Motors moving opposite direction of what they should?

So in trying to calibrate the machine using GC 1.09 I’m following the calibration “wizard” and have noticed a few things. I selected chain off bottom in the first menu as I’m building the new default frame. I did make an adjustment and put a 12’ beam across the top and added just over a foot to each chain to compensate which I’m sure will cause different issues down the road.

ANYHOW, when the left chain is wrapped over the top of the motor CCW (Chain off bottom, as pictured in the calibration steps) and I pull the left chain over to the right motor and click extend it actually retracts and gives me even less to work with and vice versa. When both motors are connected via the chain and I click “Pull Chain Tight” the left motor turns CCW and the chain falls off the end.

And when I Zero the motors everything turns the direction it’s supposed to when the CCW or CW buttons are clicked.

Am I missing something absurdly obvious?

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Hmmm that sounds like it’s using the incorrect chain over the sprockets direction.

Your firmware is up to date too, right?

If you go into the settings and manually switch it from one to the other do you see the direction that the motors move switch?

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I wonder if we need a firmware version check at the beginning of the Automatic Calibration sequence to warn of zombie :zombie:‍♂ apocalypses if an old version is present?

We have one! :grin:

If the version numbers don’t match it will say :wink:

Yup, this actually is a “new” computer that has never had the software installed previously and I downloaded/installed the latest version of everything. So it’s likely not a hold over (ghost) of previous versions.

As far as what to check in the settings and changing one to another I’m not entirely sure what setting you’re looking at. If you could point me toward a specific setting I’d appreciate it.

I also noticed something else. Just in playing with the z-axis, if I hit “raise” the entire sled raises up the work space and the Z motor doesn’t move. And running the test feature of the motors works just fine, left goes when it’s supposed to, same with the right, and the z-motor raises and lowers as it’s supposed to. But if you specifically tell the z-motor to raise and lower the entire sled moves. So I’m not sure if that’s just an issue since the calibration hasn’t been completed yet.

So I went and installed 1.08, and as it didn’t give me the option of which direction the chain was running I’m guessing it assumed that I was running the chain over the top as I ran into the same problem.

Ok…found the setting in the advanced settings to manually change which direction the chain comes off and changed it to bottom (default is top). I decided to play with the chain length calibration and in following the instructions/picture I put the first link at 12 o’clock and let the chain hang off the right hand side. When I clicked adjust left chain the left motor started running and turned clockwise and the chain fell right off.

It has to be me…right?

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Have you wor

Stepping through the calibration in the current version (v1.09) of GC, when you get to the step for measuring the distance between the motors, the chain needs to hang from the left side of the left motor regardless of the eventual choice of chain path. The first link of the chain sits on the top tooth as in the left-hand picture. This measurement counts the number of links that it takes to extend to the right motor, then pulls back until it can’t move any more and subtracts that number of links. A later step will once again zero the sprockets and extend the chains by turning the sprockets depending on the top/bottom choice.
When you are at the step for measuring the distance between the motors, and have the chain hanging as shown in the left-hand picture, does the ‘Extend’ button turn the left sprocket clockwise? If so, you’re on the way. If your motors are really almost 12 feet apart, you can click on the number ‘100’ and change the amount of chain that each click of ‘Extend’ feeds out, using a millimeter value. For my 11 foot top beam I usually use 3200 for the first one, then 50 to get closer, etc.

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OH Duh. That makes total sense now! I had gotten wrapped around the initial detail of selecting the path of the chain. Perfect! Thank you!


It may well be that the instructions need polishing on this. Is there a way to improve them to avoid confusion?

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Now that I’ve gotten past that part it appears to be pretty obvious as the calibration goes on. I tend to follow directions pretty literally (my wife would say otherwise). For me, I think the only thing would be if it doesn’t matter which direction the sled is connected until after that step maybe ask that question after the measurement step.

But I’m running into a new problem now that I’ve progressed. Even though it measured the distance between the motors it doesn’t provide enough chain to center the sled. I saw this in another post but it hadn’t been resolved. I’ll actually probably continue this thread here as it’s more appropriate for the new issue I’m having.

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Quick question (and maybe stupid question)… after you measure the distance between motors, your left chain should still be on the right sprocket (and slackened). Did you remove it from the right sprocket (leaving it where it was on the left chain) and press “extend left”? It should retract the chain back to an appropriate distance to attach the sled.

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Is this before or after completing the calibration cuts? Before the cuts, the machine doesn’t know enough to accurately provide the right amount of chain. After the cuts, that’s a different matter, and would be an error. Which is the case?

Apologize for keeping you all in suspense! Actually @bar figured it out in that I was missing a digit in the offset between the motors and the work space making the machine think the center was way higher than what it was, another “Doh!” moment for me :frowning: But now that I got that all squared away the machine runs beautifully and my cuts so far are turning out great!

To answer your question @madgrizzle, after doing the measurement and the chain goes slack I removed the chain completely per the instructions. Click next, then it instructed me to zero the motors and hang the chain off the left side for the bottom connected sled. Once that’s accomplished I clicked “Adjust left” and the countdown begins. Which I might add is SUPER HELPFUL as I calibrate by myself and I’m able to catch the chain before it completely wraps itself around again. That actually is probably should be incorporated into any operation where the chain is instructed to move. The chain is measured out, now what I did before attaching the sled was click next as bar had mentioned in another thread that’ll center the sled which made it easy to attach, until the chain broke.

But I believe even though I didn’t have a need to attempt to press the extend button again when I had it seemed somewhat counter intuitive to have it shorten the side I needed to connect to the sled.

But either way I really appreciate the help you guys provided…the patience and the ability to help identify problems (even silly ones) is great!


Don’t forget to post pictures!!!

That was a community suggestion :grin:

That’s the thing with metric units when your used to imperial units. I did a similar thing with step 5 calibration… I entered the distance between top of the board and Cut 5 in cm instead of mm.


Is it reasonable to add a sanity check for this and other configuration values?


Yes, I think it is! The more sanity checks the better.