Rage_Hobbit

[MOC] 4-Speed Seq. Sync. Transmission (Instructions)

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Video Found Here:

Specifications:

Number of Gears: 4

Gear Ratio Spread: 5:1 - 1:1

Shift Reliability: 99%

Friction Level: Low

Transmission Type: Dual-Sequential

Synchronized? Yes

Auto-stop? No

Optimal Transmission Motor RPM: 15 - 40

Length: 10 studs

Width: 11 studs

Height: 5 studs (6 with optional support)

Note on dimensions: dimensions are measure to the furthest protruding point of the transmission; that is to say, the transmission does not actually occupy all of the space designated above. Also, I know that the measurement for width is greater than that of length, (which is against their very definitions) but length was measured as being parallel to the drive axles.

This is the transmission I used in my RHM Wutzwerg (http://www.eurobrick...opic=125571&hl=) supercar. It is a dual-sequential transmission, meaning that it is actually a pair of 2-speed transmissions (one with ratios of 3:1 and 1:1, the other with ratios of 1.67:1 and 1:1) which are shifted in sequence to produce 4 distinct, sequential speeds. It is very smooth and very reliable, the only potential concern being that it can slip under <b>extreme</b> stress situations; this can be remedied by added a gear reduction later in the drivetrain. It does also lack an auto-stop function, however I will be posting an appropriate stepper-motor shortly.

Instructions are here: https://drive.google...XVFRGc. Before building, please read the following important notes:

-Instructions are in *.lxf (LDD - Lego Digital Designer) format. Sorry, I am horrible with other Lego CAD programs.

-Green marks the drive input, red marks the drive output, and purple/pink marks the transmission shifting input.

-I do ask that if you use this in a model, you give me credit as the designer of the transmission.

-Elastics have to be fastened like this:

http://www.moc-pages.com/image_zoom.php?mocid=426942&id=/user_images/116595/1459193308m

…so that the yellow part (orange in the instructions) is pulled on axis towards the shifting axle.

-The yellow ribbed axle connectors in the instructions need to be replaced with the part below:

http://www.moc-pages...595/1459193300m

-Any questions, comments, or otherwise can be addressed to me in the comments and I will make an attempt to respond as quickly as possible.

This thing won't accept pictures at the moment, so here's a full catalog of them: http://www.moc-pages.../moc.php/426942

Edited by Rage_Hobbit

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In the video the output shaft is spinning a little then stopping for a moment. Why is that ?

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In the video the output shaft is spinning a little then stopping for a moment. Why is that ?

That's actually because the output driving ring is slightly damaged from use in a previous model.

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