5 Speed Linear Gearbox
Idea of a linear gearbox extended beyond the usual 3 speeds. Features fixed input and output shafts.
The idea of a linear gearbox is quite popular and far spread, although the usual design features 3 speeds, or 3 + R at most. I was curious if more is possible, and it resulted in that design. Basically, it uses the idea of a 3-speed linear gearbox, but flippedand set on a sliding middle shaft. The latter solution eliminated the biggest drawback of the usual linear gearboxes, that is sliding input and/or output shafts. Here, they remain fixed, connected by the sliding middle shaft, so the gearbox can be incorporated into a construction much easier. There are, however, the problems with unsynchronized clutching/unclutching, typical for all linear gearboxes. I have not yet solved these so far, nor have I been able to think of a linear gearbox with a higher number of gears. There is one serious drawback concerning the parts needed: the middle shaft requires an axle no shorter than 16 studs. 16-studs long LEGO axles exist, but are only available in 7 LEGO sets as of the end of 2008. Their availability in the online shops is quite satisfactory though.
Back to this type of gearbox after failing to build the Veyron-box… I think I just managed to build this type of gearbox in a 9-speed configuration and a stepper+Reverse seems feasable. A great inspiration this gearbox is! Fingers crossed
@Ruben
No, thanks.
@Sariel
but i have to do is put it on it and make a program! and you kan doe it wit other motors but that hard.
@Ruben
I don’t have NXT.
I like this gearbox!
can you make one with 6 gears with a nxt like this: http://www.youtube.com/watch?v=4hKCEMFpV7I&feature=feedlik
the one how build it don’t give a reactoin of how it made!
plzzzzz
@hacatu
I would love to see it, but your photos are smaller than post stamps.
I have recently designed a stepper/selector mechanism for this purpose. It is bigger than the gearbox, but allows remote control. https://picasaweb.google.com/104815240336781491383/LegoRemoteGearboxShifter
For the stepper mechanism, you could have a worm gear between three 8 tooth gears on the bottom and two on the top. These 8t gears would have another 8t gear on the shaft in front of them. Then, a slider with one 8t gear would run between these so it always meshes one of the five 8t gears. Another slider would be pushed and pulled by the worm gear and attached to the first slider via a rubber band. This way, when you activate the motor, it pushes the worm gear one stud, which moves the gear selector (second slider) one stud. When the motor stops, the gear is no longer turning so the first slider is pulled into place by the rubber band. This mechanism is 5 studs by seven studs by five studs.
@Alan
Well, I’m not using vacuum engines.
@Sariel Well, if you are hooking it up to a vacuum powered engine or something that can run in reverse, it would be helpful.
It would be fun to have an R gear on a gearbox actually.
@Wei
You don’t. Why would you need an R gear when you can simply switch the motor to run backwards?
How would you create an R gear with the linear gearbox??
Cheers Wei
@arnau
Well the problem is to make it move by one stud every time. It has to be exactly one stud, and that would require a very accurate stepper mechanism, which could be larger than the gearbox itself.
@Sariel
I think it could actually work, if you use a clutch gear. Every time that the gear changes, it just moves one stud, so no matter what position the actuator is in it will always be meshed with another gear. When driving the car you don’t know what gear you are using at each moment, but you do know when you’re going to a higher gear and when you’re going to a lower one.
@arnau
No, it would suck. Firstly this gearbox is not synchronized, and secondly I would have to keep an eye on the actuator’s position all the time.
could you not motorize that with a linear actuator and use it on the Lamborghini you’re building?
@Sariel
I have not the time to do it myself.
For detailed information why I want such a gearbox(es) please use my email adress.
Ralf
@Ralf
Why would you buy it if you can easily build it yourself? I think the construction is clearly visible on photos, the only thing you ned are parts which you can get at Bricklink.
Hi Paul,
might it be possible to buy one of this 5 speed liear gearboxes from you?
Regards
Ralf