Home laser cutter

[John Rist]

Looks like laser cutting is coming to home user.   Still above my pay grade but at $3,000.00 you too can have a 11"x 19" laser cutter.   https://glowforge.com/      

[Mike Greb]

I bought a ebay blue and white 50w 500x300 laser engraver about four years ago. I got lucky and it was focused well out of the box, and so far I have not had to readjust anything.   I use it on balsa 3/8 and thinner.  Also It cuts 1/8 lite ply well. It does not like 5ply plywood, taking several passes on 1/16 and many passes on1/8. Where it really shines is cutting ribs.   It has a very small amount of backlash, but not enough for me to worry about. Currently using Lightburn software. but the included rdworks works fine after you figure it out. Balsa thicker than 3/16 requires multiple passes to cut cleanly through and balsa density makes a large difference in the power and speed used to cut the part.  My machine did not come with a door interlock, something I really need to add.   Remember these can cause severe burns and eye damage if you are careless. Also the co2 laser is infrared, so you cannot see the laser.  Be aware the power supply to the laser outputs tens of thousand volts.

[ericrule]

Yep, the cost of laser machines has come down. I remember my first machine was a 30 watt that required 110 volts and was listed at $30,000.00. I got a really good offer at the end of the year and picked up a floor model for $18,500.00. The last laser I bought was a 100 watt water cooled 20" X 36" with two Rechi laser tubes and needed 250 volts. It was purchased directly from the factory in China for $5,000.00. Of course I had to pay shipping plus port entry fees  plus ship it from the port to my location so that added an additional $1,200.00 but a really good laser for very little cost when you consider that similar machines from US based distributors would have cost me $14,000.00 to $19,00.00.

Almost all of the current lasers available use RD Works as the print driver software so you have to insure that you download the AutoCAD interface so you can cut files directly from your computer. RD Works converts the dxf file into their own internal code and although it does have a couple of unusual quirks when reading text (like part numbers) it works pretty well.

If anyone is interested in purchasing a laser for their own use I suggest checking on line using Alibaba and making contact with a customs broker who will handle all of the import requirements.

[Howard Rush]

I got a good deal on a 100W Chinese laser from some folks where I worked.  Robby Hunt helped me move it safely and Pat Johnston taught me how to prepare files for cutting.  It works, but I keep coming up with questions.  Current questions are:

How come the limit switches don't do anything?

What's a good exhaust system to blow smoke outdoors?

How do you hold balsa down for cutting?

What tape will hold balsa down, yet not take away a lot of laser power? 

[phil c]

I got a good deal on a 100W Chinese laser from some folks where I worked.  Robby Hunt helped me move it safely and Pat Johnston taught me how to prepare files for cutting.  It works, but I keep coming up with questions.  Current questions are:
Congrats Howard, now you can spend more time getting the parts designed than it takes to build the first plane!                                                                                                                       

How come the limit switches don't do anything?   They aren't hooked up, maybe?? 

What's a good exhaust system to blow smoke outdoors?  Get an in-line 6-9in. duct booster fan from Home Depot or similar.  I forget, may $40.00 plus some matching PVC pipe.  If you need a long duct run two can be put in series.

How do you hold balsa down for cutting?  I just laid small weights on it.  ALWAYS run a test cut on paperboard to see where the software put the tool paths.  They can be different than you might think.

What tape will hold balsa down, yet not take away a lot of laser power?  The machine should have a honeycomb table to suck the air down and out.  If it sucks air out of the chamber over the balsa make sure the wind doesn't flap the sheets around.

Have fun and MAKE SURE you ALWAYS!! use infra-red safety goggles!  A hundred watt laser, or anything that can cut more than 1/16th in. balsa is going to have enough watts in the beam to fry the retina in a few seconds just from a glancing beam from a shiny surface.

[Alan Resinger]

Howard,
The limit switches have reached their limit.
Invite some of your  longwinded friends over when you cut something and make sure and open the windows and doors.
Use duct tape as Red Green would suggest.
Use invisibe tape so the laser can't see it.

If you have any other questions just give me  a call.

[ericrule]

I got a good deal on a 100W Chinese laser from some folks where I worked.  Robby Hunt helped me move it safely and Pat Johnston taught me how to prepare files for cutting.  It works, but I keep coming up with questions.  Current questions are:

How come the limit switches don't do anything?

What's a good exhaust system to blow smoke outdoors?
** Since it is a 100 watt laser I am assuming that it has a large 6"  exhaust pipe sticking out the bac. Go to either Harbor Freight or Amazon and buy a 6" blower. Hook the blower to the laser exhaust pipe and run the flex tube from the other side of the blower to the outdoors.

How do you hold balsa down for cutting?
** If you lift up the cutting table you will see a grate in the back side of the laser. It may be clogged with balsa or other exhaust dust so clean it with a wire brush. The grate is attached to the laser exhaust pipe. The blower will create a vacuum inside the laser to pull the dust and smoke out. It also creates a vacuum to hold down the balsa you are cutting. You will also see that there is a gap on the top or front of the laser to allow air to be pulled inside. You need to check this grate anytime the vacuum on your new laser declines.

What tape will hold balsa down, yet not take away a lot of laser power?
** Normally you should not need to to this unless the vacuum from the blower lessens. I have used scotch tape with good success in the past.

Hope this helps Howard.

[Howard Rush]

Thanks, Eric.  The machine came with the requisite 6" duct going to a large box containing a loud fan and 50 lb. of activated charcoal.  It works as well as those ventless kitchen hoods in cheap apartments--namely, not at all.  It sure doesn't hold balsa down to the honeycomb.  I'll get me a real fan one of these days. 

[Wolfgang Nieuwkamp]

Some cheap vacuum cleaners have a circular air outlet, where you can connect an extra hose,  leading to your window.
Regards,
Wolfgang