Upgrade? Chinese CNC Machine

[Carlb1058]

Recheck Y in a couple of places and in both directions
Reason for this is 62 mm doesn't work out to a normal pitch and you did say y was jerky.

I'm wondering if you have a loose coupling or similar ?

Just measured it at centre of table and the other end to original and still got 62??

Addon bit: Just re-checked and made sure all connections were tight and they were, this is where it gets weird again - using a spanner on the opposite end of the Y screw I turned it 20 got 80mm, turn the knob on the end of the motor and get 62 but if I try and tighten the grub screws up any more all I succeed in doing is bending the allen key????

[John S]

Is the knob on the end of the motor slipping ?

You need to sort this bit out first, try welding the stepper motor to the ball screw.









Just joking.

[Carlb1058]

Is the knob on the end of the motor slipping?

You need to sort this bit out first, try welding the stepper motor to the ball screw.

Just joking.

Welding - cool, now ya talking

The knob itself is on the motor that tight I'd break it if I tried to remove it so the only thing left is the coupling I might go tear the motor off and suss that lot out

[Carlb1058]

Y now equals 80mm on 20 turns and I've got one bent allen key

[Ricardoco]

Y now equals 80mm on 20 turns and I've got one bent allen key

Now your where you should be... thats cool it was the hardware(maybe LOL) not the electrics (maybe) All the clever ones are called john in one form or another LOL

Rick

[Carlb1058]

Now your where you should be... thats cool it was the hardware(maybe LOL) not the electrics (maybe) All the clever ones are called john in one form or another LOL

Rick

Rick,

Yep gettin' there, just uninstalled, rebooted, re-installed, rebooted, re-setup Mach3, rebooted, loaded the g-code for the 100mm X line and the 100mm Y line and get 102mm on both. . .

used stock settings of 400 steps, 2000 velo, 200 accel for both X&Y, Z is 400s, 700v, 100a

[Ricardoco]

Rick,

Yep gettin' there, just uninstalled, rebooted, re-installed, rebooted, re-setup Mach3, rebooted, loaded the g-code for the 100mm X line and the 100mm Y line and get 102mm on both. . .

used stock settings of 400 steps, 2000 velo, 200 accel for both X&Y, Z is 400s, 700v, 100a

its very odd because the measurements indicate that you have 4mm pitch screws.
Well at least they are both the same now.. LOL You can now try the math we talked about last night.. 400/ (cut length - tool dia) x input cut length= new steps per..

Rick

[Carlb1058]

its very odd because the measurements indicate that you have 4mm pitch screws.
Well at least they are both the same now.. LOL You can now try the math we talked about last night.. 400/ (cut length - tool dia) x input cut length= new steps per..

Rick

I'll try the new number (413.11 to the nearest dp) shortly, it's bucket'in down and the part time work I've got to keep me in toys keeps askin' me when I'm gunna do some so I best do some aye LOL

I'll let ya know how it goes. . .

[Jonathan]

its very odd because the measurements indicate that you have 4mm pitch screws.

The eBay listing indicates he has 4mm pitch screws and 20 turns moved it 80mm, which also indicates 4mm pitch screws as 80/20=4mm. So nothing to worry about.

The voltage readings are strange - should have got 5V or 0V, but nevermind as we now know they're set to 1/4 microstepping.

[Carlb1058]

(bit snipped for space)
The voltage readings are strange - should have got 5V or 0V, but nevermind as we now know they're set to 1/4 microstepping.

I didn't get anywhere near 5v, the readings I got were after atleast a dozen tests the first few were around the 2.7 - 3.2 range and they slowly dropped until they stayed pretty static at 2.2 - all three chips did exactly the same thing.

I wonder if it's worth just throwing an extra 90 bux at it for a board with dip switches etc?