Carson Barry wrote:
I’m still advocating for moving towards fixed arms for the belts and for those
being at the edge of the carriage rather than using the router, or eventual
tool mount sleeve, as a hinge pin. The math needed for calibration for this
has been figured out, it’s just a matter of seeing if it is feasible to do
something akin to that solver function I used in my code example in the actual
calibration program.
I agree, keeping the arms at a constant height (and ideally the same height)
should have noticable advantages in stifness. The math should not be a problem.
one possible problem is that if they are too low, the sled will want to tilt.
This isn’t a problem when on the floor, but would cause grief when tilted.
This greatly reduces the needed complexity in the design of the arms because
they would be able to have the motor mount in the center, which also removes
the issue of the belt being near the gears that keep chewing them up when
things go wrong, and allows those parts to be much smaller as well and doesn’t
have them being tied to the diameter of the router/sleeve anymore, which was a
problematic design restriction.
One problem is that it takes a lot of space for the belt when you have a small
diameter spool. If you have a 15mm hub (given a 5mm motor shaft and thickness to
anchor the belt, you aren’t going to go a lot smaller than this) to fir the same
14.5 ft of belt requires that the outside diameter be about 95mm. fitting four
of these spools at the same height is a problem
It also comes with the added benefit of the carriage orientation being
maintained at all times, which should allow for off-center tooling, such as
drag knives
since drag knives swivel, this is not a problem for them.
and should also increase accuracy slightly, as the carriage
rotating has some level of negative effect on that, though I couldn’t speak
to exactly how much.
I think it depends on the precision. one nice thing about being centered on the
bit is that it’s more forgiving, if the tool isn’t centered and the sled rotates
under force (by the belts having different tension than expected) you can’t
compensate for it. Since belts act as springs, and do stretch over time (and
different belts stretch at different amounts), I would fear that it’s trading
one type of error for another, and it’s much easier to center the bits on the
armss.
If coupled with a panel-saw-like gantry, this would hugely increase the
versatility of the tool. My long term plan is to turn my frame into a hybrid,
for both a panel saw and for the maslow, and to make it so I can mount the
maslow in place of the circular saw. Still working out the best way to handle
adjusting for thickness of material, but I’m no longer worried about the
gantry interfering with the maslow after some testing I did of putting casters
on my sled so it wouldn’t catch on paper for plotting jobs.
if you have a gantry, then just build a corexy drive system, it’s much simpler
and much better supported.
I still intend to design mounts for my arms that let me move them out to the “corners” of the carriage to test this with the existing hardware, I just shifted those plans to winter.
let’s setup a new thread for this. I have ideas about what it would take.
So it’s said, I do understand that this might be a bit much for a first
revision, but I do feel like it’s something that would be a huge force
multiplier for increasing versatility and reducing complexity.
yep, not a maslor 4.1 change.
David Lang