Router losing steps. Solution needed. Will this help?

[cncbobuk]

Hi Jazz,
A few details to update you

The machine has rack & pinion drive to the x and y axes and 10x25 ballscrew to Z Y axis has 2 motors with the drivers connected to the same pulse/dir circuit. All motors have 5:1 reduction drive to the screw/pinion via toothed belt. Motors for X and Y are set to 1600 steps per rev and machine output set to 0.01042mm/step, the rack pitch is approx 4.15mm which is confirmed by the drive ratio and machine setting. I therefore calculate the maximum speed of the motor in rapid at 10000mm per min is 600RPM. Drive current is 4.86A. The motors are Nema34 type about 115mm body length They have 86BYGF 450B on them but a google search reveals only ads for machines no specs. The machine manufacturer reckon they have no details they can let me have. Hope this all helps.

I take your point about using Mach3, I'll be getting around to making the change asap. NcStudio offers no motor tuning facilities at all, it's not possible to alter the pulse duration.

I do have a USB driven breakout board for use with Mach 3 which has on board a PWM spindle control circuit and differential drive outputs for step/dir. I would like to make use of the PWM spindle control but have also been looking at the smoothstepper board which may mean better control. Any thoughts?

Many thanks again for whatever you can do.

Bob.

[JAZZCNC]

The machine has rack & pinion drive to the x and y axes and 10x25 ballscrew to Z Y axis has 2 motors with the drivers connected to the same pulse/dir circuit.

This needs explaining better.? Do you mean your just using 1 Step and 1 Dir signal to drive borh drives.? This is a Big NO NO. One reason is the drives have resonance compensation circuitry built into them and doing this just confuses the drives so they don't know which drive to apply compensation too. The net result is that one drive/motor can get thrown into resonance. Then you have timing issues thrown into the mix and this just results in all sorts of random and strange happenings.!!

Not saying this is the problem but it certainly won't be helping any if it is setup this way.

Regards the R&P setup then what size are the pinions, ie diameter not No teeth.?
Reason I ask is because from the 0.01042 per step then that translates to 16.672 pitch with 1600MS and with a 5:1 ratio this means a pinion diameter of approx 83.5mm and this means a small pinion size.!
With Module size then pinion size for same number of teeth increases which means your module size would need to be small to have diameter of only 83mm And I'd be surprised if it's less than module 1 and more likely to be Mod 1.5 or even imperial.? . . . All this makes me wonder if your actually set correctly.?

Regards the Smooth stepper then it doesn't have any spindle speed control built into it or really any real I/O capabilty's that you would use directly so this means using with a BOB. It's main function is Motion control which it does very well.
Regards USB then I'd steer clear of using USB to power the BOB as it's unreliable and if it as the option to use external power then do so.

If you want the Best Motion control card for Mach3 then look at the Cslabs Csmio-IP-M or IP-S products which blow the others away. They also have Spindle speed control built into them. DONT use BOB so take away the biggest hassle in any control box and provide 24V I/O which connects directly to the Unit thru nice DIN rail mounted connectors so very neat and industry standard. (See pic.)

[cncbobuk]

This needs explaining better.? Do you mean your just using 1 Step and 1 Dir signal to drive borh drives.?

Sorry I probably didn't make this clear. Y axis has one motor at each end of the gantry each driving their own rack. Each motor has it's own MA860H driver but the pulse and direction inputs are connected to the same output from the controller.

Regards the R&P setup then what size are the pinions, ie diameter not No teeth.?
Reason I ask is because from the 0.01042 per step then that translates to 16.672 pitch with 1600MS and with a 5:1 ratio this means a pinion diameter of approx 83.5mm and this means a small pinion size.!
With Module size then pinion size for same number of teeth increases which means your module size would need to be small to have diameter of only 83mm And I'd be surprised if it's less than module 1 and more likely to be Mod 1.5 or even imperial.? . . . All this makes me wonder if your actually set correctly.?

I assume you mean 83mm circumference??? if so you are correct, the pinion diameter is approximately 26mm I can only conclude the basic setup is right as when I do a simple full depth cut the produced dimensions are essentially correct.

Regards USB then I'd steer clear of using USB to power the BOB as it's unreliable and if it as the option to use external power then do so.

The board does have external 12-36v supply connection, it connects to Mach 3 via USB not parallel port.

If you want the Best Motion control card for Mach3 then look at the Cslabs Csmio-IP-M or IP-S products which blow the others away. They also have Spindle speed control built into them. DONT use BOB so take away the biggest hassle in any control box and provide 24V I/O which connects directly to the Unit thru nice DIN rail mounted connectors so very neat and industry standard.

I'll check them out, cheers.

[JAZZCNC]

Sorry I probably didn't make this clear. Y axis has one motor at each end of the gantry each driving their own rack. Each motor has it's own MA860H driver but the pulse and direction inputs are connected to the same output from the controller.

Ok well this is BAD news and needs sorting. Chances are this has been done because NC studio cannot use slaved motors. Mach3 does allow slaved motors and is what you need. This allows each drive to have it's own set of pulses which are controlled as one axis. Effectively you are slaving 2 axis together Ie: X with B or whch ever axis you designate to be slaved.

The USB device you have isn't just a BOB if it connects to the USB and doesn't have Parallel port. It's Motion control device that provides I/O.
So in this case then you could just connect this and use with Mach. It will need a Plug-in to work with Mach. How good it will be will remain to be seen but will get you going.? Also use the external supply don't rely on USB to power.
Do you have details of it.?

Yes sorry ment circumference and if this is the case then that's ok.! . . estimate pinion about 18T if it's Mod 1.5.? 20T if Mod 1.25

[cncbobuk]

Many thanks again for your assistance, Ill try the Mach 3 option as soon as I can get round to it. The board is freely available on ebay a version of it is here http://tinyurl.com/kpwfrel

Cheers,
Bob.