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Didumos69

Eurobricks Dukes
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Everything posted by Didumos69

  1. Didumos69
    I think I understand your point and I also agree that the setup I shared does not resemble the real GT3 front suspension. As I stated in the OP of the ultimately playable Porsche I aim for playability rather than authenticity when it comes to modding the Porsche. So McPherson strut suspension and rear wheel steering? No. But HoG steering and HoG shifting? Yes. The MOD you are quoting improves the way the suspension arms are fixed, it improves the front ground clearance - which is less than a stud in the stock model - and it adds Ackermann geometry. All these things add to playability, while preserving the stock body. So yes, these are all improvisations. If you rather seek for authenticity, then please ignore. Having said that, I think it's kind of gratuitous to make a statement like 'I beleive that there are a lot of eurobrickers who share my thoughts'.
  2. Didumos69
    Before I start with the body here's a last addition to the chassis which secures the seats properly and reduces twist significantly. It relies on the properties 3^2 + 4^2 +12^2 = 13^2 and 3^2 + 4^2 + 5^2 ≈ 7^2 (7.07 to be more precise). I also managed to move the seats half a stud backwards. Gives a little more air behind the steering wheel .
  3. Didumos69
    In turns the steering links (5L suspension arms) close in on each other due to the tilting of the 3x3 liftarm. The effect is that one wheel turns sharper than the other. You could say you created yourself the inverse of Ackermann steering. So what you could try to do, is flip the whole suspension setup backwards. Then this angle difference might even turn out useful.
  4. Didumos69
    Yeah, I'm affraid that 'll be the next step. I have to admit designing the bodywork feels like a bigger challenge than the chassis. Building chassis is my comfort zone. But I will certainly give it a go.
  5. Didumos69
    Thanks! Although the overall rigidity of the main structure was quite okay - it's much stiffer than for instance the Porsche chassis - I wasn't completely satisfied about the stiffness in the area directly behind the seats. The 15L liftarms running between the seats were only connected with a single pin to the 5L levers running over the shifter compartment behind the seats. So I made some adjustments to improve this. I also finally received the right parts to make red calipers for the front wheels . I also followed @Meatman's suggestion and got rid of the pin joiners used in the gearbox. I replaced them with fixed parts (black): And here's a latest update video showing the finished main structure: LXF-file (with placeholders for the Porsche wheel hubs!) can be found here. Comments and (suggestions for) improvements are welcome.
  6. Didumos69
    Thanks for coming back on this. This once more confirms the friction that is generated when clutch gears transfer drive on axles rotating at different speed. This is also why I set myself the target to avoid this in my AWD chassis FST NML. There's a known issue with the red clutch gears that are not actually involved in one of the two clutches - the ones lined up between the normal 16t gears just in front of the actual gearbox. There is always one of them involved in transferring drive, which gives problems when its axle is forced into a very different rotation speed. This issue has been fixed in the errata. Reasoning from the gear ratios in the gearbox I arrived at the following conclusions with respect to the RPM ratios between the mentioned red clutch gears and their axles for the situation with Boratko's fix: 1st gear, right clutch gear involved, gear / axle RPM ratio is 1:1 2nd gear, left clutch gear involved, gear / axle RPM ratio is 1:3 3rd gear, right clutch gear involved, gear / axle RPM ratio is 25:9 4th gear, left clutch gear involved, gear / axle RPM ratio is 1:1 So in 2nd and 3rd gear the axle of the involved red clutch gear rotates almost 300% faster or slower than the gear itself, Taking into account that the clutch gear will be pushed against its axle as it transfers drive, it's not strange that this causes severe friction. Especially in 2nd gear when the engine needs to rotate faster than in 3rd gear. Now let's see what the ratios are when we don't apply Boratko's fix: 1st gear, right clutch gear involved, gear / axle RPM ratio is 1:1 3rd gear, left clutch gear involved, gear / axle RPM ratio is 5:9 2nd gear, right clutch gear involved, gear / axle RPM ratio is 5:3 4th gear, left clutch gear involved, gear / axle RPM ratio is 1:1 These ratios are much better compared to the situation with Boratko's sequence fix. Especially 2nd gear, which has to work harder than 3rd gear, has a much better ratio. I think this explains the difference you and others are experiencing. Actually, this would make the explanation given by TLG for having the 1-3-2-4 sequence partly correct. They said: "Too many gears are engaged at the same time and smooth running with all those tolerances is just not possible." Indeed, the 1-3-2-4 sequence allows for a more smooth running of the whole drive train. However the first part of the statement remains to be untrue, because in each gear all axles rotate and in each gear the same number of gears is involved in transferring drive from input to output.
