Thread: Bah - setting the mill up just doesn't end!

So, I thought I was finally all done today. Put my oil pump back together yesterday (Big thanks to Stustoys for the handle bracket and supplying a sketch of the handle). Also properly mounted and wired the VFD into the location I wanted it, improving the mount for the DRO readout while I was at it. Also hooked power up to the transformer for the power feed. Pull the Varispeed housing off the front, and wound the chain the correct way, so that when the dial speed increased, the motor did the same thing (before it was working ass about!).

Pumped the oiler handle a few times, and discovered that most of the oil just came out of the Y axis slideways, particularly the left side! A bit of a dribble from the back of the X axis, nothing on the front. So having spent about 8 hours on trying to clear all the oilways, I finally worked out where the blockage was this morning, and cleared it out. Put the gib back in, pumped the handle a few times, and success! A bit of oil started oozing down the front of the saddle!

Brilliant, says I, and hit the powerfeed button to run the table across and get some oil all the way along the slide. Watching, watching, here comes the limit switch, now it should stop... Nope. Fortunately I had my hand next to the powerfeed controls, and just flicked it off. It appears that when the replacement power feed was fitted before I took it, their idiot electrician didn't check the operation of the limit switch. So now, I have to work out why thats not working. Of course, I'm assuming that the Align 250 powerfeed thats fitted actually HAS an input for limit switches, but I guess I'll find out when I can be bothered looking into it.

Not to mention that although there IS oil getting to the front slides for the X axis, its definitely not as much as gets to the back, and to the Y axis slides, the elevating screw, the X screw - basically, oil absolutely drips off everything EXCEPT that one slide (cue black spots of oil all over the floor. So I think I may have to have another go at the groove that distributes the oil along that slide, it must have a lump of fines in the middle that I missed, as the oil oozes down the saddle on the right (the side the oil is fed from) but not on the left. Ideally I should probably take the table off and clean it that way, as the oil coming from the rear is a bit dirty too, while the oil on the Y slides looks like it's just come out of the bottle.

I wonder what will need fixing when I finish those little jobs up? Incidentally, my mill is a varispeed, and has a small fan in the back of the belt housing there, looks like a computer fan. At the moment, I haven't hooked this up, as it was fed by a 415v-240v transformer in the motor terminal box, and my motor is now wired for the 240v output of the VFD. What purpose does that fan serve - as in, does it only really acchieve something if the mill is being worked hard for long periods of time, does it remove dust from the belt area... Can I just pick up two legs of the VFD output (3~ 240v) to the motor to drive this, if it's really needed (its only 0.5 amp or something, can't see it unbalancing anything by much)? I'd ideally like it just to come on with the motor, not be on a seperate switch or on whenever the power is on....

Hopefully my tooling from CTC arrives this week too, then I may actually have something to put in it!

Hi Jekyll and Hyde,

Three options for you to consider,

1. Do what you suggested (connect to the vfd output) and see if the fan runs, I wouldn't be surprised if it won't run at lower frequencies.

2. The VFD might have a "run" output, (you might have to configure the drive for this) that you can use to drive a relay that switches the 240V to the fan.

3. Change the switch that does the ON-FWD-REV to one with extra contacts that you can use to drive a relay as in option 2.

Regards
Ray

Originally Posted by RayG

Hi Jekyll and Hyde,

Three options for you to consider,

1. Do what you suggested (connect to the vfd output) and see if the fan runs, I wouldn't be surprised if it won't run at lower frequencies.

2. The VFD might have a "run" output, (you might have to configure the drive for this) that you can use to drive a relay that switches the 240V to the fan.

3. Change the switch that does the ON-FWD-REV to one with extra contacts that you can use to drive a relay as in option 2.

Regards
Ray

Hi Ray,

I think option 1 is the one I'll try first, as I don't really intend to use the VFD for speed control much (well, at the moment anyway).

Option 2... I'll have to read through the HOPELESS manual again (its one of the Huanyang drives), I don't remember seeing much in the way of descriptions of all the input/output terminals, but then again I was mostly investigating the settings for startup and shutdown times....

Option 3, I'd rather not, as I've tried to keep the mill itself as original as possible, meaning if I ever sell it there is a minimum of work to return it to running on real 3 phase.

Do you have any thoughts on the actual purpose of said fan? I can't really see a belt needing much in the way of cooling, which is what has me a little puzzled....

Cheers, Ben.

Originally Posted by Jekyll and Hyde

Hi Ray,

Do you have any thoughts on the actual purpose of said fan? I can't really see a belt needing much in the way of cooling, which is what has me a little puzzled....

Cheers, Ben.

Your guess is a good as mine, it would most likely be cooling, perhaps when the covers are on it draws a bit of air through the spindle bearings, or motor? Either way, it's there for a reason...

Regards
Ray

Originally Posted by RayG

Your guess is a good as mine, it would most likely be cooling, perhaps when the covers are on it draws a bit of air through the spindle bearings, or motor? Either way, it's there for a reason...

Regards
Ray

That is a possibility I guess, although the air would have to come in over the top of the Varispeed dial to then go out the back . Would have thought the airflow to be pretty minimal... Definitely agree that it must be there for a reason, I just wish I knew what it was!

Some more thinking, another look at the mill and a look at the exploded diagram in the manual for the mill (which describes it as 'fan'. Helpful.), and I reckon you're dead right - it must be for cooling the lower bearing on the motor. Probably an important job that.

