The Breakroom > The Water Cooler

An Ill Wind

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klank:
A bit of a shaggy Dog story, but it may be interesting :-

Earlier in April this year, I traded my first small lathe - a Chester DB7 - for a new Sieg C4 from Axminster power Tool Centre (usual disclaimer). I wanted a bigger, more powerful lathe and one with T slots on the top slide. Both lathes are electronically controlled variable speed types.
The Chester lathe has gone to the "tool room" of a nearby village hot shot competition-car tune-up garage - didn't loose much on it as I'd only had it for about 18 months from new, since starting this hobby, and the garage owner wanted it.
(In retrospect - I should have bought the Sieg first, but then I did not know enough about lathes to make an informed choice. The saying "get the biggest you can" is so true.)

The one advantage that the Chester had, was that the lathe motor speed was set by a rotary pot - very easy to use and responds instantly to twiddling if things are getting too exciting.

The Sieg has a funky membrane type touch-pad contol with spindle speed digital read out - in blue!! - too funky for its own good I now realise.
Lathe motor speed control is by an Up/Down pair of pads - not the easiest way of speeding up or slowing down since you have to take your eye off the work and find the little b*****s to tap on with greasy fingertip.
The panel also has green start/red stop pads (also hard to find quickly) and clockwise/anti-clockwise rotation pads.
Below those is an Emergency Stop - "top hat" button - twist to release. Hitting this, and releasing re-sets the speed to the lowest setting automatically on re-start.
I have got into the habit of using this rather than the red touch pad (which does not re-set the speed if used) in "urgent" circumstances.

Anyway, I was machining a piece of steel in the 3 jaw with the power feed on, got to where I wanted to be and hit the emergency stop - NOTHING HAPPENED!!! The lathe kept on running quite happily, and before I could find the red pad, tool hit chuck - plink noise and broken lathe tool. Fortunately no injury to self.

I re-tested the button several times and it had absolutely no effect. I assumed "dud switch".
I removed the panel and looked at it - no wires off, no swarf in there. I tested the switch with a continuity meter (mains power disconnected) - switch works fine. There are 4 wires to it - two fat black ones (one comes in from the main rocker on/off master switch and the other goes into the bowels of the machine (mains current I assume). The other two are thinner (blue) and disappear into the bowels - low voltage wires to sensor perhaps?
I removed all of the wires from the switch and still the lathe ran with no problem! WTH is going on?
The "manual" which comes with the lathe has a wiring block-diagram - not easy to understand. No labels on it showing the various switches etc.

I telephoned Axminster - to ask for help and to be fair, the "technical" help guy was excellent - initially, he couldn't believe what was happening and very sorry about the problem. We talked it through and (like me) came to the conclusion that the problem must rest on the main power circuit board (which is fan cooled and hidden inside the headstock casing).
Fortunately, I only live about 18 miles form Axminster's premises - they would send "The Man" out next day to have a look - and right now he would have a look/play with the demo. model they had in the showroom to see if he could figure the problem out. He went on to say that they (APTC) had never ever had a problem with this lathe before - in all the years they had been selling it not one had ever come in for repairs. I suggested that The Man bought a spare power board with him.

The Man (John) called at my house the next day at the appointed time. After introductions and putting the coffee on,
we both tried to figure out the wiring block-diagram. After much testing with my continuity meter eventually made some sense of it. The lathe is designed to accommodate, as an optional extra, a small bolt on vertical mill to (thus) turn it into a "machining centre". The two fat black wires on the emergency switch have nothing to do with the lathe but go from mains in, via the emergency button to the mains socket on the back of the machine, into which is plugged the mains cable to the milling circuitry. The emergency stop switch thus controlling both "machines".
The two blue wires are connected to a "sub-unit" on the main lathe power board, and when the emergency switch is (opened), the unit should shut everything down, and re-set the lathe motor speed to lowest at re-start. That "unit" appeared to have failed.
APTC did not have a spare board in stock and one will be air freighted from Taiwan for John to fit next week.
As a short term fix, he piggy backed the emergency switch to the micro-switch operated by the chuck-guard. (The chuck guard and stud fittings having been removed by me on first receipt of the machine - it fouls the 4 jaw and face plate. John smiled at seeing this - "everyone does it - its a piece of poorly designed add-on that gets by current safety legislation" he said)
The emergency switch now turns the machine off properly but does not re-set the speed - this I can live with.

Before John left, he said "Got any use for a rotary table?" and plonked down a top of the range 6" rotable on my workbench - "Don't ask" he said - a gesture from him to say "sorry" for my troubles!!! What a handsome and unexpected present! I suspect it may have been a customer return or some such - but it looks brand new and seems to work perfectly.

As luck would have it, John noticed my big amateur radio dipole antenna sitting above the house - he too is a licensed (ham) radio operator - we got on well. He promised to bring some other goodies from the "returns" bin and or warehouse skip next time he comes.

An ill wind which blew in my favour I'd say.

PTsideshow:
 :D :) Glad to hear a good story, with the bad ones going the rounds. My wifey is now home and not much prospect of ever getting hired again. Age, Health problems etc. so that means a big change in my retired life style. More honey do's a long with the house chores she can no longer do  :doh:  Then getting a letter yesterday my builders supply/hardware is closing have had an account with them for 30 years. Close down the street and round the corner.

Special discount, bonus gift If I bring the envelope, with the invite to pre public sale. Plus $2,000 closing bonus bucks. I had though t That I hit the jackpot  :lol: :lol:. That is till I find out today everybody with two postal zip codes got the same letter  :doh: and now I don't feel so "Special" just hope they have one more box of vinyl siding By GP (which they Georgia Pacific no longer distributes) :lol: :lol: :lol: :lol:

Man it's been a bummer of a week so far! So it's nice to hear some body coming out on top of the pile instead of buried half way in it.

 :thumbup: :clap: :thumbup: :clap: :thumbup: good on ya!
glen

Darren:
Wow, I bet you're chuffed    :clap:....I had a similar thing when visiting someone recently

I must get around to setting it up as I think I'm going to need it soon.... :ddb:

DeereGuy:
Peter glad to hear they not only showed up but are taking care of you very well.  Can't wait to see that rotary table!  Talk to you soon....

klank:
Well, thanks for the good wishes everyone.

Glen - I know what you mean - I got "retired" from 35 years work as a surveyor a while back (back injury) and given a modest pension, then last month, out of the blue - wife made redundant from job she had for last seven years (she has a bad back too). No chance of either of us finding work now. (Bless her, my XYL let me get the new lathe as a silver wedding and birthday present combined - her job "went" a couple of weeks later!)
Our dog just developed diabetes (cost of insulin is horrendous), two sons in university - can no longer help them with rent or living costs, then yesterday (separate thread re. rain!) really really heavy rainstorm (thunder lightning et al.) and big leak appears in felt roof of porch/garage (workshop).

All in all, until yesterday life was getting to be a bit of a bummer - just occasionally a bit of sun shines.

Got to keep smiling.

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