60W Chinese Laser Engraver Modification

[awemawson]

A little while back I bought an eBay Special 60W Chinese laser engraver / cutter which has featured in the odd thread here on the forum, but I've decided to start a new thread to gather all the bits I do into one place.

It's been mentioned here : (and perhaps a few other places  )

http://madmodder.net/index.php/topic,10883.0.html

Today I finally got fed up with the lousy mains wiring to the peripherals and made up a new power output panel. The problem was that the originals were 'universal' sockets of rather poor quality that didn't retain the plugs sufficiently to take the cable weight

This is what there was

[awemawson]

Not only were the sockets poor quality, they didn't grip in their cut outs properly so the manufacturer had jammed bits of wood in to fix them 

[awemawson]

I decided to use "IEC" power outlet sockets from a reputable UK manufacturer (Bulgin) and make up a steel panel to fill the existing cut outs and mount the sockets.

So draw it up in FeatureCAM, cut a blank on the guillotine, mount it in the CNC mill and make it . . . it was one of the few occasions when the whole process went smoothly, even down to the slightly dodgy mounting of the panel as it was being cut - yes there are parallels below the panel   

[awemawson]

I decided to keep the "Earth Terminal" that all these lasers seem to have, as although I don't use it (as the machine is earthed via it's standard 13A inlet) it was a convenient way of minimizing the wiring changes

[awemawson]

So I was more than happy to consign all the old stuff to the dust bin and put the new into use.

I'm sure that there must be robust two and three pin US style plugs and sockets, but these weren't they 

At least now I'm not having to constantly check that the plugs haven't fallen out. One is for the water circulation to cool the laser and only a matter of a few minutes disconection would scrap £250 / £300 worth of laser tube 

[nrml]

Nice job (as always). If accidental disconnects  are critical, have you thought of  making little brackets to hold the plugs in their sockets? Some of the electrical equipment we use in the operating theatre have little plastic brackets that wrap around the plug and are fixed by a couple of screws to the chassis of the piece of equipment. They prevent accidental disconnects when things get moved around. They should be very easy to 3D print.

[awemawson]

Thanks NRML for the kind words.

The laser needs water cooling, and now I've sorted out the power out sockets (incidentally labelled power in on the machine  ) the time has come to sort out my water system.

They supply an immersible pond pump and suggest using a bucket, which is what I've been doing, but that has a few disadvantages:

A) I'd like to use anti-freeze as the machine is next to the roller shutter, but not in an open bucket when my dogs come to visit me playing in the workshop - anti-freeze is poisonous.

B) I just know that I'm going to kick it over at some time, because I do that sort of thing (unintentionally  )

C) An open bucket attracts 'stuff' - this one fills up with dead spiders, some of which float, and others sink 

Now there are commercial coolers available with enclosed tanks, flow alarms and temperature alarms. All very good but they are really rather expensive for what is essentially just a coil of pipe with a fan blowing over it, so I've resisted up until now.

[awemawson]

However one popped up on eBay at half the normal price, so suddenly the equation started to balance 

As it was a one off 'buy it now' it seemed rude not to so I placed an order, and Angie, our local 'My Hermes' lady struggled in with a large box this morning 

Obviously the first thing a real mad modder needs to do is pull it apart and see how it ticks 

It's actually quite nicely made

[awemawson]

A nominal 10 litre plastic reservoir tank with embedded temperature sensor that feeds a panel display. Outlet from the tank goes to a 24v pump that circulates water through the laser tube, and back via the flow sensor and cooling pipes.

Note  that there is no 'active' cooling, (compressor / evaporator or Peltier element)  the heat is just dispersed to atmosphere by a fan

In built is an alarm that is triggered by either over temperature or low water flow, a very handy feature

[awemawson]

So putting it back together I removed the crude bucket affair, installed the cooler, and filled it from my stash of pre-diluted anti-freeze (*). Connected up the plumbing and set it to work.

It is too tall to go on the shelf under the machine, and long term I intend to mount it on the side so as the machine is moved on it's castors you don't have to fuss around with pipes and cables, but for now it just sits on the floor.

I had contemplated making one but frankly the bits would have cost much the same as I paid by the time it was boxed and working.

A very useful side effect of the way that the engraving machine sequences up, is that as it goes though it's start up routine water flow isn't instant as some has drained back to the tank, so the alarm sounds for a second or two confirming that it still works !

(*) When I de-commissioned my 100 kW induction furnace when I moved 8 years ago I kept something of the order of 300 litres of pre-diluted ethylene-glycol coolant as not only was it going to be needed in the future, it was not easy to dispose of anyway being a poison - still not re-commissioned the induction furnace 

[John Stevenson]

I have one of the larger Ikea plastic storage containers with a lid, under the bench / stand that it sits on, like your with anti freeze as it backs onto a door that isn't used.
Handy as I can vent the exhaust through the door with a laser cut plastic grille over it.

Don't know if this applies to yours but somewhere in the menu's, File, I think there is an options tab so you can fine tune but it needs a vendors password.
RD8888 seems to work on most machines.

