Bridgeport Interact 4 Series 2 to Acorn6 build

[richardb15]

I recommend Trantorque keyless bushings instead of keys and keyways.

I hear you, but they are around $100 each here in Australia and I'd still need to machine up the pulley ID. I've made the bushes a press fit and the keys are tight, plus I have two taper point screws into matching taper point indents in the shafts. If they move (easy check by testing backlash occasionally) I'll just make new split collar collets sandwiched between a two piece pulley adapter and fit them. Nothing I've done is irreversible so if it all fails miserably I can still machine the pulleys out to take Trantorque or similar! For now, for $0, what I've done will get me up and running.

[richardb15]

Good progress again, the X and Y motor pulleys broached and fitted and the motors installed on the machine using the original mounts and belts. This means i can re-use the original belt guards and motor swarf/splash guards too. The encoder wiring and motor power wiring has been appropriately separated and wired into the cabinet main terminal block so that gives me an X, Y and Z, starting to look like a CNC mill again

X asis drive/belt/mount in place


X axis belt side


Y axis motor in place


Belt side of Y axis drive


I wired in the homeall to IN1 and limitall to IN2 (both set as NC so cable/wire/switch failure shows up) so that allows me to auto home the machine, a big day to get it doing something automatically after the weeks of work to get to this point

[richardb15]

With the axes working it was time to get into other stuff, like the spindle and accessories. The old DC spindle motor is a huge lump, 8.8kW rated and a forklift job to get it out. They are mounted on a wheeled carriage so you can loosen the adjusters, push the motor forward to pull the belt off, then pull it backwards on the rails which was quite handy.


You can see the rails here and the rather large hole that was left behind


The motor uses a ribbed belt to the spindle at a 1.5:1 reduction (6000rpm motor, 4000rpm spindle) and above the ribbed belt is a toothed pulley for the spindle brake.


The sliding carriage the motor mounts on is shown below, I was hoping to use a 7.5kW induction motor but at a 132 frame size it would be too big to fit. The carriage spigot and bolt holes are the same as a 112 frame so for the sake of avoiding a load of grief I'll use a 5.5kW 2 pole motor


The only hassle is a standard B5 flange mount motor fits the carriage but the shaft diameter is 28mm (old one 32mm) and 60mm long (old one 120mm) so I'm going to have to make an adaptor of some sort I guess unless I can get a pump type motor that has a longer shaft that I can cut to length.

I'm planning to order a Techtop TAI motor and matching 5.5kW E3 drive mainlky because I can get trade price and Techtop Australia are an hour from me, so any issues etc I have local warranty and support and good manuals in English.

TTA-3-340140-3F42: 5.5kW drive (I can get this at half this price, just a link to show the drive)
https://www.aimsindustrial.com.au/ac-va ... Z7a6CzffDI

TA2B0555TAI 5.5kW 2 pole motor
https://chainanddrives.com.au/store/pro ... tput-frame

[richardb15]

Next job was some accessories, first job was machine lighting. The machine came with 2 lighting transformers laid in the cabinet so I figured I'd just re-use those. They are in the bottom left here.


I checked them electrically, 240v input and 12v 7amp AC output measured up okay but putting my voltmeter between the bulb outputs and each other gave 11.8VAC, but 120vac and 132vac between them and earth! Not exactly low voltage...... I took the steel lids off and saw they are basically just an isolation transformer but neither the steel case or the 0v secondary side were wired to earth! Good job I checked, so a bit of earth wiring later we have safe low voltage lighting using H3 car spotlight bulbs in the lamps, easy to get if I need replacements.

Now to dive into the air/hyd cabinet


This has two air-hyd units (one for the drawbar release, one I guess for a bed mounted chuck/vice that is no longer here. There is a Bijur Spraymist unit, a machine lube pump and deep inside the column is a flood coolant pump. It seems the two air solenoids for the air/hyd units are 24vdc and everything else is 110vac. Easy job as I have kept the old 110v transformer in the cabinet. The lube pump wired in and Acorn OUT relay board looks after the operation, seems like it only runs when a drive is moving as default but that is okay.

