[chich2]

If you have troubles with alignment then you could fit an arbour with a tool in it to your Z axis and "line bore" your head stock using the Z axis. Then put the spindle into the bore.

Chich

[shridhar]

Guldberg, great job and a best guide book to build a lathe...!
I have built a lathe with same auto tool changer but not been able to configure it to work with Mach3 lathe macro. What port pins should i have to connect the clock and direction inputs? Can anyone help..?

Shridhar
Bangalore

[Guldberg]

Its just a stepper motor like the rest, so you can config it just like a third or fourth axis. The pins you choose depends on the breakout board you are using. Do you have any pictures of the setup? Would be interesting to see. Maybe you should start a thread.

[shridhar]

I know it works using one of A, B or C axis. What i need to know is which axis the macro is written for? Or am i using a wrong macro? I am using "ToolChange Macro For Bed type tool changer 11/05 Brian" macro.

I haven't taken pics of my lathe but with your permission i have attached the model pics of it. I have planned for a tail stock too.

I am waiting for my machine to work first and will decide on starting a new thread.

Shridhar

[Guldberg]

Im pretty sure you have to write your own macro, at least im pretty sure there is no macro included for this kind of application with Mach3. But I maybe wrong.

Begin a new thread right away, this way you can also ask this kind of questions

[Guldberg]

Finally I finished both the toothed rims and could assemble the turret mechanism. It can be turned by hand, so I hope the stepper wont have a problem turning it.

From CNC

I did a sample of the cover for the Z axis. This is going to work just fine
´

From CNC

[Khalid]

One among the Great build .. very professional machine and you are a good engineer

[asuratman]

Hello Guldberg,
Good day. How many TPI on ballscrew on x and z axis? Thanks.

[Guldberg]

Thx for the kind words. Hope to inspire somebody, got a lot of my inspiration from talented people on this site.

5mm/rev for both the x and z axis

[Guldberg]

Got to make the Z axis stainless covers today. I will give them a go with a orbital sander when the build is finished

From CNC

From CNC

From CNC

[GaryCorlew]

Here is a macro from the mach3 forum, I have built the same tool changer but I have not used it yet, The macro has some problems but it does work for the most part

[LeeWay]

Very cool.
Like those covers.
I just finally installed decent covers on my mill table. Sure makes clearing chips easy.
You won't have to even worry about that with your design.

[Guldberg]

I got my turret wired up today, but im having trouble with the stepper stalling, even at low speed. There are some resistance when i turn it by hand, but not anything serious. Its a 200oz/in stepper geared with a 1:2,76 gearing. It can turn both ways, but can I have wired it up wrong? Its a 8 wire motor connected to a 4 phase drive in parallel wiring.

From

Here is a video of it doing some indexing. You can see it stalling at the last move, but other than that the concept works just fine. Oh, except i just realised that the angle seams to be 12.5 degrees of, maybe i have to drill some new holes in the turret base itself

[BillTodd]

It seem to do a little jump prior to the stall (as if there were a spring detent or a really bad bearing) I assume the turret moves smooth when turned by hand - does the motor?

Could it be a resonance? (you're moving a large mass with a 'springy' belt) Have you run it over a range of speeds to see if it resonates badly at one of more frequencies?

[edit] Looks great BTW

[Guldberg]

There is a lot of spring in the sloppy belt and I had considered if it could make a different. I will create a tensioner for the belt and see if that helps. Also I can juice up the motor half a amp and maybe even more. It is only going to run a couple of seconds at a time, and then it will go standby with 0 amp (free wheeling), so I guess it wont hurt to give a 20% extra current.

Is there any advantage in wiring it in series instead? I read somewhere that it gives the stepper more torque at lower speed

[phomann]

Hi,

What Stepper drive are you using for this? Also what is the supply voltage for the stepper drive?

Cheers,


Peter.

[Guldberg]

The drives are called Centent CNO162 (http://www.centent.com/). I wired the motor according to this thread http://www.cnczone.com/forums/showthread.php?t=86160

The voltage is around 60v and the current is set for 2.5amp

[phomann]

Hi,

That all seems Ok. What about halving the stepper speed? that should provide more torque.

Increasing the current will only heat up the motor if the rated current is 2.5A. If not then increase it to the rated current. BTW the motor consumes most current when stationary.

Having a "loose" drive train should be fine. It is better than a rigid one.

In the end, It may be that you just need a biggeer stepper motor.

Cheers,

Peter.

[Guldberg]

They are rated at 3 amp, so I will try and turn it up a bit. Next step is to oil/grease up the bearings and to tigthen the belt. If that doesnt work ill order a 500 oz-in motor

[phomann]

Inceasing to 3A should make a big difference.

Cheers,

Peter.