View Full Version : Bought a laser, now there's a thing

Robin Hewitt
02-02-2013, 10:33 AM
I was Googling for someone to laser some acryllic for me, idly typed "laser cutter" into fleabay, price + P&P lowest first...

I found a dinky little laser engraver/cutter with a buy it now of 550 + 45 shipping from Cornwall.

I thought, "What's the worst that can happen?", offered 500 and got it.

Laser cutter machine Laser Engraver | eBay (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=281056488088&ssPageName=ADME:L:OC:GB:3160)
You may now tell me what is wrong with it and where I could have bought a new one for less :joker: :hysterical:

02-02-2013, 10:53 AM
Nice find. I was looking at 700 just for the laser Industrial 808nm 15000mw 15Watt Infrared Focusable high power laser burning TTL | eBay (http://www.ebay.co.uk/itm/Industrial-808nm-15000mw-15Watt-Infrared-Focusable-high-power-laser-burning-TTL-/180943013777?pt=LH_DefaultDomain_0&hash=item2a210b4791)

Web Goblin
02-02-2013, 11:09 AM
The laser tubes on these dont normally last very long so the fact that your getting a spare is a major bonus.

02-02-2013, 11:13 AM
The laser tubes on these dont normally last very long so the fact that your getting a spare is a major bonus.

Mines at about 1500 hours at the moment :) Not sure if thats long in the laser world though.

02-02-2013, 11:28 AM
Not read much about these Chinese lasers, can you do a little review of it when it arrives & you have had a little play with it Robin please.

Is it the same machine you have Philly

02-02-2013, 11:51 AM
Very interesting. I bought a black cat laser (900x600 bed) about 18 months ago and am hoping to get it set up next weekend. Anyone else got one?
I,m sure Robin will have his up and running long before me. Await your comments about set up and performance Robin (I mean the llaser of course). G.

Robin Hewitt
02-02-2013, 12:03 PM
The laser tubes on these dont normally last very long so the fact that your getting a spare is a major bonus.

Thanks for not telling me I am an idiot, but perhaps that is yet to come :thumsup:

I have read a bit about Chinese lasers and quality seems to be a bit of a lucky dip. I think the tube life also depends on whether you run the poor thing at top whack. If I stick to cutting thin Plasticard in no particular hurry I could probably wind it back somewhat.

Note: Back in the good old days, before political correctness, they used to grade schoolchildren on a sliding scale. Idiot was the bottom of the scale, one step below moron.

02-02-2013, 01:01 PM
Hmm I'd have considered getting that... favourite search now set up. My current plan is to attach a laser to my router, but on a second gantry. Since I'm using rotating ballnuts, I can easily have two gantries running independently on the machine, so one lightweight one for laser cutter (+3d printer) and a robust gantry for conventional cutting. The one you've got says 21m/min, which is manageable and I should be able to do it without loosing much, if any travel.

I expect to see your mayan calender on Monday...

02-02-2013, 01:04 PM
It's hard to know what to believe Robin, some of the negative stuff I have read is from people who have absolutely no experience with any kind of machinery what so ever, probably bought because they thought it would be an easy and cheap(ish) way to make lots of money.
From someone like yourself I would expect to get a more balanced view of the machine.
The tubes probably don't last as long as on better quality machines but if they are a lot cheaper & you have the ability to change them yourself (which you do) then it might not work out any more expensive to run than a more upmarket machine.

02-02-2013, 01:05 PM
It is mate, had it 2 years now.

02-02-2013, 01:27 PM
well if you have had it 2 years, it's got 1500 hours on it & still going strong then that doesn't sound like to bad an investment for Robin, especially as he has 2 tubes for it.
What do you use it for if you don't mind me asking, was looking at laser machines & routers at the same time but went with the router as I thought it would probably be of more use to me.

02-02-2013, 01:53 PM
Acrylic cutting/engraving and leather engraving. I made a small modification to it that lets me slow down the laser, speed adjustment is great, I never run it over 80-90% power either. Take care of it and it will work well. My next job is to change the bed to an adjustable one.

John S
02-02-2013, 02:32 PM
Tubes deteriorate with use and age so it's not a good idea unless you use it in anger and need spares to buy a tube when you buy a machine.
In 2 - 3 years time when the tube goes your spare will be half ? used by age.

CNC Zone has some good post on these machines.

General Laser Engraving & Cutting Machine Discussion - CNCzone.com-The Largest Machinist Community on the net! (http://www.cnczone.com/forums/general_laser_engraving_cutting_machine_discussion/)

Look for Chinese 40w laser or Moshidraw which is the software they come with.

Web Goblin
02-02-2013, 06:03 PM
I was going to post that John when I got a chance. There have been a few discussions about them on the zone.

02-02-2013, 06:47 PM
Thanks for that John, read on a few occasions what a good site cnczone is but keep forgetting to check it when I'm looking for answers. Must be an old age thing :sour:

03-02-2013, 08:00 PM
Do they cut 1mm and 2mm polycarbonate with out any discolouration?

John S
03-02-2013, 10:31 PM
I expect to see your mayan calender on Monday...

Sunday any good ?


Been kicking about for a while and it's lost some of it's detail. Should have sealed it but didn't bother as it was just part of the packing case the laser came in.

About 4" diameter and took 7 minutes.

Robin Hewitt
06-02-2013, 06:07 PM
can you do a little review of it when it arrives & you have had a little play with it

It has arrived and the glass looks intact so there is hope. It arrived freezing cold so lots of condensation, it will need a day or two to dry out before I dare plug it in.

Basically it is a big box formed from 1mm steel sheet with aluminium extrusions inside to hold everything together. The steel is powder coat over the occasional rusty bit.

