Bridgeport Manual to CNC Conversion...

[sohcpwr]

thought I would chime in on the VFD subject since I have a step pulley head mill with a 3hp TECO L510 VFD. The info from the site i bought it froml was somewhat misleading, I thought you could connect an external braking resistor to it. Found out it had an internal one when it arrived and was in business... but spinning down from anything over 1800 with it set very aggressively will cause it to fault out. I guess it makes sense considering the size of the drive and typical braking resistors.





I will start a new thread for some questions about my setup instead of hijacking yours

[lt00273]

Where you guys able to get Mach3 to control your spindle if so how did you setup the motor?

[davek0974]

Yes, Mach 3 controls the spindle, it uses the 0-10v output from the CSMIO controller, this goes into the VFD for the motor. I have an encoder on my spindle for rigid tapping, it shows speed is accurate to within around +/-10 rpm, the encoder is not used to close the speed loop though, tried it and it was not as good as i hoped so went back to open loop speed.

[davek0974]

Started work on powering the knee with a servo, i plan to send it tool length offsets so i can retain full Z travel with any length tool, hopefully.

Got the motor mount fitted, hopefully get the limits and home switch fitted tomorrow.

[mactec54]

Started work on powering the knee with a servo, i plan to send it tool length offsets so i can retain full Z travel with any length tool, hopefully.

Got the motor mount fitted, hopefully get the limits and home switch fitted tomorrow.

That looks like a good plane, others have, done this also for the same purpose, of being able to adjust for tool offsets

[davek0974]

That looks like a good plane, others have, done this also for the same purpose, of being able to adjust for tool offsets

Yep, there's nothing new, i'm just following info from here and there, adding my twist etc.

Got a rough idea worked out for the M6Start macro to test, if it works i'll split it so in the M6Start it drops the knee for easy tool change and then in M6End it raises to correct height allowing for tool length. Thats the plan anyway.

[vmax549]

HIya Dave , IF you are using the Auto tool change mode it does not use the END macro just the Start macro.

Just a thought, (;-) TP

[davek0974]

HIya Dave , IF you are using the Auto tool change mode it does not use the END macro just the Start macro.

Just a thought, (;-) TP

Hiya TP, nah, i use the "stop & wait for cycle start" option, as i understand things that runs the "start" before it stops and the "end" when you press cycle start.

[davek0974]

Got the limits and home switch fitted today, moving switches and fixed cams so I could do it all with two switches
Top switch is limit and bottom is home.



had to alter my plan of homing to top as with the vise fitted the bed will crash...



All the way down, a lot of cranking....



Wired the limit switch into the loop, just the home to take back to cabinet...

[vmax549]

Hiya Dave, YES I understand that BUT you will never be able to walk away from teh machine IF you have tool changes in mind. You will always have to walk back to teh machine to hit {Cycle Start}.

OOOOOOPPPPPS I forgot you do not have an ATC at this point. Never mind (;-)

(;-) TP

[davek0974]

HIya TP, yes still manual TC for me, I doubt this build will see an ATC, it's not really that important more of a pleasure project I think.

Although, with the new (soon to be) powered knee giving me mega spindle/table clearance, and something like the TTS ATC tooling system and a power drawbar, I can now see how i could fit some sort of ATC in there

[davek0974]

I'd forgotten how busy it was in the cabinet



The knee axis servo drive will have go on the right-side wall i think.

Hopefully get the drive temporarily fitted tomorrow and powered up the day after.

[vmax549]

Where are you going to put teh 4th axis hardware Then there is teh Mill_turn hardware

(;-) TP

[davek0974]

Where are you going to put teh 4th axis hardware Then there is teh Mill_turn hardware

(;-) TP

Gonna need a bigger cabinet

If i ever go ATC, it will need a shoe-horn to get the stuff in it. When i was welding that cabinet up i thought it was way too big

Maybe i'll refit one day and make a wall-hung monster cab, will be easier to wire up than crawling about in the swarf and chips.

[davek0974]

Ok, got it wired and powered up.

Little snag to start with, i'm a bit rusty here....

When you take Mach out of reset, the servo starts creeping without command, anyone give a pointer as to where i start digging??

It does not creep for long as you get an ePid fault.

Thanks

[davek0974]

My fault - i had the encoder on A axis but the analogue out on C axis


Its running now, needs more tuning as it oscillates when it stops after homing.

Not sure what axis is best, the 2010 screen set seems to be set for XYZA but a good friend advised C axis was more aligned with the Z axis.

At least its alive

[vmax549]

You can always ADD a dro to teh screen. Mach Screen is your friend (;-)

(;-) TP

[davek0974]

Yeah, i'v already added my tool height setter DRO & reset button plus the spindle power meter DRO

The 2010 screen set is very nice but short on spare room.

I have also never had much luck with the mach screen editors, seem really awkward and klunky to use, so many ways to mess it up

[davek0974]

Axis now steady and pretty well tuned, gone for a relaxed speed - no point in thrashing the bevels etc.

Did an auto-set on the steps per, preliminary accuracy tests seem to show repeatability of -0/+0.02mm which think is pretty good for an uncompensated heavy knee. I could only test over 50mm as thats all my DTI will do so no idea yet what a long shift will do but most tools are within 100mm of each other so shouldn't be an issue i think.

Can move on to macro tweaking now.

[davek0974]

M6Start macro sorted, it works really well using measuring tools instead of real tools, I'll give it a go on a real job at the weekend once i've finished testing etc.

Its a most impressive add-on, she now has 350mm of clearance on the bed