CNC Spindle synchronization

[Leadhead]

I have small CNC lathe which has been retrofitted with a heavier 3ph. motor, due to the the old one being no longer available.
I have lost the spindle synchronisation in the process. It is running on Mach3. Would anyone know how to go about restoring the facility please. Most grateful for any guidance.

[Chaz]

How does it synchronised? Are you talking for a speed / tacho feature or something more accurate to determine angular location?

[Leadhead]

Should have been more clear. The spindle speed encoder is working fine. But for screwcutting the consistent return for each pass is not there. So does not pick up in the same place.

[Chaz]

Should have been more clear. The spindle speed encoder is working fine. But for screwcutting the consistent return for each pass is not there. So does not pick up in the same place.

Sounds like the index pulse is missing or not being read.

[Leadhead]

Chaz - Yes the guy who did the motor conversion said it would not be possible with this setup. I wanted to understand if I could retrofit a second encoder to get it to register a repeatable position.

[Chaz]

Chaz - Yes the guy who did the motor conversion said it would not be possible with this setup. I wanted to understand if I could retrofit a second encoder to get it to register a repeatable position.

Probably best to just get a new encoder. Any pics of the setup?

[m_c]

What controller are you using, as that will dictate what options are available?

Encoders/slot sensors are normally mounted on the spindle which a motor change shouldn't affect, and Mach must be seeing something if it's attempting a threading move (it should pause until it sees a suitable/stable spindle speed before moving).

[Leadhead]

Guys still trying to get my head around what I have got and what I have not. - Mach diagnostics do not show an active encoder light.
The speed is apparently being displayed, but checking with optical tacho, 200rpm set and 208rpm actual given on Mach3 screen read out on the tacho at 240. So not too accurate.
I guess I will buy a new encoder head and make a Mach3 single slot disk to run on the back of the spindle.
Any suggestions for a UK encoder purchase appreciated.

[Chaz]

Guys still trying to get my head around what I have got and what I have not. - Mach diagnostics do not show an active encoder light.
The speed is apparently being displayed, but checking with optical tacho, 200rpm set and 208rpm actual given on Mach3 screen read out on the tacho at 240. So not too accurate.
I guess I will buy a new encoder head and make a Mach3 single slot disk to run on the back of the spindle.
Any suggestions for a UK encoder purchase appreciated.

There is a guy in Iver Heath that sells good quality encoders for around £40. Search for Hengstler on Ebay, you will find him. I bought my encoder from him for my Harrison M300 CNC lathe.

[Leadhead]

Chaz - Thanks. Did you use the rotary encoder?

[Chaz]

Chaz - Thanks. Did you use the rotary encoder?

I do use a rotary encoder. Its bolted on a shaft that comes out of the gearbox of my machine (1:1 ratio). Im not using Mach however.

[Leadhead]

Chaz THanks again. Has anyone connected such a rotary encoder to Mach 3 please?

[Chaz]

Chaz THanks again. Has anyone connected such a rotary encoder to Mach 3 please?

Im sure, certainly that's the way that you deal with speed checking and indexing on Mach 3 too. I tried via my Pokeys board but gave up with Pokeys and then Mach 3.

[Leadhead]

Where did you go after Mach 3?

[Chaz]

Where did you go after Mach 3?

Centroid Acorn. So much better.

[hanermo2]

I highly recommend using an optical encoder, even like a cheap amt-102, for the index signal.

But this will need a high-speed interface board, as the signal is very crisp - what you want - and very short so only good motion control hw will be able to read it.

I tried about 10 different solutions - and am now using full industrial servos with index and a csmio-ip-s interface kit from cslabs.

[Chaz]

I highly recommend using an optical encoder, even like a cheap amt-102, for the index signal.

But this will need a high-speed interface board, as the signal is very crisp - what you want - and very short so only good motion control hw will be able to read it.

I tried about 10 different solutions - and am now using full industrial servos with index and a csmio-ip-s interface kit from cslabs.

Do you use Mach or the CS Labs' new Software?

Have you tried Centroid Acorn?

Also, we are still waiting for pics from your machine(s) please :-)

[m_c]

There's no use recommending encoders when we don't even know if Leadhead's setup will even work with an encoder.

We really need to know what kind of controller the lathe is using, or if it's just using a parallel port, as it may just need some form of single slot sensor.

Plus Hanermo, those AMT encoders are not optical, they're capacitive. They would probably be ok for a continually moving axis though.

[Leadhead]

Gentlemen, Thank you for your assistance.
The lathe is a very simple Denford slantbed running Mach 3.
I am led to believe it will work quite effectively with a £2.50 Halls effect switch and a magnet on the spindle. After all your posts. I hope you will forgive the lack of sophistication (for the moment) I just have to try it, as have just seen a little Emco 5 conversion running Mach 3 threading. With the assurance that it has not missed a beat, having been programmed from F360 and a little tweak on the post processor. Just a couple of 3d prints required to hold things in situ.
Since I do not use the lathe that frequently, a Heath Robinson car boot solution. If I can get it to work, might suit the budget very well?


Chaz - Very interested in Centroid Acorn experience. Been studying it for while. Looming pile of vertical router bits laying in the corner looking for a control solution.

[JohnHaine]

One thing to watch out for is that if your new motor is not controlled from M3, M3 won't know if it's running. You need to start the motor AND press the "Spindle" button.

[Chaz]

Gentlemen, Thank you for your assistance.
The lathe is a very simple Denford slantbed running Mach 3.
I am led to believe it will work quite effectively with a £2.50 Halls effect switch and a magnet on the spindle. After all your posts. I hope you will forgive the lack of sophistication (for the moment) I just have to try it, as have just seen a little Emco 5 conversion running Mach 3 threading. With the assurance that it has not missed a beat, having been programmed from F360 and a little tweak on the post processor. Just a couple of 3d prints required to hold things in situ.
Since I do not use the lathe that frequently, a Heath Robinson car boot solution. If I can get it to work, might suit the budget very well?


Chaz - Very interested in Centroid Acorn experience. Been studying it for while. Looming pile of vertical router bits laying in the corner looking for a control solution.

Sure. Ive just done a Lathe conversion. I might do my next mill with Centroid too.

[Leadhead]

John - It is on M3 currently.

Chas - Which Centroid option did you get please?

[Chaz]

John - It is on M3 currently.

Chas - Which Centroid option did you get please?

http://www.centroidcnc.com/centroid_diy/acorn_cnc_controller.html

[Leadhead]

Chaz - Bit persuasive that. - Did you take the extra turn software?

[Chaz]

Chaz - Bit persuasive that. - Did you take the extra turn software?

Ive bought the Lathe Pro software which allows threading and rigid tapping. The initial learning curve was OK, different to Mach but some principles are the same.

Ive had a struggle getting an ATC macro working, its now sorted although not perfect, but acceptable. Ive also had an issue with my spindle speed control but we think its related to my touchscreen.

Centroid is mature and is 'built' for touch screen use. Its a nice platform. Mach feels like a toy after using this.

[Leadhead]

Yes saw the thread on the ATC macro writing. Frightened me a bit with that!

[Chaz]

Yes saw the thread on the ATC macro writing. Frightened me a bit with that!

Its only scary for a bit :-)

Once understood / solved, its relatively straight forward. Like any other product, as it matures and more people use it, the better.