If it’s up and to the right, then shouldn’t the right chain be shorter than the left?
Thanks, that is strange. So I assume the chains fed out the same length before you attach the sled. The sled was centred on X axis / horizontal (lets focus one this on first). Then the ‘move to centre’ positioned the sled 10" up and 10" to the right? If your right chain is longer your sled should be to the left of the centre.
Where is the the sled before you click ‘move to centre’?
pictures would probably help us understand what’s happening
thanks everyone for the help. I started all over with the setup and calibration and it looks like it all working good.
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I had this exact problem. Short answer. Physically move the sled so that the bit is as close to the center as possible. Mark center first, of course. By physically I mean lift the chains off the sprockets and move them. It’s not precise because you are dealing in whole tooth moves. After it makes the test cuts and you feed. The measurements in, it will center. Mine Sid within about 1/2 mms.
I would expect this to give you accuracy issues, it is important for the firmware to know exactly how long the chains are to do the calculations to move the machine
I’ll just do the calibration over again.
Bar,
I would not disagree with you on the potential for accuracy issues. Nothing outrageous so far, but pretty basic cutting to this point. I had the exact same issue. I believe the genus is as follows. Apologize in advance for the length.
Early step in the calibration process is to extend a known length of chain over the left motor sprocket (from outboard of the frame) to the right motor sprocket third tooth. Left motor turns clockwise to accomplish this.
In the next step, the left motor turns counter clockwise to tighten the chain and establish the motor to motor distance.
A few steps later, we get to “extending” a known length of chain from each motor sprocket “toward the router” (although it doesn’t use those words specifically). We have input whether we are over or under chain direction.
I manage slack side chain outboard of the cutting field on each side of the frame.
So extend a known amount of chain toward the router means from the outboard side over the top of the sprocket into the cutting field.
Right side motor rotates counter clockwise as expected and that known amount (as chosen by the program) comes over the top of the sprocket. Good to go!
Expecting the mirror image result from the left side, chain is hung on the top sprocket with chain outboard of the cutting field. Left motor rotates counter clockwise (when clockwise was expected) an spits the chain off on the floor. Recall, that counter clockwise was the direction of rotation from the chain tightening step.
Back to the beginning…
Same result, multiple times.
So, last time left side chain gets “extended” from the inboard side, over the top of the sprocket (motor rotating counter clockwise) and doesn’t wind up on the floor.
At this time I conclude the program is smarter than me. However, the lengths of chain that connect to the router are not the same length.
Chains attached. Next step, program moves router to center (as best it knows where that is at this time).
Router moved an inch or so in each direction and stops about 8 inches left of center an 10 inches below center.
So now I’m reconsidering my assessment of smart.
Visit to the forums, got some answers, nope, physical movement exercise.
I’m an engineer with rudimentary computer skills so I’m still puzzled at this point.
My engineer brain does reach the reasonable and logical conclusion that had the left hand motor rotated in the clockwise direction, the router would have gotten much closer to center as the chains would have been the same length after the “extend chain step”.
Possible I messed something up in the calibration process, for sure. Ten times in a row, probably not.
Any help would be greatly appreciated!
Best regards,
Duane
August 10
Duane:
By physically I mean lift the chains off the sprockets and move them.
I would expect this to give you accuracy issues, it is important for the firmware to know exactly how long the chains are to do the calculations to move the machine
I’m not 100% sure I have the sequence of events correct in my head, but here’s what I’m thinking is going on. This is a “top feeding” configuration, right?
It sounds to me like what the calibration is doing is that the left chain is already on the left sprocket and so the chain will retract (rotating the opposite direction of the right sprocket) to pull the chain back to the correct length after measuring. Does that fit with the behavior you are seeing?
I think that this is one of the most confusing things to new users. I can remember enjoying it as ‘more efficient’ when I was doing repeated tests of the calibrations, but I already knew ‘the secret’ 
I’d suggest that after measuring between motors, the user should be instructed to remove the chain and do the chain calibration from the first link. The time saved by backing out the chain is lost in confusion.
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At this point, I’d have to agree with this. After the distance measure routine, rotate the left sprocket back to 12 o’clock automatically and have user reapply the chain.
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Yes.
An earlier response set me straight.
The key is to leave the chain on the left motor sprocket after the “tighten chain” step.
Then it retracts chain (rather than extends chain) on the left side - which is counter clockwise motor rotation.
I understood (more likely misunderstood) the extend chain step to be for both motors and put the left side chain first link on the top tooth. That step is actually extend right side chain over the sprocket and retract left side chain (shorten the length of chain between the sprocket and router sled).
This resulted in the left side chain length being something other than what the firmware “wanted it to be” and the router being offset instead of centered when the firmware moved it “home”.
My assumption that the firmware was smarter than me was correct, we just had a communication problem.
Great machine! Working on my “communication” skills so I can explore the capabilities.
Appreciate you looking into this. Apologies if I wasted your time.
Duane
August 13
I’m not 100% sure I have the sequence of events correct in my head, but here’s what I’m thinking is going on. This is a “top feeding” configuration, right?
I manage slack side chain outboard of the cutting field on each side of the frame.
It sounds to me like what the calibration is doing is that the left chain is already on the left sprocket and so the chain will retract (rotating the opposite direction of the right sprocket) to pull the chain back to the correct length after measuring. Does that fit with the behavior you are seeing?
1 Like
I’m with Duane. Same exact problem. First time calibration. Could move physically, but saw Bar’s comment: “would expect physically moving chains to give accuracy issues…” and now don’t know how to cross the physical to electronic control boundary…
Have followed Duane and Bar to current, 8/13. My calibration is going bad in same place Duane’s is, + or - 1 step. I think the answer is in the discussion, but will have to read again fresh tomorrow. Thanks.
Joe