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Suddenly not working Bridgeport J head

PHGV

Plastic
Joined
Sep 19, 2020
Location
UK, Northumberland, West Woodburn
Hi Forum, I am just new to this forum, hope someone can assist me...

I have a Bridgeport (BP), for years up and running in my garage, never one problem. See pics for type.

However, after a small job yesterday, nothing special, I started it up, but it seems the motor doesn't want to do anything anymore. The spindle is rotating free, the current is running to the relais... but when I push the start button (the green light of the button illuminates) only the relais clicks. My BP (25V) lights work, no unusual sounds yesterday... nothing.
Does this motor have brushes or is it brushless. It looks like that something between relais<>motor something goes wrong.
Checked three (weird) fuses, but they are ok.
I don't have a wiring diagram, have a multi-meter, but I am not a 'electronics specialist'. Years ago I did installed the BP myself to a 3Ph converter and hooked it up; from the first switch it has run for many years without any problems. Recently I did clean its coolant reservoir/pump and got the light working; all went fine and didn't need to touch anything electric of the mill itself. Milling the last few weeks without any problem... I just switched it off yesterday (as usual)...
Where do I start...?

Kind reg.
PHGV.IMG_9463.jpgIMG_9464.jpg
 
The motor does not have brushes and is unlikely to be the problem.

I would look at the phase converter as the likely source of issue.

Hi, thank you for commenting. Yes, found out no brush(Youtube 'Bridgeport Head overhaul'). I have several other machines running on the same converter; they all work.
Looking at the wiring in the box on the knee, there are 4 relais (with different amps)in the box; when I push the spindle motor button, only relais 2 kicks in (on the overview wiring (bleuprint drawing Bridgeport Textron WD162D), this could be C2 to control Mtr2, but that is the auxiliary feed(I have an E head), which in the box, its wiring is leading to the -unused- auxiliary input) but I expected, that another relais -C3- to kick in, which has the wiring leading to the spindle motor... That relais (with another amp) remains static, doesn't do anything...& looks like not giving any feed to the spindle motor. I measured (multimeter) no current at the high/low range switch feeding the motor.

Am I allowed to 'push that relais' or is it not possible to have two relais 'on or in' at the same time... since they all have their own amp range.

I have also tried to switch on the long feed motor, but that doesn't work either (possible 'wired' dependently) despite having the spindle push button on 'on' mode.

Would be great if you had 'other' thoughts, kind regards,
PHGV.
 
Use your multimeter to check for power, start at wiring from rpc, next check wiring coming into mill, then check before and after relays, then check at motor. Somewhere in there you will find that you are not getting power, if you find it still has power all the way to motor, you have an answer
 
Hi, thank you for commenting. Yes, found out no brush(Youtube 'Bridgeport Head overhaul'). I have several other machines running on the same converter; they all work.
Looking at the wiring in the box on the knee, there are 4 relais (with different amps)in the box; when I push the spindle motor button, only relais 2 kicks in (on the overview wiring (bleuprint drawing Bridgeport Textron WD162D), this could be C2 to control Mtr2, but that is the auxiliary feed(I have an E head), which in the box, its wiring is leading to the -unused- auxiliary input) but I expected, that another relais -C3- to kick in, which has the wiring leading to the spindle motor... That relais (with another amp) remains static, doesn't do anything...& looks like not giving any feed to the spindle motor. I measured (multimeter) no current at the high/low range switch feeding the motor.

Am I allowed to 'push that relais' or is it not possible to have two relais 'on or in' at the same time... since they all have their own amp range.

I have also tried to switch on the long feed motor, but that doesn't work either (possible 'wired' dependently) despite having the spindle push button on 'on' mode.

Would be great if you had 'other' thoughts, kind regards,
PHGV.

Mind you, I've never worked on a BP, or seen its schematics. You should be able to manually engage each relay individually to determine what it controls, and if the contacts are making a connection. If 1 relay is for forward, and other reverse, you would not want to engage both at the same time, they are usually interlocked to prevent that, but not always. If you manually engaged relay for motor and it runs, then either you have a bad coil, a bad switch, or a break in a connection.

