Messages

671

General Mach Discussion / Diagonal Lines not smooth

« on: March 30, 2017, 04:18:14 AM »

@rcaffin

Mach3's tool path show's the wavy pattern inside the program. 

If the tool path shows the wavy lines it can only be a file issue surely? - not electro-mechanical.

672

General Mach Discussion / Re: New to mach3

« on: March 21, 2017, 03:24:08 PM »

Never used it, sure someone will chime in with an answer though:)

673

General Mach Discussion / Re: New to mach3

« on: March 21, 2017, 02:54:43 PM »

Not as far as i know, you need to get CAM to get it into G-Code first.

Maybe try SheetCam which is very good, Vectric Aspire is great, Fusion360 is complex but good as well as others.

674

General Mach Discussion / Re: pocketing issues

« on: March 20, 2017, 04:14:47 PM »

I would disconnect the PC and make sure the weld return lead is fixed close to the area you are welding.

675

General Mach Discussion / Re: What is this RPM Line

« on: March 19, 2017, 05:09:34 PM »

Is that not the line that shows rpm from an encoder input?

I think my setup uses that line and it varies with load on the spindle etc.

676

General Mach Discussion / Re: pocketing issues

« on: March 19, 2017, 04:22:04 AM »

Steps per will not be the issue - the will affect every pass the same and just alter the overall finished size.

What motor drives are you using - the current is usually set by little switches on them.

Maybe do a pen test - get some flat board on the table, tape of fix a pen, pencil, marker etc to the head and run the job on paper so its drawing the tool paths.

If you hold the head and push it gently in X & Y is there any movement or wobble?

Is it rack & pinion, belt drive??

677

General Mach Discussion / Re: pocketing issues

« on: March 18, 2017, 04:14:25 AM »

Sounds like you are losing steps on the drive - using stepper motors?

Could be a lose joint also, maybe too fast, too deep, not enough motor current and others.

678

General Mach Discussion / Re: Spindle for Drilling/Rigid Tapping?????

« on: March 18, 2017, 04:11:50 AM »

You need a powerful motor for rigid tapping - 3Hp+ anti needs to be slow not like a router, then you need some rotational feedback from the spindle, a motor controller that can rapid start/stop, a cnc controller that can do rigid tapping like a CSMIO-IP/A or S etc.

I did this on my Bridgeport mill and it works well but its not a router.

679

General Mach Discussion / Re: Mach 3 motor tuning

« on: March 17, 2017, 07:25:07 AM »

Horses for courses

Both are accurate if set up correctly, the difference comes when things need to get heavy and/or move fast - steppers + heavy + speed = bad times, Stepper + Light + fast = OK to a point.

Servos are a different beast completely - most of stepper torque is down way at the bottom end of speed range and maybe only 5% left at full speed, servos have a linear torque and will give full power from 0 to max speed, they are also capable of stopping and starting heavy loads as they have encoder feedback so they just do not lose position - the servo will try to regain a loss in position or 'following error' almost until it self-destructs. The power from even a small servo is amazing.

680

General Mach Discussion / Re: Mach 3 motor tuning

« on: March 17, 2017, 05:18:34 AM »

Is this a plasma or router table??

My guess is router.

Nema 34's are generally seen as too big for many of our uses - they are heavy, the rotors are heavy and accelerate slowly unless you have very high voltage drives on them 0- this is rare as they cost £££

Do you have one motor driving two pinions on the gantry axis or two motors slaved??

Really, you have a bit of a problem to get that beast running smooth, you may help by adding torsional dampers on the shafts - large masses of hard rubber to help absorb the vibrations  but i dont know anyone that has done that.

Really, you need Nema 23 4Nm motors and DSP drives in there on something like 70v PSU I think, to get speed out of Nema 34's you need probably 150v PSU and serious drives - for that sort of cash I would have simply thrown in AC servo motors

Not sure what your best course of action is i'm afraid, maybe some one else can help here?