I3Brick

Thanks for the extensive reply Didumos. That makes sense. I had already read about those ratios and had indeed seen your mod to replace the red gears. But it's only now in experiencing the issue myself and you reexplaining the gear ratio problem that the pieces of the puzzle (or should I say gears) come together :-D. Not that I didn't believe your mod was useful, I just hadn't understood the exact issue it solved. Since you've provided the pictures to add in your mod for the red gears mid-build (at the steps I'm currently on), I'll give them a go and hope it solves the issue! I'll report back on my findings afterwards. BTW, I can confirm your statement from one of those threads: "Also in my case 2nd gear has more friction when driven by differential than when driven by engine axle. Still nothing drastic, but there is a difference." Still find that weird as well, since you're still moving the same gear train, but that issue should be mostly solved as well when applying your mod. Thanks a lot, a troubled model is at least teaching me a lot about gearboxes, thanks to you and the rest of the community :-). UPDATE: I applied your mod for the axles and red clutch gears and now it indeed functions smoothly. It's amazing how much friction free running gears that are brushing up against an axle at different speeds can have . Very surprising. I tried hooking up an L-Motor to the gear box (not the differential) and it worked smoothly in all gears. Still using the original paddle shifter, without the 90° limiter or inverted change-over-catches.That worked smoothly still as well, so at least TLG got that right enough. Although I'm sure the modded version with the limiter and reduced friction in the selector mechanism will work with less force. While disassembling the gearbox to make the changes I did notice one thing that made me less happy: very fine deposits of what I presume to be plastic dust on one of the axles of the gearbox (not one of the axles to be replaced by the mod). I've only been using a motor to test the setup very briefly for a few times, but clearly with so many gears (and the occasional stalling) you will wear things out quickly. It were only very fine spots, that showed rather well since it was light grey dust on a dark grey axle, so it wasn't disastrous yet. But I'm not so sure anymore that I'll be hooking up a motor anytime soon. I'll be able to show the effect of shifting gears on the fake engine by pushing the car, that will have to suffice I think.

Been continuing my build of the Porsche, and the conundrums keep pilling up :). I applied Paul Boratko's switch of the gearbox sequence (steps 267-269). Right after completing that step, I tried out the gearbox again to make sure everything still runs smoothly. Connected an L-motor for a test and gave it a spin. In the 2d gear the gears give so much friction that the gearbox stalls. Even when manually trying to rotate the wheels you get this effect. I believe I've read about gearbox friction issues in that gear before, but the weirdest thing is that when I reconstruct the gear sequence to the original version of the manual (1 - 3 - 2 - 4) the friction is severely reduced and the L-motor manages to run through all gears without stalling. Without the 3 axles of steps 267-269, everything goes smoothly in every gear. But once I add those 3 axles in Paul's configuration, one particular gear gives an abnormal amount of friction. I believe it's the two black gears added in these steps that somehow don't revolve with the same speed or something, it's really an excessive amount of friction compared to the original version of the manual, and that just when adding these 3 axles in that order. Has anybody else experienced this behaviour before? It would almost look like the original version has a much smoother gearbox than the mod (albeit in the wrong order). I'd find it hard to believe, after all the reports of people here who've applied the mod without adverse effect, but I'm a bit baffled as to why this would give so much more friction than the original version on this particular gear.

I was wondering if anyone has a suggestion for the following: I want to motorise my model, but only require it to function when the wheels are off the ground. The point is to show off the gear shifting function by seeing the wheels turn slower or faster when shifting. Since having the car resting on its wheels adds too much weight (requiring big motors and potentially running into issues with the drive train/wear and tear), and since I don't want to have a fully RC model, this should be less complicated than a fully RC model. I don't mind if the motor is external to the car. The most convenient spot I found so far to do this is at the back. My plan is to extend the axle marked in red on the picture (passing through the lowest of the two grey gears used to make the engine turn) with one stud. That way I can connect an axle connector with L-motor to it when I want to show the functionality, and I can easily remove (and hide) the motor when the car is on display. That would mean I'd have to split up the long black 15 stud beam of the rear bumper from step 597 into two smaller beams, so that the axle could pass through. Not sure what the overal impact will be on the sturdiness of the rear bumper if I do that, it seems to be a rather structural element. Any suggestions for the 'connection point' of the car and the motor? I am hoping that with the car off its wheels, a single L-motor will suffice to operate the entire drive train without causing too much wear and tear to all the gears. I'm not going to be running the car like that for long periods of time, but there's still a lot of gears involved. Thoughts and tips are welcome. PS: I did see the video posted by schraubedrin on page 13 of this thread. It looks like one of the easiest ways to connect an L-motor, but it connects to the rear wheels directly, meaning that you will only see the speed differences of shifting in the engine pistons. Those are hard to see, less spectacular and you can only apply this when the chassis is removed. I'd prefer a method that works with the chassis on as well. PSS: I also know stevenhalim tried connecting an L-motor and it worked with wheels off the ground (allbeit with Didumos69's mods, which I haven't all implemented), but I've got no idea where exactly he hooked up the motor and if anybody else tried doing this.

