[airbrush]

Motor Acceleration...whats a good value to have?

I have nema 23 270oz motors on my machine. Image attached of current acceleration on all motors.

Was wondering what others have for their acceleration...every time i've watched videos of others machines there seems to be alot more of an ease in and out than what I have...was thinking mine might be a little to quick.

tips, advice welcome.

thx

[ger21]

Generally, the quicker the accel the better, unless your machine is shaking.

[PCW_MESA]

One thing to consider is that the smallest radius you can cut is V^2/A
so if you need high (and constant) cutting speeds (say for plasma)
the more the merrier (until as ger21 pointed out you get vibration or worse, lost steps)

[airbrush]

okay..thx.
I'm just cutting wood and generally never run it faster that 70 ipm. So will keep it as is I guess. Even when watching some of Ger21 videos on your machine the accel seemed slower that what i have..that nice ease in/out sound...

[mcardoso]

On my benchtop CNC (G0704) running AC servos, I have my velocity set to 1000 ipm and my accelerations set to 400 in/s/s (1G). It really punches when making rapid moves, but the cutting is so much smoother since it can spend more time at the programmed feedrate instead of ramping into and out of cuts. I think accelerations play more into cycle time than the top speed your machine can do, especially in modern toolpaths that have lots of short looping moves.

EDIT: This performance comes from overkill servos. You don't need this to have a machine that works great, but it gives an example of a machine working well with really high acceleration values

[ger21]

My machine is really slow. When I started buying parts for it 16 years ago, you couldn't just order whatever you needed like you can now.

I think my X and Y accel are set to 10.
For the new machine I'm building, I'm hoping to set the accel to at least 200.

[mcardoso]

My machine is really slow. When I started buying parts for it 16 years ago, you couldn't just order whatever you needed like you can now.

I think my X and Y accel are set to 10.
For the new machine I'm building, I'm hoping to set the accel to at least 200.

Isn't that the truth. My first build was 10 years ago and it was hard to find parts and information even then. It is amazing how much this hobby blew up.

[wizard]

As others have pointed out you generally want as much acceleration as possible. However you don’t want to loose steps.

okay..thx.
I'm just cutting wood and generally never run it faster that 70 ipm. So will keep it as is I guess. Even when watching some of Ger21 videos on your machine the accel seemed slower that what i have..that nice ease in/out sound...

Watching videos can be tricky because you don’t know what the G-Code is doing in a specific case. The velocity might be set low for a specific move or the machine might be interpolating multiple axises with one slowing things down. There are lots of reasons why a move might appear slow.

By the way somebody hinted to the idea that high acceleration might be good for certainty tool paths. This is true, but not every use of a router makes use of such tool paths. Sometimes achieving high feed rates is the better path to follow for productivity. The other thing to consider is the proper load per tooth which with high speed routers is sometimes hard to achieve.