One BF20L more

[antomost]

Hi,

I start building the Optimum BF20L based on Robocnc plans.

Electronics that will used are from CNCDRIVE, 250W servo motors on X-Y, 400W on Z, 1.2KW power supply and UCCNC S/W.
Direct drive and i will try to open oil pockets.

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[AndyUK]

Very interesting, looking forward to hearing more! One question springs to mind, how come the Z axis requires so much more power than X or Y?

[antomost]

i am not an expert on the subject. My thought is that because of the z axi's weight, extra power may required. Also the ballscrew is M20 instead of M16 used on the X-Y axis

[AndyUK]

i am not an expert on the subject. My thought is that because of the z axi's weight, extra power may required. Also the ballscrew is M20 instead of M16 used on the X-Y axis


Ah! Were those sizes of motors recommended by another build then? There is a motor size calculator floating around these forums somewhere, although I don't know if it also calculates for servos - you might find it interesting.

My line of thought was that the Z axis is typically held in place moving less frequently with lower accelerations, whilst the X and Y have to deal with the cutting forces - hence why I asked the original question. I can certainly see your logic - and the inertia of the larger screw will make a reasonable difference.

[antomost]

Hello all, looks likes anniversary reply but I just had the time to continue the build. Y and X almost finished.. waiting for an enclosure (bottom bath) to be prepared by a local factory and the moving forward with the Z. Finally, I will use the same (250w) motor also for Z, direct but with a brake.
https://youtu.be/lbZNAqbIojI

https://youtu.be/5-wSKXQL8z4

[Doddy]

Having just this second recovered my little SX2.7 running steppers and 2:1 on a 1605 screw, all I can say is: Wow!, Speedy!

Looking good.

[antomost]

a very carefully homing!!27898
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https://youtu.be/rj-rQ3XNEvA