FrankenForge ... a Glowforge salvage project

A thread to share how to salvage a nonfunctional Glowforge.
The machine didn’t function from new.
Left “Y” axis motor was dead which caused erratic, nonsensical motion.
Company had no interest in problem solving or having the machine returned for forensic analyst.
So rather than send the machine off to the recycle it was dismantled in an effort to build a machine from the scraps.
It turns out one wire wasn’t fully seated into a connector that plugs into the “Y” motor.
Most of the Glowforge electronics / motion control is proprietary so had to be abandoned.

Major parts salvaged :
Laser tube
“X” / “Y” chassis
Water pump and cooler
A portion of the original cabinet

Being a bit of a tinker some of the needed parts that were already here in the maker cave.
Main items that on the shelf :
Smoothieboard V1
12 & 24 volt power supplies
Hook up wires, connectors, micro switches, E stop switch
NEMA 17 motors for “Z” axis
Various sheet metal
Nuts, bolts, tie wraps, tapes etc.

Items to purchase :
Laser power supply
Lightburn software
To build a “Z” axis :
Aluminum extrusions and corner connections
Pulleys, belts, belt tensioners, lead screws

Bill of materials and firmware code to follow in future postings.


Looking forward to the thread! :relaxed: Thanks for sharing.


Out of curiosity: you apparently found that the laser power supply was too proprietary to be reused. What sort of problems prevent its use?


This will be very interesting to follow. Thanks for sharing.


Looking back, perhaps the decision to dump the laser power supply might have been too hasty.
The dismantle part of the project happened well over a year ago so I’ll try to recall the reasoning for this.
Glowforge bundled several other things into the power supply including some of the motion control.

Until recently there was a Glowforge hacker forum “OpenGlow”
Looking thru their documentation I concluded it was the best option to move forward with full control of the laser cutter.
The creator of the forum still has most of the information on GitHub.
7 pages of schematics don’t seem to be there any longer.
But … he was able to create a firmware hack to gain more control.
That info is still available.

I should mention all the removed stuff sold easily and was more then enough to fund the rebuild.


A tip for removing the top panels.
They are held in place with a “blind” latch hook.
Undoubtedly there is a special designed tool to reach in thru the open lid to release the latches.
Pushing thin feeler gauges into the gap between the top and side works fine too.
Blue tape in the picture shows the approximate location of the latches.

To facilitate easy removal during the build process the “hook” part of the latch was sanded off.

An edit to mention … double sided tape is used in many places on the machine.
Examples are cabling to chassis and outside enclosure to chassis.
Have a heat gun at the ready to warm a tape area which eases the removal process.


I’m interested in hearing that there is replacement firmware: good to know if mine dies.

1 Like

The replacement firmware is pretty limited and it also depends on the version of the control board you have whether it is easy or hard to load the new firmware.


Once the original chassis was removed from the plastic case it was mounted to an aluminum sheet.
This sheet was salvaged from a Grumman box truck project.
A plywood sheet could be alternative material choice.
The attached .pdf drawing shows the cut dimensions in mm.
93mm dotted line to internal opening sets the distance to the rear bolt holes of the chassis.
The original plastic case was laid on top of the aluminum sheet and used as a template to mark the holes.
I drilled the holes first and then made the internal cut second.

BTW … Stock Glowforge power supply has 4 voltage outputs
3.3V @ 2.2A
12V @ 32A
40V @ 3A
12kV @ 20ma
This is unique and not found in the common marketplace … an aftermarket replacement is unlikely.

adapter.PDF (14.2 KB)


Sounds like a typical laser power supply that supplies all the needed voltages for operation. I am sure any glass tube CO2 laser power supply rated for 20 ma would work for the laser itself. From what I have been able to research in the past, the tube is a standard tube and has not been modified for use in the GF.


When searching for a common Cloudray brand 40 watt LPU the typical voltage taps were :
5V @ 50ma
24V @ 2A
25kV @ 20ma

Pretty sure the Glowforge LPU had some motion control or logic capabilities embedded in the device.
Definitely had a least one multi pin ribbon cable connector (25 ~ 30 pins).
Reading the Glowforge schematic it appears the 40V tap runs the light circuit.

BTW … FrankenForge is running.
There will be some questions for the forum towards the end of this build log. (final tune questions)
Starting the build log now before the cabinet is built so I have open access for pics and measures.

Yes … there are drop in replacement tubes available.

An edit to add this Glowforge control board overview.
Note connector J1 in the top left of the picture.
The ribbon connector that feeds to the LPU.
This is what makes the power supply proprietary.