The X axis is an upside down lacquered aluminium channel trying to look like a solid bar. The belt goes end to end inside it. The cutting head carriage has nylon rollers running in grooves on either sides of this channel. The head is ultra light and moves very freely without noticeable play, which is just as well because this is where the vigorous engraving movement happens.

The Y axis runs on linear ball bushings along a single 12mm round rail on the left . It has a driving belt at either end so it runs square. The belts have a common axle at the front which goes through a double shafted stepper motor. The right hand end of the "gantry" bar rests on a single nylon roller. Y is nearly as easy to move as the X but is much noisier, I assume because it is closer connected to the steel case.

The "bed" is a 2mm aluminium sheet supported by five 75mm standoffs screwed to the case base. The aluminium has a sort of frosted look, I think it has been shot blasted to make it non-reflective.

Physical limits on the laser head allow about 32.5 x 20 cm movement. It could probably do 25 cm in the Y but there is a piece of hose around the linear rail which stops it. I can't see anything that would hit if I grabbed the extra 5 cm although the #2 mirror adjustment screws might get a bit close to the case.

The bed has a strange, spring loaded holding frame in the middle which I am assuming is a copy of something a lot cleverer that might actually have been useful. It will hold objects up to 21 x 8 cm. Unfortunately the smoke extraction nozzle only cover the 21 cm clamp rather than the 32.5 cm max. The extraction fan is a chunky centripetal job which slots on to the back of the case. It has a hose on the exhaust so you can pipe it out the window. You have to wonder where all this air they are hoping to extract from the case is supposed to come from because it is seriously short of venting.

I am dubious about the Moshi software that comes with it. It seems that it cannot work with anything else. If there is a protocol it is a secret, the blogosphere is rife with rumours of encryption. I am not so sure about that, but I can see that the CPU is a 40 pin DIP with no name or ID on it. The original board in these things used a pair of 8502's. Now call me Mr Suspicious, but I think they may have now crammed it into one chip, something similar and ashamed to admit it. Now I am not saying the MoshiWare/hardware combo is bound to be naff, but I do seem to have ordered a couple of Leadshine stepper drivers before even trying it.

I could ramble on all day, but right now I am going to ebay to try and find a laser hazard label. It has to have a laser label because I think it would look cool.

More if you want it :beer:

Web Goblin
06-02-2013, 06:36 PM
I'm glad it has arrived safely and in one piece. Shiney aluminium isnt good for a laser and your right it can cause dangerous/destructive reflections.
I probably have some laser starburst stickers at work. I can check tomorrow and mail you some if you like.

06-02-2013, 11:28 PM
Robin, were you a dressmaker or an ex BBC man? cm-ugh.
Brilliant descsription and sounds like good value. G.

07-02-2013, 11:40 AM
Found these on ebay, look ideal for you


John S
07-02-2013, 11:51 AM
This one is better !


John S
07-02-2013, 12:11 PM
Talking of lasers I did this the other night just as a concept idea.

Used a sheet of 3mm MDF and cut 5 shapes out.


One had the centre profile deleted.

Just bolted together to show the idea but in real life these would be glued and dowels fitted to line up.


Another shot at an angle and with a bit of cleaning up with emery cloth.


It's noting special, just a drawing of the top of my head but from concept to finish was 20 minutes.

What for you ask ?

Pattern for sand casting, in some cases like this cover it's far quicker than using a router as the centre is taken out as a profile as opposed to a pocket.

Each layer can be made slightly larger than it's predecessor to give a draft angle.

07-02-2013, 12:11 PM
I think the biohazard one looks better, and just as useful...

07-02-2013, 12:19 PM
It's noting special, just a drawing of the top of my head but from concept to finish was 20 minutes.

You've got a funny shaped head John :applause:

Robin Hewitt
24-02-2013, 10:14 PM
Okay, I admit it, I destroyed the blooming thing :culpability:

It now has a new tube, tube mounts at the correct height, a proper power supply and it doesn't have a millimeter crust of black gunge on the lens. Probably from cutting plywood. Not me, I found bits in the bottom of the case :stung:

I've been doing the laser forums and there's more to this laser malarky than I realised. Back to school again I suppose. I see that Wee Davy Cameron thinks us over 60's should go to university :very_drunk:

It's mostly a cooling thang. You pump water through the tube, perfect temperature is -28 C but you actually have to keep above the room dew point because 20kV and condensation can make life interesting. Room temperature is fine and dandy but if you let it rise much above 30 C you lose vast amounts of power. Bubbles in the tube are a big no-no because you get hot spots. I have to fit a radiator (on it's way from China) and a big fan. I also need a flow detector which cuts off the PSU if the water flow stops, but I can make that.

As far as I can make out, the best thing you can do with a 40W is cut perspex. It goes through it like a hot knife through butter even when turned right down, but apparently blowing air down through a nozzle mounted over the lens is a good idea. The perspex vapourises. You want to clear it without condensing it or something like that.

I also plan to attack it with an angle grinder to redesign the fume extraction. The current system has way too much fan for the ducting, plus he hasn't cottoned on to 2 simple facts. Air doesn't like abrupt changes in duct size. Getting the desired flow is as much about where you let the air in as where you take it out.

Web Goblin
25-02-2013, 06:20 AM
Condensation does indeed cause problems and not just due to the HV. We have had it on the optics as well and it dont like it. As you have found out the optics have to stay clean and free from scrathces as well as this causes them to absorb power rather than transmit it, then they go bang. Done that a few times as well, takes ages to clean out the flight tubes and re-align the machine. Cutting assist air, air blowing through the nozzle, is a must as well. It helps to keep the lens clear of crap, cool it and blow away the cut material.