I picked up / rescued an old Gravograph VX Engraving machine
I just finnished building and fitting the new X/Z Carriage and its running nice.
The machine was well built in the 80's, it has a solid diecast chasis bosting solid double 25mm round rails for X and Y Axis
The Gantry is fixed, the suprt arms where solid dicast with reinforcment ribs also serving as concealed cable paths.
The spindle was rat**** and the software looked hopless
I looked at the electronics, it was old and dated.
It had XYZ Limit switches.
The Steppers looked old and dirty, clearly they had seen better days.
I wired the steppers up and tested them, they started up and ran very smooth.
The stepper couplers where rubber with a square tooth gear patern, I initialy 3D printed these, but have since cut them out of HDPE sheet.
I decided to scrap the electronics, I ordered a cheap Controller and Stepper Drivers.
These will all fit into the front right compartment when done.
Design Upgrade Considerations
--------------------------------------------------------------------------------------------
I want to retain as much of the working area.
As it would not interfear with its opperation or limit it in any way, I made the Carriage 200mm wide maxing the bearing block distance in the X direction.
I inverted the Z Axis Carriage so the bearing blocks are mounted to the Gantry, (always wanted to try this)
The thought is the 20mm rails mounted to a 12mm motor mount plate combined with 2 motor mounts spread to top and bot of spindle will stiff the Z Axis
Also this enabled me to mount the stepper to the X axis carriage to achive a carriage only 45mm deep/thick from gantry to front spindle mounting plate.
The sacrifice was I had to mount the Z Axis Stepper on a pedastal 200mm above gantry.
The original carriage is 75mm deep from Gantry to centre of spindle
I will be installing a 62mm 60000rpm spindle.
If all goes well with spindle brackets, will make my distance from gantry to spindle centre 77mm, only 2mm more then original spindle retaining almost the full original work area.
When I removed the diecast bed, I found a self centering vise for engraving nameplates and other round items like watches etc..
In the future I will be reworking these strengthening them.
Anyway here are some pics to give others some ideas if they get their hands on any of these older engravers.
Couple of the older original Gravograph images are of the internet, it was easyer then lifitng and taking pictures.
https://youtu.be/RlGBcGRVU7Q