thefabricator03 wrote: You see a lot of those aluminum extrusion tables wobble themselves apart at those speeds. I dont care what anyone says, a proper made steel table is hard to beat!
I have to agree. The convenience of extrusions is vastly overshadowed by the additional cost!
Anyway after another tuning session, I set the X axis to 36 m/min and 8 m/s^2 acceleration (just over 0.8 G). At these settings, it started to bounce around a bit and expose the spaceship's weakness. That is the 6mm folded aluminium gantry ends.
I always knew this was likely to be a problem but never knew how much wiring was going to be in there so I never designed any braces for it. So now I am working on designing a H shaped brace that will go full length top to bottom and pick up bolts through the top lid and the linear carriage mounts down the bottom. The crossbar of the H will be bolted to the gantry rail so it should stiffen it up enormously. I'm planning on using 80 x 40 x 3mm square section but might end up converting it to a U shaped section.
I'm not sure how much this idea will need to be butchered to allow for the wiring. But I think its a job for another weekend!
This weekend, I replaced the two Y axis motors
The new motors are the smaller ones with the pulleys on them. With shipping these cost about 4x what the other cheap ones are and are 7 amp vs the larges 4.2 amp motors. ANyway a bit of wight saving to offset the proposed braces.
Getting the pulley on worried me a bit. the Pulley had a 5mm keyway and the new motors had a 1/8" keyway. The old motors had a flat on the shaft and no keyway so I just used the provided grub screws. But this time with the forces I'm expecting I really thought I needed to use a keyway so I managed to machine a couple of stepped keys.
Anyway, I have not tried very hard, but this axis will easilly kept up with the 36 m/min and 8 ms^2 Acceleration after a couple of test runs. And that was only on 5 amps.
The Z axis motor is still to be replaced!
