[dck]

Good afternoon I'm from Brazil,

As I was checking hypertherm guides in order to have a good quality of plasma cutting the rate of acceleration should be around 40 miligees.

How can I do to know how many miligees of acceleration that my machine is?

Thanks!!!!

[Torchhead]

Look in the motor tuning . You have to set the acceleration in some way. It may not be in millig's for the value but get a conversion table MACH is set in IPS/sec units ut 40 milli g's is about 15 IPSec/sec There is a G window next tot he acceleration in motor tuning in MACH so you move the decimal 3 to the right (mentally) for milli g's. The number needs to go up the faster your feedrate so use that as a minimum for cutting at about 100 IPM . More like 80 to 100 millig's is needed for cutting thin material at 200 to 350 IPM . You table will do what it can based on weight and the motor torque you have. Acceleration is:
A - F/M (acceleration = Force/ Mass) to increase A you either have to increase the linear force to the load (push harder) or reduce the weight of the load. In plasma cutting acceleration is more important than speed high rapid speeds.

TOMcaudle
www.CandCNC.com

[dck]

I'm working on retrofit of a machine with cnc ANC 401, he has a top speed of 30000 mm/min and Acceleration time to 1800 milliseconds.

How can I do to know the rate of acceleration of this machine in miligees?


Thanks for listening!!!

[BTA PLASMA]

You will need to do a conversion. Hypertherm lists 40 miligees as all that's needed for quality cuts. But you have to keep in mind with their controller they are ramping down air pressure and amperage at the same time speed is ramping down. You wont find an ultra heavy gantry spanning 20 feet with a simple acceleration rate of even 40 (Like mach calculates ips^2). The conversion from miligee (Miligal or mGaL) to ips is pretty simple.

40mGal = 15ips2 (Mach acceleration rate of 15)

A simple metric conversion will tell you 30,000mm a minute equals 1181.1ipm (Great rapid speed), 1800 milliseconds equals 18 seconds.

Tables that use Mach can take advantage of CandCNCs DCC control that will allow the programmer to ramp down air pressure and amperage to achieve very accurate results with an air cooled plasma. Depending on the interface of the actual ANC 401 plasma system the acceleration may be great and it may give average results. It definitely sounds like it is a servo driven machine.

[brouser1]

take advantage of CandCNCs DCC control that will allow the programmer to ramp down air pressure

Can you explain this process?

[BTA PLASMA]

It is a different electronics and software package. Sold on CandCNC.com. One of the greatest advancements ever of open type source control

[brouser1]

It is a different electronics and software package. Sold on CandCNC.com. One of the greatest advancements ever of open type source control

BTA, I use this software but have never ramped or adjusted the air pressure. Can you explain your method & procedure?
Thanks

[dck]

Below is how I get it to calculate the acceleration miligees.

1 G = 9810 mm/s

30000 mm/min / 60 s = 500 mm/s

500 / 1,8 s = 277,77 mm/s

277,77 / 9810 = 0,028 miligees

Therefore the acceleration of machine is 0,028 miligees.




Below is the acceleration in seconds that the machine should have to have the acceleration of 0,04 miligess.

0,04 miligees x 9810 = 392,4 mm/s

500 / 392,4 = 1,27 s

Therefore, the acceleration of the machine in seconds should be 1.27 sec.


That's right the way it was calculated?

[zhivko]

You will need to do a conversion. Hypertherm lists 40 miligees as all that's needed for quality cuts. But you have to keep in mind with their controller they are ramping down air pressure and amperage at the same time speed is ramping down. You wont find an ultra heavy gantry spanning 20 feet with a simple acceleration rate of even 40 (Like mach calculates ips^2). The conversion from miligee (Miligal or mGaL) to ips is pretty simple.

40mGal = 15ips2 (Mach acceleration rate of 15)

A simple metric conversion will tell you 30,000mm a minute equals 1181.1ipm (Great rapid speed), 1800 milliseconds equals 18 seconds.

Tables that use Mach can take advantage of CandCNCs DCC control that will allow the programmer to ramp down air pressure and amperage to achieve very accurate results with an air cooled plasma. Depending on the interface of the actual ANC 401 plasma system the acceleration may be great and it may give average results. It definitely sounds like it is a servo driven machine.

I appreciate this answer - but would it be hard to put also metric conversion here? When we are talking acceleration I would like to know how to convert miligee (or mGaL) to m/s². Does anybody have the formula to post here?

[Torchhead]

1 inch = 25.4mm
1G = 386.1 ips/sec
.001G = 1 milliG = .386.1 ips^2
or i milliG = 9.8044 mm/sec^2
or 1 milliG = .0098 M/sec^2

or using the equation stated of 40milliG = 15ips^2:

If 40milliG - 15ips then 40 milliG = 381mm/sec = ,381 M/sec^2
therefore
1 milliG = .009525 M/sec^2 (slightly off because of rounding errors )

[zhivko]

1 inch = 25.4mm
1G = 386.1 ips/sec
.001G = 1 milliG = .386.1 ips^2
or i milliG = 9.8044 mm/sec^2
or 1 milliG = .0098 M/sec^2

or using the equation stated of 40milliG = 15ips^2:

If 40milliG - 15ips then 40 milliG = 381mm/sec = ,381 M/sec^2
therefore
1 milliG = .009525 M/sec^2 (slightly off because of rounding errors )

To clearify this further - maybe M could sound unclear for somebody - the iso nomenklature for meter is m - so is M thoughth to be meter? If yes is this correct:
1 milliG = .009525 m/sec^2 ?