[awemawson]

Thanks for the tip John. I'll have a try when next poking in it's controller 

[jcs0001]

Andrew

That's quite a unit.  I know nothing about them but find it interesting.

As far as anti freeze goes if you need something non poisonous you could use Propolene glycol.  I use it in my hot water solar system.  The inspectors are very much concerned about people using regular automotive type of anti freeze in their solar systems (for good reason) and demand proof of what is being used.  It's good for really cold weather - we get winters where the temp. goes well below -20 C and there have been no problems.  I've heard that propolene glycol is used in ice cream but am not sure if that is just rumour.

John.

[awemawson]

Certainly propylene glycol is safe, and used as you say as a food additive, but as I have 300 litres of diluted ethylene glycol (and another 25 undiluted) I used what I have as it is a sealed system.

When I set up the furnace I had intended to use propylene glycol but the cost was prohibitive in the quantities I needed.

[awemawson]

I'm getting to rather like this laser cutter 

Today I needed to fit a 'cigarette lighter socket' in the JCB 803 mini digger - why as I don't smoke  Well I need to sport an amber flashing beacon when I'm stream clearing on a public footpath that borders our land. Only place on console was a 'switch blanking cover' but totally wrong shape.

Needed to make up a little 50 mm x 35 mm plastic panel with a 'keyhole' for the socket. Quickly draw it up in Autocad, download it as a .DXF to the PC I've dedicated to the laser cutter, open it in RDworksV8 (which is the graphics package that came with the machine, squirt it to the laser cutter and bob's your uncle.

Literally quicker to do than type this description. Previously I'd have been drilling and filing and cursing when it didn't fit. This went in first time

[John Stevenson]

Sod it, I'd just run the buggers over.

If they can't see something like a JCB then they need a new guide dog. In fact aim for the guide dog first...............

[jcs0001]

Andrew - at the amount of propylene glycol you would need you'd be in the poorhouse in no time.  I only needed about 15 litres or so and bought about 20 undiluted.  Can't recall the dilution rate but I've got enough for a long time - still painful on the pocketbook though.

John.

[awemawson]

I decided to investigate further some switches on the front panel. I sort of half expected what I found, but it's a bit scary 

In the picture below:

a/ the left hand switch is not connected, nor are there loose wires, nor is it labelled, so OK ignore it

b/ the middle switch does what it says on the box - turns the low power red laser target finder on, so it's OK

c/ but what about this one on the right? Turns out that it is in parallel with the safety interlock on the machine lid, the one that saves your eyes. Flick this switch AND THERE'S NO INTERLOCK 

All rather nasty but easily sorted with a pair of snips 

To celebrate I made a pair of boxes - these are 100 x 75 x 50 mm out of 5 mm ply

[awemawson]

Oh no this laser thingummybob is addictive, I can't stop finding new uses for it 

[John Stevenson]

In which case do NOT go to www.908ltd.co.uk and look at all the goodies tat, they have for sale.

[AdeV]

In which case do NOT go to www.908.ltd.co.uk and look at all the goodies tat, they have for sale.

I love the way you've got the text authentically wonky in that picture - must have taken ages 

BTW, the webite not to visit is www.908ltd.co.uk...

I need to resurrect the Micromat... ancient PCB drilling/routing machine, but will make an excellent engraver.

[awemawson]

You're too late John, I was browsing their goodies last night 

[John Stevenson]

My parcel from them just landed 5 minutes ago. Also got a parcel of black anodised alloy sheet off Ebay for plates. They will engrave but not cut these.
You can use any colour but as the lettering is always white because it burns down to the base coat you need a good contrast. Black is best, the gold hardly works unless its in the right light and the clear anodised looks like the Italian flag, white cross on a white background.

Not my part but this is what the black plates come out like.



A while ago I bought some of the parts racks from Machine Mart, the 4 x 4, 5 x 5 and the 6 x 6 drawer units. These are very good quality, not at all tinny.
In the 6 x 6 units you get 3 rows of full drawers and 3 rows with 2 dividers in. However if you only have small parts like 3mm nuts even one of these divisions is too much and they get lost unless you buy 7,000

I cut little cardboard boxes out of 1mm or 1.5mm cardboard sheet and fold them up. Then I can get 3 square boxes in one division, makes for a very tidy setup.

[awemawson]

Reviving an old thread here but it is relevant 

When I bought this Laser Engraver there were other offering from the same seller that seemed identical, but came with a 4th Axis and a VERY much larger price ticket, so I never went down that route. My version has the socket and cabling and the rotary axis is used in place of the Y axis by unplugging the Y axis driver cable and plugging this one in.

I've been keeping an eye on eBay since I bought the laser but have never seen one until recently when one popped up at an almost acceptable price, and a bit of negotiation around 'best offer' got one on the way to me 

However when it arrived the main spindle bearing had been dislodged from its housing, presumably as there was no retainer and it had suffered a bump - the mass of the attached chuck ripping it out 

Now other than this problem it was fairly well made, so after a further bit of negotiation and a further discount I agreed to keep it and repair it. Well the 'round tuit' happened today 

[awemawson]

In use there is little force on the bearing - the laser exerting no cutting force - the design seems to rely on Loctite to retain the bearing against a shoulder