Proposal "Park" functionality

Software Maslow Firmware
1

To make changing material and/or bits easier, I propose that a ‘park’ functionality be added.

Currently the user can

  • relax tension
  • disconnect the lower belts
  • hang the sled and disconnected lower belts out of the way
  • change the workpiece
  • reconnect the belts
  • apply tension

But must leave the maslow powered this entire time.

Parking/unparking would be a multi-step process

Parking is two steps:

  1. User clicks on the Park button
    • (optional/future enhancement)
      • move the sled to a preset position (I am thinking high-center is a good place to go, configurable similar to setting home)
      • Raise the Z axis to a maximum known-safe height (in the configuration, possibly preferences) similar to the current bit-change PR
    • System saves the current belt lengths and magnet angles (similar to the new feature that will be in 1.13 that saves this info across power cycles)
    • Relax the two lower belts

User can now disconnect the lower belts, pretty much as we currently do

  1. User clicks on button to retract just the lower belts
    • machine retracts the lower belts and records these belt lengths and encoder data, without changing the upper belts

At this point the machine can be powered off and restored without the rehang dance

Unparking is also a two step process

  1. On power up or when the user hits an unpark button

    • The system recognizes that it’s parked
      • Puts the lower belts into ‘extend’ mode, with the limit being just a bit longer than the length of the lower belts when they were recorded for parking (which may be different than the normal extend limit)
    • user extends and connects the lower belts

  2. User clicks on finish-unpark button to apply tension to just lower belts

  • system compares encoder positions to saved data
    • If it’s ‘close enough’ (encoders within ±1/4 turn, ~10mm) it restores the belt length and encoder data
      • adjusts the position to match any slight movement that happened.
      • sets the machine in the state ‘ready to cut’
    • it it’s not ‘close enough’ report that there is a problem and the full rehang dance will need to be done
      • possibly automatically relax tension

Thoughts?

2

I don’t think that we need a special button for this. The “Apply tension” button already does a check to make sure that everything is in order before unlocking the machine so you can already press “Release tension” then disconnect the machine from the frame…do anything, then reconnect and press “Apply tension” to resume where you left off.

Adding saving of belt lengths through power cycles would be extra nice because then you wouldn’t have to worry about keeping things powered up

3

you have merged the PR to save the belts across power cycles when we are in retracted or ready-to-cut

we are having a discussion elsewhere on if it’s safe to save the belts after releasing tension.

If that is safe, then you could release tension, power off, disconnect belts and recover (but you would have the long belts dangling, in the way and risking being damaged)

This is better than that because it lets you leave the top belts connected while retracting the lower belts to get them out of the way, and then have a path to resume cutting without having to disconnect the upper belts (with or without a power cycle)

4

Park position of Middle left or middle right might be a better idea:

In vertical orientation top might be tall and out of reach for some.

In both orientation dust hose would be dragged on top of work piece.

Maybe only one top corner belt keeps tension?

Dano

5

Dano wrote:

Park position of Middle left or middle right might be a better idea:

if you set it like you do home, it can be wherever it makes sense for you.

but the idea of top was to get it and the belts supporting it out of the way.

Maybe only one top corner belt keeps tension?

If the sled will be out of reach, the top anchors will be even more out of
reach.

but you can currently move the sled off of the workpiece, and even when we add
soft limits, you can change them to let you move off the workpiece. so you could
make a point to the side where the router can move to (even if the belt angles
are bad, you aren’t cutting)

David Lang