§M4c mentioned "a custom UV curing station." This is that station, a nail-polish lamp with its safety timer shorted out and four heatsinks taped to its back, and it has post-cured every resin part in this project.
The real appliance costs real money
The proper tool here is a wash-and-cure machine, and Anycubic's current one lists at $129, on sale for $89 as I write this [22]. That is most of the cost of a second printer, and all the machine does is spin parts in solvent and shine UV on them for a set time.
I already had the washing half, two plastic tubs of 99% isopropyl alcohol, dirty bath then clean bath (the workflow is in §M4c). The curing half needs a UV source that can run for minutes at a time. Mine is an XCHENIMO portable LED nail lamp from Coupang. Gel-nail curing lamps run in the same near-UV band hobby resins cure in (~405 nm class, general knowledge, since the listing does not state a wavelength).
I paid 5,990 KRW for the lamp, about $4.10, so it was a $4 lamp instead of a $90 machine. The same listing showed 3,990 KRW (about $2.75) when I screenshotted it for this chapter. Coupang prices drift around [20, 23].
The 30-second timer
A nail lamp is built to cure a thin, flat coat of polish on fingernails, so mine switches itself off about 30 seconds after the button is pressed. The timer is presumably also what keeps the UV LED modules from overheating on long runs.
Resin parts are big and have several sides, and per the §M4c workflow each side needs 5–10 minutes of direct UV. Pressing a button every 30 seconds for an hour is not practical, so the timer had to go.
Shorting the timer
On the lamp's control board, I soldered hand-cut, silicone-coated jumper wires across the part of the circuit responsible for the auto-off timing, which disables the timing and on/off logic entirely (the LEDs are on whenever the lamp is powered and off when it is unplugged). I never noted which pads I bridged. What I can vouch for is the joint itself, which I made with the same syringe flux and rosin-core solder as every board in §M3b [builder, 2026-08-07].
The overheating showed up immediately after I disabled the timer. In continuous operation the LED modules climb to temperatures I wasn't comfortable with.
Becoming the cooling system
To fix the overheating, I gave the board a heat path. The LED board's metal back is the natural surface for it, so I mounted four aluminum heatsinks onto it with a thin layer of ARCTIC MX-4 thermal paste (the 4 g tube) [21], held in place with electrical tape.
With the heatsinks on, the lamp runs for more than three hours continuously without significant heat buildup, which covers even a full multi-part, both-sides curing session with margin. I checked it by touch, not with instruments, feeling the heatsinks and the PCB for buildup again and again over a run, so there are no numbers. Staying comfortable to the touch for hours was the acceptance test [builder, 2026-08-07].
Cost box
| Item | Paid | Notes |
|---|---|---|
| XCHENIMO LED nail lamp (Coupang) | 5,990 KRW ≈ $4.10 | listing at 3,990 KRW ≈ $2.75 when screenshotted [20]. USD at 1 USD ≈ 1,453 KRW [23] |
| ARCTIC MX-4 thermal paste, 4 g | [21] | |
| Aluminum heatsinks ×4 | mounted with MX-4 + electrical tape | |
| Two plastic tubs + 99% IPA | the washing half (§M4c) | |
| · vs. commercial wash & cure | $89–129 | Anycubic Wash & Cure 3, store price [22] |
Even against the sale price, the lamp is roughly one twenty-second of the commercial machine's cost (Derived: $89 ÷ $4.10 ≈ 22×). The cost of the whole station has to wait on the prices still missing from the table above.
Two caveats
First, the timer I removed was a safety feature, and after the mod the lamp will cook itself if the cooling is not there. The heatsinks are the replacement safety system, so they are not optional, and I still do not leave the lamp running unattended.
Second, the lamp is now a continuous near-UV source. It gets pointed down at parts, never toward eyes, and the IPA tubs stay well away from it, because warm alcohol vapor and a hot lamp are a bad combination.
What the printing chapters add up to
The four resin-printing chapters built the full pipeline: exposure calibrated per resin (2.6 s, §M4a), orientation and supports systematized (§M4b), clearances measured at 0.15/0.30 mm and a two-bath wash routine (§M4c), and now unlimited post-curing for about four dollars. Beyond the printer itself, the total investment was tubs, alcohol, a nail lamp, thermal paste, and a few evenings of mistakes.
Every functional part in the actuator chapters (the dome foot in §M2, the friction coupons in §M9, the flexure legs in the Phase 2 plans) comes out of this pipeline. The stick-slip actuator literature treats this fabrication capability as exotic (§M1's "no 3D-printed SSPAs" gap), but in practice it is a bedroom setup held together by jumper wires and electrical tape.