Large format laser build - 24"x 48"

[Rad Racer]

A few years ago I got involved with the MechMate Group and built a 49" x 97" CNC router from plans available on the site. After hours and hours of use and many completed projects I was looking to build another machine. A laser seemed like a natural addition to my suite of tools as it can make cuts that would challenge my MechMate. The cost for large format cutters was out of reach so I decided to do my own thing.

Inspired by others on this forum, I have moved forward with a large format C02 laser build.

[Rad Racer]

The machine is built using 8020 extruded aluminum. It's the first time I have used this material....it is very robust and is easy to work with. Much of the machine was designed in CAD, for some components I used the TLAR (that looks about right) method

I will upload some build photos shortly....they are currently on my shop computer.

[Kellerkind]

Hi,
i'm looking forward seeing your buildlog...
i have one short question already
- are you going to take special precautions to avoid alignment & laserpower fluctuation issues with this size?
greetings
Nico

[Rad Racer]

Initial mock-up to make sure all is good

[Rad Racer]

More photos of the 8020 frame.

[Rad Racer]

Good question Nico.

To minimize alignment issues and/or power fluctuations due to beam wander, all laser components (tube, optics, slide rails, etc...) are placed on common base plate. (the grey assembly you see in the photos) The idea is to minimize components movement due to thermal expansion(CTE's) differences. To assure precise mechanical alignment of all components, the base plate was machined on a CNC router so all the holes, slots, alignment pins, etc... line up perfectly.

The base plate is made of MDF, a very stable material. To get the thickness required, 3 sheets were laminated together using epoxy, this not only sticks the plates together....it seals the material from moisture absorption. By design, this plate is very heavy which should also help with beam wander by dampening the vibrations due to rapid machine movements.

Before the question comes up.
Yes, I realize MDF could pose a fire hazard. I am not concerned about base plate problems for a few reasons; 1. MDF has a good fire rating 2.The cut head can not make contact with the base plate. 3. The cut box is all aluminum (more on that later).

Wayne

[Rad Racer]

Photo of the base plate

[Rad Racer]

It's a poor picture but you can see the aluminum walls of the cut box. The hole is for the exhaust fan.

[Rad Racer]

Making some progress.

[daverad]

Looking good Wayne