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Jul 2015

I would go for common ABS, although PC/ABS was used in the initial part. First of all because ABS is cheaper and secondly because you will have a hard time finding somone to print PC/ABS as it needs a very high printing temperature, which the least of todays FDM printers can archieve.

Additionally you can use the acetone on ABS to strengthen the part, this will improove the durability in the z plane mostly, but also inbetween all printed lines, so I’d definitely do that. However be carefull when handling acetone, it evapors at room temperature (like alcohole) and it’s highly flammable, any ignition source has to be moved away. You may find acetone vapor smoothing methods, but applying acetone with a paint brush works just as well and nearly as evenly (you have more control over what parts to smooth out and which are fine already). Also the brush method is a lot safer, because you work with liquid (visible) acetone, while the vapor may sneak through any small hole in your container to reach an ignition source.

Since acetone dissolves ABS, you can also brush on some acetone to two surfaces and just press them together, within a few minutes (sometimes even 30 sec) the two parts are chemically welded together, the created bond is usually even stronger then the 3d prints themself.

Painting ABS is very easy, you can use a primer, but usually that’s not necessary, any acrylic based paint sticks very well. I’d recommend to use spray paint as it spreads very evenly and the thin layers stick to ABS very well.

Especially if you don’t use any primer you should clean your ABS prints properly, use plastic cleaners and silicone removing liquids, both can be found in artists stores or hardware stores (basically any shop, that sells paint related stuff). It’s definitely worth the investment, to get a bottle of both cleaners, they last forever and peeling off the paint from your print would be very painfull.

ABS is available in a huge variety of colors, if you are looking for a normal black, you might want to get it precolored.

Using at least (!) two coats of clear spray paint is highly recommended, otherwise scratches etc. may damage the layer of color.

Feel free to ask me, if you have any other questions, btw ABS tends to shrink a bit when 3d printing it, I’ve used a scaling factor of 1,016 which gave me tolerances of less then +/-0,5mm.

The factor might be changed for your specific machine, printer settings and ABS. Color and composition of the ABS can have a huge influence on this factor.

Cheers,

Marius

I agree with Marius’ comments, and for your first attempt it should all print just fine in normal ABS, it’s a good material for the job. The more exotic materials can be trickier unless you have an all metal hot end.

I also echo that you are designing a replacement, 3D-printed part. Some parts will need to be identically shaped to the original for the parts to fit, elsewhere you have freedom to add material for bracing, or thin out points to ensure flex etc.

Acetone vapour smoothing could add a lot to your strength and appearance, but practise on a sample, it’s fiddly and an analogue process. Painting with epoxy, or smoothing with car body filler and then painting car paint, could also improve finish and strength

Thanks Marius, all this will help me and a lot of people I think

1 - I will go for ABS for both parts, and glue them together with Acetone. Making them stronger by brushing acetone on the edges is a very good idea (especially for the snap-fits which are the weaknesses of the design)

2 - For the front part, I will need to paint it, so I will probably sand it by hand using a sanding block before printing. Maybe using some bodyfiller, I gonna try to find one working good with ABS

I will let you know about the result, I hope it gonna work.

My only concern will be that the parts dont break when trying to insert them in the center console of the car, I will probably have to use a little bit of force for that :slight_smile:

Amazing help guys !

HIPS (High Impact Polystyrene) is probably a good choice here, similar temperature for extrusion as ABS, but VERY resilient and good for ‘snap fit’ parts.

PC/ABS is exactly what the Up! (Afinia, if you’re from the states) printer uses as its “ABS” filament. (Yes, I was with a company who got some Up! filament analysed and it is around 20% polycarbontate). PC/ABS is not hard to extrude, if an printer as basic as the Up! can handle it, most will handle it.

Personally I would investigate HIPS. Where I buy filament, HIPS is cheaper than ABS anyway, can be used as support material for ABS prints if you decide you don’t like it (dissolves in limonene). The real strong point for HIPS is that when printing snap-in fittings, they bend and spring back a lot more than ABS parts - ABS fatigues very quickly, a printed ‘buckle’ will always last longer printed in HIPS than ABS.