Electrical engineer

[AndrewG]

Is this a dying trade? I’m looking for someone to repair my guillotine, removing a Programmable control panel to replace it with a simple manual setup. What do you do for electrical repairs to machinery? Seems plenty Electritions around this way to wire your house but show them an old 3phase Control box and they come out in a cold sweat!

 

[KennyO]

We are lucky to have a local firm that will do everything from wiring a house socket to jobs like yours.

No one local to you that does work for the harbour/ fish factory or are they all closed now?

 

[Sharpy]

We are lucky to have a local firm that will do everything from wiring a house socket to jobs like yours.

No one local to you that does work for the harbour/ fish factory or are they all closed now?

@TechWise ?

 

[TechWise]

Bit of a strange one this. As you say, its beyond most electricians, yet a graduate engineer like me hasn't been taught it.

I think industrial control and programmable controllers tend to be taught as part of a college level engineering course. Halfway in-between a basic spark and a graduate engineer ie HNC or HND in Electrical Engineering. One or two guys I went to uni with said they'd done this at college the previous year. Might be worth talking to a local college to see where those sorts of guys end up.

If it were my own machine, I would set about it with pen and paper and a multimeter and try to work out how it all worked the hard way over a few evenings. Obviously you don't want to be paying someone by the hour to do that though and there's always the risk of someone not being as clever as they think they are and ballsing it up.

 

[br jones]

I have a friend who is the electrician for a very large factory and has spent his life fixing stuff .i take stuff to him,and he hasnt failed to fix amything yet.the job above would suit him to a tee ,shame a bit far away

 

[fiatf130]

You need an instrumentation engineer or technician. PLC's are their bread and butter.

 

[sjt01]

Bit of a strange one this. As you say, its beyond most electricians, yet a graduate engineer like me hasn't been taught it.

I think industrial control and programmable controllers tend to be taught as part of a college level engineering course. Halfway in-between a basic spark and a graduate engineer ie HNC or HND in Electrical Engineering. One or two guys I went to uni with said they'd done this at college the previous year. Might be worth talking to a local college to see where those sorts of guys end up.

If it were my own machine, I would set about it with pen and paper and a multimeter and try to work out how it all worked the hard way over a few evenings. Obviously you don't want to be paying someone by the hour to do that though and there's always the risk of someone not being as clever as they think they are and ballsing it up.

If you can program, PLCs are a slightly different mindset. The only thing to worry about is the cost of the programming software. I knew nothing about PLCs before getting the digester, but have since modified the Allen Bradley ladder logic, then changed it out for a Mitsubishi. I do have an Ag Eng masters, and further degree in "Control of Fluidized Bed Tea Drying", which must help a little. If it was closer to us, I would be intrigued to have a look. However the safety controls might be a bit more specialised.

 

[Highland Mule]

I'd be asking @topcat2006 if they could give any advice, based purely on his post in the Home brewing thread elsewhere.

 

[topcat2006]

I'd be asking @topcat2006 if they could give any advice, based purely on his post in the Home brewing thread elsewhere.

Thanks @Highland Mule It's a bit far from me. But realistically early PLC's were programmed with laser logic which was designed to let an engineer who was used to making relay boards write software with little training, so it would be fairly simple to replace the controls with a manual set up albeit in a big box with lots of wires and relays.

Safety would be an issue - something like that now a days would have to be fitted with a safety class plc (so that if the plc fails or the code fails it would fail safe) and also have something like light curtains to prevent limbs being trapped.

I probably know control engineers who could have a look - but they would be more interested in replacing the existing plc with another up to date one. Cost - anything between £2-5k and above depending what is required under the machiney directive.

You'd be better off finding someone like me or stj01 who is closer to have a look and figure it out. I reckon an evening to figure out what needs controlling in which sequence with which Interlocks then a couple of days to build a box with the relays and buttons in.

Another alternative is something like a Siemens logo which you can program with bolean logic. The software and cables are relatively cheap to purchase. But it wouldn't be a safety class plc.

I hope this helps.

Tom

 

[tinman]

after reading the posts and good ones they are i started to think about what safety measures is in operation for a guillotine to cut a sheet of steel and tbh, i cant think of too many on them.. what have i missed @AndrewG ?


