First…is the Nomad the ugly stepchild of the Shapeoko? It just seems like there are a million posts/forums for the Shapeoko and practically nothing for the Nomad. I realize that fewer people have Nomads and alot the info crosses over both machines…but still…
Second, so if my Nomad serial number is 1500 does that mean they have only manufactured that many Nomads? If so, that provides a relatively small universe of other Nomad owners to bounce things off of. Also, I wonder who has serial #001? That one will likely be worth some bucks on Antiques Roadshow 20 years from now.
So I cut out the wrench and now I’m looking to cut my second project. I bought some 1/2" thick pine that I thought would be a good safe material to test. My goal is to (1) “engrave” a 4" tall “S” (college font) and then (2) cut a second one completely out. By engrave, I mean machine it about 1/8" deep. So if anyone can give me the speeds and feeds (S&F) for these two projects, I wouldn’t be mad. But I do want to figure out how to calculate them myself.
I’ve been reading as much as I can about S&F (including the Shapeoko Wiki that lists dozen of materials and the Nomad S&F chart that summarizes that info) and here is what I think I have learned:
I THOUGHT that every material (pine, brass, delrin) had a fixed industry SFM but the Wiki shows two entries for Delrin one with a SFM of 58.89 and another with 62.39. Is the reason why there are two different values based upon the cut depth? I found another chart (Destiny Tool) that listed Delrin with a min SFM of 800 and a Max SFM of 1300. Why is there a min and max? Should I be calculating SFM or is it a fixed number that I get somewhere?
The second “fixed” number that I thought I needed was the “chipload” and that the chipload is defined by the cutter manufacturer based on the material you are cutting. However, when I go to the Carbide 3D store and look at the 1/8" flat cutter (#102) it only lists the cutting diameter and length and the shank diameter. Am I supposed to ask Carbide 3D for a “chipload chart” (or is that what the Wiki is?). Again, back to the Delrin example on the Wiki…it lists two “chiploads per teeth”…so do I need to not only know the material but also the depth of cut before I can ask for the chipload?
So once I know the SFM and chipload for the material I want to machine, then I can calculate everything else, including the five variable numbers that are needed to plug into the CAM software (Depth Per Pass. Stepover, Feed Rate, Plunge Rate and RPM)? Just trying to figure out where to start and what is the first number I need to start calculating everything else.
The Shapeoko Wiki lists the following for Pine using the 1/8" endmill (#102):
Cut depth - 0.03"
Stepover - blank (?)
Speed - 4500
Feed - 72"
Plunge - 32"
SFM - 147.375
CPT - 0.008
MRR - 0.27
So am I heading in the right direction or totally off base?
Lastly, I bought the Edge Finder…what is it for, how do I install it and how do I use it? Again, the lack of documentation is baffling.