John Palmer wrote:Paul, I am very sorry to have provided information about a product that is unfit for your intended purpose. I did so in the misguided belief that the various retailers of the double roman tile sheets must be re-badging an imported product all manufactured in the same mould.
A reasonable assumption that I would have made so don't feel guilty about that.
As always caveat emptor.
John Palmer wrote:I must admit that when I looked at the photographs of Andrew's model of the Cheddar goods shed the ridge depth of the tiles did seem more pronounced than the ones I had been using, but I put this down to difference in finish - Andrew has aplied a much darker finish to his than I have to tiles on Burnham buildings.
Now that I have taken some measurements of tiling applied to Burnham building models I am forced to the conclusion that the product supplied by Ali Express must indeed be different from the one used on Burnham roofs. On the Burnham tiling sheets, the ridge pitch is 4mm (cf Ali Express 5mm) and the ridge depth is no greater than 0.5mm (cf Ali Express 1.7mm (!) - an enormous difference that is highly significant visually). I was surprised by this finding because, viewed face on, the Ali Express tiling looked identical to the sheets we have used and tiles of this design seemed too esoteric to attract the attention of more than one manufacturer.
Incidentally, I am suprised by your figure of 6" as the ridge pitch of the prototype tile. I don't have a locally made double roman to hand that I can check, but I suspect the tiles made hereabouts were to a wider pitch than that. 'Bridgwater' double romans currently advertised by wienerberger.co.uk measure 420mm X 340mm (16.5" X 13.38"), which is a bit bigger than your sample.
Don't forget that a Double Roman has ridge pitch half of exposed tile width so mine aren't hugely different to Wienerbergers
John Palmer wrote:
Far from being a meticulous modeller, I confess to being only too ready to accept certain dimensional compromises provided I find acceptable the visual end result. It is so in the case of the double romans used on Burnham. The sheets we obtained from Penduke Models we recognised as being somewhat overscale, but not to such an extent as to disqualify them, given the alternatives. The fact is that there is, to my knowledge, no source of 4mm scale double roman tiles that are dimensionally accurate (whatever that may mean, given local variations). That meant that we either had to fabricate extensive areas of roof tiling from scratch or we had to accept a dimensionally compromised commercial product. I opted for the latter, and have few regrets about doing so.
I am not fussed about dimensional errors of say +/- 25% but x6 depth is horrendous. I have seen Burnham often enough to know yours look OK and that is what counts. I look forward to seeing Cheddar again noiw it has more roofs!
John Palmer wrote:Further investigation indicates that the probable UK source of the double romans we have used on Burnham is Tasma Products. The URL for the relevant sheets is https://www.tasmaproducts.com/materials/plastic-sheet/embossed-plastic-sheet-a4-tile-00-scale. But note from the 'About us' web page of this seller that the company is a distributor, and that the diversity of products offered is such as to suggest that Tasma is primarily an importer, so probably did not produce the tile mouldings in house.
I will get some Tasmas in and cross fingers.
John Palmer wrote:So, it seems that there are at least two different moulds somewhere in the world that are being used to churn out double roman tile sheets, both ostensibly for the mythical 'OO scale'. One, for the tiles apparently available from Tasma, appears to be superior to the mould for those supplied through Ali Express, particularly as regards ridge depth. Both are dimensionally inaccurate for 4mm : 1' scale. Whether you are prepared to accept the compromise involved in using either product only you can decide.
My deepest apologies also go to Andrew if I have led him into buying an unacceptable product.