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Showing results for tags 'reversing'.
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TechnicBrickPower posted a topic in LEGO Technic and Model TeamHi All, Have just published the build instructions for my recent automatically reversing gearbox on rebrickable: https://rebrickable.com/mocs/MOC-49276/TechnicBrickPower/auto-reversing-gearbox Here's the video about it:
I'm building a swinging ship to go with my amusement park. I'm trying to drive the thing with a large rubber tire underneath it, but I'm out of my depth when it comes to gears. I need the wheel to spin clockwise for a few seconds and then switch to counter-clockwise. I have tried using a power functions switch, but without enough momentum to flip it, it always gets stuck in the middle off position. I tried using the remote and the IR sensor and manually controlling it, but I'm running my PF motors off of the old 9V train controllers, and there isn't enough power that way to run the IR sensor. I don't want to go with batteries. I wish there was a wall power option for the PF product line, but there isn't. So now I'm trying to create a gearbox that periodically reverses direction, but everything I've tried is close, but not quite there. Does anyone have the know how to create a gearbox that reversed the output direction every 2-4 seconds?
As part of Splat's To-and-Fro GBC, the mechanism that provides a means to halt the GBC if there is a jam I found to be particularly interesting. RohanBeckett then posed a challenge (half in jest?) to adapt the mechanism to automatically reverse the GBC for a short period of time and then for it to resume normal behaviour. So I decided to take up the challenge and came up with the following. In the video, my hand simulates the case of a GBC mechanism becoming jammed by holding the output axle. Following the "jam" there is a pause, the output axle momentarily reverses, pauses once more before resuming the original rotational direction. This mechanism is in the experimental stage and there is a minor defect. The defect, as shown in this second video, is that the differential continues to turn a very small amount even when there is no jam. The gearing ratios are correct, so I suspect that the rotation is being caused simply by the rotation of the axle. I'm posting this thread for two reasons; 1) to garner possible solutions to address the defect 2) to see whether anyone else has interest to/is able to improve/alter the mechanism. I'd be open to any suggestions as to how the incidental rotation of the differential could be eliminated. I'd also be open to seeing other peoples' interpretations to make a mechanism to achieve a similar result. For convenience, I have made the build instructions (PDF format) and the LDraw file (MPD format) available for download from BrickSafe. There are also a couple of images of the two sides of the build: Regards, David