The Laser4DIY Supply Unit contains all power supplies needed plus the water cooling system (pump, reservoir, radiator, fans). 

Warning: mains voltage involved!

Electrical setup

The Laser4DIY engraver needs quite a few voltages:

  • 15V: For the peltier elements
  • 3.3V: For the pump diode (controlled by the laser driver)
  • 12V: for the water pump, the fans, and the motors of the XY table
  • 5V: TEC Controller, Laser Driver
  • 24V: Safety relays

All circuit diagrams of the project can be found in this repository:


  • Keep the electrical and the water cooling parts at an distance to each other. In our setup the water pump and the water tubing are on the left side and all electrical components are on the right side. All parts are mounted on the rack tray, so in case some water leaks and collects at the bottom of the enclosure, it won't touch electrical parts
  • The safety switch is in a small extra enclosure connected with rubber hose cable. This way the supply unit can be placed e.g. under a table but the safety switch next to the laser engraver
  • Mains power connector is at the back, key switch, sockets for the connecting cables are at the front
  • Make sure all metal sides of the enclosure are connected to PE

Water Cooling

  • Note on the used radiator (Coolstream PE 360): When installing the threaded couplings on it, be gentle. It seems, that the metal is really really thin around there and if you thread the hose-coupling in to deep, you rip it apart.


QtyPart nameManufacturer PartPart LinkComments

Electrical Components

1Power supply laser diode, 3.3V, 20AMeanwell RSP-100-3.3
In beta test system: Meanwell RSP-500-3.3
1Power supply peltier elements, 15V, 21AMeanwell RSP-320-15
In beta test system: Meanwell RSP-500-15
1DIN rail power supply, 5V, 2 AMeanWell MDR-10-5

1DIN rail power supply, 12 V, 3 AMeanWell MDR-40-12

1DIN rail power supply, 24 V, 1 APOS Power MDIN20W24

1Emergency SwitchGeorg Schlegel SIL_QRBUVOOstex24
1Key switchRS PRO 188-1149RS Online
2Switch NO, for key switchRS PRO 188-1170RS Online
1Plug, fuse, power switch 6 A, with filterSchurter KMF 1.1161


1Fuse holderSchurter KM 01SH-1


2Fuse 6A slow blow, 5x20mm5x20mm 6A TR


1Quicklock chassis socket, size 20, 4 polesLUM 0272-04 or Lutronic 2620 04 T22CB100


second one needed at laser side
2Quicklock plug, size 20, 4 polesLUM 0252-04 or Lutronic 2650 04 T12CB T


1Quicklock chassis socket, size 16, 7 polesLUM 0271-07 or Lutronic 2420 07 T18CB100


second one needed at laser side
2Quicklock plug size16, 7 polesLUM 0251-07 or Lutronic 2450 07 T09CB T


1DIN Rail 35 x 7,5 mm

ca 30cm
6Terminal block greyPhoenix Contact PT 2,5-QUATTRO, 3209578

2Terminal block blue Phoenix Contact PT 2,5-QUATTRO BU, 3209581

2Ground terminal block green/yellowPhoenix Contact PT 2,5-QUATTRO-PE, 3209594

1Disconnect terminal block Phoenix Contact PT 2,5-TG, 3210185

1Isolating Plug Phoenix Contact P-DI, 3036783

4Plug-in bridge, 2 positionsPhoenix Contact FBS 2-5, 3030161

2Terminal block end cover Phoenix Contact D-ST 2,5-QUATTRO, 3030514

3Fuse terminal blockPhoenix Contact ST 4-FSI/C, 3036372

1Fuse 2A, regular ATO (ISO 8820-3 type C) 

KFZ Flachsicherung 19mm
2Fuse 15A, regular ATO (ISO 8820-3 type C) 

KFZ Flachsicherung 19mm
25x1,5mm2 rubber flexible cableH07RN-F 5G1,5, length 2 meters

4m in total, one 2m piece for connecting the safety switch, the other one for the 3V connection to the laser. 4x1,5mm is enough, but 5x1,5mm is more common
17x0,75mm2 rubber flexible cablelength 2 meters

connecting unit supply and laser (voltages other than 3V)
1cable gland M20, nylon

Water Cooling Components

1PU tube 12x8SMC TU1208BU


ca 5m
1Radiator for 3x 120mm fansCoolstream PE 360


3Fan120mmNoctua NF-A12x25




4Stop fitting G1/4"

2Fitting, bulkhead union 2x 12mmSMC KQ2E12-00A


4Fitting, male connector, R1/4", 12mmSMC KQ2H12-02AS



1Server rack 19" 4HEARLI Soho 4Uebay
1Rack tray
1Laser cut sheet metal front custom part, 2-3mm aluminum
github link
1Laser cut sheet metal backcustom part, 1mm stainless steel
github link
1Laser cut sheet metal revetment custom part, 1mm stainless steel
github link

Customizing the ARLI Soho enclosure

In case you are using the ARLI Soho enclosure, you may want to use our custom plate for the back side. You find the DXF in our repository. To fit in the enclosure, you need to bend the sheet metal:

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