Post up some pics of your controls.
 
Hi DG61,
I am back again & thank you; I've made a picture, did some measuring and tried 'manually' to activate C3 (spindle = brown wiring in top).
To start with the latter, as you suggested, when I pushed C3, the spindle motor started to turn (!) but quickly I witheld my push (was also scared) and the C3 didn't stay on and the motor stopped. Activating C3 made that C2 also jumped in by itself? Don't know why...

It means the motor wants to turn but I don't dare to do it again as I might 'burn' the motor. There must be a reason not wanting to stay on... or is it because I 'bridged' PB1, the 'on switch on the control box in front (4 toggle, on & off button)...

Before, I measured, taking out the fuses CB1 to CB3, one at the time and with all out. It apears that line 2 is differently from the others (not supplying the trafo), but all get 415v when meter bridging (between main switch and supply C1 to C3) switch and contacting line 1 to 3.

Next thing I am going to check above C3, the OL3 with the (pot-?)meter 2.7 Amp., to see if the OL3 is stil ok... or I can find a current.

To clarify the following 'switching box' on the side of the BP. Parts names.jpg

Thank you all for helping me out... will let you know my next moves...and results.
PHGV.

Just a quick extra as I went to the garage in between; the C2 (Aux) just switched on as the toggle switch for Aux was (always) on on the front control box... Now switched off; when I push the PB1 on now, only the green light goes on but it doesn't stay on anymore when I release the on button. I appears there is 'no' relais switched/activated... it looks like as if relais C3 has a problem... but how to check that/why?

2hrs later:
I've made a few additional pictures of my controls in my next reply:

Side Control box; the relais which needs checking (only how?). Very info, I understand the red wires (on the left) come from the front control box (with nr 1 yellow code label) to 'power' the relais
Following the code on the relais, are all (4) relais the same? DIL 00 40... in this box? <> interchangeable?


Front Control box with toggle switches, the on and the off switch. I think the terminal on the pack are powering the lamp in the switch, the terminals 3 and 4 at the back of the ON switch (PB1) are the normally open contacts to close and power the relais. (the Off switch PB@ is the opposite hence the other terminals are used)..
 
Last edited:
checked a few things

Check the E stop switch down on your little control panel on the knee. Make sure that wire hasnt come loose.

Jon

Hi Jon, I checked the stop button on the small control box, which is a normally closed type, and works properly (even after isolation). All wires (L1 and wire 2) are connected and in the long side box also no loose connections.
May I ask; there is a OL3 connected just above the connector C3, which is described as a 'overload'; can they go wrong over time? I haven't had an overload whilst milling, it just didn't start (the spindle) when I tried to re-start it.
I looks like either the OL or the connector (relais) C3 is faulty... I wouldn't mind buying a new relais, but they are pricey.. esp. as a try. I thought first trying to 'exchange it' with the relais for the Aux, which works (the relais only, not the potmeter & OL) as it has the same part code.

Thanks in advance, PHGV.
 
Hi DG61,
I am back again & thank you; I've made a picture, did some measuring and tried 'manually' to activate C3 (spindle = brown wiring in top).
To start with the latter, as you suggested, when I pushed C3, the spindle motor started to turn (!) but quickly I witheld my push (was also scared) and the C3 didn't stay on and the motor stopped. Activating C3 made that C2 also jumped in by itself? Don't know why...

It means the motor wants to turn but I don't dare to do it again as I might 'burn' the motor. There must be a reason not wanting to stay on... or is it because I 'bridged' PB1, the 'on switch on the control box in front (4 toggle, on & off button)...

Before, I measured, taking out the fuses CB1 to CB3, one at the time and with all out. It apears that line 2 is differently from the others (not supplying the trafo), but all get 415v when meter bridging (between main switch and supply C1 to C3) switch and contacting line 1 to 3.