  7. Didumos69
    You are mixing up the minimal and the ultimate version. For the minimal version the pdf and (short) parts list can be found on Rebrickable. This version only applies the modifications needed to get the shifting mechanism working and to eliminate the most severe friction in the drivetrain. The ultimate version is only available as LDD-file and there won't be an instructions-pdf for that version soon. The OP of this thread provides more info.
  8. Didumos69
    Nice seats! I do have some doubts about their adjustment though. My experience is that a worm gear slides over its axle very easily. So I'm affraid this way the worm gear will slide off very quickly. Or pull its axle out. You should brace the worm gear on both ends IMO. Maybe wait for the new 1L work gear? EDIT: Just noticed you're using an axle with end stop. So it won't slide off. But it still might pull the axle out off the 8t gear.
  9. Didumos69
    @Meatman, I managed to improve the shifting links. You were right that the links were disaligned by almost 1 stud over their full length. The intention was to lengthen the change-over catches max .5 stud to avoid friction and double engaged gears, but I extended them by appr. .75 stud. Together with the ball-joint with axle that doesn't fully insert the disalignment was simply too much. So I removed two half bushes to make sure the catch extensions are exactly .5 stud and at the same time I replaced the +0 liftarms attached to the shift axle with 2 2L thin liftarms and the attached ball-joints with pin with ball-joints with axle. This also reduces the disalignment. Now the red clutch gears at the front are engaged practically as good as the ones in the back of the gearbox without reintroducing any squeezing or double engaged gears. Thanks again for pointing this out. It made the whole setup work even better.
  10. Didumos69
    Thanks! I actually need a 6.5L axle and I can't think of a way to obtain that length using a 5.5L axle. Initially I used a 6L axle that was inserted only 0.75L into both U-joints, but the axle slowly slided out of one of the U-joint and fully inserted the other. Eventually the axle popped out of one of the U-joints. This way - with indeed a 2L axle inserted into two axle joiners for 0.75L and a half bush in the middle - the full 6.5L is spanned, so it won't pop out of the U-joimts and the 2L axle in the middle won't go anywhere.
  11. Didumos69
    Wouldn't you get into trouble with the correct orientations - 45 degree vs. 90 degree - of the knob gears if you do that? Or am I misunderstanding something?
  12. Didumos69
    Then I'm a lucky guy to have only normal 16t gears meshing with the 16t end of the diff .
  13. Didumos69
    Haha, I thought I missed something, but the 24t side of the diff is not used, which can't be ok. The other version does make sense though, as long as you don't mind clutch gears transferring drive on axles rotating at different RPM.
  14. Didumos69
    Thanks for thinking with me @Lipko . There were a few objectives I had in mind for this gearbox. One of them is 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 (see this post). So I wanted red clutch gears to only make dummy rotations when not engaged. The other objectives are that I want to cover 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. And finally it all had to fit underneath the engine; I didn't want the gearbox to be wired through the entire chassis.
  15. Didumos69
    Okay, now I understand what you mean. I watched the video again and see the difference too. Half a stud on each side should be enough to align the links evenly. Apparently it doesn't cause any trouble, but it would be nice to improve on this. I will look into it. Thanks.
  16. Didumos69
    The length between the wheels is 39 studs (38 if measured heart to heart) and the width between the wheel hubs is 23 studs (22 if measured heart to heart). This is quite common for a 1:8 scale build. However, the car that I use as a reference (I won't tell), also for the position of the seats and steering wheel, is 4.5m long, has a wheel base of 2.7m and is 2.07m wide. Taking these measures into account my build is actually a 1:9 scale model. You are right about the pin joiner. I have the habbit to use too many parts, so this time I made several iterations to remove unnecessary parts. But in this case I think proper bracing is more important, so that's what I will do. It's actually quite easy to do: About the return to center of the shift lever. I have been playing with this a lot. The operation of the shift lever just feels so 'right' that any addition meant to help the lever return reduces that 'feel'. It's also not really needed, because to complete a shift, it is not needed to return the lever. The return doesn't do anything. You can actually postpone the return until the next shift. So I decided to leave it like this. Another advantage is that I only need silicon bands for the 90 degree limiter. This video shows the exact behavior of the shifter: The driving rings are not engaged as far as for instance in the stock Porsche, but they are engaged deep enough to not slip. It's not because I use links with odd length, but because I extended the change-over catches deliberately with half a stud. Actually this has also been a result of a lot of trial and error. There are two advantages of this approach: 1) The red clutch gears won't get squeezed against their neighbouring liftarms (this happened in the Porsche and caused friction) and 2) The chances of double engaged gears during shifting is reduced. In the Porsche there is a short moment during shifting with two clutch gears being 'half' engaged, which may cause the gearbox to halt. By engaging the clutch gears a little less deep, there is a short moment of neither clutch gears being engaged instead, which is far less dangerous.
