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Author Topic: Lathe turret design  (Read 6473 times)

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Re: Lathe turret design
« Reply #10 on: April 07, 2012, 05:28:25 PM »
reflective disc and sensors.

make before break rotary switch

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Re: Lathe turret design
« Reply #11 on: April 07, 2012, 05:30:48 PM »
The OP said
Quote
My plan is to use stationary Hall sensors and a rotating disc with magnets.
Hood
Re: Lathe turret design
« Reply #12 on: April 07, 2012, 05:35:54 PM »
have the magnets set up on a disc so they dont have a gap, using that flexible magnetic strip

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Re: Lathe turret design
« Reply #13 on: April 07, 2012, 05:39:46 PM »
Yes a possibility but then you would have to be accurate and with the backlash in the gears it may not be so good, but possibly worth a try to save on a switch if you needed to.
Hood
Re: Lathe turret design
« Reply #14 on: April 07, 2012, 05:43:49 PM »
4 sounds good to me too
Re: Lathe turret design
« Reply #15 on: April 07, 2012, 05:46:38 PM »
there will be a fair bit of work to get them to fire at the same time anyway (a read delay in the macro possibly). An 8 position rotary switch would be the easiest to work with.

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Re: Lathe turret design
« Reply #16 on: April 07, 2012, 05:49:51 PM »
Possibly if it would stand up. I have just written a ladder for a friend who has a duplomatic 8 pos turret and it uses a rotary switch with 8 positions so I suppose they can last, then again I dont think its a standard off the shelf switch they use.
I use a servos with indexing drive on mine and makes it a breeze :)

Hood
Re: Lathe turret design
« Reply #17 on: April 07, 2012, 05:55:55 PM »
Barrafuldi use one in there 8 station toolchanger, and it's been known to fail.

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Re: Lathe turret design
« Reply #18 on: April 07, 2012, 06:05:04 PM »
My original turret used normal limit switches and it worked well, it was 6 pos and just had 3 different cams (one for each switch) and it worked well but when I first got the lathe they were a bit hit and miss. I put it down to the switches internal springs being weak, the lathe hadnt been used much in the 20 or more years before I got it, probably only about 50hours so some of the switches had likely been sitting in a compressed sate for years at a time. I replaced the limits and it never missed a beat up until a month ago when I hauled it off to replace with the new turret.
I think if I was going to use switches again I would use optos and slotted discs or possibly if space wasnt a problem some of the honeywell limit switches that I use on the axis for limits.

Hood

Re: Lathe turret design
« Reply #19 on: April 12, 2012, 11:50:27 AM »
Gytarr,

You mention avoiding PLC's but my take on this is that a PLC could really simplify the design. I say that having 12 years in factory automation that almost eveything ran on PLC. My concept on this would be to use a combined mechanical and electrical/electronic solution much like the orginal turret. If you could index by turning the turret with a stepper or other motor to get you into the near vacinity, turn the motor off, then use a simple air cylinder to clamp the tool table secure with air pressure, you could get a secure repeatable position on every tool change. This is a bit oversimplified but you get the concept.

Regardless of my opinion I am fascinated by the concept of a tool turret and would like to keep tabs with you on how you work this out. Gang tooling is killing me!

Robert