E46 M3 cluster swap

[nando]

sure, lol. I get that at my local NASA supply store, right?

I don't think it needs to be terribly thick. maybe 1/8" or less. once you get some bends in the material it should be pretty stiff. I'll probably experiment with a few materials and thicknesses. thinking of making the mold out of an old cluster since it's already pretty smooth. should work fine for at least 1-2 uses. maybe make a prototype out of wood until I can figure out my material, thickness and method.

I'm going to get the wiring complete and tested in the car, get the black face glued and painted, and make the clear cover last. I still have to do final coding for the K-factor and fuel gauge calibration - I don't want to put a bunch of effort into a nice shiny clear lens and then realize the whole thing doesn't work at all. :p

[LJ851]

Fish tank cluster ? It could double as a heater !

[nando]

Fish tank cluster ? It could double as a heater !

lol. I didn't get that the first time I read it..

[nando]

Couldn't resist starting on this thing..



Already had most of the materials laying around. Might do the platen today, but its snowing :)

[nando]

Do work..





Definitely not perfect but this was just a test run to see how it works. I put zero effort into my mold, it's literally a spare cluster face i grabbed from the garage, wiped off, and taped to the platen.

I think i will want to use a thinner material, possibly 0.050". This was 0.09" and it didn't like some of the sharper bends. I could also leave it in the oven longer. You can see the crease where it didn't confrom to the "nub" for the trip odometer reset.

Optical clarity actually isnt too bad for a first try, the only problem i see is acrylic is hydroscopic, so you have to dry it or you get bubbles. I did dry it for at least an hour but it wasn't enough, it probably needs 4 hours at ~170f.

The rest of the defects could easily be polished out no problem. I didn't do anything to the stock face, which had some scratches but none of them appeared to take.

[UNHCLL]

You can see the crease where it didn't confrom to the "nub" for the trip odometer reset.

Could you sand/fill the OE hole for the reset on your "real" form and then drill a new hole where needed for the e46 reset pin?

Looks pretty good for a first shot Chris!

[nando]

yeah that's what I'm going to do. I knew this wasn't going to work the first try so I didn't bother to modify the original face. what I'm thinking is I'll put two "bumps" where the new holes will go so it sort of sticks out like the original did. I also need to trim the flange around the edge so mine conforms to the right shape.

next try I'm going to seal the frame that holds the acrylic a bit better and use modeling clay between the platen and the cluster face, to elevate it a bit and cover a few more holes. I also need a new shop vac so I'll probably pick one up, this was using my house vac which is problematic because it's full of dust.

then I'll dry the other sheet I have for 4 hours and leave it in the oven longer at full temp. I think the 0.090" will work as long as I can solve the bubble issue which just means there was still water in the extrusion. The manufacturer says I can also leave the film on during the thermoforming process which I may try to eliminate dust problems, but it means the film can't have any scratches or those will transfer to the form as well.

btw once it's formed the bends make it much stiffer than just a flat sheet. That will help if I need to go thinner as it won't be all that flimsy. It feels really nice in my hands, I think this is going to work perfectly!

[AndrewBird]

Rule of thumb for temp on the plastic is it should droop half its width. My guess is you didn't have it hot enough and it had trouble forming around. I formed a piece of 1/8" abs over a 4" tall mold and had no problems. Something as thin as a cluster lens shouldn't have any problem.

[nando]

Yeah, i figured it should have stayed in longer. It was drooping 3-4" but the sheet is 12"x18".

[AndrewBird]

Yeah, definitely not enough. It's actually pretty amazing how far it will droop before it tears.

When the plastic is hot enough, it will pull down into each one of the holes in your platen and suck down tight into ever sharp corner.

[Ray Smoodiver]

Awesome first attempt Gronholm!

[nando]

Yeah, definitely not enough. It's actually pretty amazing how far it will droop before it tears.

When the plastic is hot enough, it will pull down into each one of the holes in your platen and suck down tight into ever sharp corner.

I knew as soon as i put it down that it wasnt hot enough. I also have some gaps in the frame that holds the sheet i can seal up better next time. I'm not sure if the foam i used is closed cell either, could be losing vacuum there too.

[george graves]

That's a lot of work to make the push button work. Skip it. Use the stock e30 cluster glass, and if need be, house a tiny micro switch in a 3d printed doghouse kind of thing for the switch.

But I know where you are coming from. I do the same thing.....make it work till it's perfect.

[nando]

it's not that much work. I had all the materials except the pegboard and acrylic. I think I've spent maybe an hour or two on it so far?

there are two switches on the E46 cluster too, not one. it will bug me, and the other guy's solution didn't look good either (he tried to sand down the nub and fill it in, but it stuck out like a sore thumb). that nub is basically right in the line of sight for the fuel gauge too.

there's way, way more time in the rest of the stupid thing, why skimp out on the finishing touches? besides, I have other ideas for vac forming.. :)

[nando]

try #2..




the second pic is a close up of the "major" defects. see if you can find them.. there are 2. :)

I'm still considering this attempt experimental, but wow! it actually does have some defects, but once you put it on the cluster you can't see them. it basically looks just as clear in person as it does in pictures! It's not perfectly clean, I just wiped it off with a wet towel really quick for pictures after I cut it out.

I plan on making two more. I realized I could get around having to finish the inside edges of the cluster perfectly if I masked a small edge of matt black paint on the lense. Also, I need to raise the "mold" up about an inch so I can get flanges on it and probably support the corners a bit with some modeling clay or something. when I turn on the vacuum the "mold" flexes a bit so the produced part doesn't have as much of a curve as it should.

My "mold" is just a cluster lense that I cut the outside flange off (using a acrylic knife). For the hole where the E30 odo reset button goes, I drilled it out with a 7/16" bit and "filled" it in with a piece of clear packing tape. lol. I put a piece of tape on the other side too so the vacuum wouldn't pull it in. But in actuality because the mold heats up when you put the hot sheet over top, the air expanded inside the tape and made a small bubble. I just have to put it back on with less air inside next time.

This time I dried it for about 4 hours, and didn't notice any bubbles this time. But I do have a problem with dust. The manufacturer says I can leave the protective film on, so I'm going to leave the outside piece on next time and see if I can eliminate that. I ended up with what looks like a piece of wood in the middle of the lense, lol. you can't see it though.

for heat I think I actually wnat to do it semi-cool because it's less likely to transfer defects from the mold into the final part. It came up to temperature pretty fast, about 5 minutes with the oven set to broil at 320 degrees (the manufacturer recommended 320f as the optimal forming temp). I didn't even have time to use my infrared thermometer because after 5 minutes it was already drooping about 4". the only issue I had with forming this time is my mold was too low so I couldn't really get a good flange around the edges.

anyway, now I'm 100% positive I can make it work. I'm actually pretty happy with how this piece turned out, optically you can't see the defects but I know I can make it better and I only need another $9 sheet of acrylic to make another pair. That leaves room for more experimentation and screw ups.