ZR1 42093 MOC

[mudseason]

Hello,

I'm starting a project to modify the ZR1 42093.

The plan is to modify it with:

• the Racing Brick Buwizz 2L motors MOC
• a full independent suspension front and rear axles.

To include the suspensions I will most probably need to:

• get rid of the fake motor
• make the rear of the car larger 2 studs per side.

For the front: I saw a beautiful suspension mechanism for the front from one of the users here (it's a [TC18] thread) I would like to implement his solution.

For the rear: I attach a couple of images, this is my first attempt with LDCad.

The rear suspensions are more for a visual effect, their travel will be one stud more or less.

The "rest" position of the axle is nearly horizontal.

I cannot place anything over the axle as there's the 8stud buwizz mounted above (with half stud clearance).

Questions for you experts:

• Is the 3L joint an acceptable compromise for the vertical suspension motion? I know I should use two joints, but I would like not to increase the size to 25 studs.
• would the 3L joint survive the two L motors in parallel? Or should I look for "metal-semi-illegal" parts?
• would you suggest a different approach?

I'm not going to place a floating differential, in case of failure I will just use a straight axle and call it a day and having the suspensions just for visual.

thanks a lot.

Rear Axle 01

Rear Axle 01 - Top

Rear Axle 01 - motor view

Edited April 20, 2020 by mudseason

[Jurss]

That axle won't work, because of that U-joint used in that location.

Why You used TC21 in topic name?

Pictures can be embedded posting direct link to image, which has file extension at the end

[agrof]

Hmmm, looks like a fell asleep quite deep, are we at TC21 already?

If we are still at TC18 to date, please note, that no electronics is allowed.

EDIT: also, the u-joints in the rear axle have no use, but make the power transmission less effective, as they are unnecessary weak points there.

Edited April 20, 2020 by agrof

[mudseason]

first of all sorry if the title is not the correct one.

I thought it was referred to the total width of the model.

I will change it by removing the [] part.

About image, I can only upload up to 100k images, then I used imgurl.

If I got you right ONE single joint won't never-ever work even if the displacement of the suspension is around 1 stud, am I right?

I fail to understand if:

• it is a problem of effectiveness (reduced) / fragility
• it cannot work at-all

Thanks a lot.

Another option could be to switch to the ball joint and make an illegal piece by stacking (gluing) two 3L CV joints (32494) one against the other and maintain the total length to 4 or 5L only.

 

[amorti]

I think you should put down the digital designer for now. Build some test rigs, and you'll soon figure out why the axle you've drawn can't work. You need the pivots of the U-joints or CV-joints to be in line with the suspension pivots.

Be careful when testing it though, because what you've designed will break universal joints.

Build some more official sets and or look at/build some MOCs, you'll soon see a pattern of how U-joints are used correctly.

The first problem is you can't use the piece you've used, as an upright. At least not how you've done it. Because it doesn't let you put the CV joint pivot in the right position.

Edited April 20, 2020 by amorti

[Jurss]

16 minutes ago, mudseason said:

I will change it by removing the [] part.

[TC18] means Technic contest 18. [MOC] My own creation. 

17 minutes ago, mudseason said:

then I used imgurl.

this is OK, but You can copy there link, where file extension is at the and, and then paste here, it will embed automatically.

But best way would be to start reading forum rules/faq.

4 minutes ago, amorti said:

Build some more official sets and or look at/build some MOCs, you'll soon see a pattern of how U-joints are used correctly.

+1000

[mudseason]

Title modified!

Thanks a lot for the explanation of TC18, I fell really dumb... it was just a progressive number... shame on me. 

About the meaning for MOC it is clear. I do not know if you're arguing if a MOC shold or shouldn't be 100% "own" or in case of starting from an actual set it would be better to call it a MOD. I'm really not interested in such discussion.

What I was concerned about was clearly described when talking about the aligning of joints to suspension pivots: clearly I would nee two joints as there are two pivots. I will try something different the design won't work.

Ah, I posted as I lack both the experience and the parts to do the experiment, you have to start somewhere and I will do a bit of both.

Thanks a lot for the hints, I will report any progress.

regards,

f.

 

 

[agrof]

Don't feel bad, it was actually funny, I hope You see this side of the story too. 

U-joints are exactly 3 studs long, and create 1 stud offset - so just replace the current setup with 9 or 10 long axles, or even better with a combination of axles of 5,5 L + 4 (or 5) L axles, connected with axle connector, to prevent sliding out from the differential. As a ususal design (3L axle coming from diff - axle connector - 5.5L):

[mudseason]

20 minutes ago, agrof said:

Don't feel bad, it was actually funny, I hope You see this side of the story too. 

U-joints are exactly 3 studs long, and create 1 stud offset - so just replace the current setup with 9 or 10 long axles, or even better with a combination of axles of 5,5 L + 4 (or 5) L axles, connected with axle connector, to prevent sliding out from the differential. As a ususal design (3L axle coming from diff - axle connector - 5.5L):

 

yes, I can hardly stop laughing. TC21... I also understood the joke about falling asleep for long time. 

Anyhow, in the above schema I would miss any suspensions movement, correct?

What about the crazy Idea to create a 4/5L CV joint by cutting gluing together two 3L CV ball joints?

