Calibration problems

I have been trying several times to calibrate my system however no matter what I do it comes up way short of where it should be. I have the triangular sled mounts,

Here are my approx settings:

Dist between Motors: 3610 mm
Height above work space: 580mm
Rotational sled: 255 mm
4x8 sheet in mm

Every time the chains come up short to link up to my sled… What am I doing wrong this is getting old.

Thanks

you aren’t doing anything wrong, the system has the distance to feed out the
chains hard-coded, and it only works for the stock frame size. you will need to
feed out additional chain from each side to get it to where you can hook it to
the sled.

There may be an option in the advanced settings area, but I don’t remember the
details.

David Lang

It’s the extend chain length setting. Try 2032 mm

I am not sure what you mean by extend the chain length setting… Is that hard coded in a config file? what is the relevance to that number? I guess what I get concerned about is once I get the sled attached how can I be sure the motors won’t rip the system apart if its not aware of where each of them are extended.

Also I have been trying to find a video or instructions on the manual calibration process with no real luck, would this process be better?

Thanks for all your input can’t wait to see it all work,

What do you mean by “triangular sled mounts”? The three most common sled attachments are L brackets, the Ring, or a Linkage. Two of these enable triangular kinematics, one does not. Your rotational radius number will be different for each method.
-Logan

I have the linkage I guess is what your calling it that is made of wood and sold on the site.

So my triangular radius I have been using is ~ 255mm or ~ 10 inches either way the chains come out extremely short of linking up with the sled. Total chain length left and right after final adjustments are made is ~ 65 inches 1651 mm which does not reach.

I am not sure what you mean by extend the chain length setting… Is that hard coded in a config file? what is the relevance to that number?

it’s the setting (under the advanced settings tab) telling the system how far to
extend the chains in the manual calibration step at the point where it’s not
working for you.

I guess what I get concerned about is once I get the sled attached how can I
be sure the motors won’t rip the system apart if its not aware of where each
of them are extended.

unless you move the chains manually (or loose power unexpectedly), the machine
always knows how far they are extended, it’s just that the manual calibration
step doesn’t extend them far enough (in my opinion, it doesn’t extend them
properly for a stock machine, let alone for a wide machine)

As @dlang has said, you need to increase the extend chain length distance in advanced settings. I recommend 2032 because it’s a multiple of the chain pitch. When you do extend the chains, mark (permanent marker, nail polish, something) the link of chain that is on the 12 o’clock tooth. If you set the distance that’s a multiple of the chain pitch (6.35 mm) you should end up with one tooth of the sprocket back at 12 o’clock. So, next time you have to reset the chain lengths, you can set the sprockets to vertical and then place the marked links on the sprocket and then tell ground control to manually set the chain length. No need to go through the adjust chain process.

2 Likes

I have the same problem. You can hit “Move to Center”. This will extend the chains.

Oh I like this too.