tebee

He's Tebee!

In the software I use I can resize in multiple ways. I can include a part or a collection of parts in another part and specify the ratio of original size to current size. I can adjust the size when I turn it into an STL file .It's also a parametric cad so I could write a formula to calculate the optimum thickness based on the size of the part. I don't use this as I'm printing to multiple targets ( a couple of Shapeways materials , resin printers and FDMprinters ) preferring to adjust manually. I do normally design things for 4mm scale and scale up or down from there - I use more than the minimum thickness in most cases and can easily thicken a part when scaled down if needed. Tom

Now I remember the name and that I liked the layout, but have no recollection of what sort of layout it was or why it was good. Can someone please enlighten me ?

The Minitrix T3/dock tank 0-6-0t - Like I said it was designed 12 years ago , there are probably better chassis around now. It was originally on Shapeways, this is one of a batch of resin print one I did a few years ago. There is a side tank version I did later too. Somewhere I have a picture of the original Pugbashes, but after they got wrecked coming home from an exhibition. The van was in a minor collision when a car pulled out in front of it from a side street. The stock box containing the locos went flying across it and smashed on the dashboard.

For comparison, this is the 009 version

And another 3D print, this time on a Black Anna chassis This is also sort of a pugbash twice removed . Back in 1971 or so I did two 009 pugbashs to a Kerr Stuart Tattoo style loco with a bit of Bagnall thrown in. 12 years ago I replicated this as a 3D print, Now I've taken that 3D, design reworked it as an SG saddle tank

Well Thanks. The saddle tank is actually a virtual kitbash - the boiler/smokebook/firebox tank came off an On16.5 Hunslet quarry tank and the cab is off a pug or more accurately a pugbash I recreated as a 3D print. It was your locos that inspired my friend to nudge me and remind me that I'd promised him some similar ones 2 years ago when I was building a freelance OO layout and he copied me ! The good ol' Smokey Joe is not an easy chassis to design for the motor is high at the back and that clip is wide at a bad place for saddle tanks

Are 3D printed replacement bodies bashing ? if so here 2 of mine done to fit the Smokey Joe chassis. Originally done for a friend who's building a 00 freelance layout. If you want to pint your own they are on Cults 3D as paying downloads Tom

They also made a number of G scale steam outline models

You need a watch maker rather than a repairer - I had an uncle who was one, but he retired about 18 years ago and is in his 80's now - I don't think there are many left ! Resin - think people are referring to the fact that most resins tend to be on the brittle side. However there are specialist resins that are more resilient - this is one I've used - https://siraya.tech/collections/europe/products/tenacious-eu-1kg-by-siraya-tech

It's the support structure flexing slightly during the up and downs of the printing process. I put 6 heavy supports in to minimise this - 3 along each long edge touching somewhere strong but inconspicuous. If that doesn't cure it, increase the exposure slightly, so that the supports are harder and stiffer

This just popped up on Facebook Ferrocarril Central Argentino No.9 'Cordoba' Canada Works, Birkenhead, works No.218 of 1867

because it's semi-liquid it's getting squished outward in the build plates downward stroke, you get a little extra resin traped each time which then gets part cured. Eventually this extra resin slumps downward under gravity, forming the too thick layers.

My guess is it's not actually pooling but something similar, because it's a solid mass you can't get pooling a such. It's a transparent resin, so you need reduce the exposure due to UV bleed through from the layers below. But a side effect of this is that the last few layers are not exposed quite enough as there are no layers below. Coupled with the area being exposed reducing each layer as we near the apex, those last few layers will be underexposed, more liquid and sag a little under their own weight, before being squashed outward when the build plate returns to the bottom. As the build plate rises after the print has finished, those layers will sag again giving layers of increased thickness.. I'd solve this by making it hollow, angling it front to back by 30 degrees and putting supports along the valleys and edges only

Prepping things for print is a different skill from doing the CaD work