Home proximity switch activating, axis reversing but then moving forwards again?

[JAZZCNC]

metric

Ok well your motor tuning is setup for imperial.!

To set up correctly you need to know the screw pitch and the micro-steps set on drives. Divide the micro-steps by the pitch and this is your steps Per setting. If you have any ratio on the motor then you'll need to factor that in as well.

The velocity and acceleration you will have to set according to the machine by adjusting until motors stall then back them off 25%. Vel =2000 Accel=500 is a good starting point if you are unsure. If a router can't do those speeds it's not much use as a router.!!

[chillybo]

Thanks Jazz, The drivers are set at 1600 and the ballscwews have a 5mm pitch. I have a 26 tooth driver pulley and a 20 tooth driven pulley. So do I divide 26 by 20 which gives 1.3 then add it on to 5 = 6.3 so the calculation is then 1600 divided by 6.3?
Thanks again Chris

[Muzzer]

You will want to multiply the ratios, not add them. So 1600 multiplied by 1.3, divided by 5. So 416 unless I misread?

[chillybo]

So I tried my formula for the motor tuning and it seemed to solve my origanal problem (the awful noise and no movement when continuosly jogging or setting the homing speed percentage anything above 3%). Muzzer, when I altered it to your formula (with the resulting value of 416) the issues came back. Anyway changing it back to what I thought it's now homing nicely on X and Y, next job is to wire Z home proximity switch.
Just a thought though, perhaps 1600 divided by (5 x 1.3) maybe correct way to do it. Seems logical?

[chillybo]

That calculation also works and isn't far from the origanal value.

[JAZZCNC]

Thanks Jazz, The drivers are set at 1600 and the ballscwews have a 5mm pitch. I have a 26 tooth driver pulley and a 20 tooth driven pulley. So do I divide 26 by 20 which gives 1.3 then add it on to 5 = 6.3 so the calculation is then 1600 divided by 6.3?
Thanks again Chris

Come on boys think about it and what the ratio is actually doing.? . . . . If it was 1:1 then 1600 / 5 =320 steps to travel 1mm. But you have a larger pulley on the motor so the screw travels 1.3 revolutions for one revolution of the motor. Or put another way 6.5mm per revolution. So to move 1mm we need fewer steps per mm not more.

There is a long-winded formula in the manual but the 1.3 was correct but you need to divide the 320 by 1.3 or 1600 / 6.5 which gives 246.1538 plus load more numbers but that will work.

Now Chillybo, you need to know the Steps per setting isn't something you can guess at or set to any number you like because it's an exact calculation based on pitch and ratios etc so it must be correct or the machine will never move the correct distance or be accurate.

Mach3 does have a feature that will calculate the steps per setting for you and I suggest you use it when using belts as it works using the distance traveled.
Go into setting Tab and just above the Reset button you'll see it says "Set steps per unit" Click it an follow the instructions. You will need an accurate measuring device, a tape measure isn't good enough. If you have a set of Digital calipers use them or a very good steel rule at worst.
The more accurate you can measure the better it will be.

[JAZZCNC]

Just a thought though, perhaps 1600 divided by (5 x 1.3) maybe correct way to do it. Seems logical?

Didn't see that bit but yes that's correct.

[chillybo]

wow I got it right. I've got digital calipers and a digital height gauge so i'l do some measuring and use that feature in neccessary. Going to finish wiring z home tomorrow and I'l put a celebratory video of it homing on here. Thank you for being so helpful guys

[chillybo]

Moving home!