  17. Didumos69
    I agree this could be very useful. You can use them in a very small space. However, don't expect this to be the holy grail. Like normal worm gears they will suffer from a lot of friction when a lot of torque is involved - which is quite likely in case of gear reduction - as they tend to push themselves against one of its stoppers. For the same reason the bracing in your example could be done better. This way the worm gear will disposition one of its stopping liftarms.
  18. Didumos69
    Thanks! You're right, the seats would look better in another color. Black doesn't look good in renders, but it's the most likely option in the real life build. However I don't have the right angled parts in black right now, so I will stick to DBG until I have decided about the final color scheme. Thanks! It may not surprise you that the T-bone piece is my favorite part , I use them for right angle rigidity. Btw, I know you are in pursuit of adjustable seats for your DB11. During my lunch break I had the time to mount one of my adjustable seats as well as the engine. But you probably want to make your own seats. The engine nicely covers the gearbox, but you can still look underneath to see what's going on in the gearbox. A few more images. Click on an image to enlarge:
  19. Didumos69
    I finally had the chance to build and testdrive the gearbox and shifting mechanism. And it works like a charm! I wanted to have 3 modules - front suspension, mid-section and rear suspension - that could be easily separated, but that reduced the overall stiffness of the chassis too much. So I ended up building the whole chassis around the gearbox and I'm really happy with the result. Shifting works very smooth and there is no substantial friction. Because of the drivetrain's simplicity you can hardly do anything wrong which would introduce serious friction. @brunojj1, I also managed to keep the mid-console 5 stud wide, although only in the area where the seats will be located. The whole chassis is still more rigid than I expected, but I will extend the mid-section to make it even more rigid later on. I really think this is my best work sofar. Next steps will be 1) moving the shift lever one stud backwards, 2) adding the engine and 3) adding the seats. The LXF-file of the current state can be found here. What do you think?
  20. Didumos69
    It looks great already and it's good to see that this wip is still alive. As for the challenges you're still facing, that's the real fun of Technic, at least for me it is, endless tinkering and redoing things untill its good. I was wondering, did you use the 90 degree limiter or did you come up ith another way to make 'perfect' shifts?
  21. Didumos69
    Welcome @jfb9301! I know @Jeroen Ottens did some work on an 8-speed sequential shifter for his DB11. Note that the auxiliary shifter axle with green +0 liftarm needs to have a 45 degree orientation. Also note that the track rod driving the green secondary clutch needs to make twice as much travel to make sure it always engages one of the adjacent clutch gears, hence the yellow construction between the secondary shifting axle and the attached track rod. If you are to use the 90-degree limiter, be sure to use one for each shifting axle. And when al works well you could of course try using my stepper (without limiter) to drive your shifters . Courtesy of Jeroen Ottens.
  22. Didumos69
    Great! Keep us posted !
  23. Didumos69
    I thought these seats are worth sharing here too. For my FST NML moc I got the idea of redoing the adjustable seats of the Steppenwolf. I'm not sure about the final color scheme yet, so for now I made them bluish gray. LXF-file of the seats can be found here.
  24. Didumos69
    Great! I'm afraid the bodywork will be a big challenge. Back on topic. I finished the design of the shifting mechanism and the rest of the mid-console. Before I can build and test it I have to wait for some parts that I had to order. Meanwhile I've been playing with the seats. I want to have an idea of how much space they exactly need. So I stumbled upon the idea of making the seats adjustable. It's not a very conventional way and I'm not sure about the ergonomics, but at least the driver can scratch his a-s-s while driving . I'm not sure about the final color scheme yet, so for now I made them bluish gray. LXF-file of the seats can be found here.
  25. Didumos69
    Thanks! @legolijntje, yes there are two easy mods that I would incorporate immediately while building: HoG steering, which is included in the LDD-file mentioned in the OP of this thread. And the hispabrick removable body mod. I don't have the link at hand, but the video should be easy to find on YouTube. Both mods add a lot to (dis)playability. The latter mod can also be done afterwards.
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