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The mass depends on pi * R^2 to determine the area of zero length. That times the length gives you the total mass and the simultaneous distance from the axial center.
The first moment of inertia I...

Pete,

Interesting pic. Looks like you have a longer than usual Z axis. the first table I build 4' x 8' had a 24 inch Z travel. I was doing a lot of styrefoam 3D models. I found it was much...

Have to say I'm not sure about the r^4. It seems your looking for the total mass of the cylinder regardless of solid or hallow, and the radius the mass occupies from the axial center. multiplying...

Hello Pete,
Your exactly right as I suspect I might eventually get into using high speed feeds and acceleration rates. I am using Linuxcnc which can handle quite high operating speeds due to it's...

These are speeds I can't imagine using unless trying to polish a metal surface and not take all day. Anyhow I plan on going with 2 Nema23 steppers (425 oz/in) on the Y, 1 of the same on the X and Z,...

You raise some interesting points I haven't considered much since my days of machining steel with a converted Bridgeport Mill. When I built the monster 4' x 8' router table mainly for cutting 3D...

No it was a 20mm lead screw but still vibrated. Haven't purchased the spindle yet. thought I might use my 2.5hp router to start with.

Thanks Peter,
Very useful numbers to think about. Can't imagine running at 200 ipm but this might be able to do it. To answer your question, the 8' lead screw was vibrating. I know the shorter...

Thank you Peteeng for your response. Hiwin's calculations are impressive however I previously built a 4' x 8' table with a 20mm lead screw with a 10 pitch on the Y axis. Very heavy gantry but at...

Once again, thank you for your mathematical analysis, very telling and convincing. It looks like a nema 23 or 25 with with less than 2mH inductance that could maintain at least 150oz/in at high...

Thanks a lot for this information. Looks like you are right in the sweet spot for my application. Could you resend the page for the nema 23 and 24. I can't make out the model numbers. Need to get...

I follow your reasoning on inductance. I think I'll look for a nema 23,24 motor with low inductance and use it to drive a sfu2005 ball screw on the x y axis .

Many thanks

Mactec54, practically speaking I think you may be right about whip. I bought a 16mm lead for the z axis and from the looks of it I can't imagine it not hitting resonance at higher speeds on the x y...

Thank you all for your input, very valuable. I don't have the motors yet as I am taking it a step at a time. I previously built a 4' x 8' table using 20 mm lead screws on x and y. Y limited me to...

I am building an 4' x 4' cnc router table for wood plastics and possibly aluminum (aluminum not a must). After all the reading I have done I come up with a lead screw of 16mm diameter (sfu1605) for...

I am looking to build two 4 foot by 8 foot cnc plasma cutters. I previously build a same size cnc wood router table using two 2692mm or 105.0 inch x 1 inch lead screws. Also a 10 mm lead. The load...