Recent Posts

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Tools / Re: Measuring backlash on rotary table
« Last post by philf on March 27, 2024, 01:42:50 AM »
Another possible problem is that the backlash could vary over the 360 degree movement. In that case I doubt backlash compensation would be much use. As Muzzerboy has suggested have you tried to adjust the meshing of the worm and wheel to reduce the backlash to a minimum?
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Project Logs / Re: Steady for Harrison
« Last post by shipto on March 26, 2024, 03:28:20 PM »
Bit more progress, made some knurled nuts which I had intended to add some slots for a C spanner but I really hope they are not needed because that knurling has come out really well.
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Tools / Re: Measuring backlash on rotary table
« Last post by Muzzerboy on March 26, 2024, 01:21:24 PM »
Can you not adjust out (or at least reduce) that backlash? Many / most rotary tables have an eccentric adjuster on the wormwheel for this purpose.

Backlash adjustment in software assumes the table is driven against a friction-like drag load that resists angular movement but you may well have a machining load that biases the wormwheel in the other direction, in which case the anti-backlash may actually double the error when you change the direction of movement.

To measure the angular error, perhaps you would want to lock the table and then apply a controlled torque to the wormwheel in each direction. It's not a perfect science, since there is inevitably a degree of spring so that the backlash will depend on the torque you apply. If you applied no torque but simply moved the wormwheel in alternate directions, you'd get a smaller backlash - but not necessarily what you will see with a real world load applied.....
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Tools / Measuring backlash on rotary table
« Last post by Dell on March 26, 2024, 07:26:56 AM »
am motorising my rotary table using stepper motor and World of ward’s controller and it has backlash compensation in the settings but how do I measure it , on the handle vernier it’s just over 1 and a 1/2 notches but that’s not very accurate is it so I would like to be more precise .
Dell
https://www.worldofward.com/
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Project Logs / Re: Steady for Harrison
« Last post by shipto on March 24, 2024, 09:22:51 AM »
Decided against making the end nuts do double duty and have knocked up 3 7/8UNEF grub screws instead. pic makes them look much worse than they are but I really should have faced them after parting them off but its not like I'm going to give them anyone else.
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Project Logs / Re: Steady for Harrison
« Last post by shipto on March 23, 2024, 01:34:28 PM »
Spacers are made and with them in the way shown it will take about 65mm bar. I may need to make some half size spacers but need to get hold of more tube for that as I just about had enough for these.
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Project Logs / Re: Steady for Harrison
« Last post by shipto on March 23, 2024, 08:23:39 AM »
Progress so far: I have made the brass holders and all thats left to do on them is to bore the end once I have the brass which I forgot to pick up on friday  :doh: then work out how I make the adjusters. I am thinking that the end caps might do double duty but not decided yet.
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Our Shop / Re: My cubbyhole
« Last post by vtsteam on March 22, 2024, 03:14:38 PM »
Nice!  :thumbup: :thumbup: :beer:
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Our Shop / Re: out with the old in with the new
« Last post by vtsteam on March 22, 2024, 03:03:55 PM »
The shop looks great, Bob!  :thumbup: :thumbup: :clap: I don't blame you re. waiting for good weather. Same here..... :beer:
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Project Logs / Re: Steady for Harrison
« Last post by vtsteam on March 22, 2024, 02:56:45 PM »
That does look nice!  :thumbup: :thumbup: :beer:
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