Scaling up parts

[Fkouch]

Hi Guys,

Does anyone know or have any reference of how I might go about enlarging parts to different scales. Say if I had a 1:24 part of a car but I wanted to copy it in 1:18 or 1:12 scale. What is the best way of achieving this?

Cheers

Farrokh

[MPWR]

Be more specific. What are you trying to do?

[Fkouch]

Umm..lets say you had a seat or dashboard in 1:24 but you wanted to make an exact copy of it in 1:18. Not including 3d scanning ( ), whats the best method of achieving this? Caliper measurements? Masking tape templates?

Cheers

Farrokh

[MPWR]

Depends on the seat or dashboard in question. What are you trying to do?

[drunken monkey]

i'd say make templates from what you're wanting to scale up (masking tape works....), copy them into a drawing program (scan, trace, whatever) and scale up the templates in there.

or you can do it the old fashioned way and measure fixed points for known distances and scale up for the main mass, then reference more points and begin carving.

that'd give you a starting point.
the rest is down to how well you made your templates, how you decided on your reference points for templates
i.e is it really useful to have a template of a surface when you want a solid?
and how good your sculpting skills are.
when making a master, your choice of materials also plays a part because of their behaviour and how well they carve/shape.
in some cases, you might want to make extra steps inbetween each stage of work so you are not working on the only example.

Learning to cast in silicon/resin helps..... but god help you, it aint cheap.

[willimo]

Originally Posted by drunken monkey

Learning to cast in silicon/resin helps..... but god help you, it aint cheap.

It ain't that expensive, either, particularly when you consider how much effort that first copy was!

All that advice is sound. If you were looking for a method that didn't require you to make it, bit by bit, from templates or measurements, the only way I can think of is a... um... I forget what it's called but it is a device that has a probe at one end, which is connected by a nice mess of linkages to a cutter, and scales the item up or down by a certain ratio (just like the drawing transfer device things that allow you to trace a picture, and it follows with a pencil, drawing the picture to scale). A device like this was used a while back for making molds and masters for models, when they would scratchbuild a model at a large scale (like 1:8) and cut a mold by this method to make the mass produce kits.

Your best bet, though, is to make it like Drunken Monkey prescribed.

[cinqster]

Originally Posted by willimo

It ain't that expensive, either, particularly when you consider how much effort that first copy was!

All that advice is sound. If you were looking for a method that didn't require you to make it, bit by bit, from templates or measurements, the only way I can think of is a... um... I forget what it's called but it is a device that has a probe at one end, which is connected by a nice mess of linkages to a cutter, and scales the item up or down by a certain ratio (just like the drawing transfer device things that allow you to trace a picture, and it follows with a pencil, drawing the picture to scale).

A pantograph! opcorn:

[gionc]

Originally Posted by cinqster

A pantograph! opcorn:

Willimo, buddy, register the phrase "which is connected by a nice mess of linkages to a cutter" and I'll pay rights any time I use it

I guess it's less expencive a 3dscan>proto service than bild/find a panthograph, BTW if you need to do it at home I guess one way could be extract sections: there is a tool (OK John I wait for the name, I forgot LOL) done like a linear assy of pipes that will replicate your shape, simply extract sections with the tool, design and scale them.

[klutz_100]

Originally Posted by gionc

there is a tool (OK John I wait for the name, I forgot LOL) done like a linear assy of pipes that will replicate your shape, simply extract sections with the tool, design and scale them.

Do you mean "profile gauge"?

[gionc]

Originally Posted by klutz_100

Do you mean "profile gauge"?

exactly!

[cinqster]

Originally Posted by gionc

exactly!

I've just bought a cheap one and it's rubbish as the rods are so tight that it damages anything you want to take a profile from! I tried taking it apart to adjust it!

Well worth spending the extra money and buying the best quality version IMHO.

The other day my father mentioned a website for a tool (like a 3D pantograph) that scales up objects and reproduces them using in wood using a router but I've not been able to find any more info on it so far.

One of my tricks to re-scale a part is to scan the object (in various elevations) and then output the scans at what ever scale change is required - it's an easy way to get important dimensions quickly without having reach for the calculator.

[Fkouch]

Thanks for the help guys. Looks like its the slow tedious template way for me! Although I might consider some of the more costly methods you suggested on later pojects.
Oh and I got a cheap profile gauge too, all the bloody pins fell out!

Cheers

Farrokh