Next thing I am going to check above C3, the OL3 with the (pot-?)meter 2.7 Amp., to see if the OL3 is stil ok... or I can find a current.

To clarify the following 'switching box' on the side of the BP. View attachment 299829

Thank you all for helping me out... will let you know my next moves...and results.
PHGV.

Just a quick extra as I went to the garage in between; the C2 (Aux) just switched on as the toggle switch for Aux was (always) on on the front control box... Now switched off; when I push the PB1 on now, only the green light goes on but it doesn't stay on anymore when I release the on button. I appears there is 'no' relais switched/activated... it looks like as if relais C3 has a problem... but how to check that/why?

2hrs later:
I've made a few additional pictures of my controls in my next reply:

Side Control box; the relais which needs checking (only how?). Very info, I understand the red wires (on the left) come from the front control box (with nr 1 yellow code label) to 'power' the relais
Following the code on the relais, are all (4) relais the same? DIL 00 40... in this box? <> interchangeable?


Front Control box with toggle switches, the on and the off switch. I think the terminal on the pack are powering the lamp in the switch, the terminals 3 and 4 at the back of the ON switch (PB1) are the normally open contacts to close and power the relais. (the Off switch PB@ is the opposite hence the other terminals are used)..

I forgot to tell you, don't be scared when you manually engage the contactor:D, and do it with purpose, not lightly as that is bad for the contacts, if need be, use something insulated, NOT a screwdriver. If motor started when you engaged the contactor, your next step should be to engage the switch that controls that contactor, if nothing happens at contactor (it does not engage), you need to check voltage going to coil, if it has voltage, the coil is bad, check by ohming. If coil has NO voltage, check wiring back to switch, and the switch.

The fact that your motor started when you manually engaged the contactor indicates that your overload is NOT the problem.

Your pics in post 8 did not come thru.
 
I am still working on it, but need to 'work' also...

Any progress?
Hi, as you suggest, I have to check the coil of contactor (that is new to me, measuring the ohms..); I think it is this component if the 'overload' is ok. I have put the not loaded images 'in between' in a later post.
To check the contactor I have to fully open the door of the side control box (now it is only less than 30% open. I am able to make photo's and point with my multimeter. But if I need to isolate a component (to do the 'ohm') I need better access, meaning to 'move' my steel cabinet on the side (my BP is fully built in side ways <> space shortage). Need to do that first, which will cost me two days (in my spare/own time). Hence my late response, sorry, but I have to work at the same time... Positive thing is I have to do it, as my 'to be milled car engine crank' is on it and can just leave it all as it is, but I do have to respond to 'work orders' and am allowed only to do the repair in my 'own' time... I will come back in the end part of this week... and will keep you informed

Thanks in advance,
PHGV.
 
Please do not confuse me by inserting images in previous posts:).

Set your meter to ohm scale (may be indicated by the omega symbol), if digital meter you should see a 1 on far left of screen, touch your probes together and it should quickly go to 000, this shows continuity. On the off hand chance you are using an analog meter, you should use zero function to zero your needle, connect probes and needle should peg scale, been a while but I seem to remember that is how it worked.

Locate 2 wires going to coil, power ON to machine, switch ON for motor, test for voltage to coil, if NO voltage check switch (power to machine OFF), if switch is good, check for voltage coming into switch (power to machine back ON).

If coil HAS voltage, turn power to machine off, disconnect leads to coil and check ohms, if meter does not change at all, it has a dead short and is dead. If meter does change and goes to 655 (random numbers out of my head) this would show there is continuity but resistance, coil may or may not be bad, we would need to know proper resistance to determine. Do these tests and report back with results.

Your contactors (relays) are Klockner-Moeller DIL 00-04, coils come in different voltages, unsure what you have. Judging by your pics you will most likely have to pull contactor and overload out together, and separate them to install a new coil, if that is the problem.
 








 
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