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Post by dragonbot on Feb 27, 2016 21:51:01 GMT
Design A: simple - lever is attached to motor horn and 200g of weight 6" away needs to be moved up / down -- so the torque (effort) by motor is 1200) .. yes? Design B: A vertical shaft is added - VERTICAL SHAFT is NOT attached to motor. Lever is extended past the axis by 1.5" We are not able to go past this, yes, I know the longer this is the less stress on motor, however, we are not able to do this. Then the motor is mounted 5" BELOW the axis. A vertical ligament attached to motor horn which is also 1.5" long. I assume the 1200 effort is reduced to 800 then increased again to 1200. So from what I see theoretically there is no advantage to this design over design A... however, it just feels like it should since much of the weight is transferred to the axis and then absorbed by the vertical shaft... So the motor in design B should not be doing as much lifting. .. What am I missing.. why aren't the numbers reflecting this? Thanks! DB. Google drive share link: drive.google.com/open?id=0B_gaJbtaTVANdXM2WmRPd29FQXc Attachments:
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Post by hexpod on Feb 28, 2016 2:03:44 GMT
Very interesting concept. deserves a serious study. you can better avoid the actuator/gearbox collisions in such a design.
small clip to get motivated...
vimeo.com/157014689
I would say, that in my animated model, you need the same amount of torque as with a conventional attachment.
With different levers ratios you could get a multiply factor, but I have the feeling that it will be a compromise on the main lever motion range and his speed.
Is there any mechanics engineer on this forum?
Guys, please assist.
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Post by vicpopo on Feb 28, 2016 7:51:47 GMT
We can't see the file attached ! And it's better to have a little drawing attached to the explaination.
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Post by hexpod on Feb 28, 2016 10:53:09 GMT
We can't see the file attached ! And it's better to have a little drawing attached to the explaination. now should be ok:
vimeo.com/157014689
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Post by tronicgr on Feb 28, 2016 13:49:35 GMT
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Post by dragonbot on Feb 28, 2016 18:41:38 GMT
We can't see the file attached ! And it's better to have a little drawing attached to the explaination. So sorry - ok - added the image as an attachment in my above posting. Dee.
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Post by dragonbot on Feb 28, 2016 18:49:35 GMT
We can't see the file attached ! And it's better to have a little drawing attached to the explaination. now should be ok:
vimeo.com/157014689
Very cool !! Love it.. ! Thank you for sharing!
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Post by hexpod on Feb 28, 2016 18:58:22 GMT
The stress on the motor is the same, just inverted to the other direction.
another motion study:
vimeo.com/157036565
and Safety factor (FOS) comparison made with two fixed geometry fixtures and 200Nm of torque CCW.
by comparing the FOS, you can deduct the different forces involved in different configurations.
cheers
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Post by vicpopo on Feb 28, 2016 20:09:17 GMT
Thanks for sharing all information . Great study hexpod . Hope dragonbot happy with your answer and also the link given by Thanos.
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