Arm ordering: does it matter?

Troubleshooting
1

Does the order in which the arms appear on the router matter?

I remember when I first assembled it, I put the arms on in exactly the order specified in the video.

I’m now looking at it after taking it apart and reassembling it a few times due to troubleshooting, and I see that I’ve put the arms on in a different order.

They are still on in a way that the opposite belts are “neighbors” in the z axis, so it should minimize the torque applied, but aside from that, the order differs.

I’d rather not take it apart and reassemble it again… will this affect the function of the firmware or is there any other problem with this? The only potential problem I see is if the kinematics take into account the z-height of the arm in each direction, does it?

2

The key is there are z height settings for the anchor points you will need to adjust in Maslow configuration .

Some people in vertical frame layout have made the arm order change to help reduce sled from raising off the material during operation.

Dano

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3

Yep - it does.

You’ll find these in the maslow.yaml file as the Maslow_??Z values. These should be 22mm different from each other, matching the stacking order of the arms. They also should have some ‘base offset value’ (starting value) that matches the difference between where the belt ends are at on the anchor points, and the exit point of the belt from the lowest arm in the stack.

But wait! There’s more.

If you’re doing a verticalish orientation, then you definitely want opposite belts as neighbours in the z-axis, and the highest and lowest belts (relative to each other) being neighbours along a long side (horizontal) rather than a short side (verticalish).

If you’re doing a horizontal (on the floor) orientation, you have an option to stack the arms so that they describe a plane, rather than a saddle as per what the verticalish orientation requires.

In all cases you’ll have to modify the Maslow_>>Z values in your maslow.yaml file to match.

… and recalibrate …

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4

@md8n

Can you elaborate on the Arm order for the vertical setup. We have yet to build the frame but I did assemble the machine (will change the offsets to match the arm layout)

I have ours built, listed in order highest to lowest:

BL - highest
TR
BR
TL - lowest

5

After some testing, where I ended up was this:

  • For vertical-ish frames the principles guiding arm layout are:
    • Opposite corners should be next to each other in the stack of arms, i.e. the pairs are:
      TR<->BL and BR<->TL
    • The ‘highest’ and ‘lowest’ arms in the stack should be separated by a long edge, not a short edge. i.e. TL ↔ TR or BL ↔ BR

And from the above the ‘best compromise’ order I could come up with was:

  • For vertical-ish frames I’d go with the layout of (starting topmost ‘down’ to the sled) BL → TR → TL → BR

With changing the arm order I would strongly recommend redoing calibration. BUT BEFORE THAT, change the Maslow_**Z values in the ‘stock’ maslow.yaml to correspond to the changed order. And use it to wipe any existing ‘maslow.yaml’ file on your machine.

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