smart ForTwo 453 headlight dust covers for Novsight 22000LM LED bulbs

thingiverse

###Motivation I have halogen headlights in my smart ForTwo 453 and wanted something brighter. I decided to try LED ones. I could have sourced factory LED headlight assemblies for this car, but they are expensive, and the retrofit requires coding. Additionally, some drivers who had the halogen headlights and now have the factory LED headlights say that the factory LEDs are not significantly brighter than the halogen headlights. ###Searching for a solution Aftermarket LED it is then. The best LED bulbs I could find at a reasonable price are Novsight 22000LM H4 LED headlight bulbs. There are cheaper LED bulbs on the market, the problem is with the light pattern. The light emitting chips must be exactly where the halogen bulb's filament is supposed to be. The reason is that the headlight assembly, especially the reflector, is designed and tuned to maximize light output and beam shape for the H4 bulb, whose dimensions are standard. If the light source is off by a few mm, the light pattern will be wrong, and you will blind oncoming traffic. Many LED bulbs have this problem, but it seems that the Novsight 22000LM is well designed, the light pattern is very close to the original halogen bulb's, incoming cars do not flash me. It is also well made (solid aluminium body including the adapter ring, copper heat pipe). Yes, Novsight should pay me, but sadly, they don't. Guys, I could use a million dollars. Or a pair of H4 LED bulbs, from the Quick & Angry line. Family? One bulb? Not even one LED? Oh well. Fortunately, while these LEDs are much brighter than the factory halogen ones and they do heat up, the cooling is very good, so that the headlight assembly runs much cooler than with the halogen bulbs, while the lights are on, even for a longer period. The factory halogen high beam heats up the headlight to around 137°C max after a few minutes, the LED high beam only to about half of that. I measured both with a thermometer gun, from the front of the stationary car. While driving, the airflow will keep the headlight a little cooler. I did not measure either bulb's body, it is probably hotter. However, these - and most - LED headlight bulbs have a fan, to take away the heat generated by the LED chips, towards the back of the bulb. Unfortunately, the original halogen bulbs are protected with a watertight dust cover and the new LED bulbs are too long in the back, they do not fit under the dust cover. You need to change the dust cover. ###Alternative solutions - You could make a hole in the dust cover, so that the LED's fan sticks out in the back. I find that a bad idea since you lose moisture protection. - You could use lower brightness LED bulbs (still brighter than halogen), which have the exact same size as the original halogen bulbs. The fan is integrated in the middle of the bulb's body, instead of sticking out in the back. One problem with that is that the fan keeps the heat inside the headlight housing, instead of taking it away. It will survive, although I've read reports that the reflective layer inside the headlight housing might get damaged. Novsight has some 1:1 LED H4 headlight bulbs like that. I also saw another model: https://www.aliexpress.com/item/4000497767128.html. I bought a pair of these with 9006 shape, for a Toyota which has projector type headlights. The light pattern seems ok and my eyes find them as bright as these 22000LM Novsights with rear fans, but those Toyota headlights do have giant lenses in front of them. - You could use the brightest halogen bulbs you can find (Philips +150% or OSRAM or others), but a good LED is brighter. - You could use a rubber insert specially designed for LED headlight bulb retrofits. However, I could not find one which fits. This does not fit either https://www.aliexpress.com/item/32915204487.html , because in the smart 453, there's not enough space around the bulb, unlike the video they show. - You could get a closed dust cover, like the factory cover, but deeper. However, this would enclose the LED's fan and it would be working in a hot environment, shortening its life. If you decide that it is an acceptable compromise and will not melt anything, you need the 80mm inner diameter dust cover, like these: https://www.aliexpress.com/item/4000415182734.html. Make sure that you get a pair (two dust covers). I did not try this solution, maybe it would not fit well (the original cover is oval, this is round). ###Chosen solution In the end, I decided to design and make my own dust covers, specifically for these LED bulbs. They can definitely be improved, but they work for me. The dust cover is made of two parts, printed separately: - the inner part, which goes on the LED bulb's body; - the outer cover, which goes over the inner part and the car's hole. ###Left-hand drive, right-hand drive Due to the curvature of the car's design, the inner part is different for the driver side and for the passenger side. The outer cover is not different for the two sides. I have a left-hand drive car, but I'm certain that right-hand drive cars (in the United Kingdom, Japan etc.) have the exact same headlights, probably adjusted differently. However the 12V battery seems to be on the other side for RHD cars, so it always sits in front of the passenger. This means that for RHD cars (UK, AU, JP, others), the part "Inner part, for headlight far from the 12V battery.stl" is actually the one near the 12V battery, in front of the passenger, while "Inner part, for headlight near the 12V battery.stl" goes far from the 12V battery, so in front of the driver. ###Compatibility - Car: it works for the smart 453 ForTwo, most probably also for the smart 453 ForFour, electric or internal combustion. - LED bulb: the parts are designed specifically for the Novsight 22000LM H4 LED bulbs (bulb dimensions here: https://ae01.alicdn.com/kf/H1e94add1d83d4c9b9300af1706036882o.jpg). However, it might fit other LED bulbs, too. The bulb's aluminium adapter ring's diameter, onto which the inner printed part slides on, is 22mm. The biggest problem with fitting other bulbs would probably be the diameter of the fan. ###Printing Use an elastic material for printing. The only one I worked with here, is TPU. I do not know how it will hold up, especially around the LED bulb's body, where it probably gets hot. I installed the bulbs and these dust covers for a month now, and haven't noticed anything wrong, but the maximum driving time with the lights on (mostly high beam) was about 30 minutes. I did test them with the low beam on for about an hour, with the car stopped. The TPU neck on the LED bulb's body is not a structural support element, so if it melts a little - improbable - then it will seal the bulb even better. If you can find a high temperature filament blend that is reasonably elastic (TPU+nylon, TPU+PC, others), you could try it. This one seems resistant, but too hard: https://www.aliexpress.com/item/1005002661165151.html Maybe even PLA or ABS, or PC for temperature resistance, would work, but putting together the parts would be tricky and they would probably disintegrate from the vibrations/heat/cold. TPU is said to be hygroscopic, so it absorbs moisture from the air, more so than rubber. If this dust cover works for a few years, that's good enough, I can print new ones. The trick is to know when to print the new ones, which I don't. UV resistance is not an issue, the parts will stay in the dark, most of their lives. If you have connections in the industry, it would be interesting to injection mold these out of heat/cold/moisture resistant automotive rubber. It is probably not viable, economically. Let me know if you do make them, I'm interested in a pair. I printed drafts because I wanted to see how the parts fit onto the car, then I kept the drafts. Otherwise, it takes a really long time, instead of seven hours total. For the drafts, I used 0.3mm layer height, 10% infill, supports but no adhesion, printing speed 60mm/s, infill speed 80mm/s, outer wall speed 30mm/s, inner wall speed 60mm/s, enable retraction NO, on an Anycubic i3 Mega printer with TPU mod. It does work with the TPU mod well, when your TPU roll is full, but when it is less than half, it has to pull harder, and the filament becomes stuck. Do some TPU printing experiments beforehand. This was my first time. The filament dryer helped, but not as much as I hoped. If you have a printer capable of printing reliably with TPU, everybody recommends going slow, around 20mm/s or less. If you have experience with TPU, you will do better than I did. ###Assembly and installation - print the four parts: - 1x Inner_part_for_headlight_far_from_the_12V_battery.stl; - 1x Inner_part_for_headlight_near_the_12V_battery.stl; - 2x Outer_cover.stl; - do not fit the parts together yet, because it's difficult to take them apart again; - remove the supports from the printed parts; be careful around the small inner hump and the holes, to not rip material from the part itself; - use a sharp cutter to make a cut in the inner part's three holes, so that the car's headlight cable can be placed into those holes; make only cuts, do not carve away material, or you will make the cover less watertight; see these photos for the cut (rough draft): https://photos.app.goo.gl/XmQ3RAcsHwYjxCB19 - examine the new LED bulbs; observe that the LED bulb's aluminium body protrudes from its aluminium adapter ring, about 1mm towards the front; - take off the car's bonnet (instructions here https://www.evilution.co.uk/panels/453_bonnet_panel_removal.htm); you will see that the 12V battery is right there; - take out the old halogen bulb (steps and photos here: https://www.evilution.co.uk/exterior/453_headlight_bulb_change.htm); - take the aluminium adapter ring off the new LED bulb, by twisting repeatedly while pulling the ring off the bulb; use the included gloves; - install the aluminium adapter ring in the car's bulb hole, in place of the old halogen bulb; the wide tab must be facing upwards, and the longer cylinder must be facing towards the rear of the car; make sure it sits properly, the space is tight, but it should not wiggle at all; do not let the ring go, but check from the front, through the headlight, if it looks ok; - while holding the ring in place and not letting go of it, use your other hand to turn the spring up, onto the ring; clip the spring into place; this might be difficult, because this ring is thicker than a standard halogen bulb's ring; - pull the car's headlight cable out of the car's hole, as much as possible, but do not pull too hard; - pick up the correct printed inner part ("near" or "far" from the 12V battery for LHD cars, opposite for RHD cars), position it with the bulb hole cylinder horizontally towards the front of the car and the pointier part downwards; - push the inner part onto the installed aluminium adapter ring; push all around the hole material, so that the part slides well onto the ring; rotate the part a little, so that it matches the car hole's plastic lip as well as possible, all around; - look at the photos of the cut, again: https://photos.app.goo.gl/XmQ3RAcsHwYjxCB19 , squeeze the middle section of the installed inner part together well, so that the cut opens up as much as possible; keep it squeezed; - with your other hand, wiggle and push the car's headlight cable sideways into the cut hole, as much as possible, so that it goes from the outside of the part towards the inside; this was the most difficult step for me, due to lack of space for my hands; - now undo the squeeze and try to pull the squeezed walls towards the side of the car, over the cable, while keeping the cable pushed into the hole, until the cuts in the three walls are realigned, over the cable; - pat yourself on the back; - if it moved, push the inner part onto the aluminium ring again and rotate the part again so that it fits the car hole's plastic lip as well as possible; - pick up the outer cover printed part and push it onto the car's hole and into the inner part, as much as possible, without breaking the car's plastic; for me, it does not fit as well as I hoped, but it seems to be reasonably watertight: https://photos.app.goo.gl/ok3BPgEVm87UHzqKA - take the LED bulb and push it into the installed ring, turning right and left a little bit, until it doesn't go forward anymore; the LED's cable should be straight downwards; push and seat the cable into the groove for it in the cover's bottom inner edge; - check from the front, through the headlight, if the LED bulb's body protrudes about 1mm from the adapter ring, and if the LED bulb is positioned vertically; this is the optimal position for this LED bulb, in this car's headlight housing; - connect the car headlight cable plug into the LED bulb's socket, as tightly as possible; if you consider it necessary, insulate the connection, for example with rubber tape; - it would be useful to insulate the car's headlight cable inside the printed part against moisture, with silicone, but I don't think that it is necessary, and it would make changing the LED bulb difficult (when it's necessary); - preferably, use the included cable ties to fix the LED bulb's CANbus box to a non-moving part of the car; - go to a car service to have your headlights adjusted properly, by turning them in their rings, until the light beam cutoff is horizontal; or search an online tutorial and do it yourself, but a shop with proper equipment is better.