New Mill ..Is this wired R

I hi all

Little bit puzzled by the new Toolco wm32 mill. I think it's the same as the warco wm18 so warco owners might be able to help. To try and explain there are 3 switches on the electrical panel on the side of the head. Emergency stop button normally out. The red green start / stop button separated by an amber neon to show power on. A 3 position switch to select forward neutral reverse.

With power plugged in the green start button will not latch  (no power) unless the direction switch is in forward or reverse. On my warco lathe when plugged in rpm display, neon all come on with the direction switch in neutral centre position.

The problem is that when you switch the power on at the socket you need to leave it in forward or it's switched off. This means the spindle rotates continually. Hope this makes sense

Edited By Brian Rutherford on 03/10/2017 21:31:35

Edited By Brian Rutherford on 03/10/2017 21:54:07

That's a bit too cryptic for me, Brian

MichaelG.

Michael

You are losing your touch, perfectly clear to me!

I’m sure what you have described is correct apart from the spindle rotating continuously . You place the rotary switch in forward or reverse and then start the motor with the green button and stop the motor with the red button emergency stop or guard covering the spindle

So what is yours doing if not the above?

.

... I'm sure we both know that Brian's second edit was done after I posted.

Brian

My (new) Warco WM18 spindle rotates when switched on, in forward or reverse, even with the speed control turned down to minimum.

From memory it is about 50 rpm on low speed range, and about 180 rpm in high speed range.

Warco told me this is normal.

Edited By David Standing 1 on 03/10/2017 22:34:13

Michael

Of course you and I do, but better you pointed that out for anyone new to the thread after it was edited!

Oh, and it was edited after I posted too, I was just teasing you initially 

Edited By David Standing 1 on 03/10/2017 22:38:20

Hi Brian,

I have a HBM 25 milling machine, similar to the Warco WM 16, but with a MT3 spindle. When I plug it in it does not start until I press the green Start button (direction switch in Forward or Reverse position), and I turn the speed control to about minimum before pressing the Stop button. I don't think the motor should start unless the Start button is pressed and you should start with the speed control turned down.

Thor

Edited By Thor on 04/10/2017 05:47:13

.

Well-played, Sir

It seems mine is normal then. So each time you stop the spindle you are cutting the power to the machine. Unlike the lathes (warco or toolco) where you only cut the supply to the motor I.e inverter and boards remain powered.

Seems a daft way of doing things as it won't do the electronics any good. Also as the instructions say you should start the machine on minimum rpm why Don't they incorporate the on off on the speed potentiometer?

Yes, not ideal is it. I guess it's the simplest way of providing fail-safe operation, the downside being that the whole machine is either ON or OFF.

Why there isn't an ON/OFF switch on the speed control is a mystery to me too. I suppose it's down to cost. The pot, associated wiring, and control board would all be more expensive. And it's something else to go wrong as well!

Good news though - your mill isn't faulty, it just has the same deliberate eccentricity as all the others.

Dave

Brian, I cannot see any reference to this being a VFD controlled machine. Warco machine is a DC motor

If its a variable speed motor a likely technical reason is that the motor controller has an internal "run-up to the set speed" process when first turned on to avoid any potential overloading issues during acceleration. If the system is effectively just a simple motor on switch set-up coupled to an already running control board there is no intrinsic control of start up loads as the motor tries to demand all the power it needs to get going.

There are various ways of implementing this sort of load control with the motor board still powered up. Forcing a full power down sequence on the control side each time the motor stops is probably the simplest, near bullet proof, method. If the control board stays powered up there are also, arguably, potential issues should the user change their mind and restart things during the run down period after the stop button has been pressed. Another potential problem area is if the motor fails to start or properly run-up to speed when the start button is pressed and the user simply presses the stop button before instantly hitting the start button for another try. Inadvertently trying to run up a large cutter with the spindle speed set close to maximum or trying to start one too close to the job so it immediately goes into cut sound like the sort of thing that could cause such issues. The ease of making such errors is one reason why I'm not particularly in favour of wide range varispeed motors.

As ever the practical validity and impact of such concerns depends on the engineering of the machine in question. As always things done right will be fine but in a practical word the price performance / ratio required of product that folk can actually afford means some compromise between always works whatever, works but don't be stupid and usually works. Sometimes bit of tweaking on how you can use something keeps you out of the region where, presumably less costly, usually works doesn't.

Clive.

Edited By Clive Foster on 04/10/2017 13:17:42

Edited By Clive Foster on 04/10/2017 13:28:26

Kwil no it's a dc motor. Fitting a pot with on / off is cheaper than the stop start buttons. Just like the old HiFi tv volume on off control.

Went up to Axminster this afternoon and they do this on there smaller siege mills.

Anyway it won't stop me enjoying it. My er32 collet chuck came today all the way from China so it's happy days

Kwil no it's a dc motor. Fitting a pot with on / off is cheaper than the stop start buttons. Just like the old HiFi tv volume on off control.

The way it's implemented it does nothing to stop you starting it up at full load speed anyway

Went up to Axminster this afternoon and they do this on there smaller siege mills.

Anyway it won't stop me enjoying it. My er32 collet chuck came today all the way from China so it's happy days

Edited By Brian Rutherford on 04/10/2017 15:54:51

The on-off switch is an NVR unit and performing a different function to a switch on the pot. It is a safety measure to prevent the machine re-starting in case of a power loss or indeed if the forward-off-reverse switch or the guard interlock is tripped. In normal use the direction switch can happily be left in the forward position and the machine just started from the NVR push button.

On my mill (WM14) there is no reverse and I can't really think why you need to run a mill backwards (someone will be along shortly to explain why this is a must have function) Also I don't turn the pot back to zero each time I start the mill. I just set the speed for the job in hand and then use the stop-start buttons. I have been doing this for 10 years with the mill and am still on the first DC controller board!

Enjoy the new machine.

John

I think reverse milling is provided specifically for me. I always accidentally mount slitting saws upside down!

Dave

Hi John. I have reverse on both of my mills, it makes for easier tapping also for drilling out broken bolts. Some time a go I was given some carbide milling cutters and to my surprise they were left handed so the reverse makes them usable.

regards.

I can see that for tapping it could be useful. I have never tried power tapping. either in the mill or drill, with my luck and general lack of skill it would be a sure fire way of generating lots of broken taps

John

Thought I'd share my experiences/knowledge of the speed control boards......

The speed control boards fitted to these machines are either made by KB in the States or they are a Chinese clone.

Either way, they use two thyristors/two diodes in a full wave bridge rectifier....There is a soft start function built in or rather circuitry that accelerates the motor, which is adjustable. ( not necessarily by the end user..)

Theoretically, the soft start should prevent the motor from damaging the electronics if the speed control were set to any speed other than minimum, same with the current limiting on the boards, it too should protect .

The motor basically has a very low dc resistance hence there is the potential for a high current draw at switch on. Hence why our sellers tell us to set the speed at minimum before switching on.....

All the above is irrelevant if a board from another manufacturer is fitted and doesnt have the same design features......