Printing custom window latches: what worked for me

PLA does tend to get soft and warp, especially if your windows face direct sun. I’ve had better luck with PETG - still pretty easy to print, but it holds up a lot longer in heat. ABS is even tougher, but it’s more finicky to print and can stink up the house if you’re not ventilated. I’ve also tried annealing PLA in the oven to toughen it up, but honestly, the results were hit or miss. For outdoor or sun-exposed hardware, I’d go PETG or even nylon if you can swing it. Just my two cents from a few too many latch replacements...

- PETG's been my go-to for window hardware lately - doesn’t get soft like PLA, and I don’t have to mess with a bunch of extra ventilation like with ABS.
- Tried nylon once, but it was a pain to keep dry and didn’t stick to my bed without a fight. Not sure it’s worth the hassle unless you really need that extra toughness.
- Annealing PLA… yeah, I’ve had mixed results too. Sometimes it warps more than it helps.
- Curious if anyone’s tried ASA? Supposed to be UV-resistant but I haven’t messed with it yet. Wondering if it’s worth the learning curve for outdoor stuff.

PETG’s been solid for me too, especially in spots that get a lot of sun - doesn’t go brittle like PLA. I’ve used ASA on some exterior door handles, and it’s definitely more UV-stable, but dialing in the print settings took some trial and error. Warping can be an issue unless you’ve got a really stable enclosure. For me, ASA was worth it for stuff that’s outside all year, but it’s definitely not as forgiving as PETG.

Warping can be an issue unless you’ve got a really stable enclosure. For me, ASA was worth it for stuff that’s outside all year, but it’s definitely not as forgiving as PETG.

PETG’s been a bit hit-or-miss for me, but definitely less drama than PLA once the sun starts baking everything. I tried ABS once on a latch and, uh, let’s just say my garage still smells like burnt Legos. ASA’s on my “maybe someday” list, but I’d probably need to build an enclosure that won’t get hijacked by my cat first.

One thing I tried - probably not super scientific - was painting the PLA latches with a couple coats of outdoor acrylic paint. Figured it might block some UV and slow down the warping. It actually helped for a while, but after last summer’s heatwave, they still went all twisty. Not sure if it was the paint or just wishful thinking.

Honestly, I keep coming back to PETG because it’s forgiving enough to print without a lot of fuss, and it doesn’t turn into a noodle in the sun. Still gets a little soft in direct sunlight, but it hasn’t totally failed on me yet. I live in an old 1940s place with windows that seem to have their own personalities, so sometimes I just brace for reprinting every year or two. At least it’s cheaper than replacing the whole window.

Anyone else tried weird post-processing tricks? I saw someone online used a clear epoxy dip, but that seems like a lot of work for a latch that’s about two inches long…

Tried the epoxy thing once on a door handle - honestly, it looked shiny but felt kind of overkill for something that’s gonna get beat up anyway. PETG’s been my go-to too, especially since I don’t want to run the printer all night just to keep the enclosure warm. My one “hack” was sticking some old window film scraps over the latch - figured if it keeps heat out of the house, maybe it’d help the plastic too. Not sure it did much, but at least it matched the rest of my DIY energy fixes.

My one “hack” was sticking some old window film scraps over the latch - figured if it keeps heat out of the house, maybe it’d help the plastic too. Not sure it did much, but at least it matched the rest of my DIY energy fixes.

That’s a pretty creative move, honestly. I’ve done similar with bubble wrap and duct tape when I was desperate for insulation - looked like a science fair project but hey, it worked (sort of). I’m with you on PETG though, especially for stuff that actually gets used. Ever had issues with PETG warping near drafty windows? Mine seems to sag a bit after a couple summers, but maybe that’s just my old house...

Ever had issues with PETG warping near drafty windows? Mine seems to sag a bit after a couple summers, but maybe that’s just my old house...

