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Author Topic: Rotary table, home switch & backlash . . .  (Read 3274 times)

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Offline Raca

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Rotary table, home switch & backlash . . .
« on: August 10, 2006, 08:28:28 AM »
I have both recently Sharline CNC ready rotary table, but without home position switcher and with noticeable backlash. Das any of you people had same problems with this. If you can suggested suitable switches for it and idea how to fix backlash on rotary table. Best regards Raca.
Re: Rotary table, home switch & backlash . . .
« Reply #1 on: August 10, 2006, 09:27:59 PM »
I have a Phase II 4" rotary table that I retrofitted.   I am only going to use this table at low speeds and light milling mostly wood and aluminum.  Also I only use the table with the controller and never manually.

What I did, and by no means am I an expert,  I started by stripping down the table.  With the Phase II there is an eccentric bushing to engage and dis-engage the drive gear to the table.  I am never going to dis-engage my table. So I found the high spot on the bushing and tightened the set screw that adjusts the tension on the bushing.  The bushing no longer moves.  I used lithium grease on the gears and I do not plan on using light spindle oil as suggested.  After some extended use I disassemble and add more grease.  The grease allows for a good fit and also allows the gearing to move with much less friction then the oil. 

I also removed the handle and the dial gauges (the scribed dials) since I never use them as a reference.  I would think you can leave them on if you want but I did not even try.  The shaft attached the handle and held the shaft in tension with a double spanner nut and thick keyed washer.  I removed the spanner nuts and washer and replaced the washer with a steel needle-roller thrust bearing and washers and the spanner nuts I replaced with a threaded clamp-on collar.  I purchased these items from Mcmaster.com.

I mounted the motor and basicly now have no backlash.  I did not add any home position switch, again I would never use it, If I needed I can make a jig to find a reference zero.

Dan.

Offline Raca

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Re: Rotary table, home switch & backlash . . .
« Reply #2 on: August 11, 2006, 04:16:59 AM »
Thanks Dan,
I also will use rotary table at the low speed, but I need high accuracy since my intention is to cut Wheel and Pinion for watch industry, and I haveĀ  backlash on gear transmition , other parts are well made. Sarline make upon one revolution of handle 5 degrese on rotary table, but on the handle you can feelĀ  backlash of 3 degrease. Can that be solved thru Mach3 backlash adjustment, will that work? Raca
Re: Rotary table, home switch & backlash . . .
« Reply #3 on: August 11, 2006, 07:10:09 AM »
I have never used backlash comp on a rotary table but I know it does work fine on the x-y axis.  The problem will not be the backlash comp it will be movement of the table when you are milling.  Basicly the table can move freely while you are milling unless you either ensure the direction of your cut is not going to allow the backlash to effect the cut or you can lock the table down during the cut.

Just my thoughts.

Dan.