CNC Colchester chipmaster

**Ross77** · 11-07-2016

Thanks Guys.
I have been going back and forth on the open loop vs closed loop vfds. some say that a closed loop vfd will keep perfect time and then mach only needs the 1 pulse per revolution.

The existing motor is the original 1.5hp so would be looking to switch up to a 3hp, its the vector vfds that jump up in price.

I'll have a look at the cards. as I want to do fine threads. I have just got two pci card encoder controllers but they are absolute and not incremental so probably no good. any motion controllers you can recommend?

Thanks for all the Links Rcnc, I will have a look later.

**m_c** · 11-07-2016

Unless you're going to replace the v-belts with a toothed belt, a closed loop motor isn't going to be much benefit, as the belt will cause slight speed fluctuations as load changes.

You also need to consider gearing, and how much torque you're likely to need at the spindle. Are you going to continue to use the gears, if so you need to factor that in, at which point you need to use a spindle encoder, as you'll struggle to get threading to work in multiple gears without a spindle encoder.

Off the top of my head, the following motion controllers spring to mind-

PoKeys 57CNC something or other (I think it supports encoders)
PMDX have a couple motion controllers, but they're Mach 4 only, and you'd need to check they support lathe (I think they do, but not 100% sure)
CS-Labs CSMIO/IP-A or S along with their threading module.
Dynomotion KFlop either on it's own, or with any of their add-on boards (Mach 3 only, or use their own KMotionCNC software)
SmoothSteppper, however I'm not sure if they have implemented full encoder for the spindle yet.

There are also the UC100 and 300, however I'm not sure if they support turn/threading.
A key thing to consider, is if the boards support turn/threading. Not all boards do.

**Clive S** · 11-07-2016

Without getting a load of flack. Linuxcnc with a mesa card is what I use on the lathe with a 60 slot encoder disc on the spindle.

**m_c** · 11-07-2016

Originally Posted by Clive S

Without getting a load of flack. Linuxcnc with a mesa card is what I use on the lathe with a 60 slot encoder disc on the spindle.

Get the pitch forks sharpened! ;-)

I've got a Mesa card sat on my desk just now, which is on my list of things to try, as I want to have a play with PathPilot. Got no intention of fitting it any machine, as I like my KFlops.

**Clive S** · 11-07-2016

Originally Posted by m_c

Get the pitch forks sharpened! ;-)

I've got a Mesa card sat on my desk just now, which is on my list of things to try, as I want to have a play with PathPilot. Got no intention of fitting it any machine, as I like my KFlops.

I take it then you have read the posts from cncbasher on the other channel.