I will be doing some high speed machineing on this machine center. I am not sure how much though. I plan to do mostly aluminums and woods, but am designing to be a sturdy workhorse capable of handling steel and stainless as well. That is why I am going with a 7k rpm servo as a spindle motor to give me the option for rigid tapping and other options. I will be using a 2" wide timing belt to run the drive shaft on a 2:1 ratio. I have a air release cat 40 taper to automatically release and grab tools. Also I am hopeing to get 10k to 12k rpm comfortably at the tool. This machine center is in the "from scratch" stages. I have all the machine frame designed, and most of the parts fabricated. I have only ran into the problem of the electronic parts (what all pieces needed to drive servos), but thanks to some good responses here, I will be moving forward shortly. I had to stop fabrication due to motor mounts, and the electrical enclosure needed.
The gantry weight of 125# is just the gantry FRAME, not the drives rails, motors, etc. I expect it to come in around 160 - 180 pounds when complete. That is why I was looking at 1/3 hp dc motors for the axis drives and retrofitting encoders to the output shaft or drive shafts, to turn them to servos. I would prefer to ac motors and encode them to work as servos, but I have not found much information about ac drives. There are a ton of them out there, but no good explanation of how they work, hookups, etc. I prefer ac over dc for a hp and economincal reason, more power for less juice, and motors are far cheaper 1/3 the price.
I have the machine designed in SolidWorks, and this weekend I can generate some 3D models and post them if you like. You would be able to open them in Internet Explorer and rotate in 3D measure, etc. As a quick background note, I am the Engineering Manager at a medium sized fabrication plant. We have just about every cnc fabrication tool you can think of, from plasma's, laser's, shear's, turret's, brake's, mill's, lathe's, and on , and on, and on. I am good friends with the owner, so I have the benefit of using anything I need to build my machine (mainly cause he wants one too
, which is a project for later)
My plan is thus: I want to finish this machine and use the experience (and hopefully revenue) to build a larger 5'x10' machine mainly for wood routing, and extremely light machining on soft metals. I would like to incorporate a 4th axis and tool changer onto my bigger machine, but at the moment it is just wishful thinking.
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