Laser cutter power switch modification

This is the inside of the mains panel on the back of the laser cutter. It looks like the existing power switch - which controls all the peripherals (cooler, coolant pump, fan) are switched from here.

It looks like it’s a spade crimp terminal connection to the switch, so we should be able to move the switch to the front by making up some new longer mains leads with spade terminals on them.

There is some space and a couple of existing holes on the front panel next to the existing bed raise/lower switch, although I might mount the power switch further away to avoid confusing the two (I’ll label them both, too)

I’d prefer to buy a new switch for it as they aren’t expensive and it makes it easier to predict what tools I’ll need to make the front panel cutout. I’m happy to buy the switch, wire and crimp connectors, but I’d like someone else to do the crimping if possible as I’ve never had much success with them. What do we think? Is this a sensible approach?

We’ll need to email all current laser users about the change and update the training information, of course.

(NB. If you’re not a laser maintainer, please don’t go poking around the inside of the side panel of the cutter. There are some delicate electronics in there.)

Sounds good to me!

What kind of switch would you use? Would a surface mount isolator switch in a pattress box work?

A pattress plate switch would work but I think it’s a bit of overkill; I was thinking of something like https://cpc.farnell.com/arcolectric/c1353atnan/switch-dpst-16a-250vac-ill-red/dp/SW05091?st=switch, which is equivalent to the existing switch so far as I can see.

I was going to suggest we probably want something BIG and red. We have a real problem with communicating with the membership about new processes, so we want something that foolproofly says what it is by how it looks.

My suggestion was going to be a big emergency stop button that can’t be missed, that also works as a power on/off. Your suggestion looks pretty good though, could it be a bit bigger?

Only other comment is I’ve seen a lot of those rocker switches fail in the past due to dust ingress. But if its in that alcove you’ve photographed, maybe it’ll be alright.

I did the initial wiring for this, Jim’s idea seems like it’ll work well. If needed i can pop in one evening with my electronics gear to help crimp spade terminals.

Another option if you want to avoid crimping might be:

  1. take a 1.8m C13 → C14 cable
  2. cut in half
  3. get pattress box, switch & 2x 20mm cable glands
  4. assemble with switched inline pattress box in the middle
  5. screw pattress to laser cutter base, use a c14 and c13 in-line with existing power cable

If you want something big and red - https://www.screwfix.com/p/british-general-cprsd432-4-pole-rotary-isolator-switch-no/8227R? is 15 quid and could go inline with a couple of 20mm glands

I agree it’d be good to make the switch as visible as possible. I’m not sure about the e-stop button though, as an e-stop button isn’t something I’d normally think of as a power on/off switch. If we want to add an e-stop as well, that’s fine with me as the current reset/stop button isn’t particularly visible.

I like the idea of the inline pattress box. If I can find somewhere sensible to mount it, I’ll probably do that.

There is now a power switch mounted next to the laser cutter. It doesn’t do anything yet, so the laser cutter is unchanged, and there is a label on it saying “Not in use yet”.

It’s just a switch with a UK mains plug on one end and a C13 (kettle lead) socket on the other end, so it can easily be swapped into operation when we’re ready.

Is there a way we can email all the current trained laser users to let them know about the switch? I will put signs on the cutter and post on Telegram, but I’d like to make as many people aware of the change as possible when we do it.

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Nice work!

There’s been a suggested “email all trained users” feature which hasn’t been implemented yet - but we can email all laser trained users manually from the info@ account.

Could it be a good time to send out a refresher on the rules for using the laser?

Maybe also take the chance to remind people about payment which could tie in with the contactless reader that’s being installed by snacks?

To be honest I haven’t kept up to date with the contactless reader discussion. I’ll draft an email to be sent out to laser users, and if you want to add anything about the contactless reader, that’s fine.

Here’s my draft of the notice to send out:


The laser cutter will soon have a power switch added. The reason for doing this is to reduce the electricity use of the laser while it’s not being used. The switch is already mounted next to the laser, but not currently connected, as in this photo:

We’ll connect the switch in the next couple of weeks. When it’s connected, you’ll need to turn the switch to turn the laser on. This should turn on the chiller and extractor as well as the laser cutter. You still need to check that the chiller is actually on and at about room temperature when you start, as is explained in the laser cutter training.

After you’ve finished with the laser, please leave it on for 15 minutes for the chiller to cool down the tube, then use the red power switch to turn everything off - leave the chiller’s power switch on.

Before we make the change, we’ll put printed notices on the laser cutter explaining this, and update the online documentation.

Thanks,

The laser maintenance team


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Ace, I’ll get this emailed out when it’s connected up :+1:

The laser power switch is now active. There are signs on the laser cutter (hopefully) explaining it, as above. Let me know if this causes problems or confusion, it’s an easy thing to revert.