs in MASSO instead of wiring them all together as MASSO will stop all drives on an individual alarm. This will then tell me which drive is having the problem.

Thanks Arie

 

Major snag!

These series 1 MkII have a 7.5hp DC Spindle motor!! This will obviously not work with the 15HP Hitachi VFD I have purchased and I am unable to find a DC drive that will power this motor from 240v SP. So, I am thinking of replacing the motor with an AC unit unless somebody out there has found a different solution?

Chris

Quote from bobster75 on March 15, 2020, 11:16 pm

Great, makes sense. Presumably I can wire the 0v into the common DC ground bus rather than directly into the MASSO? and is there any reason not to wire each drive into the individual drive alarm inputs in MASSO instead of wiring them all together as MASSO will stop all drives on an individual alarm. This will then tell me which drive is having the problem.

It is good idea to connect all negative wiring into a common negative bus as that way you won't miss a negative wire somewhere.

Each drive can have it's own alarm input, Machdrive only suggests commoning the ERR line so that an error on any drive will trip all drives. But as MASSO can do that if fault appears on any drive, why not use the MASSO inputs to show which drive tripped.

Major snag!

These series 1 MkII have a 7.5hp DC Spindle motor!! This will obviously not work with the 15HP Hitachi VFD I have purchased and I am unable to find a DC drive that will power this motor from 240v SP. So, I am thinking of replacing the motor with an AC unit unless somebody out there has found a different solution?

Had quick look for DC motor controllers but I couldn't find one that used 0 to 10v speed signal and handle 7.5 hp motor. So I think you will have to do search for a AC motor that is the correct physical size for the Bridgeport, as to what power output will depend on what's available. Happy searching.

Regards,

Arie.