CNC Router vs 3D Printer

[techhelpbb]

I own the following personally:

Heavily modified SoliDoodle 2 ($400) and an Up! 3D printer ($1,600).
A ShopTask Mill/Drill/Lathe with CNC retrofit (my own tinkering).
A small gantry router I cobbled together myself years ago.
Several small X/Y/Z axis robots made from Intelligent Actuator linear systems.
2 LPKF Protomats (older series with paste injectors no auto tool change).

If your goal is to make 'normal' parts out of aluminum you can use the 3D prints to make molds and pour aluminum into the molds. Cast aluminum...real cast aluminum...is quite durable. Though metal forging seems to have made it's way out of most school metal shops Mount Olive High School did have a casting sand forge until it was removed. That forge was used to educate high school students so I know it is age appropriate. I decided to take it upon myself to build my own forge at home. It really is not all that hard to make a standard small forge but it is an art and the tools are not as important as the technique. Luckily I know a very talented metal worker and she has been helping me out. In reality you can liquify aluminum cans on a barbeque just to make ingot. I am constantly tinkering on a vacuum forge as well but for the moment I can only liquify steel in small quantity.

As far as the durability of the 3D prints themselves. I disagree that they themselves are not durable. If you are clever you can make working gears with a 3D printer. There are many restrictions to this but it can be done. I find this device as invaluable as a tool for making oddly shaped parts for brackets and the fella I bought my Up! printer from was a NYC photographer who used it to make crazy mounts for the film industry in his quite normal 8th floor apartment.

The rigidity of most bridge (ShopTask), turret (Bridgeport style) and some knee mills is usually desirable over the gantry when milling aluminum is the core achievement. However the work handling size of a gantry mill makes them a perfect fit for larger and professionally production wise softer pieces. Odds are you wouldn't want a piece of 4'x4' metal sticking out the front and back of your bridge mill on an unsupported keyway so it only makes good sense. Also a grantry mill is a nice gateway to a plasma cutter table or sometimes the other way around. If hot jagged metal everywhere is an issue for you you might consider where you plan on using these tools.

As someone that contributes to the RepRap project and the SoliDoodle if you want something 'out-of-the-box' that just prints you will be spending more than $1,500. If you want something out of the box that could print something really properly high end in the industry right now you'll be spending easily more than $5,000. This is why making firearms on a 3D printer out of: nylon, polycaprolactone or ABS is sort of silly. You could easily buy the firearm for *way* cheaper than the printer most people are designing those plans with. So that is really more FUD than practical application.

I will say that if you want to learn how to build a 3D machine the basics can be learned from a 3D printer kit. You've got: slicing, G-code, M-code, backlash, injection rate, friction and PID loops. All sorts of things you can learn. All sorts of things you will be learning or your print outs will be: warped, twisted, ovoid and otherwise defective. My Up! printer is the sort that 'just works'. I rarely need to do more than level it and keep it in an enclosure I made for it. In fact sometimes I use it to modify my SoliDoodle printer.

Ways to contain the mess from routers and plasma cutters. Plasma cutter slag assuming the actual cutting arc issues are considered and dealt with are sometimes controlled by cutting on a water table. Plasma arcs will easily flash off any water that gets in the way of the torch. So yes you could be pouring 240VAC and 50A into a plasma cutter system with a torch moving above a piece of metal laying in a pool of water. Doesn't that sound comforting? Your work volume is small for your router so may I suggest an enclosure with a shavings tray you can remove at the bottom? Think of it like a bird cage with a metal eating bird.

I am personally quite serious about making plans for a CNC gantry mill with axis driven by FIRST CIM motors in a closed loop and compatible with a PC based CNC control like EMC2 or Mach3. I know it can be done and I intend to do it and produce plans to help others turn their old robot parts into robot making tools. I am not going to commit to an immediate time frame on this. Team 11 just got a Haas mill and for the moment my more immediate goal is to get them going with it and potentially a CNC lathe. If anything I will use the CNC gantry I am constructing right now as a gateway tool for them and potentially a starting reference for what I would like to make.