Thanks.

[amorti]

The Lego pieces aren't holy and you can cut them up if you want... But don't expect any applause for doing so.

Have a good look in all the tc18 threads. Take the time to understand how everything works from the pictures and diagrams. You wil gain a lot of ideas that will be relevant for your MOC in the scale you're building it.

If there's something where you can't "see" how it works, most of us are happy to help by explaining but really the only useful way is to build it and see what it does. If you have limited stock of pieces, it can still be helpful to only build one side of an assembly 

If you're wondering about how to use CV joints in a double wishbone suspension, look at (for example) the smaller Porsche from Lego. You'll see how the two CV joints are lined up, how the pivots have to line up with the ball joints, and in general get a first idea which you don't yet seen to have.

And again... put down the digital designer for a while. It won't let you build assemblies which don't fit but it'll surely let you design mechanisms which don't work. Until you're experienced enough to spot them, the design tool won't help you.

[mudseason]

1 hour ago, amorti said:

The Lego pieces aren't holy and you can cut them up if you want... But don't expect any applause for doing so.

Have a good look in all the tc18 threads. Take the time to understand how everything works from the pictures and diagrams. You wil gain a lot of ideas that will be relevant for your MOC in the scale you're building it.

If there's something where you can't "see" how it works, most of us are happy to help by explaining but really the only useful way is to build it and see what it does. If you have limited stock of pieces, it can still be helpful to only build one side of an assembly 

If you're wondering about how to use CV joints in a double wishbone suspension, look at (for example) the smaller Porsche from Lego. You'll see how the two CV joints are lined up, how the pivots have to line up with the ball joints, and in general get a first idea which you don't yet seen to have.

And again... put down the digital designer for a while. It won't let you build assemblies which don't fit but it'll surely let you design mechanisms which don't work. Until you're experienced enough to spot them, the design tool won't help you.

I really see your point and I appreciate your availability.

Regarding how to properly install the CV joints, you assume I have no idea, however I have some, (at least for simply suspensions schema). I knew the U-joint placed like that was sort of "hack" with little-no hope to work.

The schema I have in mind is similar to the 42096 model and to the 42099 one: I just built the Efferman's mod, it's Efferman's fault if, after 30+ years, I'm starting putting bricks together again .

Coming back to this new build, I have issues with the total width as I would like to maintain some proportion in the model: +2 studs per side are ok, +3 are a bit on the edge. +4 is a no.

I checked a lot of posts of the TC18 family, they are very informative in fact for the front I found an amazing solution by one of the forum users. His solution for the rear axle (floating differential) did not convinced me 100% I need also to fit the electric part and motors, thus I would prefer something fixed, at the expenses of increasing the total width a bit.

 

About putting down the digital designer I also agree with you, I use the designer for pieces I do not have in my hands, but building them for real is the most effective way to learn. Unfortunately I do not have U-joints at the moment.

I'm trying to make an idea with the help of the few pieces I have, LCad and your suggestions, then I will buy some piece to experiment with.

Cheers.

 

 

 

 

[agrof]

The good news is, you don't really need u-joints, or cv-joints to make a motorized model, just focus on rear wheel drive, front can be steered only. Honestly, in the scale of the 42093, suspension doesn't add much, especially if You want to enjoy the speeding with the juice of Buwizz. Keep it simple, and drift it! 

My advice is than, that build a very simple chassis, no body or suspension at all, just to see how the motors can be placed, and how you can bracket those properly. This will give You some ideas, and most importantly: some success. Than You can go for more complex build, and You will find yourself in a flow, where you find the fun side of building. If You go for a very complex build for the first try, might be the necessary trial-error process will demotivate You - which shall not be the result of any hobby. Small steps.  I recommend to study the Building Instructions for smaller official sets, like 42022, 42075, 42037. You will find motorization for these on Youtube / Rebrickable for sure as the next step. 

Here is also a useful topic, includes a lot of advanced solutions for the future MOCing: https://www.eurobricks.com/forum/index.php?/forums/topic/92099-axle-collection-thread/

Edited April 20, 2020 by agrof

[amorti]

As @agrof says, it's the way forwards. Baby steps.

I'm also just back into Technic after some 20 years. It's taken a while to get used to the huge steps since the days of studded technic beams!

For now I'm happy with building kits and other people's MOCs. I find enjoyment in tweaking this or that, because then I feel like I've understood how it was designed and seen how (for example if you remove the constraints if it being an unofficial B model) it can be better. All these ideas go into my ideas Library and maybe one day I'll do a big MOC good enough to publish. Everyone has a novel in him, right??

Edited April 20, 2020 by amorti

[mudseason]

I understand, suspensions do not add anything functional at this scale for the type of car.

I figured out the min. width I can achieve (still with a fake piece: I would cut and glue two CV joints) is 21 studs, 25 with all original pieces.

This means that such decision will force myself into modding the external rear part, and this will be a fun exercise.

Motor placement is already decided by the instructions.

If it won't work I will just revert to the original mod (the motorized version is already a mod) with fixed axles and enjoy it as it is.

Thanks to all, I will let you know the result.

 

[agrof]

Great, enjoy the journey of building!