Another DIY Bench Power Supply

Update: Commenter pointed out that I overlooked the current rating on the buck converters I linked, we should be using something like the XL4015, I updated theDIYBench_Bottom file with a XL4015 variant.07/08/2020

This is yet another DIY bench power supply. It is designed to be printed with minimal supports, be roomy enough to work in comfortably, and for the final product to be nice and strong. All the components I used have been linked below. The supply was designed to rely on m3 bolts tapped into the plastic, I'd recommend getting an m3 tap if you're going to build this, you can also use the bolts to tap the plastic but a tap would be easier. The box goes together with 15 or 16 5mm m3 bolts (a 16mm bolt can go in place over the step down converter as a set screw if tolerance is loose), the fan requires 20mm or 25mm m3 bolts and nuts, and the fused mains plug requires a couple bolts (15mm or 20mm will do) and nuts.

The side walls of the box all slot together, when printing there is one area on each wall that requires support, I've modeled a support structure that will need to be aligned with its corresponding wall (you can adjust its Z scale to get the right offset from the parts, depending on your printer). Also the front panel needs support under the XT60 connector housing.

Note: The bottom plate does have a 'front', you should be able to see a small notch in the lip around that bottom part, that allows for clearance for the XT60 connector's housing.

Note2: The XT60 and USB port may need a dab of super glue to secure them in place.

Note3: I'm no electronics expert so I won't be providing a wiring diagram, though if you're going to attempt this project there are a lot of resources or similar diy supply schematics available. Be careful with mains power when wiring up your switch! It can kill! I also included a link for a pre-wired version. The gist is it goes from switch to power supply, then step down converter to power outputs (banana jacks, etc). You can also divert some of the DC power to a buck convert to your fan directly or through the a rocker switch.

Features:
36v 5A power supply mounting points
2 small buck converter mounting points
80mm or 92mm x 10mm cooling fan mounts
Fused power switch mount point
Rocker switch mount point (for fan power)
XT60 female jack mount point
USB female jack mount point

Components used:
Power Supply - https://amzn.to/3f2cySq
Banana Plug Jacks - https://amzn.to/3h5L2oR
Step Down Converter - https://amzn.to/2YcSea8
Buck Converters (UPDATED) - https://www.amazon.com/Organizer-Lithium-Battery-Converter-Constant/dp/B07V7F5K8T/

80mm Fan - https://amzn.to/3dLzLbl
92mm Fan - https://amzn.to/30mF5Ot
Fused Power Switch - https://amzn.to/2MG176L
Fused Power Switch (Pre-Wired!) - https://amzn.to/3f3xc4z
Rocker Switch - https://amzn.to/2YeIKv8
XT60 Connector - https://amzn.to/2Ur80x1
USB Port - https://amzn.to/2AgcfVm
20mm Rubber Feet - https://amzn.to/37l2Wja
3MM Thread Tap - https://amzn.to/2YmasGu

Shout out to my buddy Alan who inspired this project!

Print Settings

Rafts:

No

Supports:

Yes

Resolution:

0.2 - 0.3 is fine

Infill:

15 to 20% to reduce pillowing

Filament: Any PLA, PETG, or ABS Any
Notes:

Sorry they're not pre-oriented for printing but they should all be easy to place on the bed! Most of the parts print flat on their face so the layer heights don't matter much. The front panel needs to be printed with supports under the XT60 connector, all the side walls have an area that either need slicer generated supports, or they can be printed with the modeled supports also uploaded. You'll need to align the component origins before orienting them together for printing. Let me know if you have any questions, I can't provide help for aligned the support piece for all slicers however, sorry.

Post-Printing

Remove supports and any brim you may have printed with, assemble the box to make sure everything is slotting together properly. Once all the walls are in place and the top and bottom are seated its good to tap the holes all together so the thread runs through both parts. Tap the center top front hole all the way through the front wall part beneath it, this will allow you to use the longer m3 bolt as a set screw to help keep the step down converter from wobbling.

Once thats done test fit all the components. The rocker switch is a tight but positive fit, the step down convert may be a tad loose once its in place but that can be corrected with the set screw idea. Also now tap the mounting spots for the power supply and buck converter boards. The usb port may be tight depending on the print results, a light amount of filing may be necessary.

Category: Electronics