Here’s a material list to build the “Z” axis chassis.
All items link to Amazon
Hopefully the line descriptions are understandable enough for when the links goes dead after a few months …
Drawings, sketches coming in a day or two …

2pcs 2GT Driver Belt 1220-2GT-6 Timing Belt in Closed Loop Rubber L=1220mm W=6mm 610 Teeth

4pcs needed 2GT Pulley 60 Teeth Bore 8/5mm 60T Timing Pulley Width 6mm

2 pcs needed 2020 Profile Synchronous Belt Straighten Tensioner Bearing Type

20pcs 2 Hole Corner Bracket Right Angle Brackets for Aluminum Extrusion Profile Slot 6mm

4pcs needed GT2 Pulley 20 Teeth 8mm bore 6mm Width 20T Timing Belt Pulley

20pcs Black T Slot L-Shape Interior Inside Corner Connector Joint Bracket Slot 6mm

4pcs needed 300mm 8mm T8 Lead Screw Set Lead Screw + Copper Nut + Coupler + Pillow Bearing Block

180pcs 2020 Series T slot Nuts, M3 M4 M5 T Slot Nut Kit

2pcs needed Nema 17 Stepper Motor Mounting Bracket w/ M3 Screws

2000mm Silver 2020 (20mmx20mm) T Slot Aluminum Extrusion

12 pcs needed 3-Way End Corner Bracket Connector


Attached .pdf shows the bed tray dimensions.
Document includes the outside dimensions and material cut dimensions with appropriate subtractions for the end connectors.
Honeycomb bed is salvaged in it’s original size so the bed tray is built to fit with a little extra gap.
Total “Z” axis movement is 250mm.
Note the threaded rod with blue tape attached.
This is a helpful simple tool used to keep the sides / dimensions parallel.
Once the tool length is locked the extrusion couplers can be held against the tool’s washers and then tightened.

bed tray.PDF (13.6 KB)


Today’s .pdf attachment is the “Z” axis chassis.
Same routine as before … it shows overall dimensions and material cut lengths.
All material cuts are 4 pieces needed.
Where possible two connectors are used at every corner connection.
Next .pdf drawing will be the sheet metal designs for the :
linear drive nut mount, limit switch mounts, honeycomb bed tabs.

Z-axis-chassis.PDF (34.3 KB)


Today’s post shows the limit switch locations on the machine.
The “X” axis switch is mounted on the left side of the gantry where it can be activated with the cutting head.
Maybe not the most ideal as when the head is removed for cleaning there is nothing to strike the switch. So don’t home with the head removed.

The “Y” axis switch is mounted on the front right side “Y” axis rail where it is activated by the pulley wheel bolt.

The .pdf is :
(left to right in the drawing)

  1. lead screw nut to bed tray bolt plates
  2. bed tray side tabs (one tab is also the “Z” axis switch mount)
  3. switch mounts for “X” & “Y”

These parts were cut by for $30
Material is .060" thick 6061 aluminum

cut-.060-aluminum.pdf (8.7 KB)


With the “Z” axis being the major change to the design I thought it best for it to have an adjustable height switch.
It is mounted to the front but due to the adapter plate is a bit hidden and harder to show clearly in pictures.
The bed is moved down and honeycomb removed in an effort to be more understandable.
The switch strikes a fender washer soldered to a nut and copper tube.
Adding the copper tube allows easy access to adjustments.


This post is wrapping up the chassis details before moving on to the electronics.
The belt tension / idler assembly needed a riser block to match the height of the motor pulley.
These are made from white UMHW plastic although any other material will work.
See attached .pdf for dimensions.

Idler Riser Block.PDF (14.9 KB)

The second picture shows how the “Z” chassis is mounted to the adapter plate.
One angle bracket on each upright.

Third pic shows the distance between the head and cutting bed.
Before dismantling the machine I had measured this distance to be 45mm.
While taking this pic I noticed it actually measures 35mm so there may be some adjustment to make.
The original “Z” axis adustment happens inside the cutting head so I may be able to make the adjustment there … otherwise simply sliding the mounting brackets on the uprights solves the mistake.


OK … here’s the start of the controller write up.
Motion control is handled by a Smoothieboard V1 with the firmware updated to cohesion3d (last June)

alpha and beta axis (X & Y) are the stock Glowforge motors and movements.
gamma axis (Z) motors are Wantai 42BYGHM809 ~ .9 degree per step

steps per mm for the 3 axis
alpha_steps_per_mm 106.5 # Steps per mm for alpha stepper
beta_steps_per_mm 106.5 # Steps per mm for beta stepper
gamma_steps_per_mm 2400 # Steps per mm for gamma stepper

Pin configuration for the laser
smooth-laser-hook-up.pdf (743.0 KB)

Laser module configuration

laser_module_enable true
laser_module_pin 2.5 # this pin will be PWMed to control the laser.
laser_module_maximum_power 1.0 # maximum duty cycle that will be applied to the laser
laser_module_minimum_power 0.0 # minimum duty cycle that keeps the laser active
#laser_module_default_power 0.8 # default laser power
laser_module_pwm_period 200 # pwm frequency in microseconds

switch.laserfire.enable true
switch.laserfire.output_pin 2.6!^
switch.laserfire.output_type digital
switch.laserfire.input_on_command M3
switch.laserfire.input_off_command M5

1 Like

I’ve been meaning to ask if you’re keeping the Glowforge optics and the flying bridge design.

Optics from inside the head have been removed.
Haven’t bother to remove the camera from the lid … yet … I don’t have plans to use it figuring it’s probably more trouble to track the circuits then to change to a different camera … If I decide to have a camera.
None of the industrial lasers I’ve used in the past has had a camera so not so sure why it’s necessary to have one.
Also changed the lid LED’s to 12V so the originals are available, as is the ribbon cable that feeds the lid.
Not sure what you mean by “flying bridge” ?
I would call the original motion a “gantry” design.
Original X & Y movements were retained.
Left over Glowforge parts are available if someone wants them.

1 Like