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After shortening the travel required to shift gears in my improved paddle shifter unit for the Porsche (42056), I put some effort in trying to use the same concept - a lever knob gear driving a central knob gear - as a base for a 90 degree stepper. I was able to make a compact setup with the shift lever directly operating the shift axle that could in turn drive the clutches of a gearbox (the gearbox is not part of this unit). By using the knob gear inside the shift lever, the rotation speed of the central knob gear is twice the rotation speed of the shift lever itself. As a result each shift requires only a relatively short travel. The stoppers that catch the upper knob gear when shifting are the crucial part of this mechanism. They had to be reliable when it comes to catching the knob gear and needed to allow for a smooth return at the sane time. The whole setup relies on its interaction with the simple 90° limiter., which has been integrated in this unit. I'm very happy with the result. EDIT: I've been working on this a little more. I'wasn't completely satisfied about the return of the shift lever. It requires a lot of silicon power and I couldn't get it working with a new set of red silicon bands. Apparently the old ones (+/- 8 years old) are stronger. So I decided to skip the auto-return completely. The return is not needed for a full shift and a completely manual operation of the shift lever gives a nice feel. Returning the lever can actually be postponed until the next shift. This also allowed me to make an even more simple version of the stepper. In that simple version a different 90° limiter now operates directly on the lower knob gear. The limiter allows for some free movement of the orange paddles, but my guess is that this won't give any trouble when they operate the clutches of the gearbox. So all together I now have two versions: The compact stepper with separate 90° limiter and the simple stepper with limiter directly applied to the lower knob gear. Compact 90° stepper with separate limiter (LXF-file) Simple 90° stepper (LXF-file) Comments and (suggestions for) improvements are welcome!
Sequential AWD 4-speed gearbox with V8 fake engine Features - AWD with center differential - Sequential 4-speed gearbox - One-finger shifter - V8 fake engine This gearbox is an excerpt from my rugged supercar project. The mid-console has an important role in the overall stiffness of that model. It had to be narrow as well. If you build (have built) it, you will also notice it has very little torsional flex. I wanted a 4-speed sequential gearbox covering a wide range of ratios. So not something like 1:2.5 upto 1:1, but rather something like 1:3:5 upto 1:0.8. Another requirement I had, was that I didn't want red clutch gears to transfer drive on axles rotating at different RPM. This is a common practice, but from modding the Porsche I know it induces a lot of friction on the axles involved. When not engaged, red clutch gears better only make dummy rotations and not transfer drive. And finally, all had to fit underneath the engine; I didn't want the gearbox to be routed through the entire chassis. Instructions available on Rebrickable.com. Have fun!
If you don't like things that use axles as torsion bars, then please skip this topic. In the march of steppers, shifters and limiters, here's my throw at a 90 degree stepper without silicon or rubber. I started off with my compact 90 degree stepper which uses silicon bands for returning the shift lever as well as for limiting the shift axle to 90 degree orientations. Because the rotation movements that had to be limited are quite small (max 10 degrees), using axles as torsion bars seemed to be a valid option that wouldn't put too much stress on the axles involved. After some trial and error I found a setup that actually works. It uses 3L axles with knob and half pins (also with knob) with a flat round 1x1 tile attached to them as stoppers and pole reverser handles as torsion levers. In idle state, there's practically no torsion stress on any of the involved axles. Only when you pull the shift lever, the axles get twisted, but not more than about 10 degrees for the shift lever and even less for the 90 degree limiter. The casing had to be made quite strong to prevent any other bending then the intended axle torsion. LXF-file here.
Hello fellows, Let me present my idea for a stepper mechanism for sequential gearboxes (4 speeder). Please forgive me giving such a a short description, but I wanted to share this idea before I take of to my hollyday. I didn't even packed yet and I depart tomorrow So I'll insert the video and copy its description here. I'm going to try to get online every day and react on questons and comments. Finally let me say a big thank you for Didumos69 and his 90 degree limiter for the inspiration. This video meant to demonstrate the stepper, not the gearbox. The nature of this design allows it to be used with almost any kind of gearboxes. I'll make instructions for the gearbox later however I've been trying to show it from every angle in the video so you can attempt to reverse engineer it. It isn't that complicated. Stepper: I've got the inspiration from an other idea what Diederik van Leeuwen came up with. He goes by the name of Didumos69 on the Eurobricks forum. Click on the link below to see his post: http://www.eurobrick.../forum/index... The reliability of this stepper depends on the right rubber rings. For the limiter I was using the small lego silicone ring and for the stepper (the green ring) a non lego one that is much weaker than the white. If it is too strong it pulls the knobwheel back instead of sliding trough on it when it returns to the basic position. So find the right combination by experimenting. It requires the frictionless driving rings in the gearbox. The motorisation can be solved by using PF medium motor combined with return to center mechanism too. Sorry for the lack of quality, it was a hasty work. I hope the point I was gonna make gone trough. If there is any question, please use the comment section. I'll try to answer it as quick as I can. Thanks for watching an reading. Hope you find it usefull. There is a few failed changes in the video, those wre caused by applying shorter route on the handle. This design requires to be turned to the end point (about 65 degrees). UPDATE Gearbox instruction video is uploaded: