OT - but maybe less OT than most posts here.
Old car has the common enough plastic lenses to the sidelights which are screwed in place. Just a plain plastic (of some sort) moulding. And they are getting difficult to source new. On Ebay, they might fetch 50 quid or so.
I do have a perfect pair of spares, and was wondering about having them copied and a run of new ones made.
Any tips on who to approach? Any guesses as to minimum production run? Or any guesses as to set-up costs?
A classic application for 3d printers. They can do a stereoscopic scan of the pattern and copy it.
Optically clear finish matters with lenses.
IIRC most of the cost is in getting the mould made.
NT
Almost any injection moulding company.
How much do they weigh? Injection moulding machines are normally rated by the shot weight, which includes the moulding sprue as well as the part(s). As a general rule, the larger the shot weight the bigger the machine and the more expensive the moulding, both in terms of tool and material costs.
Minimum run will depend upon how much you are willing to pay per piece. For one set of mouldings I buy regularly, the minimum practical run is about 500 pieces. Any smaller run would push the unit price up and the total cost would be much the same as for the 500 run.
The biggest cost will be the mould tools. I haven't bought any of those for many years, but, unless technology has greatly reduced their costs, expect to pay several thousand pounds. This really is an area where you need to talk to an experienced moulder though. You might, for example, wish to consider a softer (hence easier to make and thus cheaper) mould material. They used to be known as prototyping tools, but I suspect prototyping these days is all done on 3D printers. The disadvantage of a softer material is that they wear out quickly, but that shouldn't be a problem if all you ever want to make is a few hundred items.
The one thing I would check is whether a copy needs to be certified as meeting the same specifications as the original and whether that is necessary to make it legal to use on the car.
Can you cut a plastic bottle to shape?
Vacuum forming?
I don't know but unlike Citroen, you will need to be sure the plastic used is UV stable as so much oof this stuff goes milky or brown as it ages. Brian
Acrylic is inherently UV stable. It is also inexpensive, available in optically clear versions and can be injection moulded.
Maybe you can get away with less clear for side lights?
For a steel mould tool, the cost is typically in the tens of thousands for the tool**. If not many of these lenses are being sold, £50 sounds really quite cheap, given the likely cost of the tool. Aluminium tools are much cheaper to make, but they don't last very long.
** My friend, who is an engineer, told me.
And your friend ain't wrong. I've designed for injection moulds, and the costs of making them are humongous.
Once made, the cost is pence per part.
Sadly, there's not one round the corner here in Balham. ;-)
So light I dunno.
Just to clarify, it is the front indicator lens on a Rover SD1. The later ones are amber - earlier cars white. But the two although looking the same ain't quite identical. So what I'd like is the amber shape made in 'white'. Which is more accurately clear plastic smooth on the outside but castellated in the inside. Which gives an opaque appearance.
500 would likely be too many unless very cheap. I was thinking I might shift 50 pairs maximum. Maybe less - much less. I'm willing to risk a grand - but no more.It's one of those things I doubt an MOT chap would pay much interest in - provided it appears to do the job meant at first glance.
Thanks very much Colin. Just the sort of info this group was once famous for. ;-)
Can they, for example, produce an ordinary clear lens?
These would have an upper selling price of maybe 50 quid a pair.
I'm happy enough to fund the making of them, but would need to at least recover the costs. The problem being plenty will say they'll buy a pair at such and such a price but then don't.
We did get some plastic brackets made up using 3D printing, but the results which looked excellent were nowhere near as strong as the originals, which were presumably injection mouldings.
If you need strength then FFF isn't the best tool. If its all you have then you can print your part in ABS and surface treat it with acetone for a bit more strength.
If that isn't enough you can make a rubber mould from the (printed) part and then cast new ones with glass filled resin.
On 29-Nov-16 1:42 PM, Dave Plowman (News) wrote: ...
....
Have you considered resin casting? That is something that can be done at home for minimal outlay and is well suited to short runs.
Can't acryllic be cast at zero pressure from precursors? I don't think it is as strong as tthe moulded form though. But the mould would not need any strength and would be quite cheap.
It might be interesting to 3D print a mould.
There?s also ?hand mouldable plastic? (Polymorph, Instamorph, ?), which I didn?t mention before because it tends to be translucent white rather than transparent, but it sounds like that might be OK.
Instamorph,
Can get that sort of thing from here too.
there's more interesting stuff which is really for animatronics and things like that and it's expensive.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.