Velocity and Acceleration settings as well as table travel nos for a RF30 mill

Hey guys, after reading and deciphering the units (oh why oh why is it units/s for one and units/s/s for the other :headbang:)...anyway, do these numbers look reasonable? I'm using these stepper motors with 36v www.amazon.com/gp/product/B00QG2HPMM ste
The mill is a RF30 with 2500 MAX spindle RPM mostly used for cutting aluminum and HDPE. I came up with these numbers based on 20IPM for cutting speed for Aluminum. Acceleration is based on 4 in/s based on someone's suggestion. Just looking for a reasonable base setting here which I'll dial in as I get everything hooked up.

Velocity = 0.33 in/s
Acceleration = 0.06 in/s/s

Also, the table travel numbers- just to clarify these should be wherever you home the machine to how far the table will travel? So for the X axis if I home it where the spindle rests at the center of the table and I have 10" on both sides of the spindle I should use 0 and 10 as the table travel numbers?

If you home at the center of your table (are you using a home switch?) and you have 10" of travel either direction (20" toatal).
You can set it up many ways, use your preference. For example you can have your home position be X=0 and your positive (max_limit) and negative (min_limit) limits be 10 and -10, or you can set home=10 (and home_offset=10) and have a min limit of 0 and max limit of 20.

PS If those velocity and acceleration numbers you posted are what you are considering for the maximums, they seem rather low, especially the acceleration. (10-30 is more normal for accel.)

Thanks Todd! isn't 10 in/s/s 600 in/s, isn't that smoking fast? :ohmy:

600in/s IS smokin fast (36000ipm), But I don't think I ever said anything about that number.

The inches/sec number is your velocity (how fast it's moving).
The inches/sec/sec number is your acceleration (how quickly it changes speed).

If you have a machine that can move 10i/s (600ipm) with and acceleration of 1i/s/s it will take 10 seconds for that machine to go from stopped to full speed and it will take 50" distance to get up to speed.
If you use the numbers you gave of .33i/s and .06i/s/s it will take 5.5sec for the machine to accelerate from stopped to 20ipm, and nearly an inch of travel. (anything but smokin)

You know your machine better than I do, but 1i/s(60ipm) and 10i/s/s sound like more reasonable numbers for a starting point.

Sorry, I should've been more clear. I was referring to 10 in/s/s (600 in/s) because you said 10-30 in/s/s range for acceleration is more reasonable. I converted 10 in/s/s to 600 in/s and thought that would be too fast. I'll try 1 i/s and 10 i/s/s and see how that sounds/feel. Thanks Todd!

Several of the cnc routers I have set up use acceleration settings of 25i/s/s and 10i/s max vel. And those are very reasonable numbers for a router table. A milling machine might be better served with a max vel of half that but the acceleration should still be fine.

stioc wrote: Sorry, I should've been more clear. I was referring to 10 in/s/s (600 in/s)

10 in/s/s is _not_ 600 in/s

One is a velocity and one is an acceleration. Different units because they are different things.

Andy, thanks for the response - enjoy your YT videos. Anyway, I get that they're two different things basically a Yamaha R1 doing 190mph (km/h for you) vs. the same bike doing 0-100km in 3 secs. So they both can be described in the same <distance>/<sec> unit. Just trying to understand what I'm missing here.

My mill is pretty close to being functional and the values I chose for it are 0.35 in/s for velocity and 1 in/s/s for acceleration and they seem to work well.

stioc wrote: Andy, thanks for the response - enjoy your YT videos. Anyway, I get that they're two different things basically a Yamaha R1 doing 190mph (km/h for you) vs. the same bike doing 0-100km in 3 secs. So they both can be described in the same <distance>/<sec> unit. Just trying to understand what I'm missing here.

Actually, I am in the UK and my R1 does mph. (and tops out at 186 mph, apparently).

But, anyway.

190 m / h has units of distance over time.

0-100 km / h in 3 seconds has units of distance / time / time.

You are losing the /h in your 0-100km/h