All DXF files for the enclosure are located in the github repository at https://github.com/Laser4DIY/Laser4DIY_Enclosure. The parts are lasercut 1mm stainless steel sheets. The assembly guide has some notes on laser cut metal parts, see Building your own Laser4DIY device.
The metal sheets need to be bent. The repository also contains bending plans (in the bend_diagram subfolders), please refer to them and to the CAD files in the repository and the images below.
Some additional notes for making the bends:
Below is a step-by-step guide for assembling the metal parts. Some general notes on the process:
Start with the MainSheet:
Add CompartmentRightSheet (and connect it with rivets)
Add 2 CornerBrackets (again, connect them with rivets, we omit this in the following steps)
Add BigShim and LabyrinthSheet. Only use rivets for the holes in LabyrinthSheet, leaving the other holes open for now
Add CompartmentLeftSheet. Now use rivets for all holes in BigShim
Add 2 more CornerBrackets:
Add CornerBrackets on all 4 corners:
Add 2 Shims, one on top of CompartmentRightSheet, the other below. Do not rivet them down. Instead, add BracketRight, and use rivets to connect the 3 pieces together.
The third image shows a section view of the result.
The same steps are repeated on the other side. Add 2 Shims, add then BracketLeft:
Add the 2 LidChannels:
Add the 2 brackets for holding the laser chamber:
For the lid, 4 metal pieces have to be spot welded to the main sheet. make sure the pieces sit flush to the edges of the main sheet:
The 2 handles (3d printed, STLs are found here: https://github.com/Laser4DIY/Laser4DIY_Enclosure/blob/main/3dprinting/handle.stl) are mounted using 2 M4 screws. Use screws with flat heads.
The enclosure must be light tight. There should be no direct way for light shining out of the enclosure. To test this, put a light inside the enclosure, close the lid and inspect the enclosure in a dark room
Do not use the enclosure (without wearing laser safety glasses) until you have ensured light tightness! |
The magnetic safety switches consist of two parts: the actual switch is located inside the enclosure, while the activating magnet is mounted at the bottom of the lid. The following image shows the two parts (lid not shown). Each of the parts has a 3d printed bracket (STL again available in the repository: https://github.com/Laser4DIY/Laser4DIY_Enclosure/tree/main/3dprinting). The lid bracket is mounted with screws to the lid, the magnet to the bracket. The switch bracket is mounted with screws to the side of the enclosure.
The switch bracket has slot holes, allowing for some adjustment of the distance between switch and magnet. For safety reasons, mounting with (only) slot holes is undesired. Therefore, there is an additional mounting hole in the side of the enclosure. When you have found a suitable position for the switch, drill a hole into the switch bracket through that additional hole and fix the bracket position with an additional M3 screw. We recommend doing this step at a later time, when the electrical assembly has been done to allow for checking the activation of the magnetic switch.
There is a second safety switch on the other side of the enclosure, it is mounted the same way.
The two cables coming from the supply unit are plugged in into sockets at the back of the enclosure. For details on which components to use, see BOM below.
The safety circuit uses a safety relay and to standard relays, redundantly allowing to cut off power supply for the laser. The safety switch monitors the state of the magnetic switches at the lid as well as the proper functioning of the other relays.
Again for details on which components to use, see BOM below. The PNOZ S3 safety relay is operated in mode A, In2-.
For mounting the relays (and later the electronics components) we place two pieces of DIN rail in the electronics compartment. Wiring is done using terminal blocks
Qty | Part Name | Manufacturer Part | Part Link | Comments |
---|---|---|---|---|
Electrical Parts | ||||
2 | Magnetic switch Pilz PSENmag | Pilz 504220, PSENmag PSEN 1.1p20 | RS | See datasheet for pinout |
2 | cable for Pilz PSENmag switch | Pilz 533111, PSEN cable straightplug 2m | ||
1 | Safety relay PNOZ S3 | Pilz PNOZ S3, 24V | ||
2 | Relay 24V, 25A | Finder 22.23.9.024.4000 | ||
1 | Quicklock chassis socket, size 20, 4 poles | LUM 0272-04 or Lutronic 2620 04 T22CB100 | second one needed at supply unit side | |
1 | Quicklock chassis socket, size 16, 7 poles | LUM 0271-07 or Lutronic 2420 07 T18CB100 | second one needed at supply unit side | |
6 | Terminal block grey | Phoenix Contact PT 2,5-QUATTRO, 3209578 | ||