[Calico]

I have a problem figuring out with my 1 inch Pitch between thread, and I'm using Metric Project CNC.

can anyone give me an example which parameter on Mach I should change ?
formula ?

regards
cal

[Kipper]

Hi Cal, if you have 2000 steps per shaft revolution then divide that by 25.4 and that is your steps per unit. I think

[neilw20]

5mm pitch is 0.19685"
5.08mm pitch is 0.2"
2000 steps per rev on 5mm gives 0.1965"/ rev.
2000 steps per rev on 5.08mm gives 0.2"/rev
Now that just went a bit too far.
1969 steps per rev gives 5.00126mm. Error 0f + 0.0252mm / meter About +0.001"
1968 steps per rev gives 4.99872mm. Error of - 0.0256mm / meter. about -0.001"
How to solve this?
Change microstepping to 4000 steps / rev if you can.
Now use 1968+1969=3937 steps per rev and error will be smaller than you can measure. - 0.00001mm.
3937 is very close to 3937.007874 which is the ideal value.

[Calico]

Thank you guys,
but now I just check the pitch thread, it's 1/2 Inch. not 1 inch.

so I guess 2000 x 10 x 12.7 = 157.480315, should I input the whole digit into mach3 ? that's what my Iphone limit. is this accurate enough if my axis is 1800 mm long (1 meter 80cm).

now what should I do with the velocity and other setting.
I don't want to "loose steps" because of this velocity and acceleration, or this is nothing to do with loose steps ?

because when I change the accl and vel, the distance change also without changing the steps per unit.

cal

[Calico]

wow excuse me,
200 x 10 x 12.7 not 2000 x 10 x 12.7

cal

[TOTALLYRC]

I have a problem figuring out with my 1 inch Pitch between thread, and I'm using Metric Project CNC.

can anyone give me an example which parameter on Mach I should change ?
formula ?

regards
cal

Of course once you are close, you can go into the configure tab of Mach3 and use the distance setting thingy, It tells you to move the machine and then measure how far it actually went, then it tells you what to set the step per at. Mach will take a decimal in the steps per unit box on the motor tuning page.

The accel and speed are set depending on the ability of the motors and the drivers. Let us know what you have for motors, drivers,ps voltage and anything else that you can think of and we can give you some settings to shoot for. Just to get going, use 10 ipm or its metric equivilant and an accel of 2 in/sec/sec or its metric equivilent. This will get the table moving and then you can go up from there.

If the distance changes when changing the velocity and the accel and you don't make a change to the stepps/unit setting, then you have a problem. The only way that setting the accel and speed will affect the distance traveled is if you are loosing steps via gooing to fast and stalling the motors or having a bound axis.

Post what you have and we will try to help.


Mike

[Calico]

Mike,
thank you, as far as I remember the X and Y ballscrew are the same, it's 12 mm pitch, the motor is stepper motor nema 34 maybe and it's 200 steps.
I gues that's all I can recall.

according to the mach3 manual, the max velocity is limited by the max pulse rate by mach3.
if I use 25.000hz and 2000 steps per unit , max vel is 750.
how they come up with 750 ?
i guess this is my max setting.

the other Z ballscrew is 1/2 inch pitch. (12.7 mm)

other question, qould it be a problem using different velocity between axis's ?
during cutting ?

cal

[TOTALLYRC]

Mike,
thank you, as far as I remember the X and Y ballscrew are the same, it's 12 mm pitch, the motor is stepper motor nema 34 maybe and it's 200 steps.
I gues that's all I can recall.

according to the mach3 manual, the max velocity is limited by the max pulse rate by mach3.
if I use 25.000hz and 2000 steps per unit , max vel is 750.
how they come up with 750 ?
i guess this is my max setting.

the other Z ballscrew is 1/2 inch pitch. (12.7 mm)

other question, qould it be a problem using different velocity between axis's ?
during cutting ?

cal

Hi Calico, always glad to help.

25KHZ is 25,000 steps per second divided by 2000steps/unit = 12.5 units/sec times 60 sec/min = 750units/min

Run the mach3 driver test and see if your computer gives a nice line with few and small spikes. If it is good at 25KHZ then try one of the higher settings. Set it as fast as you need and can get a clean driver test. I am assuming you are using the pport. Driver test is located in the C:/mach3 folder.

Using different max velocities is not a problem because mach3 will only go as fast as the slowest axis when more than one axis is moving. Mach3 will also only take a feed rate that is less than the motor tuning speed setting, otherwise it will just go as fast as the motor tuning speed and no faster.

There are a lot of machines out there that are slower in the z, by a significant amount, than the x-y, and they work well.

[Calico]

Guys,
I think I solved my problem, thank you allllll

merry Xmas too

cal