When 1/2 scale a design, do you 1/2 scale bits?

Hi, I’m new to the CNC world. I have a design that is 30" x 12" drawing. I would like to shrink it to 11.5 x 4". The tool paths in original require 1/4" end mill, 1/2" ball nose, and 90 degree v-bit. I fear the original tools (other than 90 deg v bit) might blow out the 1/2 scale design. Is my thinking to use a 1/8" end mill and 1/4" ball nose a good try? If a 1/8" end mill does not exist, possibly try an engraving bit? I’m just looking for reassurance. Thanks,

Are you not calculating your own toolpaths? If you’re not you really should. Toolpaths need to be specific to your machine and your tooling. Using tool paths generated for a different machine using different tooling is simply asking for trouble. When generating your own tool paths you obviously generate them using the tools out of your collection that fit the project.

Hi Martin,
I used a learning module on you tube posted by vectric for Aspire. I followed the specs in the video for the drawing. I tooled using their suggestions in the training video for that design.
In the video they chose onefinity as the postprocessor. I am hoping the settings and tooling they posted are good. (For that is what I am using: Aspire and onefinity).
Now I want to modify that design to a smaller size. I feel confident I reduced the design in the 2D design in Aspire. I have only had the onefinity for three days now. I smoothed the spoilboard and created a grid on it. Now upward and onward!

So are you saying if I open the 1/2 scale drawing and open the tool path menu, Aspire will make the comparable suggestions? You can probably tell how new I am. If you know of any good resources to learn more I would appreciate it. I printed out the Aspire manual but have not digested all 419 pages yet.

You should always calculate your own toolpaths for projects you are completing. My comment, in general, comes from a number of posts that I have seen where individuals are wanting to download completed toolpaths to run on their machine. This is a mistake as it could create problems if your tools and/or machine are different at all from the machine/tools used in the original project.

In my opinion you are doing exactly what you should be doing to learn this stuff. Download the project, run through the tutorials, and then modify it to meet your needs. Once you have modified the project you will need to open the toolpaths tab and recalculate all of the toolpaths. Aspire will not make any change or suggestions to your toolpaths; that’s all up to you. You will recalculate your toolpaths using the selected tooling, run the preview and then determine if the selected tooling is adequate for the project. You may very well find that once you have downscaled the project your tooling may no longer lead to an adequate outcome. For instance, you may find that your 1/4" end mill is too large to provide the level of detail you are looking for. On the other hand it might work just fine. The bottom line is that you need to use the tool path calculation and preview functions Aspire provides to determine for yourself what tooling model is going to work for your machine and your project.

In terms of resources, Vectric provides many tutorial videos that I have found very, very useful. Mark Lindsay also has an extensive YouTube channel that provides excellent information and examples for learning this software and process. The Aspire manual as a printed document is of limited usefulness (at least for me). Aspire’s online help manual is a different story. As you probably know, in the Apsire program you can click on the ‘?’ button to bring up the help pages for the specific tasks you are working on. Getting help right at the moment that I am trying to do something in the software is always more helpful for me. But everyone learns this stuff in their own way and at their own pace.

Stay with it. It is frustrating at times and getting your head wrapped around the big picture process can be a bit time consuming. But it is so very worth it when you start to complete projects you really never thought you’d be able to pull off.


Thanks for the good advice. As I was laying in bed last night the idea of running a preview pop in to see the results before commiting. I’ve downloaded several sources of Feed and Speed recommendations and starting points. So far so good. Some concerns are what setting should the Makita be set at. I think I saw in a forum a statement that the Makita should always be set at 4. In one of the Feed and Speed documents it says to run the router for 10 min before any cut as to be mindful of the expensive bearings …
Today i will search if there is a published chart of makita settings and rpm. I never checked the manual so that might be a good place to start.
It’s all slowly starting to make sense. I just need time to let thoughts process and settle in. Testing bits and materials…
Today I plan just a simple v cut sign to say I did something as an ego boost. Then I will start testing bits on various materials I have to find the differences. I might find out that for my needs I am overthinking things.
I have a similar opinion about the printed Aspire manual. Very vague, talks in circles, …but as a newbie it seemed like a good idea to have a safety blanket of some sort.
Thanks for your time. You have helped me to go a step further in my cnc adventure.

To begin with the following information provides a pretty decent estimate of the speed settings for the Makita router dial settings:

1 = 10000
2 = 12000
3 = 17000
4 = 22000
5 =27000
6 =30000

These settings aren’t perfect and you can find slightly different numbers online. But using these numbers allows you to get a pretty good estimate of your ‘spindle’ speed as specified on your feeds and speeds charts.

I’ve never heard the rx to run the Makita for 10 minutes before making any cuts. I’ve been using the Makita for hundreds of cuts over the last three years and never run into any issues and I have never ‘pre-run’ the router. I do have a set of brushes handy for the inevitable day when they need to be changed.

Good luck and enjoy yourself.