Vented Dust Caps for LED Headlights

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Many thanks to Russ for giving us access to the 3D files. I knew nothing about 3D printing but I did know to get the deepest caps possible to allow for my 3 year old LED lights. The high beams were the hardest to fit, however I am pretty persistent.

I used a company called Xometry and my 4 caps were $251 including shipping.

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[MENTION=4740]Russ[/MENTION], can you elaborate a little on how the cup sizes are measured and/or what exactly to measure (from what, to the back edge of the bulb/fan) to determine size needed? I want to print the smallest size that will work for me, but not sure how to determine that without having had one of these in my hands to understand what the sizing means in practice. I suppose even just knowing what size the OEM cap would be considered would be sufficient info.
 
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@Russ, can you elaborate a little on how the cup sizes are measured and/or what exactly to measure (from what, to the back edge of the bulb/fan) to determine size needed? I want to print the smallest size that will work for me, but not sure how to determine that without having had one of these in my hands to understand what the sizing means in practice. I suppose even just knowing what size the OEM cap would be considered would be sufficient info.

I would refer you to this post.
 
[MENTION=4740]Russ[/MENTION] ,
Thanks. What software did you use to create these? I’m tempted to figure out how to eliminate the vents, since I suspect there is a reason Mother Honda made these units sealed and the LED companies are saying OK to run under dust caps.
 
[MENTION=4740]Russ[/MENTION] ,
Thanks. What software did you use to create these? I’m tempted to figure out how to eliminate the vents, since I suspect there is a reason Mother Honda made these units sealed and the LED companies are saying OK to run under dust caps.

I don't know...those LED heat sinks get pretty hot. My Hikari 2020's have an active cooling fan, which tells me they get plenty hot. The vents on the caps are fine- they let enough air in to keep the heat sinks working well, but keep moisture out. Also, the bulbs themselves have a silicone O-ring that seals the actual light projector cavity. The dust cap is just to protect the connectors.
 
I don't know...those LED heat sinks get pretty hot. My Hikari 2020's have an active cooling fan, which tells me they get plenty hot. The vents on the caps are fine- they let enough air in to keep the heat sinks working well, but keep moisture out. Also, the bulbs themselves have a silicone O-ring that seals the actual light projector cavity. The dust cap is just to protect the connectors.

The OEM seal with o-ring is airtight. These vented caps are not airtight. Are we sure that the metallic back of the projectors/reflectors is coated and the dust caps are not there protecting the back-side of those mirror-like surfaces from condensation-related corrosion? That (not the connectors/fan/heatsink/cavity) was my area of possible concern.
 
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Actually the OEM cap is not airtight, the gasket contact area has a cutout which is reproduced on the LED cap.

This got me excited. Not only would this validate that it is OK for these cavities to not be sealed, but also that cutout would allow a place for wires to run if I wanted the plug to be outside of the cap. So I printed up a 50.5mm cap...and then upon attempt to assemble learned...

The cutout area you highlighted is not related to the o-ring's mating surface, which is continuous and does result in a fully-sealed compartment.

Also, measuring things I'm back to being confused about how the depths are measured. I get these depths:
38mm = OEM Honda Cap
39mm = "50.5mm" Printed Cap

I did learn that the caps are wide enough for the VLEDs plug thing to fit in there sideways. So, a cap with inside cavity that is actually 67mm will hold everything inside (bulb with heatsink then fan then plug oriented sideways). I imported the "80mm" stl file (which I think will be about 68mm in practice) into Blender, but am fumbling around and failing with edits to delete the vents (well, I can delete the vents literally leaving holes where they were, but that's not quite what I'm after).

Photo of OEM cap and "50.5mm" printed cap with the o-ring applied:
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Photo of what I'm measuring to get the above measurements:
(Seems like 1-17/32” from inside back surface to surface of o-ring that will contact light housing, 1-17/16" converts to 39mm)
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That is interesting & I stand corrected. Do you have your headlight assembly out the car? Can you determine the cutout's function? Could it be a relief for the wires? When I designed these three years ago I had the luxury of having the headlight assembly on the bench and was able to create a cap that fit my own LEDs perfectly never thinking there would be so much interest. I wish I took more data on the various features and dimensions of the housing and cap together. The cap size "50.5mm" should indicate the depth of the cap to the furthest dimension, i.e. the bottom of the bayonet lugs.
 
Do you have your headlight assembly out the car?

I was trying to find a way to do all this with the headlight assembly in the car, as I wanted to avoid the effort some made it seem to be (removing wheel liner and such). I today noticed just how simple it is to remove: Pop headlights up, loosen painted plastic cover (four screws, two covered by tabs) and tilt forward, then four bolts to remove the headlight assembly. Easy!

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Can you determine the cutout's function? Could it be a relief for the wires?

Just inside the bottom of the light is a stationary wire-retention peg that the wires are looped around, leaving just enough wire past that for the plug to reach back of the bulbs. Maybe that helps ensure the wires to not make contact with back of the reflector/projector (either to protect wires from heat related to the halogen bulbs, or keep the wires from scratching the reflective metal back side, or just to be tidy and over-engineered). The cutout appears to accommodate this peg and the wires approaching it from the housing.

