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### Author Topic: How to? Long accel/decel profile  (Read 6313 times)

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#### BR549

• 6,916
##### Re: How to? Long accel/decel profile
« Reply #10 on: November 29, 2012, 05:42:18 PM »
I think you would be better served with another solution.

Just a thought, (;-) TP

#### ger21

• 6,291
##### Re: How to? Long accel/decel profile
« Reply #11 on: November 29, 2012, 06:31:41 PM »
Is my math right? Off the top of my head, that seems to be somewhere upwards of 75,000 inches/minute? Accelerating at something like 600G? As 1G would get you about 125" in 1/2 second.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

#### Ya-Nvr-No

• 993
##### Re: How to? Long accel/decel profile
« Reply #12 on: November 29, 2012, 06:36:04 PM »
80feet per second = 960inches * 60 seconds = 57600 inches per minute
80 feet/sec = 4800 feet/minute * 12 inches per foot = 57600
54.54 mph

80 feet /sec = 2.49 G

Based on my Convert Program
« Last Edit: November 29, 2012, 06:45:53 PM by Ya-Nvr-No »

• 4,893
##### Re: How to? Long accel/decel profile
« Reply #13 on: November 29, 2012, 07:13:09 PM »
Black Powder for the accel. ....... and a Bale of Hay for the decel.
Not exactly sinusoidal, but it would be hard to see the difference.
Russ

#### Ya-Nvr-No

• 993
##### Re: How to? Long accel/decel profile
« Reply #14 on: November 29, 2012, 09:03:23 PM »
Assuming my math is correct:

80   f/sec   =   960   in/sec
5000   rpm   =   83.33333333   rev per sec

Assuming a   4   in dia pulley   12.5664   inch circumference

1047.2   in/sec
87.26666667   ft/sec
-------------------------------------------------------------------------------------
80   f/sec   =   960   in/sec
7500   rpm   =   125   rev per sec

Assuming a   2.5   in dia pulley   7.854   inch circumference

981.75   in/sec
81.8125   ft/sec

Good Luck
« Last Edit: November 29, 2012, 09:13:13 PM by Ya-Nvr-No »

#### ger21

• 6,291
##### Re: How to? Long accel/decel profile
« Reply #15 on: November 29, 2012, 11:05:27 PM »
You have to accel AND decel to a stop in that one second, so you need to go much faster than the 57600ipm. I guessed at 75,000. Accel goes up as well.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

#### Ya-Nvr-No

• 993
##### Re: How to? Long accel/decel profile
« Reply #16 on: November 30, 2012, 07:30:59 AM »
No doubt, Send us a video clip on first test. LOL

#### ger21

• 6,291
##### Re: How to? Long accel/decel profile
« Reply #17 on: November 30, 2012, 09:40:37 AM »
Not sure why this wasn't more clear yesterday, but if you're going half the ditance, the velocity just doubles, if accel is linear. So, it's 115,200ipm, accelerating at 96G. He wants an s-curve accel, so it will actually be higher than 96G, I've seen a linear stage accelerating at 3-4G, and it's so fast you almost can't see it move.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

#### Ya-Nvr-No

• 993
##### Re: How to? Long accel/decel profile
« Reply #18 on: November 30, 2012, 09:49:46 AM »
Guess I am lost by how you are getting the 96G's
115200ipm = 160fps = 4.973g from my convert program.
Help out an ole toolmaker. LOL

#### ger21

• 6,291
##### Re: How to? Long accel/decel profile
« Reply #19 on: November 30, 2012, 10:33:43 AM »
The online calculator I was using was broken (sort of. )
Your right, but you have to double it to get to 115200 ipm in 0.5 seconds. So it's a little less than 10G. Still pretty damn fast.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html