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Unread 03-11-2015, 11:25
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Re: pic: 8wd 6 cim WCD with PTO

Quote:
Originally Posted by Nathan Streeter View Post
This looks like a tank! Seems like a good design, that could pack a lot of capability in a reasonable weight. I've not designed a WCD, so I can't comment much on that...

As others have said about your gearbox in its own thread, it seems on the "overkill" side of things and seems to be geared aggressively high... I understand though that this is an "R&D drivetrain" and the goal is to evaluate how fast is "too fast" and such... so I won't comment further on that.

One little thing I thought I would comment on though, it seems to me that you may want to swap your belts from inside/outside... move the belt across the center two wheels into the middle and move the two belts that go to the outer 2/4 wheels closer to the frame. The 15mm belts require a lot of shaft on the inside of the frame, so the cantilevered axle length seems pretty long. By swapping like this, the moment arm that the belt tension on the two end axles is pulling on will be shorter and the middle axles may be better able to tolerate that dynamic loading because they have belt tension pulling in opposite directions... Seems like with all the available torque from that gearbox your dynamic loading could be pretty intense! This could mitigate any shaft deflection and resulting belt hop...
The problem with switching the belts is that the belt in the middle has to be close to the frame to clear the PTO cylinder. If we end up ditching the PTO, i will definetly switch the belts, although the majority of the load will be on the center 4 wheels, considering the outside wheels only touch the ground when the weight shifts to the front or back. So I feel that the belts in this configuration wont be a problem.
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