rp1007 wrote:
I wonder whether there’s some trick that you could do messing with the belt
path so the belt attachment/pivot point is all the way next to the router
rather than constrained to the outside of the rings.
what do you mean? one thing that Bar has said is that the arms are not going to
be moving up and down with the router on this version. That will eliminate a
significant source of error.
David Lang
So this is all just fun speculation until we see some real prototypes. but one of the unexpected things about the Maslow 4 for me was that the drive motors don’t pull directly on the belts. they pull on the spools which wind the belts up. That means there is another point of failure where the spool teeth can break. I could see playing with a direct motor to belt drive and maybe even throwing the encoder on there as a way to reduce parts. Parts and engineering already exist for machine belt drive gears so it could also make more off the shelf parts available.
Two other thoughts are that encoders don’t need 360 degrees of spin around the spindle. They are already limited so you could possibly work with just four 90 degree bits of track or rotation for each one.
Also when you pull belt in on one side you are extending on the other, I could see playing with a system that just stores a little slack in the machine that is the difference between the opposite diagonal belts. Probably messy but it could be fun
I kinda want to see people’s sketches of what a fast fun mini Maslow might look like.
wouldchuck wrote:
So this is all just fun speculation until we see some real prototypes. but
one of the unexpected things about the Maslow 4 for me was that the drive
motors don’t pull directly on the belts. they pull on the spools which wind
the belts up. That means there is another point of failure where the spool
teeth can break. I could see playing with a direct motor to belt drive and
maybe even throwing the encoder on there as a way to reduce parts. Parts and
engineering already exist for machine belt drive gears so it could also make
more off the shelf parts available.
the problem is that you then need some other mechism to provide the tension on
the spools to take up the belt slack.
the ~8:1 reduction from the drive motor to the belt movement also helps
Two other thoughts are that encoders don’t need 360 degrees of spin around the
spindle. They are already limited so you could possibly work with just four 90
degree bits of track or rotation for each one.
the maslows currently are limited to ~50 degrees of movement and that causes
problems in the corners. they don’t need 360 movement, but it would be good if
they could cross over the top/bottom to have two 140 degree tracks.
Also when you pull belt in on one side you are extending on the other, I could
see playing with a system that just stores a little slack in the machine that
is the difference between the opposite diagonal belts. Probably messy but it
could be fun
let’s say your frame is 8x10’, in the center, corner/sled/corner is 12.8 ft, in
the corner, it is 9.2 for one belt and 6.1 for the other, or 15.3 ft so you have
2.5’ of slack to handle.
David Lang
Since the belt and the drive gears are acting at the same radius is there any mechanical advantage there? The gear on the spool and the belt move at the same speed along side each other. I know there is a gear box on the motor but I would keep that.
So I already like how simple and how few parts the maslow has. if one was redesigning it what are the failure points? are they expensive or difficult to source? Belts break. Belts are easy to buy. Spool gears get stripped. There is only one limited source for those. Idler plastic gears break if the belt gets tangled. They can be printed? I have seen the idler gear axle fixes on the forums. Clamps fail, You can print better ones. I am right now buying a few more spools. Computer board is unique.
When redesigning the maslow How do we increase reliability and reparability?
good point
David Lang
Blockquote
and for an arm
the only question is if this is rigid enough or if it would need a lip on the bottom of the spool and a second big ring or just the small cap
