ARM LENGTH

[nitewatchman]

Has anyone seriously looked at increasing the length of the Delta Arms to control stability of the Effector Plate as the print nears the outside boundary of the print bed.

When I printed the 4" Akemake Spirulida Speakers, the parts maxed out the build zone and the arms would go nearly flat to reach the edges. The effector was shaky and the nozzle would tend to lift at the extreme reach.

Would increasing the arm length by 5mm, 10mm, 20mm, etc. help solve this or violate the basic karma of the Delta Geometry. I realize that there would be a loss of build height but to me a more than fair swap. I am trying to sweat through the design parameters, reminds me of engineering school.

[Earthbound]

I've been contemplating the arm length, too. There have been several threads where complaints were made recently regarding the undersized build area - the advertised 280mm diameter vs. actual ~270mm. I'm no geometry expert, but it seems to me that arm length is important to build area. For a delta printer to have a build field diameter of D, the arms need to be at least D in length - OR - the arms must swing through more than 90 degrees of travel. Is it just odd coincidence that the arm length on a Max is so very very close to the actual build diameter? I have not looked at the underlying math to see if/how the firmware handles delta calculations when arm angle hits vertical.

[Renha]

I think it would be great to have longer arms. Looks like there's nothing really hard in making, for example, fiber rods arms longer. I think I'm o'k with losing some centimeters of build height, or even decimeter. In worst case, one could make his Rostock taller for compensation

I think that adding 1-3 centimeters is good but not great, while adding about 5 and more centimeters (or as much centimeters as needed for making resulting length metric round number, enough 123.456789s) is good and great same time

[RegB]

Without doing ANY calculation I think you would be trading one problem for another, perhaps acceptable, perhaps not.
Longer arms probably means magnification of position repeatability errors.
What if you could build very high towers and use say 10m arms on a mere 280mm build plate ?

Not something I can express in geometric terms, I can only waive my wrists and forearms around to show what I mean (-:

There is an on-line calculator for rostock geometry SOMEWHERE.

[Mac The Knife]

I've installed the Trick Laser arms this past weekend, and I have been playing around with the "Tower Rotation" settings in the EEprom settings. There is settings for arm length also so it would be a simple enough to experiment. Easier if you are already set up with the carbon fiber arms, and have the odds and ends to build arrows.

[Mac The Knife]

Hmmm, I could even dig out the fletching jig and glue on some fletchings for the hell of it,,,,, call em resonance dampers or something.

[nitewatchman]

I've installed the Trick Laser arms this past weekend, and I have been playing around with the "Tower Rotation" settings in the EEprom settings. There is settings for arm length also so it would be a simple enough to experiment. Easier if you are already set up with the carbon fiber arms, and have the odds and ends to build arrows.

Kinda the plan in the back of my mind.

Got a pile of CF tubes and ideas but a little short on time right now.