WIAD puzzler

Here is one for the forum. If you put the spindle switch in forward position, the contactor closes but the spindle does not revolve, in reverse it works. If you manually close the forward contactor in the DC box with a pencil , it works perfectly. If you close the contactor with the pencil and hold it, then move the forward switch while the spindle is running, still holding it closed, it shuts off. If you put the switch in the forward position and the contactor closes and then manually poke on the contactors,thinking that the solenoid might be weak.....nothing. A head scratcher and probably something simple....or not.

daryl bane said:

Here is one for the forum. If you put the spindle switch in forward position, the contactor closes but the spindle does not revolve, in reverse it works. If you manually close the forward contactor in the DC box with a pencil , it works perfectly. If you close the contactor with the pencil and hold it, then move the forward switch while the spindle is running, still holding it closed, it shuts off. If you put the switch in the forward position and the contactor closes and then manually poke on the contactors,thinking that the solenoid might be weak.....nothing. A head scratcher and probably something simple....or not.

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I shed that switch, but ISTR one of the gangs of it 'enforces' a neutral condition. That only from repairing a Beel drive wherein I had to jumper his terminals that went there..

If so (and it may not be..) does it seem possible that the FWD selection section is working, but a truant neutral(izer) section is over-riding it?


Bill

I feel there is a pesky relay involved that is energised ( and now faulty) by the switch and by passed when I manually close the contactor. It has been working for years and this just raised its ugly head. It has the feeling that it is a protection circuit and I haven't figured it out yet. The spindle moves alittle when the switch is activated, but something shuts it down, but reverse works perfectly...damn.

daryl bane said:

I feel there is a pesky relay involved that is energised ( and now faulty) by the switch and by passed when I manually close the contactor. It has been working for years and this just raised its ugly head. It has the feeling that it is a protection circuit and I haven't figured it out yet. The spindle moves alittle when the switch is activated, but something shuts it down.

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'Moves a little' reinforced my SWAG that the Motor Switch cam for that neutral/safe position is worn on the FWD direction portion.

All of them probably are. This just the first one to show it. FWD wudda been the side / transition most-used all these years.. unless you turn in REV most of the time out of Texian perverseness..



"The good news.." jumpering to test, then pulling the switch for repair is a job one can do standing up, not bent over.

Means a lot as one gets older.

If the spindle lock is engaged the behavior is something like what you describe. Engage the spindle lock, put the machine in forward and it shuts down. Same thing in reverse which you are not seeing. Never the less I would look around the spindle lock switch and relay with the idea that maybe the spindle lock relay is falling out when it shouldn't.

Alan

I agree, the spindle lock sounds suspicious, but why would it work in forward only and not reverse, it is a simple switch and was new? I will isolate that from the circuit and see what happens. I will investigate the micro switches, but they were new when I built this, and the contactor closes solidly, but maybe there is something amiss in the timing , I can certainly jump the switches, and we'll see what that does. Unfortunately
I am into the red wine now and all bets are off, till later. Thanks

daryl bane said:

Unfortunately I am into the red wine now and all bets are off, till later. Thanks

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Of a Sat'day night? Not a bad example to set.

I dunno wot's "unfortunate" about that unless it is some truly evil plonk yer pourin'.



Wot the hey. I might as well follow yer lead and finish the remains of that bottle o' Blue Top before it goes entirely flat.

Meanwhile, either location, FWD-REV diff could be as simple as a loose screw allowing floppin'. or a terminal, or .. Given that you get 'some' movement before all-stop in FWD and apparent normal in REV that suggests a physical player rather than purely 'lectrons.

Bill

Curiosity got the better of me, and I isolated the spindle lock switch, no change, still won't work in the forward position. AND, jumped the micro switches in the ELSR housing and same result. Manually operated the switches and no go only in the forward, while making sure the neutral was not activated which it wasn't, and the contactor was solidly closing. Any other ideas?

daryl bane said:

Curiosity got the better of me, and I isolated the spindle lock switch, no change, still won't work in the forward position. AND, jumped the micro switches in the ELSR housing and same result. Manually operated the switches and no go only in the forward, while making sure the neutral was not activated which it wasn't. Any other ideas?

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Can we be sure jumpering at the ELSR covered the entire 'chain'? You have the schematics, I do not.

Well.. I do for the MG-era, but... that could be a route to confusion.. I don't even HAVE a spindle-lock switch, for example.

Bill

Well that's the catch, I am trying to figure whats left in the chain. The key here is what is being activated...or not when the spindle switch it put into forward, because when I press the forward contactor with a pencil, it runs perfectly, but not when I engage the switch in forward. And the neutral micro switch is not affected.EVEN though it activates the contactor. AND when I hold the contactor down and it is running, and then engage the forward switch, still holding the contactor, it shuts down. Very odd.

daryl bane said:

Well that's the catch, I am trying to figure whats left in the chain. The key here is what is being activated...or not when the spindle switch it put into forward, because when I press the forward contactor with a pencil, it runs perfectly, but not when I engage the switch in forward. EVEN though it activates the contactor. AND when I hold the contactor down and it is running, and then engage the forward switch, still holding the contactor, it shuts down. Very odd.

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Irony is that the solid-state DC drive - or a VFD even more so - have several orders of magnitude more complexity inside of them.. but we don't 'see' into an IC, nor ordinarily even do PCB-level repair.

We just swop the whole dagone box. Problem goes away with it.

