[tubeguy]

Im looking to convert my bed mill and wonder how many guys would go with mach if they had to do it all over again?

Along with the above, is there any truth to the muttering that you have to have a BOB thats smart or has a mini cpu to have good smooth control of your servos? I read that just running a BOB to your servos with your PP is slow and trouble prone. Have you done it, is it true? I see those smart BOBs are around 1400 bucks VS like 150 for the dumb ones.

[Masterbrew]

I currently am running two Mach machines. A 5' x 10' router and a 12 x 36 lathe.
The router is pp with servos and a bob( must have ). I have no problems doing 600ipm, it will run almost 1000 but it scares the hell out of me so I slow it down.
The lathe runs with a ss ( and bob ) generally no problems.
Both methods have their issues as would any system.

I am planning another mill project and will use mach on pp for that one.

Randy

[TOTALLYRC]

+1 on the would by again.
I have it on my mill and love it with the dspmc.
I am in the process of setting it up on my lathe and second mill.

Mike

[tubeguy]

OK Interesting, yet no mention of the "smart" bobs, is this sorta a selling ploy by the outfits that make them? Thats is to say a Mach'n PP driving a bob driving a amp'n servos is notchy, or slow etc. Is this, ahh baloney? Do those 1400 dollar boards have a place.?

[ger21]

I think "Smart BOB" is the wrong term. I think what your talking about is an external hardware motion controller.

As Mike mentioned, he uses the DSPMC.
This allows you to use drives that accept ±10V signals, instead of the normal step/dir that Mach3 uses.

I read that just running a BOB to your servos with your PP is slow and trouble prone.

The parallel port is not trouble prone at all. But it does have a speed limit

One issue with servos is the resolution of the encoders. The parallel port is limited in how many steps/second it can send, depending on the PC being used. In most cases, the maximum is between 60Khz and 75Khz. If that is not enough to achieve the required speed, then you probably should use an external motion device.

And they don't all cost $1400. A Smoothstepper is $155. Kflop from Dynomotion | Motion Control Boards is $250.

There are several other options.

I don't use servos on my machine, but if I were to build a servo driven machine, I'd definitely use Mach3.