I hear you on the PETG warping. My place is about 80 years old and those windows don’t do me any favors - summer heat just bakes the latches, especially on the south side. I tried PETG for a set last spring, thinking it’d be tougher than PLA, but by August they were drooping like overcooked noodles. Maybe it’s just the combo of sun and those ancient wood frames leaking air everywhere.

Funny enough, I slapped some leftover car windshield shade behind one latch as an experiment. Didn’t look great, but it actually kept things stiffer for a while. Not exactly pretty, but neither are most of my “fixes” at this point.

Honestly, I’m starting to think ABS or ASA might be worth the hassle if you’ve got the setup for it. PETG’s fine for stuff out of direct sunlight, but these windows chew through plastic faster than I’d like.

That’s pretty much my experience with PETG too, especially in spots that get a lot of sun. My house is from the 50s, and the windows are drafty enough that I’m surprised the latches don’t just fall off in August. I printed a batch of PETG latches last year thinking they’d hold up better than PLA, but by the end of summer, they’d all started to bow. I’m guessing the constant temperature swings and sunlight just push PETG past its limits.

Tried ABS once, but my garage printer setup isn’t really enclosed, so warping during printing was a nightmare. ASA seems promising since it’s supposed to be more UV-resistant, but I haven’t gotten around to dialing in those settings yet. Honestly, your windshield shade trick sounds clever - might not win any design awards, but if it works, it works.

One thing I did was add a little aluminum strip behind the latch as a sort of “backbone.” Not invisible, but it kept things straight through the worst of the heat. Sometimes you just have to improvise with what you’ve got...

Tried ABS once, but my garage printer setup isn’t really enclosed, so warping during printing was a nightmare. ASA seems promising since it’s supposed to be more UV-resistant, but I haven’t g...

That aluminum strip idea is solid. I’ve done something similar with steel wire epoxied into a channel on the back - definitely not pretty, but it stopped the latches from sagging. PETG just doesn’t cut it for direct sun, no matter what the datasheet says. ASA’s on my list too, but getting it to print right without a full enclosure is tricky. If you ever try it, slow down the cooling and keep drafts out as much as possible. Sometimes a little brute force reinforcement is just the way to go...

I get where you’re coming from with PETG not holding up in the sun, but I’ve had a bit more luck than most folks seem to. I printed some latches last summer, and while they did get a little brittle after a few months, they didn’t totally fail - maybe our porch doesn’t get as much direct light. I did try doubling up the infill and adding a tiny lip on the edge for strength, which seemed to help with sagging. Not saying it’s a long-term fix, but if you’re in a pinch or don’t want to mess with ABS/ASA fumes, it’s worth a shot. Sometimes it’s just about what you can live with for a season or two...

I get the “good enough for a season or two” logic, but honestly, I’m still not sold on PETG for anything that needs real durability in sunlight.

“...they did get a little brittle after a few months, they didn’t totally fail...”

I’ve tried PETG on my south-facing windows, and even with extra infill, it just didn’t last. Maybe I’m picky, but I’d rather deal with the hassle of ABS or ASA fumes once than have to keep reprinting parts. There’s also the energy aspect - reprinting stuff every year just feels wasteful, both in time and electricity.

Not saying PETG is useless, but for stuff that gets hammered by the sun, I’d rather overbuild once and forget about it. Maybe I’m just lazier than most, but the fewer maintenance projects, the better...

That makes a lot of sense to me. I’ve had PETG parts go brittle on my deck after one summer, even with thicker walls and higher infill. Honestly, I’m with you - if I’m going to the trouble of designing and installing something, I’d rather just deal with ABS or ASA once and not worry about it again for years. The fumes are annoying, but it’s a one-time hassle. And yeah, having to reprint every spring feels like a waste of time and energy. Sometimes overbuilding is just the smarter move.

I get where you’re coming from, but I’ve actually had better luck with PETG than ABS for certain outdoor latches, especially in spots that don’t get full sun all day. ABS and ASA are definitely tougher, but the warping during printing is a pain - even with an enclosure. Plus, if you’re not careful with ventilation, the fumes can linger way longer than you’d expect. For me, PETG with a UV-resistant clear coat has held up surprisingly well on north-facing windows. Maybe it’s just our milder summers, but I haven’t had to reprint yet… just my two cents.