The Spraymist system tubes are all cracked and hard so replacements on the way, and the unit looked pretty rough.....


Has anyone got one they could send me a photo of the instruction plate, mine is worn away:


Opening up the unit it contained very stinky ancient coolant but luckily not much corrosion inside:


That should clean up nicely and be back working soon.

The flood coolant pump is all but inaccessible but I extracted it from its putrid hole, it was, as expected, gunked up with all sorts of rubbish


The coolant reservoir in the machine base was a festering mess as you always get on old machines, worst job ever cleaning machine sumps out, but a bonus tool was lurking in the slime!


Someone will have been looking everywhere for this:


Cleaned up okay!


I scraped the sump out to get most of the slime out, then washing it out with detergent and boiling water, using the wet/dry shop vac to remove the offending stinky soup, but eventually it was pretty clean in there. We'll get the Spraymist and flood coolant pump cleaned and back in, I've already done the wiring via the Acorn relay board to a terminal block in the rear cabinet so good to go. The main spindle drive contactor and power is also wired into the rear cabinet now.

Next job, I think, is to work out the logic and macro for the tool change. I have the proximity sensor for the drawbar working but need to work out the setup for interlocks and "tool in OK/NG" as the bridgeport system used a whole bunch of inter-related and interlocked mechanical relays.

[richardb15]

With the filtermist system cleaned, serviced and back in I have working air and hydraulics. A new coolant line installed and the flood pump back in, wired via the Acorn relay board has that working.

I've got the spindle motor, drive and resistor bank on order but not much idea when it will turn up, later this week I hope. That gives me time to mess about with the power drawbar (see the drawbar thread.... that 5 minute job now on day 2) but I've ordered bits so while waiting for them to arrive I can get the rest of the wiring done. I bought a cheap toolsetter to give it a go, figuring its probably more accurate than me and a bit of paper or shims that I've always used. AU$60 delivered or something ridiculously cheap. I've just wired it up so the first contact set is the tool trigger, and the second (overtravel) is in the e-stop circuit so shuts the drives off if it does go AWOL. It means I can also use it as another e-stop button.



After that the Centroid touch probe was wired in but I can't test it with the setting ring as I can't put a toolholder in the spindle yet. I ran the tests/checks by doing a probe cycle and manually triggering it and all works fine.


Final job today was to wire in the W drive for the knee on the machine which I need for deep boring jobs beyond the rather limited quill 150mm travel. The knee assembly on this machine weighs 865kg (around 2000lbs) without jobs and fixtures, good job it has air assist already. I have the drive and motor configured, working and set up in CNC12 so I just need to design and get laser cut a mount for the motor to drive the old manual knee handle. Tomorrows task I guess while I wait for the spindle stuff to arrive.

[richardb15]

I spent HOURS going round in circles yesterday as I did the W drive install at least electrically at the same time as the touch probes, then updated the CNC12/Wizard/PLC all at the same time. When I did that I could not get the machine fast jog button to work on the VCP, and max jog rate was stuck at 254mm/min. I figured I'd done something with the W drive settings that had overwritten everything else, so I went round and round everything. Eventually I realised it was because I'd left the touch probe plugged in so the machine would only jog at the touch probe max setting. I think I'll sort out a light or notification on the VCP to let me know when the probe detected signal is ON.

Exciting day today as the resistor, VFD and spindle motor arrived!





The resistor is a 500W 33R encapsulated in aluminium, I was expecting a simple resistor wire thing, anyway this should mount nicely:


VFD is a Techtop 5.5kW E3 type:


Motor is a 5.5kW Techtop, chosen as the 112 frame with flange mount will go straight onto the Bridgeport carriage:


The machine is geared 1.5:1 so that still gives over 8kW at the spindle, more that I'll ever use. Mind you I am half tempted to drop the ribbed belt drive and reduction on this and go for a toothed belt at 1:1 so I can put the spindle encoder on the motor, as its going to be very difficult to put it on the spindle itself due to the power drawbar etc. Will an encoder on the motor with 1:1 gearing via a properly tensioned toothed belt work for rigid tapping?

