@pjoyce42: Sorry, all my development is in Autodesk Inventor. (I dream of there being a FOSS MCAD solution that can do the 10% of the functionality of Inventor or Solidworks that matters.) However, I am getting close to doing a full release of the files. I could release DXF files along side the Inventor files and the OpenSCAD files so you can experiment.
If you want a larger spindle, here is one idea. I am not a fan of the harder kinematics but it would work.
Not to discourage but Simpson has the potential to develop so many different (possibly catastrophic) vibrational modes that I worry about milling aluminum. I think it is worth an experiment. (I flash back to my attempt to mill aluminum on my MDF hobby mill. My fairly sturdy machine hit this natural frequency that caused the effector to oscillate by over 1/4". If you pushed with 200 lbf you wouldn't get a deflection like that. Hitting a natural frequency is bad news and in some cases can rip a machine apart. Think Tacoma Narrows bridge.) General engineering wisdom is to use one or more of the following techniques.
*Increase mass: This lowers the natural frequencies and reduces the amplitude of vibrations.
*Increase damping: This can remove vibrational modes altogether and will reduce the amplitude of those remaining.
*Passively Isolate: This is really just a specialized form of increasing mass and adding damping.
*Actively Isolate: As far as I know, no one has come up with a cost effective way to use an active control system to mitigate vibrations in a production machine. However, this has the potential to allowing a light, low friction machine to do unusual things like mill metal. However, however, the processing power needed to run a system like this would be outrageous along with the fact that reaction time needs to be a fraction of the period of the oscillation that you are mitigating. Assuming the hardware existed, the software would still have to be written. Hopefully, this will be an option someday.
As you can imagine that using any of the first three ways will reduce speed and/or increase motion control costs.
If you want a larger spindle, here is one idea. I am not a fan of the harder kinematics but it would work.
Not to discourage but Simpson has the potential to develop so many different (possibly catastrophic) vibrational modes that I worry about milling aluminum. I think it is worth an experiment. (I flash back to my attempt to mill aluminum on my MDF hobby mill. My fairly sturdy machine hit this natural frequency that caused the effector to oscillate by over 1/4". If you pushed with 200 lbf you wouldn't get a deflection like that. Hitting a natural frequency is bad news and in some cases can rip a machine apart. Think Tacoma Narrows bridge.) General engineering wisdom is to use one or more of the following techniques.
*Increase mass: This lowers the natural frequencies and reduces the amplitude of vibrations.
*Increase damping: This can remove vibrational modes altogether and will reduce the amplitude of those remaining.
*Passively Isolate: This is really just a specialized form of increasing mass and adding damping.
*Actively Isolate: As far as I know, no one has come up with a cost effective way to use an active control system to mitigate vibrations in a production machine. However, this has the potential to allowing a light, low friction machine to do unusual things like mill metal. However, however, the processing power needed to run a system like this would be outrageous along with the fact that reaction time needs to be a fraction of the period of the oscillation that you are mitigating. Assuming the hardware existed, the software would still have to be written. Hopefully, this will be an option someday.
As you can imagine that using any of the first three ways will reduce speed and/or increase motion control costs.