- Totally hear you on the ABS fumes... my garage smelled like a chemistry set for days once.
- PETG’s been decent for me too, but I did have one latch go brittle after a winter freeze. Maybe my batch was off?
- Haven’t tried the UV clear coat yet - might give that a shot, since repainting is getting old.
- North-facing windows definitely seem to help. South side? Toasted plastic city.

Can’t say I’ve had PETG get brittle in the cold - mine’s held up through some nasty Minnesota winters, but I always print at a higher temp and let ‘em anneal a bit. Might be worth a try before switching materials. As for the UV clear coat, honestly, I found it more hassle than it was worth. Ended up just printing in black ASA and calling it good. South-facing windows are brutal, though... nothing lasts forever there.

I’ve had similar luck with PETG - seems pretty tough, even in the cold, but I have noticed that layer adhesion gets a little dodgy if I don’t bump up the temp or slow down the cooling. My shop’s not exactly climate-controlled, so in winter I’ll sometimes pre-warm the enclosure with a space heater for a bit. PETG handles it, but you’re right about those south-facing windows. Sun just eats through plastics, no matter what you do.

Tried the UV clear coat route last year on a batch of latches for our back porch windows. Looked great at first, but after one summer, I started seeing flaking and yellowing. Maybe I got impatient with surface prep, or maybe it’s just not worth the hassle unless you’re going for aesthetics over longevity. Black ASA has been my go-to lately too - prints a little stinkier, but it shrugs off UV a lot better. Only thing is, ASA warps like crazy on my old Prusa unless I use a brim and keep the enclosure tight.

Funny thing - I had an old PLA latch last about six months before it turned into something resembling stale bread. Swore off PLA for anything outdoors after that.

One trick that helped: when I do stick with PETG, I toss finished parts into the oven at 80C for an hour or two (just keep an eye on ‘em). Seems to relieve stress and toughen them up a bit. Still, for high-sun spots, ASA or even polycarbonate if you can stand the printing headaches.

Wouldn’t mind hearing if anyone’s had luck with PC blends, though. Haven’t tried those yet - price tag always makes me hesitate.

- I’ve actually had PETG last longer than expected outdoors, even on the south side, as long as I kept the infill high and walls thick (like 4 perimeters). Maybe I just got lucky with my filament brand?
- Tried ASA a couple times but the warping drove me nuts. Even with a brim, corners still lifted unless I dropped the bed temp way down after the first few layers. Not sure if it’s my enclosure or just a drafty basement.
- UV clear coat didn’t do much for me either. The prep is a pain, and it always seemed to peel off in sheets after a few months.
- Haven’t braved PC blends yet either - price puts me off, and I’m not sure my Ender can handle it without major upgrades.
- Anyone else find that color makes a difference? My white PETG parts always get brittle first, while black seems to hold up better. Maybe just coincidence...

That’s interesting about the color difference -

My white PETG parts always get brittle first, while black seems to hold up better.

I’ve actually had some clear PETG latches out on my back porch window for about a year. They held up better than the white ones I tried before, but eventually they started yellowing and got a little brittle, especially where the sun hits hardest. Not as bad as the white, though - those cracked in a couple months. Black seems to last longer, but it gets hot in direct sun, which isn’t always great for moving parts.

For ASA, I did mess with turning off part cooling after the first couple layers. It helped a bit with warping, especially on bigger prints. I usually keep the fan at like 10% just so the overhangs don’t get too ugly, but honestly, ASA is still a bit of a diva in my shop. Enclosure helps more than anything, in my experience. If you can rig up a cardboard box or something around your printer, it makes a world of difference.

Funny enough, most of my window latches are now PETG in a dark gray. Seems like a happy medium - doesn’t show dirt, doesn’t get too hot, and so far they’re holding up.