New remanufactured aluminium surrey backlight just like the original ones

[stuart]

If its an original then it should be toughened and will say so in the lower centre of the screen. Normally its in a circular pattern and you have Triplex with toughened underneath it and three X`s in the middle. By reading the dots you can tell the date of manufacture.

Stuart.

[peejay4A]

Go for it Roger. If I can do it without breaking the glass then you'll easily manage it. A different story with the laminated windscreen for me though.

[Paul Harvey]

https://www.google.co.uk/search?q=triplex+glass+logos&client=firefox-a&hs=pan&rls=org.mozilla:en-US:official&channel=sb&biw=1920&bih=920&source=lnms&tbm=isch&sa=X&ei=L1aHVOKKLMv1UpXmgvgJ&ved=0CAYQ_AUoAQ

[ST TR5]

Hi All

This is the Triplex sign on my original window with the three x then toughened underneath

Incidentally it's on fleebay for top money which is reflected in its condition and delivered.

Trying to raise penny's for a new TR4 project I have my eye on

The reduced size of the picture has hazed the picture anyone wanting a clearer picture drop me a message

Cheers Sean

[Jimgreen01]

Don't know if anyone has noticed but Revival Motorsports are now saying the cost of casting made production prohibitive. They are saying they'd need 30+ to make it worthwhile. Bit of a shame. Any chance we could club together and get a group buy of 30 do you think?

 

https://www.facebook.com/revivalmotorsport

 

[AlanT]

I suspected that casting these would be expensive and tricky.

These days this wants to be made by CNC milling.

 

This will be more accurate, have less scrappage, quantity is unimportant really and you require no tooling.

 

Because of the length you may still end up making it in pieces which is a shame.

[Tr4Tony]

Hi

 

Originally made in 4 separate pieces and welded together also, which is why repair to bend frames is so difficult.

 

Regards

 

Tony

[AlanT]

As a production method, casting is finished in the UK. Too much health and safety.

 

It's OK in India tho':

 

Does this explain why you get crappy repro parts?

Edited April 12, 2015 by AlanT

[stuart]

I would have thought sand casting the 4 pieces wouldnt have been too tricky or expensive. It just needs a straight original for pattern.

Stuart.

[AlanT]

The problem is contraction. This is 1.8%.

 

On a squarish thing, about 6in long, casting off the original is acceptable.

 

But on a 4ft length it will amount to 0.9in. You will find it hard to live with this.

[Steve_B]

Contraction isn't a problem if you laser scan or digitize an original frame. A CAD system can then take care of the shrinkage and generate a program to run a CNC machine tool, that in turn will produce the patterns for the sand castings to be made from. It's pretty straight forward and most casting companies will either have this equipment or have access to it via their usual suppliers.

Cast parts will always be stronger than a machined equivalent.

 

Trouble is, this all adds to the cost, so it needs to be amortised over the number being produced.

Edited April 12, 2015 by Steve_B

[AlanT]

Not that it matters much on this frame, but castings are usually plagued by material defects like holes and impurity.

Cutting from billet will give a better part in every way.

 

You may be thinking of cast iron, which develops a tight skin, that helps to stop cracks.

[nickphuket]

I might be able to help. If you can give me accurate design details it's probably cheaper her in Thailand than anywhere in Europe?

[RogerH]

Hi Nick,

it may be worth your while going to post #1 pulling up the facebook page link and contacting Ben who was going to do the project in the first place.

 

Roger

[Tom Fremont]

I'm not at all sure it's possible to cast the backlight in one piece. I surmise that was why it was cast in (4) and jig-welded into one originally. Comments welcome, especially of the confirmation variety .

 

They do tend to last indefinitely compared to the lids, which are almost always a mess now. Terribly rust-prone in steel, bent, dented and ripped out at the moorings in alumin(i)um they're no picnic to make either, originally consisting of (5) pressings and that wonderful, compound curved stainless trim.

 

I have to say that prices for good ones still look reasonable to me.

 

Cheers,

Tom

[stuart]

Im sure they could be cast in a number of other counties quite cheaply it just needs the will to get one accurately measured up first.

Stuart.

[stillp]

What about 3D printing?

[stuart]

What about 3D printing?

AFIK Only currently in plastic.

Stuart.

[RogerH]

....you can get 3D metal printing done but you have to ask yourself the question - Why?

 

We are talking of some crappy cast parts that are welded together. to give a shape - not rocket science.

 

They can be fabricated out of steel but for what ST wanted casting was the best option.

 

Roger

[AlanT]

I would reckon the ONLY way to get these cast economically is in the East.

There is too much health and safefy, planning control, waste disposal and land cost here, for these games.

 

Also you will need to make a pattern. This is too big to cast from the original.

Making patterns is where a plastic 3-D printer would be most useful. But they are still a bit small for this job.

But it would beat wood-carving.

 

Having said that, these lights were cast in Bedfordshire about 18months ago:

https://flic.kr/p/oxSzfR

[stuart]

....you can get 3D metal printing done but you have to ask yourself the question - Why?

 

We are talking of some crappy cast parts that are welded together. to give a shape - not rocket science.

 

They can be fabricated out of steel but for what ST wanted casting was the best option.

 

Roger

There are a few steel rear frames around.

There used to be a casting company down in Hayle, I dont know if they are still going but the last time I was there about 15yrs ago they were Sand casting Bugatti blocks.

Stuart.

[stillp]

....you can get 3D metal printing done but you have to ask yourself the question - Why?

 

Low cost, no pattern needed.

I was at an exhibition last year where a company was demonstrating their ability to laser scan an object and 3D print a scaled replica. They can print metal objects, using a powder that is fused by a laser after each layer is printed.

I'll try to find the name of the company, but I think I lost it when I retired.

 

Pete

[Don H.]

3D printing is here, in polymers and metal, and additive manufacturing is expected to have big impacts on a number of industries. One of the areas is spare parts, where complex parts, expensive inventory, and logistics needs are driving a lot of high-buck equipment folks to look at it.

There will certainly be impacts on classic car parts, too. It's already starting. The July 2013 issue of Thoroughbred and Classic Cars had a tiny mention of Noble House, a Dutch Aston Martin Heritage specialist, who have been making plastic and metal parts since July 2011. The article mentioned a DBS airbox in plastic, steel DB4 door hinges, and a baffled oil sump. This is only one company, and by now I'm sure there are more.

Over the long term there will be many Triumph parts made this way, we can be sure. The technology is just getting started.

That said, one would guess for now that conventional tech could more efficiently make the Surrey top bits sing processes similar to how it was done originally. As Tom says, it's making the price of originals look not that bad.

[Steve_B]

If anyone's interested in learning more about low volume rapid prototyping, have a look at the following links. I have no affiliation with any of these companies, other than having used them all for a variety of different development projects over the years;

 

http://prototyping.arrkeurope.com/

 

http://www.3trpd.co.uk/

 

http://crdm.co.uk/automotive-rapid-prototyping-and-low-volume-manufacturing/

 

http://www.protolabs.co.uk/

 

For the Surrey backlight frame I'd still go with a 4-piece casting welded together, but the above would be good sources for the patterns.

[swood1]

FWIW I have been following this for a while. The one you see illustrated is actually made up from hand formed sheet sections and welded together, it started out as an outer skin only section for race cars. I dont see why it couldn't be cast as per original using the sand cast technique if someone was willing to donate an original for dissection.

Stuart.

With technology today you could actually use a 3D scanner on the original parts and backward engineer it