[richardb15]

Time to think about mounting a motor on the knee for my W axis. With the air assist turned off I set the manual handle horizontally and placed weights on the end of it until it moved. According to my maths that required 9Nm torque. I have a 12Nm motor and with a 1:2 belt ratio I'm happy the 24Nm available, especially when air assist is on, will be well capable of lifting the knee with jigs etc on the bed.

Removing the handle and indicator rings it seems a simple job to mount a motor to the existing shaft:


I'll just get some plates laser cut and weld them up, then use taper lock pulleys and an 8M HTD belt 20mm wide, same as all the other axes. To ensure the plates will fit/work and the pulleys have clearance, for the sake of a couple of hours 3D printing its an easy check:







I think that will work. I'll design a couple of brackets to go from the motor end of the plate back to the knee then get them off for cutting while I order pulleys, taperlocks and a belt. A simple sheet metal cover will keep swarf out, if I keep the mount plate rectangular it makes that cover easy to fit.

[richardb15]

I have a problem with the VCP fast/slow jog button not working. It used to work fine but I installed a KP1 touch probe and tool touch of probe, since then after homing the machine will not fast jog and the VCP jog button is stuck with the top corner red highlighted (slow jog). I am guessing its because of the tool touch off probe and CNC12 thinking its active so limits the jog speed to prevent nasty stuff happening?

This was the case with the KP1 as I'd left it plugged in by accident so CNC12 was limiting jog to 254mm/min. The KP1 is set up with probe detect and probe tripped. However when I disconnected the KP1 the machine is now limited to 500mm/min for X,Y and 400mm min Z and W. I have the tool touch probe set up with just one input, so its "live" all the time, I haven't used the ToolTouchOffDetected, just the ToolTouchOffTriggered into INP11. Actually the overtravel switch in the tool touch off probe is wired into the e-stop circuit so automatically triggers an e-stop event if activated.

I have been through the settings and wizard and I cannot see why its limiting this jog. I would have thought the tool touch off limits would only be active when actually doing a tool height auto set? Can anyone point me to what I've missed here so I can use the touch off probe and still get fast jog working? Report below, thanks.

[richardb15]

Sorted the limited jog speed and VCP button, it was because I had the tool touch probe input state when triggered set as closed, it should have been open. I inverted the input as per instructions so the input LED goes green when the probe is touched but forgot to switch the logic state in the wizard.

[richardb15]

Time to mount up the VFD. The resistor bank supplied by Techtop was for the larger frame drives. The smaller resistor bank option actually mounts in the back of the drive and uses the drive heatsink, but the large resistor bank only fits the larger frame drives, so not mine. Besides, not sure about the logic of putting a heat dissipating resistor bank inside a drive, that is not where you want extra heat.

After some tea drinking and thinking I realised there was a huge finned heatsink on the back of the dead Contraves drive I took out. I just took the old drive apart and if I mounted the resistor bank on an angle I could get 95% of the area touching, and 5 of the 6 mount screws in. That will do the job, can even use the old drive terminal block.



The new VFD is quarter of the size of the old one so fits easily into the rear spindle cabinet. I mounted the heatsink, complete with its plastic cover, back where it came from and the VFD next to it.





With that done it was time to wire the VFD into the circuits. I've followed CNCKeiths notes and wiring diagram S15158 ver 3 for the generic VFD. This is set up so the VFD main 3 phase contactor is energised when the main machine power is on. I put in a second e-stop relay bank that breaks the VFD common used for FWD/REV. This means on a machine e-stop event the VFD does not power down as it takes about 20 seconds to power down due to stored energy.

With the 0-10v analogue wired, FWD/REV on the same relay and the SpindleOK signal we are done. I have temp wired the motor into the VFD with the motor on the ground so I can see what its doing and use my RPM tool to check speeds etc are correct. A few drive and CNC12 parameter tweaks and it is all running fine, 0-6000rpm at the motor so it matches the old configuration. I have run it though the CNC12 fwd, rev and right through the speed range and its pretty close to correct RPM. I don't have closed loop on it as the spindle encoder is not physically mounted on the machine yet.

All good, next job is making the motor shaft adaptor to take the belt pulley and spindle brake sprocket, the get it mounted up and work out how to mount the spindle encoder.