High Precision Homing Switch

[Clive S]

Looking for a high quality homing switch so that I can get my Lathe's X Axis set correctly and allow my tool changer to be consistent.

I don't think the homing accuracy would influence the tool changer as you will have touched off on the part.
The standard proxy switched I find OK

[Chaz]

I don't think the homing accuracy would influence the tool changer as you will have touched off on the part.
The standard proxy switched I find OK

Thing is, I use Machine home as the starting point / offset.

[Clive S]

Thing is, I use Machine home as the starting point / offset.

Ok I have not got a turret. But I thought you would have to touch off on the part and that would ref the tool changer position. So sorry can't help further

[Chaz]

Ok I have not got a turret. But I thought you would have to touch off on the part and that would ref the tool changer position. So sorry can't help further

Nope. The aim of the machine zero is to be the absolute reference. This means that each tool is offset against that point. So clearly if it moves, then my tools are not referenced correctly anymore.

[m_c]

I used an opto slot sensor on my old lathe, and there was never any measurable variation. I used RS part number 480-5231 however I see that part has now been discontinued. The only problem was I had to make sure a bit swarf hadn't landed in the slot prior to homing, as I never bothered enclosing it.

The new lathe uses proximity combined with servo index homing.

You could combine a proximity or microswitch with a slot sensor on the stepper, provided you can add a suitable slot to the stepper/ballscrew, to essentially give you a poor mans index homing.

[audioandy]

Chaz

I have a Balluff mechanical switch which are very good, I don't mind sending it over for you to try.

Just pm me your address if you want to try it. I will post a link to the switch if I can find it on the RS site.

Regards

Andy

[Chaz]

Chaz

I have a Balluff mechanical switch which are very good, I don't mind sending it over for you to try.

Just pm me your address if you want to try it. I will post a link to the switch if I can find it on the RS site.

Regards

Andy

Thanks, will send you the address. What do they cost?

[Chaz]

I used an opto slot sensor on my old lathe, and there was never any measurable variation. I used RS part number 480-5231 however I see that part has now been discontinued. The only problem was I had to make sure a bit swarf hadn't landed in the slot prior to homing, as I never bothered enclosing it.

The new lathe uses proximity combined with servo index homing.

You could combine a proximity or microswitch with a slot sensor on the stepper, provided you can add a suitable slot to the stepper/ballscrew, to essentially give you a poor mans index homing.

Thanks, something like this - https://uk.rs-online.com/web/p/photo...nsors/1254515/ ?

[Chaz]

I used an opto slot sensor on my old lathe, and there was never any measurable variation. I used RS part number 480-5231 however I see that part has now been discontinued. The only problem was I had to make sure a bit swarf hadn't landed in the slot prior to homing, as I never bothered enclosing it.

The new lathe uses proximity combined with servo index homing.

You could combine a proximity or microswitch with a slot sensor on the stepper, provided you can add a suitable slot to the stepper/ballscrew, to essentially give you a poor mans index homing.

Does this need a 'receiving part' or anything that it can pick up in the slot?

[m_c]

Does this need a 'receiving part' or anything that it can pick up in the slot?

You need something that goes through the slot. It doesn't have to be anything fancy, I just used a bit bent bar suitably mounted on the cross slide -