Hi,

We have a small shop with a few cnc lathes + cnc mills.

We are in the process of learing the cnc mill as it was recently purchased. I am relatively new to machining.

While learning we use scrap metal we find around in the shop. Our regular jobs are with aluminum and steel.

I was wondering what would be the ideal material to be used while learning the machine ?

Ultimately, I was thinking of some sort of clay which could be shaped and hardened into the stock size we are working on. This would prevent us from ordering stock everytime we want to test and learn on a new part. This would probably be cheaper as well.

Is something like this available ? What would you recommend we do ? Any suggestions ?

Again, I am new to this so I apologize if this question is not realistic.

Thanks,

Fred

Is'nt there some kind of machining wax that the jewellery industry uses for molds etc?
Al

You can use particle board, cut's really nice, there is a commercial machining type but I would guess reasonably expensive just for learning, you can glue up pieces if you need greater thickness.

Ken

Wax is one of the most common prototyping/learning materials. It's about the same price as aluminum, but it's re-usable if you recover it. Also, tool wear is pretty much nonexistant.

Also good for prototyping is foam, such as HDU. Wood sometimes works as well, but all 'prototyping materials' will give you one problem. They don't demonstrate the real chip loads and how it affects cutting in the real material. This will show up as chatter, premature tool failure, broken tools, and poor surface finish when you switch to the real materials.

Once you're fairly comfortable with machining, aluminum is a good medium to prototype in for the above reason.

I was wondering what would be the ideal material to be used while learning the machine ?

Blue styro from the home building supply stores - cuts fast and smooth - but makes a heck of a mess - don't suck it in yer lungs either, but cheap and available. Glue it up with white glue I suppose - resins, acetone, etc will eat it.

I went to the craft store with my wife and bought some of that grey foam that they set flowers in. It's pretty firm, and has a small grain. You need to use a shop vac with it but it's really cheap, and cuts well. That machinable wax I have seen in the Travers catalog is big bucks. Might as well use aluminum.

I can't see anyone recovering wax chips, melting them down and reforming them. Sounds like a PITA.

For learning and testing?
Use wood.

--Sven

why dont you make a furnace that you can recast the scrap aluminum into
stock, for prototyping only