Here’s my custom two-piece gasket in focusing kits for 3030, 3535, 4040, 5050 leds. Shelf thickness 0.9mm - 1.5mm These allow you to find the best focus for each model with a 9mm reflector hole.
Two months ago I designed a custom two-piece gasket to fix all the issues with off-centre leds for Convoy, Unfortunately, Simon has taken zero interest in using these, so best I can do is share them so you all can make use of them. The centre piece remains fixed while the outer piece rotates with the reflector, this prevents risk of tearing the led off the mcpcb. This is the reason why Simon stopped using square gaskets.
I’ve changed the design slightily from this above.
You recommend printing with PETG, is the surface finish enough for the parts to move smoothly? Or did you rework them after printing?
I might consider printing them with SLA as a test.
With a round gasket there are 4 points where the sharp corner of an LED touches the smooth surface and scrapes off plastic over time, leaving plastic dust everywhere and widening the hole, making centering less and less precise. Minor drops/bumps immediately result in lots of new plastic dust, as the tiny contact point absorbs a significant portion of the kinetic energy, which goes into disintegrating the plastic. In a square gasket, the LED cannot rotate relative to the square hole, so no scraping, and the corner is tucked away in a corner-shaped indent.
Also a round gasket needs to fit exactly to the diagonal of a square emitter, which is almost impossible due to manufacturing tolerances (also some 3535 LEDs are 3.45x3.45). Also, the tighter and better the fit, the more scraping. A square gasket has more tolerance because there are fewer ways for an LED to move asymmetrically within a slightly larger hole, and any rotary motion causes the LED to align with the hole in a symmetrical way even if the hole is a bit larger.
This gasket won’t work with under 0.8mm shelf thickness because the thickness between the hole at the bottom and top would be too thin. Maybe it could be adjusted to work, but prints could become too fragile.
Earlier C8+ batches were only 0.6mm, now it’s at 1.1mm on the Osram flat white chips.
Hi, I’m new to all of this and planning to get the c8+ with cslnm1.f1. My question is do I need to get the reflector with 9mm hole only to use with this gasket? I’ve heard my combination is hard to center and focus the light properly so I am interested in printing these to try out later…
And what about the m1 host that only have 7mm smo reflector? Can these gaskets be modified to fit on 7mm hole reflector or it would not work at all?
I don’t have any 7mm reflector models to have a need to make them at the moment. These were made for Simon, but he’s taken zero interest so I haven’t gone further than the 9mm. I can’t just create them either unless someone shares the exact hole diameter. The 9mm hole isn’t 9mm, it’s about 8.88mm on the C8+ and a little larger on the L21B.
I actually stopped using these myself and created the normal square gaskets, they’re always better, but risks tearing the emitter off the mcpcb if one isn’t careful.
I wonder if this is fixable with some adhesive between gasket and MCPCB, which makes the gasket less mobile relative to the LED, and more mobile relative to the reflector. The difficulty is probably thermal stability.
This gasket requires the screws to be left loose to centre perfectly. I recently had an sft25r burn out because I hadn’t tightened the bezel enough to apply sufficient pressure for heat transfer. Simon’s thermal paste sets hard and so moving the mcpcb is an issue because ideally you should reapply the paste. I prefer to leave the mcpcb as is and crank the screws tight, then loosely screw on bezel with the fixed square gaskets.
For Simon, using my custom gasket would centre correctly with fresh paste and loose screws. He leaves them all loose anyway using his circular gaskets.
The custom gasket has 0.02mm tolerance on the inner piece and another 0.05mm around the emitter, so if the screws are tight or the paste has hardened it pulls it off-centre still. Not really an issue for the SFT40, just small LES emitters
When I’m selling heaps of these it’s faster to use the fixed gasket.