The machinery directive no doubt is an essential part of the industry but there are times i do wonder too.
I mean, the older machines, like lathes, metal cutting saws, mills and all other associated machines were plenty safe enough for the men and industry back then but now they don't pass..
it put a lad that sold a hell of a lot of second hand machines not far from me out of it, he had to quit it, said by the time he brought them up to spec the price was a ransom.

i mean, for the common sense bits that have nearly had the safety book thrown at them, should it not be based somewhat on, God gave you two eyes, could you not see it.

 

[Highland Mule]

after reading the posts and good ones they are i started to think about what safety measures is in operation for a guillotine to cut a sheet of steel and tbh, i cant think of too many on them.. what have i missed @AndrewG ?


The machinery directive no doubt is an essential part of the industry but there are times i do wonder too.
I mean, the older machines, like lathes, metal cutting saws, mills and all other associated machines were plenty safe enough for the men and industry back then but now they don't pass..
it put a lad that sold a hell of a lot of second hand machines not far from me out of it, he had to quit it, said by the time he brought them up to spec the price was a ransom.

i mean, for the common sense bits that have nearly had the safety book thrown at them, should it not be based somewhat on, God gave you two eyes, could you not see it.

They weren’t really that safe back then - we just accepted that industry killed a load more people then than it does now.

 

[DrWazzock]

Any decent industrial electrician should be able to perform basic electrical safety checks on that machine, (similar to portable appliance safety checks), examine the general state of the electrics on the machine, connect it to a suitable supply and fire it up. Then you know what works and what doesn’t. If the controller works then keep it. Replacing it with a bunch of relays won’t be a walk in the park. You cannot just get rid of the designed safety features without running into big trouble with HSE. There might also be functions of the controller that prevent the machine from damaging itself.
If on firing it up, it doesn’t come to life and isn’t self explanatory in operation then you need technical help. Ask at a factory who repairs their machines to if you can find a suitable specialist. Also try to find any technical manuals.
Good luck with it. A lovely machine?

 

[AndrewG]

The control box (which isn’t responding now) is for setting the backstop so that you can put in measurements and the stop goes there, you can go though a sequence and then move the backstop using the fwd and rev buttons on the control box. It is once you have entered the sequence the control box powers a relay that then allows the foot pedal to work the blade.
ideally i want the control box In the bin, the relay that it activates the foot pedal to be live constantly and push buttons for the backstop to be moved manually.
I don’t think any of this is rocket science and maybe i‘ll just have to find the time and figure it out eventually.
Safety wise there is only really 2 switches for guillotine up and down. If you injure yourself with this kind of guillotine you deserve it.

 

[tomlad]

Excuse my input, do they all have the lamp , sight line ,shadow line , were it cuts ??

 

[AndrewG]

My one does, not sure about them all.

 

[tomlad]

One at college, think it was a tight wire cable with bright light above to cast a shadow, were the cut will be , worked and seemed a really good idea. Just sharing.

 

[robcollins]

Have you got a photo of the interior of the control boxes?

The PLC will be controlling the contractors that operate the blade and move the table.

It should just be a matter of setting up buttons to do each function. With a bit of extra wiring.

Is there a wiring diagram anywhere on the machine? ( I didn't see much on the net)

How is the workpiece moved, is it a motor operating a big setscrew to shift the table?

It's a shame you're surrounded by lads who only do domestic, we were taught PLC as well as motor control in our electrical apprenticeships in Ireland.

 

[aidan]

yes a wiring diagram would be the place to start if there is

 

[AndrewG]

Have you got a photo of the interior of the control boxes?

The PLC will be controlling the contractors that operate the blade and move the table.

It should just be a matter of setting up buttons to do each function. With a bit of extra wiring.

Is there a wiring diagram anywhere on the machine? ( I didn't see much on the net)

How is the workpiece moved, is it a motor operating a big setscrew to shift the table?

It's a shame you're surrounded by lads who only do domestic, we were taught PLC as well as motor control in our electrical apprenticeships in Ireland.

You’ve Pretty much nailed it there. I don’t have a photo on my phone but will take one next time I’m at the machine. No diagrams unfortunately and the maker is no longer in business so no joy there.

 

[TheTallGuy]

It's the sort of thing I used to do all the time, but I tend not to anymore because it's a bit of a legal minefield. As soon as I make a significant change to a machine I effectively become the design authority & hence responsible for the safety features (or lack of) & EMC certification etc. The price I would have to charge to get the machine to a legal standard & cover my liability would make it unviable in many instances.