tripletschiee

42056 - Porsche 911 GT3 RS - MODs and Improvements

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Hi all,

I’ve finally got round to building the Porsche as TC14 is now done. I’m building it using the “community driven Errata” pdf and I’m stuck.

in the Errata there is a build stage 73 where you offer up the modified H frame and then the Errata has a stage 75 where you add a 11 long grey liftarm.

but my problem is stage 74 in the manual has you clipping the H frame into place using 2 x 3L blue pins and the Errata pdf doesn’t show these 2 blue pins on stage 75 or any stage after as far as I can see in the version I’ve downloaded.

let me appologise if this has already been answered but there’s 33 pages of comments on this thread, so I hope you can excuse me.

thanks in advance, seasider

 

Edit - ignore all this, it helps if I read the text in the Errata as it explains this!

 

Edited by Seasider

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Here's a modification of the steering block to encompass a servo-motor, along with a PF-switch to control it. The nice thing is that the switch can act as a shift stick to electrically shift gears. However since the swich only has 3 positions, one gear becomes unaccessible. Modifications to the appearance of the steering block are kept minimal.

1538441019m_DISPLAY.jpg

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Hello,

Sorry if this question might seem redundant, but I was looking through the posts for an explanation why the gearbox often completely hangs when trying to shift gears while the motor is running (even though the transmission is supposed to be synchronized). I found posts about series of changes that will, among others, fix that problem, but I'm interested in a technical explanation why this specific problem occurs. I noticed that when it happens, everything hangs so strongly that it stalls my XL motor.

Thanks!

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5 hours ago, ozacek said:

Hello,

Sorry if this question might seem redundant, but I was looking through the posts for an explanation why the gearbox often completely hangs when trying to shift gears while the motor is running (even though the transmission is supposed to be synchronized). I found posts about series of changes that will, among others, fix that problem, but I'm interested in a technical explanation why this specific problem occurs. I noticed that when it happens, everything hangs so strongly that it stalls my XL motor.

Thanks!

See this post (also scroll up to @schraubedrin's post and down to his later post).

 

Edited by Didumos69

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Thank you for the reply. I had actually seen that post, but from what I understand it's about reducing friction, and it's hard to imagine the complete lockup would happen because of friction, since friction is something continuous, while the lockup only happens at a very specific moment, i.e. when we switch gears.

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11 hours ago, ozacek said:

Thank you for the reply. I had actually seen that post, but from what I understand it's about reducing friction, and it's hard to imagine the complete lockup would happen because of friction, since friction is something continuous, while the lockup only happens at a very specific moment, i.e. when we switch gears.

Aha, I didn't read your first post correctly. Stalling while shifting gears is caused by the fact that in the original setup it may happen that two driving rings are engaged simultaneously: At the point where one driving ring engages, the one that was engaged is not yet fully released. The solution is to extend the catches as shown here. This also avoids the red clutch gears from being squeezed between liftarms and driving rings.

EDIT: Also, the original model does not have a proper way to limit the shift-axle to 90-degree positions. This may cause half shifts, leaving the gearbox inbetween shifts, with the risk of having double engaged gears like I explained above.

Edited by Didumos69

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1 hour ago, Ngoc Nguyen said:

Has anyone attempted a compact 4-speed gearbox with the new parts from the Bugatti Chiron and put it in the Porsche?

Give me a break. I’ve only just built this one :sweet:

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I’m building the Pimped version of the GT3 and I'm curious to know if I need parts from bags 2, 3 or 4 before I'd need them if building as per the original instructions.  I just don't want to have masses of parts out if I don't need to.

 Hope that makes sense.

 Any help would be appriciated.

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Hi there! Who could test new arches with 42056 Porsche wheels - how small they are, or they fit if wheels are not steered...

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On 11/19/2018 at 4:30 AM, Didumos69 said:

Aha, I didn't read your first post correctly. Stalling while shifting gears is caused by the fact that in the original setup it may happen that two driving rings are engaged simultaneously: At the point where one driving ring engages, the one that was engaged is not yet fully released. The solution is to extend the catches as shown here. This also avoids the red clutch gears from being squeezed between liftarms and driving rings.

EDIT: Also, the original model does not have a proper way to limit the shift-axle to 90-degree positions. This may cause half shifts, leaving the gearbox inbetween shifts, with the risk of having double engaged gears like I explained above.

Thanks again for the reply (I've only seen it now). I tried your fix of extending the catches, and while it seems to improve the situation, it also doesn't seem to fix the problem completely for me, as going from 3rd to 2nd almost systematically hangs (though now I was able to witness what you explained - two driving rings are indeed engaged at the same time). Note that I'm probably unaffected by the 90-degrees shift issue, since I'm using a servo-motor to switch the gears, which guarantees a precise 90-degrees turn.

BTW in case nobody reported back on your question whether or not the catch extensinon fits the frame: it appears it does.

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Here is a new mod of the Porsche : I have made an evolution of my rear axle with an anti roll bar. I have also added 2x13L long blackliftarms to enhance the rigidity of the chassis.

Porsche_stab_2.jpgPorsche_stab_1.jpg

Changes are not so much important, but we need to change the way springs are attached on the chassis using bent 3-7 liftarms. Compared to the default geometry, clearance is a little bit increased).

Porsche_stab_3.jpg Porsche_stab_4.jpg

As you can observe, the position of the bar needs old half bushes so that it can not translate between the 3L pins with hole : 

Porsche_stab_5.jpg

Gray axle pins are present to enhance rigidity when the body is present (they go Inside the holes of the 5x77 black and 3x11 black pannels), and the 13L black liftarms can be easily fixed on the chassis with a nice view on the gearbox ^ ^

Porsche_stab_6.jpg

Porsche_stab_7.jpgPorsche_stab_8.jpg

Of course, no issue with the removable body mod. It should be possible to adapt the geometry to the PimpMyPorsche of JB70. For the front axle, I am working on it, but my gemetry is really different from the JB70 / Didumos69 proposition.

Edited by DayWalker

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Well, here is the second mod for the front axle :

 - clearance a little bit enhanced compared to the default lego geometry (should be comparable to the Didumos69 proposition)

- dual springs to support the weight of the car

- Ackerman geometry

- Anti roll bar

- Compatible with removable body

- Smallest turning radius possible

The following  photos should be enought to make a copy of this front axle :)

Porsche_stab_11.jpgPorsche_stab_12.jpgPorsche_stab_13.jpgPorsche_stab_14.jpg

On the car, here is how it looks like : not that wheels are not touching the anti roll bar (even on the second photo), but it is very close to the wheels !

Porsche_stab_15.jpg

Porsche_stab_16.jpgPorsche_stab_17.jpg

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My first post so thanks everyone for your posts and improvements.  I am about 30% done with the GT3RS and just a couple questions.  I noticed that a few of you have added plates underneath the headlights. To fill in the gap under the lights.   I am curious are those the pieces 21 and 22 that are used elsewhere on the kit?  How did you attach them?  Or what pieces are you using?     Thanks for any response

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