Very true.
Producing a working CAD drawing that can be turned in to a pattern or an etch takes a bit of doing for 3D parts you need to add shrinkage factors these change depending on the material being used to cast the item.?
For etches you have to flatten the part add bending lines which change depending on thickness of material and the level of distortion you need.?
I have lost count of the number of etches I have ditched and started again with.?
And if you want to just produce a 3D print all parts have interlock or be drawn from a solid as if it's just touching and unioned the printer will see two parts not one.
I produced our first kit in 1999 and I'm still getting things wrong on test etches and you would never know until you build the prototype.
Marc?
toggle quoted message
Show quoted text
?
Colin,
?
I think you'll find a major difference between a drawing of a loco even in CAD and what is needed for an etched kit. The 7mm Narrow Gauge Association has books of drawings but most predate home
CAD systems and were probably done originally by someone to scratch build a model. A lot of the ones published in NG&IRMR are proper works drawings. Both sources need treating with care, in the former case one doesn't know how much information the draughtsman
had and in the latter you need to watch what was actually built as opposed to what was designed. All of course, thanks to someone's, efforts far better than nothing at all.
?
Nothing like publishing anything for some further information to crawl out of the woodwork and make a fool of you.
?
Frank
?
?
?
I might be wrong in thinking this, but for me an 014 loco kit will need to have weight, I would guess that if I had a half decent computer and the Auto Cad programme I would have a
go at producing 7mm drawings to make up brass etched kits and to also make the masters for the 3D Cad?castings as well.
I think 014 has a lot going for it, and if I had the space then I would consider building a model in this size, One thing which I am surprised with and that is?the lack of?narrow gauge
loco and rolling stock?Cad drawings which are available (you watch, some one will come on here now and tell me where I can find them), but why stop there??as you are half way to getting an etch of that item done.
May be it is just me getting older and trying to cope with all this new technology.
----- Original Message -----
Sent: Tuesday, October 11, 2016 12:20 PM
Subject: Re: [O14] Re: The Stronalacher Saga
There was a kit actually for the Darjeeling Garratt in 7mm scale?and I have seen the etchings and resin castings, now in the possession of a friend and 7mm NGA member. ?BUT this was, I gather, one of just two test etches and has
never been released. ?If anyone can track ?down its heritage then the possibility remains!!?
?
