Printing small parts for car restoration

Has anyone got any experience or opinions on 3D printing small components for use on cars?

I am doing various jobs on my 90s BMW and a lot of the plastic parts such as trim fixings, screws etc tend to get brittle with age and snap or just disintegrate. Replacements cost a fortune if you can even find the part number. Would 3D printing parts be a feasible solution? Is the plastic going to be strong enough?

Any advise is appreciated.

Andy

Look at polymorph..? But not for places that get hot !

There are different types of plastics for 3D printing. Some stronger than others. Nylon filament is available and used for making gears.

Paul.

Andy

A few thoughts ....

Are you aiming to print the items yourself or get them made for you, and what sort of size are you looking at .

If you are looking for a bureau , I have a few friends who have used Shapeways , they provide a good service and online advice.

Home printing using filament FDM 3D printers is practical for objects that will fit within 200mm -275mm cubic build volume. 3D Printers with larger build platforms start getting expensive [unless you make it your self !}

The best material would probably be ABS as this can survive heat better and can be finished to a smooth surface.

You will always have a patterned surface finish with an FDM printer that will need work [post processing] if you want a smooth surface finish.

The Stereolithography 3D printing process will produce much finer results but is more expensive and is really for professional use ... or if you are really dedicated !

For ABS you need a printer with a heated bed and for best results an enclosed build space to keep the surrounding air temperature constant ~70C. This helps with curling and similar defects.

A number of cheap 3D printers only work with PLA filament,

If you decide to make them yourself then be prepared for a learning curve and occasional frustration till it comes right !

Steve

Thanks All

It's something I would want to do myself. I do know (basic) CNC milling and CAD so that should help.

I have considered 3D printing for a few years but could never decide if I could make genuinely useful objects with cheaper DIY printers.

Bear in mind that if you 3D print ABS by the FDM process it usually ends up about 70% as strong as injection moulded ABS parts even if made really well with great inter-layer bonding.

If you buy a higher end printer you could print in polycarbonate with various reinforcing fillers including carbon fibre - these parts are very durable- but the print machine and materials cost far more than ABS.

If you are doing functional repairs that pass casual inspection you could use 3D printed parts. If you are restoring toward a competition, 3D printing will likely not cut the mustard.

Stereolithography can make beautifully detailed accurate parts but the resin used is too brittle for say door handles. Might be OK for an interior vent or button cover but if someone belts it or touches it on a cold day it will likely break.

Underhood parts for prototyping are made every day in high heat nylon by SLS process, including intake manifolds and coolant system parts. They can not be finished to a gloss polish though, and are usually sand-like finish in off white colour. Very useful for development/ racing / prototyping but again not going to pass inspection at a concours d' elegance.

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Mintronics who helped sort the Alibre Atom3D trial have established a bureau for 3D scanning and printing. Things like parts for car restorations are one of their specialities. They could scan complex parts for you if required as well as print them.

I suspect you will want something with a finer finish than fused filament for decorative parts.

**LINK**

Neil

Thanks for the info - i am starting to look at printers now.

Hi Andrew,

I 3D print Jaguar X Type headlamp adjusters in ABS which deviate from the original design to prevent shearing across the Z axis - you may find similar issues with parts so some trial and error orienting the physical build will be required

ABS can be smoothed using acetone, this gives stronger inter-layer adhesion and smoother finish, again, some trial and error required

Have a look at Robox printers which crop up on eBay / Gumtree from time to time, US imports are just fine, no voltage issues just a mains lead change. Beware the earlier single extruder models have a tendency to leak, replacement heads are available ~£120 and there are a few other gotchas, nothing insurmountable

Hi Andrew,

Not sure where you are in the country, but look up the TCT show in Birmingham which is on later in the year. It's free to register for tickets, and there a re huge number of 3D print manufacturers there, including filament companies too. They do give out free samples and all sorts of materials and printers are shown.

PLA will degrade over time, ABS is awkward to print and gives off toxic fumes, PETG is the next best, so they say. I did get a sample (20m) of low temperature nylon... I expected that to need 240 deg + to print, but it worked at 220 and above.

Depends on what part you need to print of course, but there's loads of knowledge at the show, AND they usually are very helpful. Everything there from filament to industrial size scanners and metal printers.

Highly recommended and costs nowt.

Regards, Ian

TCT Link below

**LINK**

Edited By Lainchy on 31/05/2019 07:35:34

Thanks Ian - that looks like a great event. Andy