Legacy 10EE have silly-few components by contrast.

But those bits are scattered across a quattah acre of iron, and do not lend themselves to 'Black Box' replacement, even if one had a spare WiaD truck or such.

In short, I'm stumped. I don't 'go there' as often as Cal or Peter. Or yerself.

You've 'manually' ruled-out the CONTACTS of the contactor arredy. More than once.

The brief bump for FWD seems to rule-out failed pull-in power TO the FWD contactor. It is getting a sniff, then being DENIED that, somehow.

If it ain't the Motor Switch or the field-FW relays throwing an immediate flag on FWD play?

I cannot see TWO motor brushes - not less than one per each set of two - gone cruddy and grubby enough to hang ... and not make rather rude noises. As happens when but ONE hangs. Got That Tee Shirt. Spare brushes as well if you need 'em quick-like..

Same again w/r Field kinkyfudgery relays. Why halt on FWD AND NOT on REV?

Thread title is a good one, if it is any consolation...

And I'm into the Taittinger arredy, so 'colour me (more) useless (than usual)' for a while...

Maybe the forward hold position on the contactor is loose when pulled in by the coil and not so loose when pushed in by pencil?

rke[pler said:

Maybe the forward hold position on the contactor is loose when pulled in by the coil and not so loose when pushed in by pencil?

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I thought the same, but when contactor engaged with the forward switch, I pushed and pulled the contactors with same said pencil to no avail. I even readjusted the spring tension on all the forward contacts and added shim to the flat contacts thinking that maybe they were not getting good connection...no change. Motor was completely rebuilt, and not many miles on it , I'm sorry to admit. I keep going back to some not yet found protection relay that I am bypassing with the heroic pencil.

daryl bane said:

I thought the same, but when contactor engaged with the forward switch, I pushed and pulled the contactors with same said pencil to no avail. I even readjusted the spring tension on all the forward contacts and added shim to the flat contacts thinking that maybe they were not getting good connection...no change. Motor was completely rebuilt, and not many miles on it , I'm sorry to admit. I keep going back to some not yet found protection relay that I am bypassing with the heroic pencil.

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Something odd about that.... I understood that the pencil-pressure was only effective UNTIL you ALSO set the motor Switch into FWD. After which it was to no avail.

So I/we have been looking for a 'low power' cause (control circuit. switch or relay..) for a 'high power' fail.

But... once you push that pencil down, none of the control circuits that speak to denizens of the OUTPUT side of the WiaD matter.

There is NOTHING ELSE with contacts heavy enough to manage its output EXCEPT the contactor.

So .. there is power TO the contactor (from the WiaD drive output. Until the MS is set to FWD.

There IS a conduction path FROM the contactor (to the motor), 'coz it also works UNTIL the MS is set to FWD.

Is the WiaD drive being shut-off at the SOURCE?

I have been ass u me ing the Thyratron rig neither knows nor cares whom has the right to do what, with which, and to whom with the power it serves-up. Dasn't internally CARE whether FWD or REV contactor is energized.

Or neither. Nor even BOTH.

Switch prevents asking for it. Final 'save' is left up to a mechanical interlock at the contactors.

But the power is still available , 'upstream'..

As a "contactor-reversing" (only) AKA "1Q" critter, all that control and interlocking is a third-party player's task - not that of the Thyratrons.

EG: the contactors and their control circuitry.

Or a pencil. (BTW .. we gots to get you an 'Orange stick'. Pencil lead can be conductive..)

I had not presumed a WiaD to have fault-detection or alarm circuitry of the sort DC Drives or VFD grew in later epochs.

And yet... if the source has gone dark... it is ACTING as if it did have..

We've been looking only at the Armature circuit(s).

Is there something erratic in the FIELD circuitry?

Field kinkyfudgery relay? Field-loss emulated in error, triggering a shut-down?

Or ACTUAL field-loss, shutdown as-required?

Bill

Looks like it is time to break out the meter and quit puzzling till the puzzler is sore!

Field and armature voltages when using the stick to poke the fwd, and again after using the switch while poking.
And the last test of switch alone.

Do you have a FL relay? Does it drop out during any of the above tests?

Before I get all down into this. What is the mechanical action of the motor overload relay? This is the one down on the bottom left of the dc cabinet. Is it a simple push button, that doesn't feel like it does anything as you push it, or does it feel like it recocks itself when pushed.? Mine acts like the former, but I haven't put any meter on it, just a quick thought. I started going over the schematics this morn, and seems like all the FL relays etc are " downstream" of the contactors and if faulty should affect both FWD and REV the same. The fact that just started makes me point to a wonky tube, maybe the 6h6 or 6n7.

I bet it's something in your ESLR circuit. Have you played with it while the lathe is in the failed state???

Tim in D

Yeah, I jumped all the micro switches, and ELSR speed pot and pushbutton (which only work in reverse, as they should) all seemed to work fine. I am going to play with the Minimum Speed pot, just on a hunch.

OK a MAJOR CLUE....and you guys who are alot smarter than me , this might be the answer. When I use the FWD switch and the contactor closes, both C16J s go DARK!! like off, and when I move the switch back they come back on, and in REV nice and steady. If I hold the contactor down manually sans the switch they both work perfectly. OK gentlemen, what have ye?

daryl bane said:

... OK gentlemen, what have ye?

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Sense enough to get TF out of the way of better men at this point so you can actually FIX it..



Bill