| Gallery, Projects and General > Project Logs |
| Laser Cutter |
| (1/3) > >> |
| PK:
This is, strictly speaking, not a hobby build. We own and run a small business that designs and manufactures electronic devices, but we do build a lot of our own equipment, and we do it in the same way, and on budgets in the same order of magnitude, as the hobbyist projects. So I hope there's something interesting in this for y'all. We started out buying a 50 Chinese W laser cutter when we got a price for cutting some rubber gaskets that was almost the same as the purchase price of the machine. The first two jobs we ran paid for the machine and we were off! Over the years we upgraded most bits. We took the tube and power supply to 120W Blew up and upgraded the DSP controller (these lasers have magic boxes that do the motion control for thinkgs like raster engraving) Added little boards to do things like turn the air assist on and off automatically. As we started using it more and more, the 'pond pump in a bucket' cooling system got upgraded to a 'pond pump in a garbage bin' and finally a 'Hacked portable air conditioner' which we ran today, all day, as the ambient temperature hit 40deg C... (We subsequently removed the strap and installed the back cover) Anyhow, things progress, and we start buying materials in full sheets to save some money, but cutting these sheets up is a PITA, so we start lusting after a full sheet capable laser.... We ended up compromising on a 1.8m x 1.2m laser gantry kit from LightObject http://www.lightobject.com/XLE-18001200-XY-Stages-complete-kit-for-DIY-CO2-Laser-2-yrs-warranty-P739.aspx and our usual construction method of welding together laser cut steel. The steel for that frame, laser cut (with all the bolt holes) and folded, cost AU$300. We reckon that makes it hard to beat as a construction technique. There's a big vacuum table under there for holding down big sheets of cardboard. I'll try to get a few more pics together tomorrow. |
| Joules:
KEEP POSTING, I don't care it's commercial, what a great build. I keep looking at the little Chinese lasers, but always find something else to fritter my money away on. :doh: |
| raynerd:
--- Quote from: Joules on December 22, 2015, 06:57:03 AM ---KEEP POSTING, I don't care it's commercial, what a great build. I keep looking at the little Chinese lasers, but always find something else to fritter my money away on. :doh: --- End quote --- yea same!! PK - lovely looking premises/workshop/office you have there. Looks similar to the commercial clockmakers workshops I`ve seen - always wanted to create something similar! Keep posting, great thread. |
| PK:
OK, so lets take a step back then. Having purchased the original machine, we spent some time building things like vacuum tables. These come in handy when cutting stuff like cardboard We also added a few extra sensors (which the control electronics had inputs for but didn't come with the machine). The most important one was an air flow sensor to the cutting air assist line. Why is this important you ask??? When cutting flammable materials (we make self adhesive foam gaskets on this machine) the flow of air through the nozzle blows out the flame, just like blowing on a candle. When it stops blowing out the flame.... It wouldn't have been half as bad if the intern running the machine hadn't just stood there watching it burn with a fire extinguisher 2 feet away. I only got to it when the smell reached my desk! In the end we just replaced the belts, cover window and mopped it out.... After about three years of daily hard use, the tube started to show a loss of power. A replacement tube was priced at AU$90+shipping, but these tubes are only of average power and quality. Besides, why buy a cheap 40W tube when you can buy and expensive 120W tube! Well, it made sense to me at the time.... You sort of had to be there I guess... So the 120W tube and power supply arrive and we neatly fit them to the machine with some PE mounts we made on the router and little bit of Al plate. You can hardly notice the upgrade, she's a bit of a sleeper.. As I've mentioned elsewhere, once you clear about 100W, a CO2 laser will start to mark metals directly. It's a little dependent on how shiny the surface is, so a bit of tape over the top, or a light spray with paint will often be required... it is quite slow though, so it does pump a bit of heat into the job.. We ran the unit in this trim for a few years, making minor mods along the way. The only significant one is the refrigerative water chiller put together from a portable air conditioner because I wasn't going to spend the AU$1500 everyone was asking for a 'laser' coolant chiller. There was little more to this than bending the lines going to the condenser so that we could shove it in a plastic jerry can full of radiator coolant. I should stress that the hobby user will NEVER need one of these. All the Chinese lasers come with a pond pump and instructions to sit it in a bucket of water. This is entirely adequate for cooling any sealed CO2 laser used for less than an hour at a time... A side note, you may have noticed that we have two laser cutters on the bench there. We bought the second one because the software that came with the first didn't support engraving sequential serial numbers on successive jobs. We would have to put 10 parts into the laser, then sit at a computer and manually change 10 text fields, send the job to the machine, run it, rinse and repeat. This got old quickly. The fix was to buy a cheap little laser, IIRC I paid AU$699 landed for it, and give it a brain transplant. Back to the build We actually started out by making the vacuum table. We wanted to be able to process full sheets (1.2m, x 2.4m) without cutting them. The working envelope of the laser is 1.2m x 1.8m so we decided to flip the table around and make holes in half of it. That way we could cut half the sheet at a time, then just pull the whole sheet forward and do the other half. Now the little vac table at the top of this post looks a bit dinky, but it has more than 300 drilled and countersunk holes in it, all marked out, punched, spot drilled then opened up with a step drill. No way was I doing that for over 2000 holes.. (yes, that's 2000 holes folks!). So onto the CNC router it went: With the counter sinking, it still took about 3 hours to run the job.... After that we just built a box frame for it and called it done. The next piece of the puzzle was a base for the machine. There was much head scratching before I read an article about IKEA making furniture out of cardboard..... I don't have a lot of pics of this stage (the young bloke has some on his phone I think) but we went out and bought some 6mm plywood and cut this core on the router. We put 2 sheets top and bottom and got it within 1mm with a laser level. The whole thing is held together without a single screw or nail. Just using polyurethane glue. I'm not a little guy and I can stand on this 2.4m x 2.4m table and it feels rock solid. So that brings us, more or less up to date. We cut a hole in the back so that we can mount the electronics on a removable plate. and I got a coat of primer on the steel yesterday, I'll put some more pics up when the paint is on. Cheers PK |
| PK:
Over the break, I set myself the goal of getting some paint on the bodywork of the new laser. I mean, how hard could it be right? I'm quite fond of the paints with epoxy in them. They produce very hard wearing finishes. The only problem is that they take about 5 hours to get to touch dry. This means that any overspray is gonna stick to whatever it lands on! Having had some bad experiences in the past, and given that our spray booth is about 400mm square, I decided to apply the paint with a microfiber roller. See below, but it sort of came out sort of OK.... Sort of... I spent a couple of days trying to convince myself that this finish was perfectly acceptable for a work machine.....awe, who am I kidding? Why have a mostly crap finish when, for only an additional week, countless hours of sanding, and another $50 in clear coat, you can have an only partially crap finish? Why I didn't just send it out to be powder coated will remain one of the great mysteries of my life.... In any case, its' done now and we can move on.. |
| Navigation |
| Message Index |
| Next page |