80Views13Replies

Author Options:

CNC mill Q's? Answered

Papa is looking into getting a CNC machine for his business and asked me about what to get. I looked into it for a little while but really I have no clue what is going to be needed.

We receive imprints (negatives) of people's feet in a floral-foam like substance and normally clean it up a little and pour a mix of plaster into it to get a positive mold, which needs intensive course and fine sanding in a sink, (as well as adding things like metatarsal pads and other custom things depending on the order) and from that point the ordered material is vacuum formed over and the rest of the insert is made.


Because of the shape of the feet and added features, it seems like we could cut out the use of the heavy plaster entirely if we use a 3D scanner to scan in the molds and then mill them out with a very basic 3 axis CNC out of cheaper/more light material for the rest of the processing.

The question is, what equipment will be needed? I see some of the cheap 3D scanners are really nothing more than glorified webcams and fancy software, while (guessing the much better) laser scanners are pretty $$$. So how can we scan these imprints into the computer as a 3D file? And what are some good cheap CNC machines that can do the main 3 axises and enough to do 6 to 10 molds at a time?

Tags:cnc

Discussions

0
None
steveastrouk

2 years ago

Look around for real second hand CNC mills, like the old Hurco KM3, they'll be inexpensive, probably screwed for real metal work, but will accept G code via their serial ports.

0
None
-max-steveastrouk

Answer 2 years ago

So what about software? I need to get the scans, clean them up a bit (probably easily done with some sort of smoothing algorithm that does like a Z axis low pass filter simalar to gaussian blur filters for pictures) and then I guess a slicer program that coverts a cleaned up and edited 3D file into G code (?) and, well I don't know anything! What is some software that will do all this stuff?

0
None
steveastrouk-max-

Answer 2 years ago

MecSoft VisualMill has an Art milling package that will convert pointcloud models into G.

I think there are tools in Linux CNC too.

0
None
-max-steveastrouk

Answer 2 years ago

Is all G code universal? Can I select the appropriate can any software work with any mill so long as I get the settings right? (like can I select what type of G code in a simalar way to a file extension?) G code is really nothing more than lines of instructions telling the machine what stepper / servo motors to drive and when, correct? I know some CNCs carvers are different in what axises they use, and the prosional ones probably have all sorts of annoying proprietary G.

0
None
steveastrouk-max-

Answer 2 years ago

G is universal, there are dialects of interpretation of it which needs to be navigated. Many cam packages come with lots of flavours of machine specific post-processors, mine has that, and an editor.

0
None
-max-steveastrouk

Answer 2 years ago

Even between different types of machines (like 3D printersvs carvers?)

0
None
steveastrouk-max-

Answer 2 years ago

There are things called M codes that you can use with G codes, they extend the command set, and you can set up macro like functions, called "Canned Cycles" for specialist ops.

0
None
Yonatan24

2 years ago

Are you looking for something that can be powered by hand, or by computer software (hence "C")?

If you can do it by hand, try making (maybe) something like this:

I'm planning on making my own CNC machine, and it doesn't have to be so expensive... :)

0
None
-max-Yonatan24

Answer 2 years ago

Yeah, I am sure it can be made cheaply, but I think papa would just prefer to buy one that already works rather than tinker like me lol. carving out a foot precisely for vacuum molding is WAY too much work, like we do as much as 100's of feet per day! If the computer can do like 10 of them at a time automagicly that would be ideal.

0
None
rickharris

2 years ago

High price is always going to be result of quality machinery!

Low cost = more manual work to do.

So your options really are defined by your budget and a trawl round the obvious suppliers with that in mind is about all you can do.

A 3D router is probably cheaper then a CNC mill if your using the right materials.

Xcarve seem to get good reviews and price isn't all that bad.

The laser scanner you could make - see Instructables -

https://www.instructables.com/howto/3d+Laser+scanne...

You could use a copy router as the item is 1:1 from the plaster.

https://www.youtube.com/results?search_query=copy+...

The floral foam will CNC route very well as will hard wax - You can make your own hard wax and there are recipes on the web and here.

https://www.instructables.com/id/Machinable-Wax/

MDF is pretty much the next easiest to route and cheap. Use a round router bit to get a smooth finish.

Personally I like this none computerised solution to copy routing

https://www.instructables.com/id/3D-Router-When-a-C...

0
None
-max-rickharris

Answer 2 years ago

Were not trying to pinch pennies, just not spend thousands more for unnecessary functionality (like 6 axis carving) or end up with a piece of junk. Looking for decent value in other words.

I am uncertain on the hobby grade DIY CNC kits especially with the amount of tweaking necessary and longevity.

0
None
-max-

2 years ago

The less digital "cleanup" required on the scans, the better. (preferably no digital cleanup :P)