Precise Scaling

[Anonymous]

 Hi there! I'm really new to the 3d modelling scene and right now I'm working on a scale model of a roller coaster. I'd like to 3d print this design I have but I can't seem to get it in scale. The issue I have is that I need the width of the track of the coaster to be 27 mm, but after trying for a long time I can't figure out how to scale in such precision. Any help is really appreciated!

[RobH2 · Accepted solution]

There are a lot of ways to do most things in Max. This is one of them. 

The method you use depends on the geometry. Here is one way you can try. If you have two rails on cross ties you can make a box that is 27mm wide and put it over your track. Then group all of your track parts but leave the 27mm box separate. Now scale your track until it is the same size as the box you made. You may have to move the box over on top of the track group a few times. As you drag the Scale spinners if you hold the 'Alt' key, things will scale more slowly for better precision. Just keep playing with it until the part of the track that needs to measure 27mm is touching the outer faces of your box. 

Now that's a quick and "dirty" way to do it. There are more precise and precision ways to do it but it sounds like you are a new user so I wanted to keep it very simple. If this does not work, write back and get more suggestions. 

Also, read the Max 'Help' file. It's very good these days and is invaluable. Even as I've used Max for 23 years now, I still use it frequently. It can really help you with basic things like this. 

[Anonymous]

That will definitely work, thanks a lot for the help! Only issue now is that I have to scale my model down so much that it's unbelievably small and kind of annoying to work with, is there any way to make the model appear "larger"?

[RobH2]

I'm not sure I understand what you mean that it's small and hard to work with. I model many, many things for 3d printing that are in the 10 to 25mm range and I have no issues. Just zoom in to them and you'd think they were huge. It's kind of relative in Max unless you get too small (fractions of mm) or too large (miles). 

But, you could scale everything by 10 using 'Rescale World Units' under the 'Utilities' tab. That would make things 10X larger and all you have to do in the 3d printing software is set the scale to 0.1 and you'd be good to go. 

I might be misunderstanding your issue. Explain it more if I've missed your point. 

[Anonymous]

It's not a major issue, just a tad annoying. Everytime I use my scroll to zoom in, it zooms in a lot more than I'd like, and when I get close to my object, it fades away as if I was inside it. It's hard to explain, but don't worry about it, the main problem I had with scaling my object is solved. Thanks again!

[dgorsman]

For mechanical design work (especially when targeting 3D printing) you might want to switch to Fusion 360.  It has the necessary tools and precision for such projects.

[RobH2]

Try this keystroke:

Alt+Ctrl+Z

It will zoom extents and fill your screen with your objects. It's a fast way to get in there without rolling your mouse wheel. 

[The-Digital-Shaman]

Thanks for the tip with alt.

However, when I press Alt to more slowly scale, camera orbits. ^^

Is there an alternative method?

[RobH2]

Are you trying to Scale in the viewport navigation with the 'Alt' key? The 'Alt' method, as far as I know, is only intended to slow down the numbers in the spinner/number fields. Try that. 

[The-Digital-Shaman]

Do you mean the floating Transform window from under F12?

Indeed, pressing n holding ALT adds order of magnitude in precision when scaling via controls in that window.

I wish that also worked in the viewport.

In Maya one needs to change size of the manipulator and that affects the precision.