Quick-n-dirty:
If you want to use the original spring-return pneumatic z-axis drive, you need about 30 to 40 psi air supply. I use a Metabo HPT EC28M compressor ($180 from Amazon), but any decent air supply would do. I only bought the Metabo because my regular shop compressor is really loud and I didn’t want to have it running all the time.
I’m using the original air control solenoid valve and controls, and the original motor speed controller. I added two new stepper motor drivers, a power supply, a couple of relays to control the x-axis solenoid valve, and an Arduino microcontroller to drive all of this from a cheap PC running Estlcam software and Windows 10 or 11.
I made a new spindle with an ER-11 collet so I can use regular router bits, but I lucked out when I bought the engraver and got a couple of dozen original Dahlgren 1/4” cutters. I’m finding the Dahlgren cutters work better than router bits for engraving.
Send me an inventory or photos of what you have, and I can make you a shopping list of what items you’ll need to resurrect the Dahlgren as an engraver.
I did fabricate a true stepper-driven z-axis using parts from a 3018 cnc machine, but the Dahlgren z-axis setup only provides about 10mm of controlled vertical travel so it was kind of useless for real three-axis machining. I felt it was better to keep the Dahlgren as an engraver rather than trying to make it do something it was never designed to do.
