7' X 4' Combi

[Ricardoco]

Ok today i put the Y to X registers in and fitted the bed to the registers, thats really all i can do untill the Y rails turn up and then I have the Z machined and fit it, so ive done one of those boring videos just to show the X axis moving on the twin rotating ballnuts and 2510 ballscrews, it is set on the conservative side at the moment and i may just leave it there, X100 input in to mach moves the gantry 1m so thats correct now..



Now that made you excited didnt it?? cmon admit it. ok it didnt me either..

By the way the irritating noise heard when the gantry changes direction is the Clamps holding the gantry on.

Rick

[Jonathan]

ive done one of those boring videos just to show the X axis moving on the twin rotating ballnuts and 2510 ballscrews,

Bonus points for filming the nuts spinning in the next video...

X100 input in to mach moves the gantry 1m so thats correct now..

Mach3 should be used in milimeters, not centimeters, so going from X0 to X100 (or just moving 100 from the current position) should move 0.1m, not 1m.

[Ricardoco]

Bonus points for filming the nuts spinning in the next video...



Mach3 should be used in milimeters, not centimeters, so going from X0 to X100 (or just moving 100 from the current position) should move 0.1m, not 1m.

Ok I will upload the one with rotating Ballnuts when i get the A/V sync sorted, and how would you correct the measurement issues.

Rick

[Ricardoco]

Bonus points for filming the nuts spinning in the next video....

Ok not a great movie i know and the audio was rubbish so i had to substitute it

Mach3 should be used in milimeters, not centimeters, so going from X0 to X100 (or just moving 100 from the current position) should move 0.1m, not 1m.

Ok let me see, its showing 100 on the DRO when it is moving 1000 so that is a 10th so steps per in motor tuning should read 200 x 10 = 2000 and then X100 should move the gantry 100mm yes?

Rick

[GEOFFREY]

Vids not boring, pics look good. G.

[Jonathan]

Hard to tell from a video, but it looks to be running smoothly without whipping, which is good.

Ok let me see, its showing 100 on the DRO when it is moving 1000 so that is a 10th so steps per in motor tuning should read 200 x 10 = 2000 and then X100 should move the gantry 100mm yes?

If the step/mm value before, which caused it to move 100cm when commanded 100mm was accurate, then you just need to multiply it by 10.

There's a bit more to it though. You need to make sure that you don't hit the kernel frequency limit in Mach3. It's best if you can to use the lowest frequency, which is 25kHz. This means the port will output a maximum of 25000 pulses per second, so if you divide that by the step/mm value you get the software limited maximum feedrate. For example if it's set to 2000 step/mm, then that's 25000/2000=12.5mm/s or 750mm/min. If that feed-rate is too low, then you either need to reduce the microstepping resolution (e.g quater stepping instead of 1/8th) or raise the kernel frequency.

[Ricardoco]

Hard to tell from a video, but it looks to be running smoothly without whipping, which is good.



If the step/mm value before, which caused it to move 100cm when commanded 100mm was accurate, then you just need to multiply it by 10.

There's a bit more to it though. You need to make sure that you don't hit the kernel frequency limit in Mach3. It's best if you can to use the lowest frequency, which is 25kHz. This means the port will output a maximum of 25000 pulses per second, so if you divide that by the step/mm value you get the software limited maximum feedrate. For example if it's set to 2000 step/mm, then that's 25000/2000=12.5mm/s or 750mm/min. If that feed-rate is too low, then you either need to reduce the microstepping resolution (e.g quater stepping instead of 1/8th) or raise the kernel frequency.

Ok i went to the workshop and in motor tuning ive set steps per to 20- Velocity to 3000 accl to 200, Oh im using metric, now when you type in X1000 the gantry travels 1M so that much is correct but im not sure it is the only way to do it the drivers are on the lowest setting which is 200 per rev. with four people sitting on the gantry it dosnt evn know you are there..

Rick

[Jonathan]

ive set steps per to 20 Velocity to 3000 accl to 200, Oh im using metric, now when you type in X1000 the gantry travels 1M so that much is correct but im not sure it is the only way to do it the drivers are on the lowest setting which is 200 per rev.

200mm/s^2 for the acelleration is very low. You should be able to get around 1 to 2 m/s^2.
The motion will be a lot 'smoother' if you use microstepping. I reckon you'll get around 8m/min, so that's 133mm/s. 200 step/rev is 20 step/mm, so 25000/(133*20)=9.4. So you can have anything up to 9.4 times the number of step/rev ... so try 1/8th microstepping.

with four people sitting on the gantry it dosnt evn know you are there..

The overall mass of the gantry doesn't make much difference to the feedrate you can get, it mainly affects the acceleration obtainable (Newton's 2nd law). Increase the acceleration and it will 'notice' plus the people will probably fall off which is an added bonus.

[Ricardoco]

200mm/s^2 for the acelleration is very low. You should be able to get around 1 to 2 m/s^2.
The motion will be a lot 'smoother' if you use microstepping. I reckon you'll get around 8m/min, so that's 133mm/s. 200 step/rev is 20 step/mm, so 25000/(133*20)=9.4. So you can have anything up to 9.4 times the number of step/rev ... so try 1/8th microstepping..

I set the accelleration slow while i was setting things up as i was affraid of missing steps in one of the twin steppers and it all getting out of shape but as you suggest i will speed that up, Ok so how do i set it up to use microstepping then, (I thought i was LOL)

The overall mass of the gantry doesn't make much difference to the feedrate you can get, it mainly affects the acceleration obtainable (Newton's 2nd law). Increase the acceleration and it will 'notice' plus the people will probably fall off which is an added bonus.

LOL that would be funny, if not for the fact i was one of them...

Was it good to see your ballnuts working then? and where are these extra points you said i could have.

Rick