[onlyinutah]

I havent quite figured out the whole forums thing so please point me in the right direction if this is in the wrong place.

Im looking to build what I believe is a 3-axis mill for milling aluminum to a depth of 2-3 inches max on most pieces possibly a bit more. I am wanting to use this strictly for gunsmithing and making molds for composites. Im a certified composite technician and I understand the the composites part of what im wanting to do but want some questions answered that would save me some time from having to scour the internet for hours. I know everyone has their opinions but im asking more for facts!!! Here goes!!!

Most important question... Is it worth it? Is it worth building a mill? Can I get the same accuracy on a homemade mill as I would from one purchased?

Frame- If I wanted the most affordable yet durable frame what material would I use?

Spindle Motor- My goal is to cut Aluminum for composite molds and gunsmithing. What are the specs that I will need in a motor to get the power required to cut aluminum and to a depth of 2-3"

Accuracy- Im restating this because both composites and gunsmithing require accuracy, as far as I know. Is it possible to get accuracy to ±.001" for gunsmithing with homemade CNC's


I know there are many other aspects to consider but I wanted to start with the end goal in mind. I believe these are some of the more important factors beyond other aspects.

My goal is to do this on a budget. So if it can be done I'm hoping to do it! Im shooting for a budget of <$1500. I know many people arent fans of Chinese products but I've been using them my whole adult life and wouldnt mind using their products for a second!


In addition, could someone show me, PM me some successful homemade CNC's that most likely would be able to accomplish what I have in mind. If its been done no need to reinvent it. Right??



Thanks for all the help!!!

[awerby]

Most important question... Is it worth it? Is it worth building a mill? Can I get the same accuracy on a homemade mill as I would from one purchased?

[It's doubtful whether a home-built mill will hold the same tolerances as a good factory-made one, but some people have very well-equipped home shops and do amazing work in them. Most people here are building routers, not mills, which are easier to build and don't usually aspire to extreme accuracy. Mills for cutting metals need to be a lot more rigid and massive than routers intended for cutting woods and plastics.]

Frame- If I wanted the most affordable yet durable frame what material would I use?

[Cast iron isn't expensive, but the equipment required to produce iron castings can be. Short of that, welding something together out of heavy steel would probably be best.]

Spindle Motor- My goal is to cut Aluminum for composite molds and gunsmithing. What are the specs that I will need in a motor to get the power required to cut aluminum and to a depth of 2-3"

[The motor required to spin a very small cutter needs to be pretty fast, but the one used to spin a big one needs a lot of torque. There are spindles that can spin fast with lots of torque, but they tend to be expensive.

3" is pretty deep for a tool that's milling metal; most tools intended for that are 3" in total length or shorter. Small tools that put the details in molds are rarely that long, and you start to get deflection issues that interfere with accuracy as they get longer.]

Accuracy- Im restating this because both composites and gunsmithing require accuracy, as far as I know. Is it possible to get accuracy to ±.001" for gunsmithing with homemade CNC's

[Possible, sure. Likely, not so much.]


I know there are many other aspects to consider but I wanted to start with the end goal in mind. I believe these are some of the more important factors beyond other aspects.

My goal is to do this on a budget. So if it can be done I'm hoping to do it! Im shooting for a budget of <$1500. I know many people arent fans of Chinese products but I've been using them my whole adult life and wouldnt mind using their products for a second!

[Even Chinese CNC mills aren't that cheap, if you're looking for something that does all the things you mention above. It sounds like you should look out for an older CNC mill with an obsolete control that someone basically wants to get rid of, and will essentially give away or sell for its scrap value just to get their space back. It's conceivable that you could retrofit something like that with a new control and motors for somewhere around your stated budget.]

Thanks for all the help!!!

Andrew Werby
www.computersculpture.com