Stackshot calibration? (And ARCA plate ridiculousness)

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Ryan_in_AZ
Posts: 2
Joined: Thu May 28, 2015 10:27 am
Location: Yuma, AZ

Stackshot calibration? (And ARCA plate ridiculousness)

Post by Ryan_in_AZ »

I just received my Stackshot yesterday. What a beautiful little tool. In my shop, I use a 3-axis CNC router so I have experience with measuring and setting backlash in the screw drives. My SShot came from the box with a 1.588mm distance/rev and .188 backlash compensation setting. Using a dial caliper, I reset to zero in the controller and remeasured the backlash. Mine came to .160 in the end. I am very impressed with the accuracy of this little machine.

My question is, do most people calibrate their SS or just run with the factory numbers?

Also, what gives with having to buy an $80 ARCA compatible plate? Are people actually purchasing these things separately? The stock plate has tons of real estate to drill and tap whatever mounting holes you need. I mounted a QR plate in about 15 minutes. $80? I think not!


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rjlittlefield
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Post by rjlittlefield »

Ryan, welcome aboard! :D
My question is, do most people calibrate their SS or just run with the factory numbers?
My gut feeling is that most people just run with the factory settings and deal with backlash by using a pre-run strategy so that all the motion that counts is done in one direction, after all sorts of backlash are taken out.

Backlash compensation is approximate at best, because what the device actually does when you reverse direction is more complicated than just a bit of free spin on the screw. The carriage usually does a small twist, advancing on one rail different from the other. If you make the rail move backward, take a picture, then move forward with backlash compensation, and take another picture, the two pictures won't quite line up even though the step size may be right. If the step size is small, then it probably won't be quite right either, for the first step or two.
I am very impressed with the accuracy of this little machine.
Me too. See http://www.photomacrography.net/forum/v ... hp?t=16323 for some interesting data on precision.

--Rik

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