Charlieca00907

I was able to make a new rear axle to hook up to the transmission. It was a challenge in the sense that I had a lot of movement between the gearbox/rear axle/chassis. After stiffening a lot of areas, I was able to get it to work well under no load. When I placed it under load, Under load I notice quite a bit of grinding and also that even with 2 XL motors it wouldn't start from a standing start in 4th gear and barely start in 3rd. I removed one of the XL motors to see if it was just too much torque but that wasn't the problem. Then after taking moment to gather my thoughts before throwing the thing against the wall, I had a moment of "brilliance". I remembered that the rear axel that I am using (BMW M4 DTM by Bunojj) has the ability to change the gearing on the rear axle by swapping two gears, and viola! The car now has minimal grinding. Mostly on start, especially in 3rd and 4th. The only issue I have now is that I only have one servo motor which I'm currently using for steering. In what the servo gets here I may be able to change the steering using a regular M motor and use the servo to test the stepper. I also made a mod to the stepper to keep the rubber band from coming off as it is making a gear change. I added a half pin with bar at the pivots of the stepper (top & bottom). This keeps the rubber band from coming off the arm as it "opens up". BTW, how can I post photos larger than 100k? That seems to be the limit on this forum.

I probably would have found out the hard way!! Thanks, I will incorporate that in version 3.

I left the differential in. I plan to power the fake engine that will sit in the front. I'm trying to build my personal sports car into a lego. In this case a Jaguar XKR. But I think the mock will be the XKR-GTS (its got more design elements that I can play with). When powered up the 2xl motors after stiffening the chassis, I found that 1st-3rd [no load] worked fine. When I shifted into 4th it got a little more challenging. The shifting is also sketchy at times with "grinding" until it gets into gear. The XL motors (if I am not mistaken) are geared up to 36:20 into the input shaft. The output is unchanged. Your gearbox seems to be sturdy enough. Most of the problems I've had are "outside" the gearbox. I need to strengthen a few areas so that the gears don't slip out. Hopefully this weekend, Ill get some time to go on to version 3.

Here is my chassis in progress. Its a combination of Sheepo's rear axel and your gearbox. I think I'm going to have to start from zero again. As I currently have it set up, the chassis still has too much flex which affects how the gearbox works especially in forth gear. Also, I've had to offset the gearbox in order to line up the motors. I'm probably going to have to make the chassis wider so that it "lines up" with your gearbox. Also, will probably use a new rear axel. I'm getting some inspiration from the BMW M4 DTM MOC. What I'm finding is that lining up the input and output of your gearbox is "a pain" but maybe that's because I'm going through the learning curve.

Very nice collection! This is mine... (I'm waiting on some parts to finish the roof of the Aventador) To date the Koenigsegg has been the best one by far. I've also started on my very first supercar. At the moment I'm working on the chasis. My idea is 2 XL motors, 4 speed sequential gearbox with RC stepper and RC steering. I'm still learning and this stuff is fascinating. I'm thinking of building the Alfa Romeo or the Sheepo's Mustang as my next MOC build. What would you recommend?

I will try that. I have the white, blue and red bands so it shouldn't be a problem.

I noticed on the new instruction video that you made some modifications that help with fixing the gearbox to the chassis. Also, I'm using a lego blue silicone band versus the green one you show. Is this an official lego band? if so, what is the part number.

Had to also make an impromptu mod as I didn't have the black part in one of the corners to make the gearbox sturdy. Also the oposite corner was loose so I added two parts so that the lever arm was firmly in place. I'll see if I can post a picture.

Last night I reverse engineered your gearbox/shifter. It was a bit of a challenge as I had to take a bunch of screen shots in order to understand it all. I found that the gears would jam similar to the gearbox from Sariel. So I decided to swap the white gear shifter connector (18948) with a red axel extension (26287). This allows the gear shifter ring to essentially have no friction. If this were a manual gearbox it would most likely "get out of gear" easily as there is no way to keep the shifter ring from unengaging. However, since the catches are held in position by the link arms/stepper it seems to mitigate this issue. I hooked up the gearbox to a motor and manually shifted gears with stepper and everything worked perfect. Tonight I hope to hookup a servo to the stepper to see if it works as I want it to. I do have a technical question. What is the purpose of the differential in the gearbox. Is it for a 4 wheel drive?

Hey Attika Any progress on the gearbox video?

I just finished building a Koenigsegg One:1 MOC to date, its been the best MOC I have built. The doors are a work of art. You can find it on rebrickable.com. I look forward to seeing the car. I'm a big fan of Koenigsegg.

I very much like your stepper mechanism. After building a few from varios different youtube videos, yours was absolutely genius in its simplicity and reliability. Currently, I am building my first supercar after getting inspired by the GT3, Koenigsegg One MOC and Aventador Pirelli Edition MOC that I have recently built. I have found that sheepo's modular system seems to be a good starting point for the chassis. At the moment I have managed to get a working remote control chassis using the modular system, RC steering, 4 speed gearbox (sariel) and stepper (sariel). but I find the gearbox and stepper bulky at best not to mention difficult to shift accurately. I believe your stepper will solve the accuracy of the shifts. I was able to reduce its size to 3 studs wide in order to replace Sarie's stepper on his gearbox. But I still find it too bulky. Your integrated design is beautiful and I would love to build it to incorporate it into my supercar. The shifting mechanism reminds me of the GT3. Have you been able to put together a video to build it? I would really like to incorporate it into my build.