Changing scale (size) of a model?

[Ben Brown]

Hi All,

 

Apologies for a very basic question: I’m just starting to learn Fusion 360 with the end goal of eventually resizing some models I’ve found online so my local hobby shop can print them. One of the models I’m looking at is an assembly kit with ~50 parts in separate files. The original model is 1/64 and I’d like to scale it down to 1/72. If one were to reduce the size of each piece, would I have a fairly reasonable chance of having everything still fit together properly? I understand that some tiny details might be reduced in size to the point where they can’t be printed, but overall, is it as simple as telling the software to reduce the model size x% or does the way the software works make it far more complicated than that? I’m afraid I’ll start with something that fits together like a Tamiya kit and end up with a resized model that fits together like an Eastern European limited run kit.
 

Thanks!

 

Ben

[Austin 7 model]

Ben,

 

You wouldn't need F360 to do that. The slicer programme that produces the file sent to the 3D printer will do it for you. Although how you scale from 1/64 to 1/72 is way beyond my limited brain power!

I drew up the files for my Austin 7 model at full size. I didn't use the cad programme to scale them to 1/10, I used my slicer, Cura. That way I could print them at any scale.

 

Lee

[Ben Brown]

Thanks, Lee! I’ll check my math several times before I do anything. 
 

Ben

[ICMF]

It's easy to do and can be done in the slicer, BUT the tolerances for all the parts will become tighter, so you may run into some fit problems. 

 

Broadly speaking, going from 1/64 to 1/72 shouldn't be a major issue as it's a relatively small (proportional) change, but it will depend on how close the tolerances are on the files in question.  If they're designed with a tight snap fit, then making everything ~10% tighter may require you to file/sand parts to fit.  If the fit on the original model is looser, then you should be fine.  Or to put it another way, if the original parts are tight enough that a coat of paint could cause fit problems, then reducing the tolerances by around 10% will also probably cause problems.  There are no set standards, so it's up to whatever the original designer thought was appropriate.

[Dave Swindell]

14 hours ago, Ben Brown said:

with the end goal of eventually resizing some models I’ve found online so my local hobby shop can print them

Is your local hobby shop printing them just for you or do they intend to sell them?

Check the terms on which the models were offered on line, most are for personal private use only irrespective of whether free or paid for. You would need a commercial licence to sell copies.

[Ben Brown]

33 minutes ago, Dave Swindell said:

Is your local hobby shop printing them just for you or do they intend to sell them?

Check the terms on which the models were offered on line, most are for personal private use only irrespective of whether free or paid for. You would need a commercial licence to sell copies.

Definitely a good question to bring up. In this case, the shop just provides the printing service and the models would just be one-offs for my own use only. The shop does a lot of printing for the local gaming community but won’t sell copies of the models they print. 
 

Ben

[Stu_davros]

I found this online tool for rescaling: https://www.scalemodelersworld.com/online-scale-converter-tool.html

It's really helpful if like me, you hate maths.

I just plug the result into the transform tool of Meshmixer to rescale.