Advice on EMCO F1 to use Mach 3 cnc software

[pacomb]

Hello,

A good friend has acquired a good old Emco F1 unit, with revolving turret. He would like to make it to work with Mach 3 software. He is not English fluent so here I am helping him with some English words ;-)

The issue, he and I dont know much about conversions and options available, so maybe just posting the question if the shortest route.

I would like to hear about different options for controller boards that can give a 4 axis control with mach 3, and what kind of stepper motors.

I am sure thre are plenty of board options, and would like to hit the bulls eye at first with the forum recommendations. Of course, Chinese or cost effective options are well come

As far as I know, the only things we need to make the F1 mach3 compatible is a pc computer with parallel port and mach 3 software, a 4 axis board, the correct power supply, and the correct stepper motors. Anything else???

 

[hanermo]

As-is, Mach3 does not thread and does not do CSS.
(Iow, threading is broken, in general).

Some exceptions;
CSLABS motion controller will thread (According to them, and very knowledgeable other users).
I have mine, but its not yet installed. I amusing a centipede, atm, on lathe. Centipede will not support Mach4, according to them. I will go to cslabs).

I used 3Nm nema 23 size steppers with 1:3 drive, using HTD belts.
And a treadmill servo for z, again on 1:3.

The index pulse thingy is critical for threading - and most sensors are crap.
We verified this with a very high accuracy test logging into a file.
(Using a high end hw pulse generator, centipede. I am using it on my lathe).

My lathe work is oriented for very good results. Time is immaterial, and costs are not decisive.
Accuracy is paramount, and surface finish is important.

There is soon to be a new mach, version 4.
It is likely to solve the css and threading issue, especially with the cslabs hw pulse engine.

I have worked on getting good threading for many years.
I am now going on to ac brushless servos and the cslabs 6 axis card.

If threading is not important, any steppers should work, 3-5Nm, at 1:3.
I think it is criminal, and very poor in resolution terms, to direct drive a lathe, either on x or on z.

Lathe threading needs to run at high rpm, otherwise you wont get a good surface finish (in steel, with carbide).
The only way to do this well, is with servos.
Steppers will do so-so, even in the best case (I am using the best case, and this has been my experience).
At the end, in pullout, you need high speed and high acceleration.
It is the only operation on lathes I know of that needs high speed.
I am using about 1/2 my max speed, for security and less trauma on errors.

You should aim for 3-10x better halfstep resolution than expected work resolution.

My step size is 0.2 microns on z, and about the same on x (although its microstepping at 10 usteps, Gecko 203v, 68V).

The chicom integrated drivers (TBxx) are crap, in a word.
And the low voltage 30V drivers, dont waste your time.

Otoh, the 50-60V stepper drives are probably all fine.
I have chinese drivers (60V), geckos 201,203, and 320 (servo dc). All work fine, upto about 300 khz.

 

[DICKEYBIRD]

EMCO F1 is a little mill, no?? I think Mach will do very well on a mill conversion with Geckos & steppers (or the like.)

Good info on the lathe by the way. My converted ORAC does threads but not without a lot of pain & fiddling. I hope Mach4 is finished in my lifetime and works well on a lathe. If I was smart enough I'd try LinuxCNC with a good encoder but sadly that's not going to happen.

 

[RonGinger]

Mach3 does work with the parallel port and threading- it is tricky and can have problems, but it is not flatly broken. I have made bolts with it on my lathe.

Mach4 is running now on lathes, Brian has posted some you tube videos of it. It has been long overdue, but mach4 will very soon be available. A test release, without motion control but with all the interface elements is on the machsupport.com website now for free download. Try it, you will likely find the new interface, and the screen designer, very clean and simple.

 

[DICKEYBIRD]

Great, thanks for the info Ron.

 

[pacomb]

Hello all

Could someone post images on the hardware conversion of the F1?? I would like to see how the new stepper motors are attached.

paco

 

[mu38&Bg#]

A NEMA23 motor will replace the original without modification. Please be aware that the original steppers are 5 phase and most everything one the market is 2 phase. This reduces your resolution. Fine you say I'll microstep. That's OK as long as you account for the torque reduction due to micro stepping with a bigger motor. I don't know the specs on the F1. I have an Emco Compact 6 CNC lathe I'm retrofitting and have done the math to get it right. I'm using LinuxCNC and Mesa boards. I have not yet assembled the axes. I'm going to try for 0.5 micron resolution.

While I agree with Hanermo that resolution is important, I'm not sure how many home built machines are built to resolve 0.2 micron (.0000078") The Compact 6 is said to resolve 1 micron (.00004"), but the hardware does 2.5 micron in reality, so 5 micron (.0002") on diameter. So a tool offset of 1 micron won't necessarily do anything, but the machines were made like this for years. The reality is that if you're trying to make parts to ±.0002" on diameter it will not be easy or maybe not even possible. Fine tapers or correcting for taper is also problematic. That's why production machines have resolutions much higher than tolerances expected in parts. I have a shop made mill with 2 micron resolution and it's been very good for me for years. I don't have a problem with rapids, so might change the encoders to get 1 micron resolution and give up rapid speeds.

Greg

 

[uli12us]

The compact 6 has not really much in common with the F1. But the machine is nearly identical with the compact5 (electric, motors). Afaik you can change the z-ballspindle from lathe to mill and vice versa. The motors have a unusual resolution of 72 steps, although the machine uses halfstep with slow feeds up to 100mm/min, 4ipm, the resolution of a 200step Motor in full step mode is some 40% higher.

 

[DICKEYBIRD]

Sam the Linux man posted his Compact5 conversion to Linux using the stock hardware here: http://bbs.homeshopmachinist.net/th...-interface-with-linuxcnc-(no-interface-mods-) Very interesting stuff that may be useful in running your F1 if you're Linux savvy.

 

[mu38&Bg#]

The compact 6 has not really much in common with the F1. But the machine is nearly identical with the compact5 (electric, motors). Afaik you can change the z-ballspindle from lathe to mill and vice versa. The motors have a unusual resolution of 72 steps, although the machine uses halfstep with slow feeds up to 100mm/min, 4ipm, the resolution of a 200step Motor in full step mode is some 40% higher.

After a bit more research, you are right. 72 step, 60 oz-in motors, 2.5 reduction and 2.5mm pitch screws. By switching to new 60 oz-in, 200 step motors with half stepping you can have almost three times the resolution (2.5um), and the same axis force as the original. Or, by using 200 oz-in motors you could further improve resolution with microstepping to 1um and still have more torque.

Greg

 

[uli12us]

dickeybird; the machine with the linuxcnc conversion is the PC-machine, which have an external conroller (in the PC). I don't know, if the F1 was sold in the same version. With the CNC, I fear the conversion will be much more complex. Eventually you can only use the stepper driver, but I don't know how they are controlable.

I need a DSO, with this I can look at the waveform and timing of the circuit.
IIRC there's only a small plug with 5 Wires for controlling the drives.

Greg, I haven't measured the spindles, but have read they have only 2mm Pitch with an 2/1 reduction. In effect theres the same 0,0138. resolution/step.
More torque isn't really good, because the spindle have an overload clutch. With this the motor runs without a movement. Unfortunately, the control don't know that.