That's a very nice redesign you made there of the paddle shifter, hadn't seen that one yet! Seems to be a bit neater indeed, compared to the version with rubber XX pieces and the change-over-catch. But in that particular design, I do now understand their reason for the piece I think, having seen it operate in real life. I do know about your ultimate version, thank you very much for the PDF instructions! They helped me to understand a lot of the problems the set has and how the modifications work. I spent half a day studying all threads and your instructions to get a clear idea about the mods and improvements :-D (wasn't always easy, since the names of the mods were sometimes not unique in all threads or forums). The 90° limiter I purposefully omitted in my list of to-implement mods, it was too much of a 'change'. I wanted to avoid mods that required medium or big changes during my first build. But it's a very elegant and effective solution based on what I've seen and read. If it turns out that for my purposes my build doesn't work well enough, it will probably be the first mod I'll add to the build. But since for now I only intend to display the model and once in a while hook up an L-motor to the fake engine to show the functioning of the gearbox (with the wheels off the ground), I hope it won't be necessary. I did just now put your 'half stud extension' mod back in, I had completely forgotten the reason behind it (thought it was more related to the double engagement, but as you rightfully reminded me it was about reduction of friction). Thanks for the reminder!

Hi guys, Just wanted to post some feedback on some of the suggested mods. I've started building my set today and had planned to integrate 6 of the most basic, easy mods to improve functionality from the get-go. The mods were: - Blackbird's step 5 mod - Attikas change-over-catches-fix - Didumos69 change-over-catches extended with half a stud - Supertechnicman’s fix for the infinite gear shifting issue - Paul Boratko’s fix for the wrong gear sequence - Jetro’s MOD for easy unmounting/remounting the bodywork I’ve not finished the model yet, but so far I’ve had an issue with 2 of the mods: Attikas’ and Didumos69’s changes to the change-over-catches. I implemented both from the start, but when I tried shifting, it wouldn’t shift smoothly at all. The yellow knob-gears in the steering wheel module kept skipping the full rotation, never really shifting the gears reliably. Some of the times they would push the thin end of the change-over-catch inwards, other times outwards. So I undid Attikas change, which at first didn’t really improve matters, until I read a comment on his video on Youtube. The commenter (Elvis Chien) stated that he had similar issues to mine, and that when he reversed the mod to the original state it worked better for him, as long as he pulled the paddles long enough. He said: “Try pulling the paddle until you think it's reached the limit then pull it harder, you will notice that it can actually be pulled even further. Release the paddle, and the shifter is right at the correct position.” This is exactly what happened to me. When you pull and it feels as if the paddle has reached its end, it actually just reached its furthest position against the thick end of the change-over-catch. If you pull just a bit harder, the change-over-catch will flex inwards just a bit more, giving just enough extra movement in the yellow knob-gears to provide a nice 90° shift in the orange XO pieces. Seeing it in action makes you realize why they used the change-over-catches, even though at first you would think that in this position, any similar (and shorter) piece would do. But the knob of the knob-gear gets better friction from the stumpy end of the change-over-catch compared to another more rounded piece (or the other, thinner end of the change-over-catch). I also undid Didumos69’s mod, because in my case I found it gave slightly more chances of double engagement. I’ll retry the effect once I’ve hooked up a motor though, to be sure. I’m very happy the mods improved the functionality for a lot of you, but it seems that in my build, the original version actually works as intended (for now). My post is not meant as criticism of your mods, just as feedback. I’ve learnt a lot about the model and LEGO Technic in general from this thread and others about the same topic, so I wanted to share my own experience with you guys, as you’ve done with me!

@E2nO - thanks for the suggestion. Not a bad idea. Space-wise not so self evident according to LDD, but an interesting challenge perhaps.

Thanks for the quick reply mahjqa. Keeping the Servo in place could perhaps be done with a lock on the PF remote, like this (rough) suggestion: http://www.eurobricks.com/forum/index.php?showtopic=93738. Not the most efficient way but doable, I like complicated and clunky remote controls :-D. My building habits don't justify an S-Brick at the moment, certainly not with the software issues it still seems to have. Your design might just allow for two IR-receivers next to each other without adding bulk, underneath the hood. At most I'll have the tops of them exposed, for the signal. But yeah, I agree that the servo motor itself is the best option, I don't think I can find a passable alternative within that space with an M-motor. Time to increase my stock of technic pieces it seems...

Amazing model mahjqa. I've been looking for a good forklift for a long time, and this one fits the bill. And it's not only the model, the video is a piece of art too. I was wondering why you used servo motor for the tilting of the forklift, but I think that while typing the question I've figured it out myself. To tilt the forklift you only need a quarter revolution of the motor, right? So I guess using an M-motor and a normal remote control (don't own an S-Brick) isn't going to work that well unless you gear it down substantially, making it bulkier and slower. Would it be even possible? Either way I'll have to swap out the S-Brick in the design for 2 normal IR-receivers, that's going to mess up the tiny design already. Let's just say you've given me a good incentive to finally get a second servo motor :-D. Motomatt, your piggybacker is quite nice as well! You don't happen to have an LDD file of it somewhere? I'm interested in figuring out it's compact design. Anything to learn a trick or two!