Ok first thing. Four Questions.
#1 how badly do you want to make handles for balsong knives.
#2 how much do you know about the the relationship of the blade to the handles and the overall geomentry of the balisong knife?
#3 how much experience do you have with a vertical milling machine or as a machinist?
#4 how much money are you willing to invest in your operation?
Once I get an idea of where you are coming from in the way of experience, I may be able to help with more specifics, but for the time being here is what I can offer.
Depending on the model, some small table top mills have the power to mill aluminum with relitive ease. $2,000.00 to $5,000.00
The one of the biggest problems with these types of mills is the amount of travel they have on the X, Y, and Z axis
You need to be able to make a complete mill cut without moving or repositioning the work piece.
For harder or more difficult materials, a bigger mill is needed. 10,000.00 to $20,000.00 and up some as much as $50,000.00
For any stainless milling you must have a coolant feed or the material will work harden and you will break mills left and right.
You can dry mill aluminum, but I don't recommend it. Using a coolant speeds up milling speed and cuts down on end mill wear and tear.
Coolants can be material specific,
get one that is suitable for all materials.
Also remember this, some materials are REACTIVE.
Aluminum is one of them. so is Titanium. The chips under the right circumstances can catch fire.
Aluminum dust plus Iron Oxide (rust) equals
THERMITE. The stuff that will burn through steel.
The biggest reason for using a vertical mill is the stability and the weight of the mill itself. It just doesn't move.
Also to get the power necessary you are talking about a 220 volt or a 480 volt machine. Getting that amount a electricty can be a problem.
Then there is the cost of your milling vise.
$500.00 and up. Figure on at least another thousand plus for tooling.
You will also need a small lathe to turn the small parts. $1500.00 to $5,000.00
Metal cutting band saws, $1,500.00 to $3,000.00
Wood cutting band saws operate at too high a blade speed to cut metel regardless of what the manufacture's say they can do
There are lathe-milling machine combos out there but one can run a minimum of $3,500.00.
The better ones will be higher.
You can easly have $30,000.00 to $40,000.00 or more invested before you make one set of handles.
If you make knifes already, then you may have some of the equipment already, if so great.
I make handles out of aluminum, brass and stainless steel. Each has its own unique problems when milling. Way to many to go into detail here.
Sorry I could be more specific, but I don't know from what level of machinist experience you are coming from.
I can tell you that it takes a long time to learn how to make a vertical mill do what you want, and you will ruin a lot of material along the way.
Been there, Done that.
If you are going to buy a vertical mill, spend the money! Don't try to make do.
It doesn't work out in the long run.
If I can help further let me know.
Regards to All
ChuckG