Ground Control (Calibrate Machine Control

In step 7 it states we are going to measure chains and reattach the sled. It does state that we are going to attach the chain to the vertical tooth but after that it doesn’'t state where we are going with the chain after that. You can extend the left chain and extend the right chain and hit stop and next. Are we extending the chain down to the attaching point on the sled.

It says that it will “measure out” chain (i.e., let chain out so you can reattach the sled) and when it’s done (after you press next) it will move the sled to the center… hopefully. So press the “extend left chain” and make sure it doesn’t get caught in the sprocket. When done, do the same with “extend right chain”… making sure it doesn’t get caught in the sprocket. Then attach the chains to the sled and press next.

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Now I am on this step and not sure what is to be done, I position the chain on the 12 o clock position and hit extend chain and it runs out to some pre-determined position. When it stops is that where I am to attach the sled because if so it isn’t in the middle of the board…Matter of fact it isn’t even close enough to attach the sled to both chains

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Is your frame a substantially different size than the original? If so when you click “next” the lengths of chains should feed out more so that it will be in the middle and you should be able to hook them up then, but be careful that there is enough chain available (you may need chains longer than 11’ for a different size fame).

Just to be clear, at that step, you only have to put the right chain on the right sprocket at the 12 o’clock position. The left chain should be left as it is (dangling down to where it’s just above the top of the work surface from the previous step).

I thought when you hit next, it retracts the chains so that the sled that’s been attached moves to the middle.

Process should press “extend left” (wait), press “extend right” (wait), hook sled up, hit “next”. If after “extend right” there’s not enough chain, then something is off.

Extend left and right will extend a known length of chain which is not frame dependant. Once you hit next the lengths will be adjusted to move to the middle for your frame which could either extend or retract chain depending on the size of your frame.

So my top bar is about 12’ across (go big or go home right?), and running through the calibration when I get to the chain length it measures out the known length there’s not enough to connect, clicked next to allow the motors to let out chain to center, but in connecting the sled (after the last link broke away…that was fun) the sled sits high center of the work space. Continuing on believing the center in the instructions was only referring to left/right I went to cut the sample cuts and the motors would have pulled the sled over the top of the work space had I not stopped it.

Clicking the extend left/right actually retract the chains making them shorter.

What’s the trick to calibrating with non-standard sizes?

Is this when using ground control version 1.09? I changed the text on those buttons from “extend chain” to “adjust chain length” because what those functions will do is retract OR extend the chains the target length.

When the sled wants to go over the top, that means that the machine either thinks the motors are closer together than they are really or that the machine thinks the size of the ring is wrong.

We’re you able to do the step to measure the distance between the motors?

Yup, using 1.09. In doing the step for the chain length the first option is to “adjust” left/right and once it’s run through that process the button changes to “extend”. And in clicking extend the motor steps back (retracts) in small increments. I’m able to run through the measurement step just fine (well, now that I realized I was doing it wrong) and consistently get approx. 3632 mm +/- 1 each time which is just shy of 12’ as expected.

As for the ring size I measured fairly close to 140mm from chain to bit, which was the estimated distance provided.

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Darn, it sounds like you are doing things just right then.

If you click the Actions -> Return To Center button what happens? It might be worth trying without the sled attached in case it tries to go off the top

High center still :confused:

Does the position readout in Ground Control show that the router is in the center?

X: 0.00
Y: 0.00
Z: 4.96

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Darn, well the picture sure is high :disappointed:

What about the vertical motor offset variable…does the value for that setting look right in the settings window?

It should be the distance from the top of the plywood to the center of the motor shaft.

Brilliant! It was missing a digit on the end :slight_smile:


Wonderful!!! That’s the best possible option. All that setting does is move the center up and down with no effect on the calibration so it’s a good one to have to change :grinning:

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