# Rotary Table Conversion



## Chris S (Nov 5, 2014)

Just wanted to thank Gary Liming for his article in Digital Machinist for an Arduino controlled rotary indexer.  I completed the conversion to my rotary table with a stepper motor and it works great.  No more index plates no more counting turns.  It works awesome as well for radiusing parts in the continuous state.  You  really don't need to be an electronics whiz to build this and there are a ton of motor mounting ideas on the web.  The download is easy for the software Gary put together which is the real time saver.

I added a couple of pictures as requested.  Going forward I want to cast a better motor mount and set it up so I dont have to block the rotary tabe up from the mill table to clear the motor.  The fan is unneccesary at the moment but I hope to finish the cover with external switches at a later date.
)


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## drs23 (Nov 5, 2014)

:worthless:

:biggrin:


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## Chris S (Nov 5, 2014)

I will take some tonite and figure out how to post them.


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## trukker (Nov 9, 2014)

Looks good.  Just ordered the parts to do the same.  Just waiting for the slow boat to bring the parts.  Looks like you used a different stepper driver than Gary did?  I see a large capacitor and wonder why you used it?  
Thanks


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## trukker (Nov 25, 2014)

My bad... tried to edit my post but too late.  You did use the same driver for the motor and his schematic shows a capacitor.  Still not sure why a capacitor is needed.


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## ogberi (Nov 25, 2014)

Very clean build!   I like it!   What's the oz/in rating of the stepper you used?

Does the table have enough backlash that you need to lock it down when cutting, or can you safely cut on a rotating workpiece?


As for the capacitor - 

If the capacitor is across + and - for the DC supply that drives everything, it's for ensuring the DC is smooth and ripple free.  Non-filtered DC wreaks havoc on digital circuits, and even a little bit of smoothing is better than none.  If the capacitor isn't big enough (in microfarads, uF), it can't supply enough current to keep the voltage up during the low points in the ripple from the rectifier.  The voltage will fall, and integrated circuits can do odd, random, and frustrating things.  

One item I usually do when putting a filter capacitor on a DC power supply, is make sure it's located upstream  (before) the fuse.  Otherwise, if a circuit gets shorted out, the capacitor is free to dump all it's energy into the short, and the fuse will pop when the drain on the rectifier gets too high.   If the capacitor is placed before the fuse, if the circuit gets shorted, the current from the capacitor will blow the fuse in very short order.


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## Chris S (Nov 25, 2014)

Thanks Guy's.  I cut the radius on the bracket in the picture without using the table locks but I can't say they were heavy cuts.  10 - 20 thou and it worked fine.  The motor is likely larger than the one Gary used but I had fished it out of the electronic recycling bin at my old apartment one morning and it was like new.  I looked the spec up on it way back and I think it's in the 368 0z- in range?  As for the capacitor you answered the question for smoothing the voltage out.  Size wise it matched the uf Gary used and it was in my scrap box.  I'm sure one that's  smaller would work as well if the uf rating is close.  

I'm currently using the  Ralph Water's PWM controller software for a tach on the mill from the Summer 2013 Digital Machinist and I will post the results when I am done.


Have a great rest of your day everyone and thanks for the feedback


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## ScrapMetal (Nov 25, 2014)

Chris,

Which issue of Digital Machinist has the article in for the Arduino contolled rotary indexer?  That's definitely something I would like to add to my shop.

Thanks,

-Ron


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## trukker (Nov 25, 2014)

If you go to _www.*liming*.org/millindex/ that will have the information you need and links to DM info.  Good Luck_


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## ScrapMetal (Nov 25, 2014)

trukker said:


> If you go to _www.*liming*.org/millindex/ that will have the information you need and links to DM info.  Good Luck_



Reading it now.

Thanks much,

-Ron


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## revwarguy (Nov 27, 2014)

Hi Chris,

Looks like you've made a nice addition to your lathe and rotary table setup!  I am glad you've found the project to be of use.  If you have any suggestions to change of add features to the software, please let me know.

Would you mind if I linked to this thread from the DM forum?  Just like to see various implementations listed there.

Anyway, nice job and good luck with all your projects.

Gary


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## Chris S (Nov 28, 2014)

No problem Gary.  Link away.  I enjoyed looking over your aircraft build as well BIG project.  Hope you are enjoying your Thanksgiving.
C


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## magu (Dec 3, 2014)

oh great, the 614 page to do list wasn't long enough, I needed one more thing to add......

Seriously though, thank you Gary for the great info and thank you Chris for bringing it to my attention.


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## Malave16 (Jan 1, 2015)

I been checking this idea out for a bit, now the big question... Is there a feaseable way to make something like this but without the stepper motor turning the work. You just turn the work by hand and the display tells you where you at on degrees. Im thinking something like a crank angle wheel from a car or something like that. This would be for indexing on a lathe


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## revwarguy (Apr 2, 2015)

_Is there a feaseable way to make something like this but without the stepper motor turning the work._

Sure there is.  If you look into "push-to" telescopes, they work by letting you input the star you want to look at, and then tell you which direction to move - "push" - each axis on the telescope until it points at the star.  Of course, the telescope has to be aligned properly first. (Search for "DIY push to telescope") 

The way those work is using an optical encoder on the shaft of each axis which allows the computer to sense rotary movement.  So, you mount a shaft encoder (the good news here is that they used to be very expensive, but have gottten cheap, like this one, or better yet, this one) on the on the cranked shaft, move the crank to some reference position, press a button, and then move the crank until it says you are on the "nth" position you wanted.  Lock it down, make the cut, and repeat until done.  By placing the encoder on the shaft of the crank, instead of the work piece, you increase the resolution of the encoder by whatever mechanical advantage to have in your gearing - i.e, if you have a 40:1 gear ratio like on a rotary table, your encoder just increased its resolution by 40.


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## Voltar1 (Jan 9, 2019)

Hi fellas. Sorry to wake up an old thread. Building GaryLiming indexer. Cannot get help from Gary yet? Not having any success on showkeys for ‘right’ zero does not show. Then when running stepper2.3 left button is the same as down and select does not work at all. I think the values in lcd keys need matching to my shield as they are indeed different than Gary used. Still no explaining why 0 is not zero on every shield?
TIA anyone?


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## Voltar1 (Jan 10, 2019)

Fellas, got it all sorted out. Adjusted the lcd keys integer values to suit my shield (dfRobot) and it is functioning flawlessly!
Very pleased with Gary's sketch. Looking forward to using this on the mill. Need an enclosure first.
Thank you Gary!!


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## Tim9 (Feb 21, 2019)

I also used Gary Liming"s Arduino code Indexer  along with a YouTube Video from MyFordBoy 




It works flawlessly. I love it.


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