I don’t understand how the quick method for resetting the chains is supposed to work. If the default extend value left the sprockets at 0 then it would make sense but mine don’t line up after extension. Is there some configuration value I need to adjust in webcontrol?
there is a chain length value in ebcontrol (default 1651mm, was 1650 in early
groundcontrol)
the idea is that you set a sprocket tooth to be straight up, and then hang the
correct link on that tooth so that the distance from there to the end of the
chain is this distance (I marked my chains incorrectly and so manually changed
this distance to match my marks rather than re-mark them)
after you hit the buttom in WC, it tells the firmware that the chains are
extended to this distance, and things continue from there.
There is a slight bug here in that this does not take into account chain
sag/stretch, so there is some error introduced when you do this, but for most
people it’s not significant.
During the full calibration process, there is a point where it has fed out
1651mm of chain on each side. That is when you should pause and mark your chains
(and you can see if the sprocket tooth is really stright up or not, and therefor
how much error you will be introducing). After this point, you ‘move to home’
David Lang
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That’s the part that was confusing me. After extended 1651mm the sprocket doesn’t have a tooth pointing straight up. Is there a way to configure the default reset distance so it could be straight up?
This is tricky. moving one tooth is 6.35mm, so in theory 1651mm is a integer
multiple of teeth so one should be straight up.
However, to account for chain sag/stretch, it doesn’t quite work that way and
the current firmware doesn’t have a way for us to track/fix this.
IMHO, what we should be doing is extend enough to hook up the sled (allowing the
user to extend more to handle wider top beams), and then let the user move the
sled down in integer tooth movements until they get it to what they consider
‘center of the workpiece’ (note that this may not be the exact center, but it
should be within a 1/4" or so of the center) and record those chain lengths (may
be different for each side) for the reset.
IIRC the firmware supports move-by-encoder-steps, but only one motor at a time,
this would be much cleaner if both could be moved at once. And the chain reset
lengths would need to be stored separately per side.
David Lang
“after you hit the buttom in WC”, what the heck is WC for a newbie?
Web Control
David Lang
WC doesn’t work with the M2, you must use makerverse.