Air assist pressure

[Things]

I have one of the Pro lens mounts from lightobject, though I've been looking at some air pumps on eBay for my air assist. I have no idea what kind of air volume I need for this.

Anyone got any ideas?

Thanks

[baccus61]

The style most people use for the cheap lasers is this one.
http://www.ebay.com.au/itm/280L-Min-Aqu ... 1c17301457

They have a pretty good life and are pretty quiet and being a magnetic drive will last for years. Mine is still going strong after 4 years and 1500 hours on the clock.
I only have a 90Ltr pump but a slightly bigger one wouldn't go astray.
If you use a mini piston compressor then it won't be able to keep up with the air flow out of the nozzle and will run continuously which will also be noisy.
I don't know if Marco has them here on his site but if he has I would recommend it to you.
Rich.

[Tech_Marco]

Ha.ha...Rich know me better.
As matter of fact, I'll get it from my trip to China the end of this month. I'll stay there for 1.5m and I'll spend most time to two things: find good resources for DIY laser. I'm going to carry most major parts good enough for folks to build their laser machine. From as small as a M4 screws, 3~4 size stepping motor, rollors, wheels, belts, security guide, moving guide, to machine frame/panels, you name it. Of course, the air pump will be on my shopping list. Plus, I'll import some parts for CNC machine as well. I'll try to get all those sources and will

Second, I'll try to build a water cooler that is enough to keep a 120W laser tube Cool and happy. Been testing a couple system since last year and result didn't meet my expection. Now, I'm waiting for the most major part to carry on my last test before I can decided whether to do mass production or not.

Marco

[Things]

Yeah, I ended up actually getting one of those air pumps from eBay, seems to be powerful enough to me!

Have fun on your trip Marco, an all in one place for DIY laser would be awesome! It's annoying having to buy parts from all different places, because shipping gets expensive. Much better to buy it all from 1 place

Dan

[baccus61]

YES! One stop shopping. That's why the big department stores do so well. Everything is under one roof. That will be good.
I must check the output pressure of one of these air pumps one day. I don't think it will be much, probably 2-3 psi but the volume is pretty good. I still want to try some Oxygen assist and a bit of metal cutting too. THAT would be good.
Marco. I will send the LCD chip back to you as soon as I can get to the post office. Thanks for the upgraded one. I still have the occasional comms problem with the USB but I just unplug the connection and re plug it back in and everything works again until the next job. It's intermittent but doesn't worry me too much. I will have a go at connecting the network again oneday.
Loving the DSP and being able to cut and engrave in one file and also raise the table when ever I want without resetting the limits. It has really matured over the past year and the programmer has done a wonderful job.

I'm toying with the idea of putting some servos on it and seeing what it can do. I have all the stuff here and just need to rip it apart and connect everything.

Oh! One other thing, Marco. Do they make small plastic lens mounts for Lasers like the ones on the Trotec lasers. You could build some cheaper lasers with smaller parts like belts and pulleys with little mass to move around. just a thought.
I must get into building another smaller portable laser for the shop oneday and using the 30 watt RF laser I have just sitting around. I'm thinking of getting some panels cut and bent and building one like the big boys do.

Be well.
Rich.

[baccus61]

I have looked into the water coolers and didn't like them too much.

I was going to buy a cheap $300 bar fridge and wrap a coil of pipe inside it to keep it cool and It would also have enough room left for my cans of energy drinks. I like to flavour my water with hops and malt and keep them cool.

I have also borrowed some Peltier devices (5) from my brother but haven't had a chance to get them all set up and try out the cooling effect of them. That may be interesting to set up.

Rich.

[Things]

I actually found an aquarium chiller at a local lifeline for $40. Jumped on it the second I saw it, couldn't take my eyes off it the entire time I was there. Was such a steal considering they go new for over $400. Works perfectly... It's only about 1/10HP, but it should keep my laser nice and cool for long runs. Not that it's needed here at the moment - it's bloody freezing!

And yes, I bought the DSP for the same reason Rich - not being able to do engraving and cutting (well, easily) in the same job with Mach3 just got too annoying for me. Mach3 is a real pain to use with laser cutters.

Curious, how have you done the Z axis on your table? I'm about to buy a 900x1200 XY stage from Marco in the next week or so, would be nice if I could just go for the best and make the cutting bed adjustable while I was at it.

Dan

[baccus61]

I made the whole table moveable so I could put big or tall things under it or fit a rotary attachment. I just used bicycle chain around some sprockets and had a threaded insert in the middle to drive the table up and down by threaded rod (all thread).

Video can be found here.
http://www.youtube.com/watch?v=wi4dKAseDCg&feature=plcp

It's a bit more work but I'm really glad I did it because I haven't found anything yet I can't engrave under it that other people want engraved.
I might even make a drop in box so I can try my hand at metal cutting IF I can get a bottle of O2 somewhere. Just thin <1mm plate. The 100 watt laser should cut up to 0.6mm stainless pretty easily but slowly.

Rich.

[Things]

Ah nice, I was actually thinking of doing the exact same thing with sprockets and allthread - probably inspired from your video way back. Good stuff.

Dan

[baccus61]

If I was to make it again I would build a scissor lift mechanism with 2 ball bearing drawer slides attached to the back vertically for guides. it would be simpler to make and would travel quicker.

I am still toying with the idea of putting the drawer slides at the back of the existing table as there is a slight amount of wobble in it even though I have 2 slide guides fitted. I simply wedge some plastic/rubber wedges into the gap around the table if I need to stop it moving. It's not elegant but it does work and is easy to do.

Rich.

[Things]

What do you use for your cutting bed? Looks like a few bits of angle alu in your clip, does that work well? No serious back reflections? Or have you replaced it with something else since that video?

Cheers,
Dan

[baccus61]

I had a sheet of galvo steel for a while in the test stages then had a sheet of martensitic stainless steel 0.6mm bent up and I glued it to the melamine on the MDF with silicone adhesive.
Works quite well and is magnetic so I can hold down thin paper etc without it blowing away. I also use the magnets to position repeatable stuff making a rudimentary edge to put things against.

I burnt small spots on the top of it when I got the 100 watt laser in a 10 x 10mm grid pattern to make things easier to line up and that works well too.
I use 10mm Al angle when I cut thick acrylic but I do get a lot of reflection bouncing back and melting the underside cut. I will need to make a drop in table for doing just acrylic and
I'm thinking of using the egg crate square mesh that is underneath fluoro lights.
It's relatively cheap and I can always make a downdraft table out of it to get rid of the smoke too.

Rich.