I doubt it would draw air through the spindle bears, that would be bad.
But I dont know what its for either.
You have a picture of this fan?
Do you have two outlets from the contorl cabinent for powerfeed?
Glad to see you're getting there
Stuart

Originally Posted by Stustoys

I doubt it would draw air through the spindle bears, that would be bad.
But I dont know what its for either.
You have a picture of this fan?
Do you have two outlets from the contorl cabinent for powerfeed?
Glad to see you're getting there
Stuart

The only thing it can really do is cool the bottom bearing of the motor - the spindle bearings are much too far down to be in the path of the airflow. The fan is located at the back of the head, right behind the belt. I hooked it up across two of the motor wires anyway, works fine although I didn't check what happened if I turn the VFD speed down.

As far as the powerfeed goes, I've just spent an hour or so scratching my head trying to work out how the limit switches actually function. It seems that power into the powerfeed is actually routed via the limit switch, and then into the circuit board. Problem is, the microswitch seems to work backwards to that theory (being open circuit when not pushed). Except not always. I'm pretty sure its a fault with the microswitches, but I need to spend a little more time fiddling. I can probably live without the limit switch being functional, as the feed itself works fine, it just annoys me that the switch doesn't do what it is supposed to!

I have had a few of these limit switches apart, some have 3 wires and some have 4. I can take pictures tomorrow if you need it.

Dave

Originally Posted by Dave J

I have had a few of these limit switches apart, some have 3 wires and some have 4. I can take pictures tomorrow if you need it.

Dave

Mine is a 4 wire (and currently disemboweled), but the bigger problem just at the moment is that I can't work out what is holding the circuit board in place in the power feed (Align AL250 btw). Appears to be nothing, but it won't budge. Which means I can't really follow the wires properly to their ends, unplug and test the microswitches in isolation, unless I cut the wiring loom - which I'd rather not.

If you've had some apart before, have you found a source for the microswitches themselves, or are they one of those unobtanium parts none of the usual electronic components suppliers seem to have?

There are little tiny pins inside the limit switch box and the lid that are molded in to hold the micro switches. They brake and let the micro switch move away from the plunger and it fails to work. I replaced a couple of these by drilling them out and putting tiny screws in to hold the micro switch's.
Have you taken it apart and had a look?
You could unsolder the wires from the micro switch if need be. I have unsoldered a few to change to a different limit switch that I had. Both were working and I have not had any trouble with the micro switches at all on any of the power feeds.
The micro switches look to the same as what you can buy from Jay-car etc, so I don't think it would be a problem chasing them up.

Dave

Originally Posted by Dave J

There are little tiny pins inside the limit switch box and the lid that are molded in to hold the micro switches. They brake and let the micro switch move away from the plunger and it fails to work. I replaced a couple of these by drilling them out and putting tiny screws in to hold the micro switch's.
Have you taken it apart and had a look?
You could unsolder the wires from the micro switch if need be. I have unsoldered a few to change to a different limit switch that I had. Both were working and I have not had any trouble with the micro switches at all on any of the power feeds.
The micro switches look to the same as what you can buy from Jay-car etc, so I don't think it would be a problem chasing them up.

Dave

Interestingly enough, my limit switch had everything held in place by, you guessed it, little screws. Hidden under a sticker on the front proclaiming it to be sealed against oil etc. I managed to get a wiring plug off the circuit board which appeared to be the 'output' wires from the microswitch, and here it got to be too much of a head....

On both microswitchs, the incoming power wire connected to a pin marked C. No problems, makes sense I guess. Now, there are two other terminals on the switches, one marked NO and one NC. Seems that would mean normally open and normally closed, and my testing would indicate that to be correct. BUT. One microswitch had the output connected to the NO terminal, the other to the NC terminal. In other words, the switch for say the end of travel to the left, is making a circuit until the button is pushed, at which point it goes open circuit. The switch for end of travel to the right, is set up to be open circuit until the button closes the circuit. It may be vice versa with regards to left and right, but that doesn't really matter.

Both microswitches are functioning as they are supposed to, the wires are soldered on and the soldered terminals are potted around with a square block of silicone. Given that I had to remove the sticker to get at the screws to remove that, I doubt its been modified in there.

The only possibility I can think of, is where the two output wires go onto the circuit board actually has five pins, used by the two pin plug for those two wires, and a 3 pin plug with other wires (purpose not ascertained). It is possible to have the two plugs in either position (ie. 2 pin bottom, 3 pin top as it is currently, or 3 pin bottom, 2 pin at the top). I wonder whether its been swapped at some stage for some reason, but I can't see why, and I wouldn't imagine the feed itself would work if these were backwards.

This powerfeed was apparently one they had lying around with a stripped plastic gear, and they replaced the gear and used it, as the one on the machine was beyond repair. Judging by the way the limit switches are run, and the way the feed has been wired into the plug out of the transformer box, I'd say these switches were attached to this powerfeed. I have a sneaking suspicion I know what caused the stripped gear in this unit

Anyway, it all got too hard at that point, so everything is back together and I'll just have to live without the limit switches functioning for the moment, unless someone mentions something (or has a wiring schematic for an AL250!) that gets me interested enough to have another go.

I have got the manuals for Align and Assong and ALGS will scan them and post them up for you. I will also take apart and take a picture of inside my limit switch for you.
I know it took me a bit to get my head around the 4 wire one, but have forgotten what it was now as that was a year and a half ago.lol

Dave

is this any good to you?

you might get some idea from this as to the way its wired?

or this one..its the same as the old AL250..... so they (Align) say