There are some things I would change in a future version. 

• The power supply is too weak. With both lamps, I have to turn it on very slowly so that it doesn't trip. I think I'll try a normal 24V power supply rather than USB PD.
• The lamp holders get soft. I need to get some PETG or ABS and reprint them.
• The LED dimmer uses small diameter wire and the wire gets too warm when the heater is turned all the way up. I'll probably replace the wires since I must have the dimmer to keep the power supply from tripping. (the dimmer is rated for 12-24V and 6A. I'm running it at 20V and 3A. There's no way it would handle 6A without melting).

Overall the project cost me about $65 USD. 

• $20 - 2 halogen work lamps from walmart
• $5 - LED dimmer
• $25 - 65W USB PD power supply
• $12 - 20V USB PD trigger cable
• $2 - Barrel Jack

A couple of these items came as part of a larger pack, so I've adjusted the prices for that since I'll use the extra parts for other projects.