Aluminum profile and alu plate 1500mm x 600mm x 150mm working area, first cnc.

**JAZZCNC** · 14-01-2017

Originally Posted by Davek0974

This is the vital fact, I have found the negative side of this equation - low accel/high speed and what it does with Mach3 is give terrible contour following because of the constant velocity engine Mach uses. Its not just a little bad, it's the difference between turning out scrap and turning out parts.

I have retuned with lower speed as higher acceleration was too jerky on my old Bridgeport conversion and its all working nicely now.

Exactly Dave. Like all things in life Balance is the Key. Good machine is tuned with nice balance of speed and Acceleration.
Getting wrong either way will have negative affect on machines performance in different areas of work type.

For instance your case of high feed but with low accelration caused corner rounding. This was on relatively small parts with tight radius on small machine. On larger machine like router with larger parts say doors or shaped work tops etc with no or large radius sections then high feeds with Lower Accel will be ideal.

Different strokes for different folks, Or machines in this case.!

This is why Mach3 and some other Control software will let have you have different profiles which can be used to have machine tuned or setup differently to optimise the type of work your doing.

**Boyan Silyavski** · 14-01-2017

Originally Posted by JAZZCNC

Not quite sure what your saying here Boyan.? . . . . Are you trying to say this isn't achievable with steppers.? Because if so then your very wrong.!

I am saying you are our hero and i am happy that i found this forum and we learned to build machines that are superb for the money and better than crappy commercial ones where usually they have some major flaw in design.

**Clive S** · 14-01-2017

Originally Posted by Boyan Silyavski

I am saying you are our hero and i am happy that i found this forum and we learned to build machines that are superb for the money and better than crappy commercial ones where usually they have some major flaw in design.

creep

**JAZZCNC** · 15-01-2017

Originally Posted by Boyan Silyavski

I am saying you are our hero and i am happy that i found this forum and we learned to build machines that are superb for the money and better than crappy commercial ones where usually they have some major flaw in design.

Ah ah now your just blowing smoke up my jacksy.!

. . . . . I understand.

**pierantoine** · 01-04-2017

Here is my Wiring diagram done with tinyCad and some Dean pictures

the Bob is a Mesa 5i25+7i76 (LinuxCnc)

1 A Pilz S4 is not in use but it could be if needed
2 a second Contactor could be use if necessary for the 70v steppers supply
3 The limits directly controls the safety S5 pilz relay.
4 The S5 cuts all signals immediatly and after a delay cuts the main on the VFD
5 Home could be connected to one input but i have 32 inputs so more than needed.

i've already tested the inductive sensor action on pilz s5, it works.. that may not be the best solution ?

Comments are Welcome !
thanks for your help

**Clive S** · 01-04-2017

Its nice to see other Mesa users on here. Do you need the 10V power supply ie can't this be got from the VFD if it is only for spindle speed?

I am not sure I would connect the 24V -ve to the star Gnd. I would however connect the 5v and 24v -ve together.

Make sure you have the switches on the 7i76 in the correct positions, W2 needs to be in the right hand position if you are using external 5v supply Also on the 5i25 W1 and W2 should be in the down position (default) when using external 5v to the 7i76) otherwise the magic smoke will appear. If you know this already then fine.

PNP sensors work best on the 7i76 although I do use NPN.

You might find this useful https://forum.linuxcnc.org/media/kun...2016-12-03.pdf

I could not open your drawing in acad so find it a bit hard to read.

**pierantoine** · 01-04-2017