Hello, I am new to the forum although I read them a long time ago.
I will be honest, it is the 1st time that I am going to build something of this size and I have many doubts. I am an electronics technician and programmer, so my problems are in mechanical design.

I want to automate a certain stage in the manufacture of wooden pallets.



The distance between guides is 950mm and the length of the screw is 2000mm.


For this, I have an X axis that must move 3 pneumatic nail guns with its own Y axis with an approximate weight of 125lbs (57Kg).
The total travel of the X axis is 1215mm, having to stop at certain points to apply nails:




- From a rest position it moves 130mm and stops to insert the 1st nail
- Then it shifts 25mm, and inserts a 2nd nail
- Then it shifts 505mm, and inserts a 3rd nail
- Then it shifts 25mm, and inserts a 4th nail
- Then it shifts 505mm, and inserts a 5th nail
- Then it shifts 25mm, and inserts a 6th nail
- Finally it returns to the rest position traveling 1215mm.

I have read and searched in this forum and in google, but the classic examples and uses are usually "slow" machines, machines where the speed of the task is not important. In my case, I need it to be done in the shortest possible time, around 11 seconds at least.




Before going to the calculations, these are the pieces that I plan to use, but I'm not sure if I have sized correctly:




- Linear guides: HSR25 + HSR25CA

https://www.amazon.co.jp/TEN-HIGH-%E...al&sr=1-6&th=1

- BallScrew: SFE4040

https://www.amazon.co.jp/dp/B07LG7BB...08&sr=8-4&th=1


To calculate the torque and rpm of the servomotor I used these equations:

distance to travel = 1215mm
estimated time = 2.5sec
lead screew = 40mm

laps needed = distance / lead screew = 1215mm / 40mm = 30 laps
rps = (laps / time) = (30 laps / 2.5 sec) = 12rps
rpm = rps * 60 = 720rpm


I want to use a servomotor from the Teknic catalog, I took for example the following:
https://www.teknic.com/model-info/CP...del_voltage=75

Peak Torque: 1,383 oz-in (9.8 N-m)
Cont. (RMS) Torque: 323 oz-in (2.3 N-m)
Max Speed: 1770 RPM



Here my doubts begin, be patient with me please:


To calculate the torque I followed this video:




Inertia= Motor inertia + Screw inertia + Carriage inertia

-Motor inertia: 15.5 oz-in² (2.8 kg-cm²) value taken from manufacturer
-Screw inertial: I have not found such value, I assumed twice the value of the video, just to put a number = 0.002 oz-in-s²
-Carriage inertia: payload mass * load mass factor (not having the load mass factor, I assumed twice the example in the video)


So: carriage inertia = 125lbs / 386.4in-s² * 0.002 = 0.00064699 lb-in-s²




Now, with the sum of the inertias, I calculate the torque:

Torque = Inertia * Acceleration = (15.5 oz-in² + 0.002 oz-in-s² + 0.00064699 lb-in-s²) * (30 turns / 2.5sec)

I convert the drives to the same system first, using this page: https://www.magtrol.com/inertia-calculators/


Now:

Torque = Inertia * Acceleration = (0.04015 oz-in-s² + 0.002 oz-in-s² + 0.01035 oz-in-s²) * (12 rps / 2.5sec) = 0.25215 oz-in-rev => 0.25215 oz-in-rev * 2 * pi = 1.584 oz-in = 0.01 N-m




Are these calculations correct?
I feel that the final value is very low, even multiplying it by 10!

If I choose a smaller motor, its inertia coefficient also lowers, so again there is excess power? I am really lost here.


Also, could you choose smaller linear guides and BallScrew? for example:

- SFE2525: https://www.amazon.co.jp/dp/B07LG6CG...75&sr=8-2&th=1

- HSR15 + HSR15CA: https://www.amazon.co.jp/TEN-HIGH-%E...al&sr=1-6&th=1


I am currently in Japan. Due to the coronavirus, I cannot return to my country and this project arose, but I do not know the country as well, so I do not know where to buy these materials except for Amazon.

I would like to be able to make more specific queries, I apologize for the extensive post.
I will be very grateful to you with any help to choose the parts and to be able to calculate the motor to choose.

I will also appreciate your opinions when choosing. I would just like to keep the brand of the servo motors, simply because I like the option they offer to be able to have a graphical analysis of the motor response in real time. This will help me get a feel for what those numbers look like in the real world. That really would have helped me right now!