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I plan to have the VLEDS plug inside the cap sideways like this as I don't think there is room to have this bulky plug next to the bulb's heatsink/fan, nor stuff it into the housing like I think you did.
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So it needs to be as deep as measured below (about 63mm). I think formula is to subtract 12mm from the cap sizes to get the dimension I'm measuring (or add 12mm from measured dimension to get cap size), which means 75mm cap with no room to spare, so I'll do 80mm for margin of error.
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If you're really troubled by the vents I can generate an 80mm ventless cap for you. LMK.

If not too much effort, that would be extra cool. I was going to remove the rear vent from design (flat end makes it doable, but will still probably take hours for a newbie like me) and then leave the side vents (too hard with the curved sides, plus supports from 3D printing should block them if I leave in place there). But a plain/clean/ventless 80mm cap would be :biggrin::biggrin::biggrin::biggrin::biggrin:
 
No trouble at all, parametric modeling is a beautiful thing.

https://www.thingiverse.com/thing:5146508

Happy Thanksgiving!

Thanks, Russ! Started the print. Should be ready when I'm home from Thanksgiving Dinner at the in-laws.

Tip for folks printing these is to flip them 180 upside down. This will require a lot less support to be added by the slicing software, making for shorter printing times and less material use.

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The cap is perfect! Thanks [MENTION=4740]Russ[/MENTION] for the design and [MENTION=4772]cmarsh90[/MENTION] for use of your 3D printer!

Now just need to print three more of them and wait for my improved (1997-2001) headlight adjusters (33129-SL0-N11) to arrive.

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Very cool. Nice print BTW, what material and settings did you use?

Material is ABS from IC3D. Printer is a Lulzbot Mini. The first couple were printed with defaults for that material in the Lulzbot version of Cura (slicing/printing application) because I generally trust defaults established by knowledgeable/experienced people. The first one eventually failed where the layers cracked/separated where the lugs engage the light housing.

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I noticed your version of the cap has the barrel a good bit thicker than the OEM cap, probably to make stronger in this regard (nice work there). Reading lead me to believe layer adhesion can be compromised by (1) not enough hot end temperature, (2) too much cooling, (3) larger prints that naturally cool more between layers, and (4) taller portions that are further from the heated bed. So when I printed the replacement #1 and then #3 ,4 I upped the hot end temps to 255C and 270C (default for that material in the program is 240C), disabled the cooling fan that will sometimes blow on the printed item right at/under the hot end (this is an option in the app), and put the printer in a cabinet to drive the ambient air a little warmer than it would be out in the open. All appear to have turned out fine. I'm not sure how to test/compare strength without testing to failure, so I'm just going to assume they are fine, which I'm not willing to do at 5 hours a pop and being low on filament. With any of them I can grab the two caps attached to the headlight housing and use them to pick up the headlight while oriented horizontally and shake it around...so they are probably good to stay intact when during normal use. Maybe the one which failed was a fluke and/or I did something to put undue stress on it at some point when doing test fitting, showing things to another NSX owner who stopped by, etc.
 
Wait...the headlight adjusters are improved? I HATE the ones on my 92. What changed?

What changed? The part number changed. lol

When I receive them I'll inspect/compare and report back as to any other/actual changes. I know all four of my original adjusters have the normal defect (bolt spins with the nut). That made it a real pain to adjust the headlights perfectly years ago. Then that adjustment became very wrong with installation of NSX-R suspension (increased rake points headlights down so they don't light up as much of the road ahead) and they're in need of adjustment again. New adjusters will be worth every penny in making adjusting not unpleasant, and doubly so if the design keeps the the defect from reappearing.
 
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... and wait for my improved (1997-2001) headlight adjusters (33129-SL0-N11) to arrive.

Wait...the headlight adjusters are improved? I HATE the ones on my 92. What changed?

After a 72-day wait, the adjusters are in!

There are two changes, both apparent without disassembly:
- The bolt has a black finish instead of galvanized (grey).
- The piece of plastic that the one end of the bolt comes out of has gained a brass grommet/interface between it and the bolt.

Disassembly revealed identical interiors. I found it interesting to discover that the nut inside is plastic - the metal tooth thing slips over that to engage.

The new ones twist significantly easier. Hopefully the different bolt will preserve this good function.

I would like to point out that if you are replacing all four adjusters, you only need to order two of this part, as two come per package.

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@Russ ,
Thanks. What software did you use to create these? I’m tempted to figure out how to eliminate the vents, since I suspect there is a reason Mother Honda made these units sealed and the LED companies are saying OK to run under dust caps.
I would note that the Honda caps are only designed to contain the connectors, which shouldn't generate any heat. With the stock set-up, all the heat is generated at the bulb. While the LED's will generate less heat overall (since they draw less current and are also more efficient) some heat will be generated in the dust cap instead of inside the lens, although it is continuous with the air outside the lens but inside the sealed housing.

But if the LED bulb companies say the LED cooling fans and fins are fine inside dust caps, you'd think they'd tested it. I'm surprised by that considering how much heat comes out of mine, but I'll go with their expert opinion. I'm waiting for a reply from Boslla. Edit: Boslla says their bulbs work fine up to an ambient of 221 degrees F (100 C).
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Hello Timothy,

Thank you for contacting us. Our LED headlight bulbs have good heat dissipation and can work normally from -94° F to 221° F. So it’s okay to install with the dust cover on, Vents are not necessarily required.

Regards, Julia Boslla Team
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Edit: I did a test with the bulbs on for 60 minutes in a housing with solid dust caps. The air inside the caps was barely warm, definitely not 100 degrees. The heatsink was hot enough that I played hot potato getting it out, but not that hot. I think I'm going with solid caps.
 
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