Math:
I was going over the spread sheet back and forth figuring I'd made a really basic error. They are the ones that are very hard to spot (you missed the existence of a third arm segment). New improved smaller fits through door drawings coming soon.
Thanks!
SumPod Math:
All delta robots have the same basic issues with shape. When you want a straight line or a circle, you move all three axis at once to get the job done. That means you always have an error related to each delta axis in the resulting circle or square.
A cartesian printer has errors related to the angles between each axis. You eye does not pick these kinds of errors up as quickly. The same is true of scale errors on each axis. A circle that is *almost* the same radius the whole way around is tough to spot.
With the LISA SumPod, rotation of the smooth rods matters. With the LISA you eliminate this. No free lunch.
As soon as you add the smooth rods, the cost starts to climb. The real evaluation would have to be a "bang for the buck" sort of thing.
Speed:
As the arm goes horizontal things do slow down. With the arm's I'm using (on a big printer),you get a 1/4" radius area that things are a bit silly in. One solution would be to take the print radius from 9.5" to 9.75". The other solution would be to ignore it. How often are you going to try to print in that zone?
If you toss out the last ~ 0.9" on a 10" radius, you no longer need to traverse ~ 4" of lead screw. The longer arms to do the radius take away about 1.5" of screw (build height), so you net win back 2.5".That's only if you can play with things to still be able to use the whole screw.
I was going over the spread sheet back and forth figuring I'd made a really basic error. They are the ones that are very hard to spot (you missed the existence of a third arm segment). New improved smaller fits through door drawings coming soon.
Thanks!
SumPod Math:
All delta robots have the same basic issues with shape. When you want a straight line or a circle, you move all three axis at once to get the job done. That means you always have an error related to each delta axis in the resulting circle or square.
A cartesian printer has errors related to the angles between each axis. You eye does not pick these kinds of errors up as quickly. The same is true of scale errors on each axis. A circle that is *almost* the same radius the whole way around is tough to spot.
With the LISA SumPod, rotation of the smooth rods matters. With the LISA you eliminate this. No free lunch.
As soon as you add the smooth rods, the cost starts to climb. The real evaluation would have to be a "bang for the buck" sort of thing.
Speed:
As the arm goes horizontal things do slow down. With the arm's I'm using (on a big printer),you get a 1/4" radius area that things are a bit silly in. One solution would be to take the print radius from 9.5" to 9.75". The other solution would be to ignore it. How often are you going to try to print in that zone?
If you toss out the last ~ 0.9" on a 10" radius, you no longer need to traverse ~ 4" of lead screw. The longer arms to do the radius take away about 1.5" of screw (build height), so you net win back 2.5".That's only if you can play with things to still be able to use the whole screw.