Customizing the ERC TimSav


This is the story of my modified TimSav.
I wanted to keep the simplicity of the TimSav, but add some features to make it more useable:
1. Larger cutting space, to accommodate 24” x 48” underlayment foam sheets.
2. Vacuum bed to simplify alignment, and wrangle warped foam.
3. Fewer 3D printed parts.
This is the result.

The frame started with aluminum from the scrap bin at work, and was completed with delrin rollers and aluminum extrusion.
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Cutting Head:
My 3D printer is not running reliably, so I made the cutting head from aluminum angle, and skeletonized it in the mill to reduce weight.
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Vacuum Bed:
The vacuum bed was inspired by seeing a sheet of pegboard in the local hardware store. The base is a 2ft x 4ft sheet of 1/4” plywood with a perimeter of 1/2” square dowels. Knowing a small pressure differential has a massive effect over a large area, I supported the bed with numerous 1/2” standoffs dispersed between the pegboard and base. Finally, I added an aluminum rail for the roller at the end of the Y-axis. A coat of Minway sealed the surface against stray water droplets.
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The biggest challenge was the software and electronics. I am a mechanical engineer by trade, and it is easy to be overwhelmed by the sea of information out there, so it took a while for me find the best software and electronics setup. In the end, I settled on using an Arduino with GRBL-Servo firmware. I wanted a more CAD-oriented drawing software than Inkscape, and that led me to discover DoubleCAD. I love DoubleCAD. It’s absolutely free, and has even more functionality than FastCAD, which I use professionally. But DoubleCAD does not have the ability to drive a CNC machine, so a bit of digging and testing led me to GRBL-Plotter.
DoubleCAD and GRBL-Plotter are a magnificent combo. Links here:

To simplify the wiring in the cutting head, I modified an Ethernet cable. With the connectors removed, you have access to a core of eight wires in one tidy package. Three wires plug into the Arduino to drive the servo, leaving one unused wire, and two pairs of two wires which are ganged together and plugged into the 12V power supply to power the ESC and drive motor. This cable, and the stepper wiring is each fed through a pair of drag chains to complete the electronics setup.
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Regarding the vacuum bed, I have it connected to the cheapest mini shop vac I could find. These vacuums require airflow through the hose to keep cool, so I added slats to the vacuum bed to allow limited airflow under the foam, without breaking the seal. The slats feed into a diffuser, which then plugs into the vacuum.
FoamyDM’s Build-Ruary competition is coming up, so I cordoned off a section on the bed to the size of a DTFB sheet at the same time.


I discovered I can run the machine more than twice as fast if I make every cut a score cut, and separate the parts by hand with an exacto blade later.
Think about it. A full depth cut means sending the needle through a layer of paper, the full depth of foam, a second layer of paper, and the top paper layer of the spoilboard. THREE layers of paper with each peck of the needle! That is a lot of load! By contrast, a score cut sends the needle through a single layer of paper, and a bit of foam. A lighter load means the motor is able to spin more freely, and the wire needle is under less strain. As a result, I am running the motor faster, and driving the machine quicker to keep up. I started at 40 speed units, but upped that to 100 units! I can cut entire sheets in less than ten minutes while maintaining crisp details!


New member
Great, you've reignited my desire to build one of these now! Just need to find space and budget...

Great looking machine, I love the cutting head and using Cat6 for the head wires.

john ferguson

New member
I just finished (+/-) my piercer attachement for my Chinese 6040 router. The throw on my rotor is about 1/2 inch. it looks to me like the way to cut 3/16 boaen fully retracted. Does this make any sense to you? If you had the issue of the stroke being more than the depth of cut needed, what did yords is to cut the wire length so that it sticks out a mot more than 3/16 when fully extended and retracts out of sight into the welding tip whu do?

john ferguson