Mick,
Soooooooo, does this mean water tank sides are printable ????
Ian
No for several reasons.
1st: Warp free requires some internal tricks and specific supports, your tank walls are too thin to do that easily if at all, I'd need to add the supports with breakaway points to minimize damage, I won't know where they are until I test print some panels. Then I have to get hold of you, explain them and get you to draw them and then run a new test print; we may have to do that six or seven times, possible for each type of panel. It's time consuming for you and me, time I don't have right now, plus you'll see how I support stuff internally
2nd: Cost, with respect you probably can't afford it and I certainly cannot afford to tie the machine and my hours up to do it. The BLP roof alone is near two weeks work and a couple of bottles of resin, add in the hourly rate and you're looking at a price tab of £4-500+ for the first roof. The signal heads were easy, small stuff done many times before, but even then we had to go through several iterations to get the final result that was workable. I was able to offset the 'true' cost as I used spare space on the build plate for other stuff whilst printing yours.
3rd: The tank parts are large, even if you resolved the warping and internal supports or even if just flat panels with bespoke supports, you're looking at 5-6 hours to print each panel, just no build plate time spare at the moment.
4th: Fit, getting 3D parts to fit together with tight joints is hard work, you can butt joint but the adhesive will fail over time, the resin is not a plastic that bonds well with most known adhesives. You'd need to design some sort of locking assembly or joint alignment aids, that takes a lot of testing to get it right so that the gaps marry up on each piece. Then you have to test print and make sure those areas remain stable and do not warp or deform.....on top of the main panel not warping or deforming.
Here's the EMD spartan cab, note beveled corners, lobes and sockets to aid alignment, even then this joint is a very weak spot and not something I'm happy with at all. The two highlighted parts are bespoke sacrificial support beams to aid printing, they're cut off the final product but are needed to ensure those edges print straight and warp free.
The top one is an inverse warp item, basically that top edge, no matter the orientation or settings would always bow upward, therefore the sacrificial support has an inverse bow that when printed becomes flat so that when you get to print the actual part the stresses are already neutralized. That simple inverse part took near on a dozen test prints to fine tune, alter the orientation in any axis and you're back to square one with a new inverse part.
There's over 50 iterations on the cab front to get it warp free and print all the detail, cab sides are over 20 and the rear wall is much easier and follows the cab front so only 5 maybe six iterations.
This cab alone is near three years 3D dev time and materials, time is never free so you're looking at something like £2k costs and now I have to redo it all with the new machine and settings I have found on the BLP roof.
Note slot in the rear of the nose, this interlocks with the cab front and pulls that face flat and square, without that slot the cab front bows inward, the cab sides (despite all the bespoke sacrificial blocks) still have a small bow inward, that'll get taken out with a thick brass floor to hold it all square.
The best way to print the cab and tank is one whole piece, takes a long time but you have no joints to worry about, the BLP roof could be broken down into three sections, it'd make dev time much easier and the final print much quicker; you can get all three sections on the plate in place of the one big one. I would have preferred that but getting a near invisible joint on the three sections would have been near impossible with all that rivet detail.
I still maintain that 3D is not the best medium for the water tank, brass sheet is, given it's size and form, there are some objects where 3D is not the right application.
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