Small Lathe TU2807 setup

[sam]

Hi,

Been a great project over the last 3 months setting this lathe up with Masso. Still some commissioning and tuning to do and a few things to work out before I feel comfortable to start making stuff.

Have tried as much as possible to make things out of what I already had, like the control panel is made from an old bed frame and timber left over from other things.

One thing I'm not real sure about is with the encoder setup. To get the rpm. in sinc, I had to set the pulses per revolution to 14, I'm not sure it will have the required resolution at that. Its going up and down in rpm. by increments of 5. adjusting Hz doesn't seem to do anything.

 

[breezy]

@sam

Sam,

Love to help, but your photos don't show. You need to post photos through the file upload process at the bottom of the edit window. Above the I'm not a robot box.

Maximum files: 5 Maximum file size: 8 MB Allowed file types: jpg,jpeg,gif,png,bmp,pdf,cnc,tap,htg,nc,scpost,zip

Regards,

Arie.

 

[sam]

Oh, ok. I just tried that and got 413 error entry too large or some such. I guess it must be 8 MB total. Will down size them directly and try again.

 

[sam]

Ok, have just been trying to find some info on the Masso Optical encoder I have and found this thread https://www.masso.com.au/forums/topic/masso-optical-encoder/?part=2. Looks like I do have the Pulses per Rev. correct.

I don't have spindle control via Masso though, still only controllable on the lathe itself. Not sure if it matters. I guess it depends on whether Masso adjusts the feed rate to any changes in spindle speed sent from the encoder or whether the reverse happens and Masso tries to govern spindle speed to varying load.

 

[breezy]

Sam,

I'm not a lathe guy, but I think the encoder is used by MASSO to control spindle speed, especially for threading. Feedrate is set by code. Don't know if MASSO does constant cutting speed on facing.

So you will need to get your spindle controlled by MASSO.

How is your spindle speed controlled now? Is the motor variable speed, controlled by VFD? If so it is an easy job to get MASSO controlling it.

Regards,

Arie.

 

[sam]

Thanks for your input Arie,

My spindle has a dc variable motor and controlled by a 5 volt pot. I have thought about putting in some relays to control spindle direction the speed with a setup like here https://www.masso.com.au/forums/topic/wiring-spindle-motor-controller-to-the-masso/ 1st. reply by Masso Support has a schematic in the file attached which may work. My spindle has 3 belt/ pully option changes through its speed range though. Not sure that would work. Maybe I would just need to adjust the spindle speed parameters in Masso each time the pully setup is changed perhaps, I don't know.

 

[ecs]

@sam @breezy

Masso adjusts the feed rate according to the RPM. As for the control of RPM it doesn't matter if masso doesn't control it. You could enter in silly figures but it wont change the out come. What ever the pulses are it'll match with the feed rate.

I have mine setup with full control by the masso using a VFD. I have the gear on my lathe set at 2000 RPM and have the masso control the inverter. But sometimes the torque isn't there when doing the heavier cuts. So i usually just select a different gear on the lathe when this happens. I choose a different gear and just rerun the program. Going in and changing settings is time consuming and not needed.

Josh

 

[breezy]

Josh,

Thanks for the correction as I said I'm not a lathe person so I'm fully not conversant with how MASSO works in a lathe situation.

Regards,

Arie.

 

[sam]

Thank you for the help Arie and Josh. I think I am set now with the encoder. At least what path to take. I think maybe my sticker on the spindle may be slightly off centre and that's why I'm getting a 5 rpm variance. I have another 5 stickers to try and get it more central. Will try and work something out.

Thank you very much for your help,

Cheers,

Sam.

 

[jim-in-michigan]

Sam

I am trying to build a cnc lathe also. I am getting ready for my spindle encoder. I am using a gear head lathe, to change spindle rpm I have to change the levers on the head stock. Will I still be able to put a encoder on the spindle to be able to cut threads?

Thank

Jim in Michigan

 

[sam]

Hi Jim,

I haven't tried myself yet, I need some stock to machine, but from ECS's post #7 a few posts up the answer is yes. The feed rate is adjusted to suit the encoder reading and is independent of any spindle control.

Cheers,

Sam.