WIP 42099 Replica

[Zerobricks]

Decided to try to build a replica of 42099, first staring in LDD:

Here's where I found a problem,:

I can't decide if the motor inside the axle is the L motor for steering, or the XL for driving:

Judging by the circled axle, it seems like a 4 tan axle with stop for driving the differential inside the H frame:

 

But if there is indeed an XL motor inside the front axle, than that leaves no space between the bottom of the XL motor and the differential to reute the steering axle:

And same issue if the L motor is steering, there is no space for drive axle to pass under it:

Any ideas, guys?

 

 

Some reference photos of the motors (stolen from RacingBrick ):

Edited June 3, 2019 by Zerobricks

[allanp]

Looking at the pictures of the motors (focusing on the line between light and dark bley) it appears as if it's the L motor that's in the axle. It also appears that the L motor is placed 1 stud higher than where you have it in your axle, so that would allow room for the axle to pass under it.

[kbalage]

No need to steal the photos, you can borrow them  I also think that's the L motor what we see on your photo.

 

[Zerobricks]

Took @efferman's advice and moved the L motor a stud higher and improvised a bit:

I used the new connectors from Spike where I thought they may be useful

I used the same centering mechanism for front steering ZEUX uses:

 

How the replica currently looks:

I think from this point on there will be more or less just improvization and I think I can start IRL building.

Edited June 3, 2019 by Zerobricks

[efferman]

@allanp is the one which has made this hint. 

My hint is, why not rotate the upcoming L for 90 degrees?

[Zerobricks]

Just now, efferman said:

@allanp is the one which has made this hint. 

My hint is, why not rotate the upcoming L for 90 degrees?

Yes, right, my mistake. You can see the motor's orientation in the photo.

[JonathanM]

I reckon it's an XL, placed 1 stud higher than you originally placed the old XL. The L will be used for steering in the middle of the chassis is my guess.

There's 2 XL's for drive, so it makes sense for one per axle as per 9398.

[Zerobricks]

16 minutes ago, JonathanM said:

I reckon it's an XL, placed 1 stud higher than you originally placed the old XL. The L will be used for steering in the middle of the chassis is my guess.

There's 2 XL's for drive, so it makes sense for one per axle as per 9398.

Can't place XL motor in L's place, because than the gears are out of system... Unless they used 3x20z tooth gears? 

[pleegwat]

Is this 4 wheel steering or 2 wheel steering? If only the front wheels steer, there's no need for the steering motor to be in the middle. And actually it may give more accurate steering if the steering motor is on the pendulum axle, instead of outside it.

[1gor]

1 minute ago, pleegwat said:

Is this 4 wheel steering or 2 wheel steering? If only the front wheels steer, there's no need for the steering motor to be in the middle. And actually it may give more accurate steering if the steering motor is on the pendulum axle, instead of outside it.

Based in info we have about 42099 set it has only front wheel steering.

[Zerobricks]

I decided to wait for more photos to pop up before continuing on the replica.

[Yevhen]

Sorry, but what's the reason to waste time on such work?

Why don't you build your own jeep with the new hybrid suspension to find out how it performs?

[Void_S]

6 minutes ago, Yevhen said:

Sorry, but what's the reason to waste time on such work?

Why don't you build your own jeep with the new hybrid suspension to find out how it performs?

Take it as a kind of challenge: build the model using only some photos and then compare your result (your way of thinking, imagination, skill, building techniques, some interesting features) with the TLG designers'. Like a training for "see the picture > known how to build it inside" skill that is very valuable for MOCs are based on the real-life prototypes. 

I tried to do the same for 42069 (can say that succeeded at about 80%) and the most of time I was like "whoa... now I know they have done that" 

 

[Zerobricks]

1 hour ago, Yevhen said:

Sorry, but what's the reason to waste time on such work?

Why don't you build your own jeep with the new hybrid suspension to find out how it performs?

Because it's fun to see how things are made?

Also a day before pictures of 42099 popped up, I posted my creation:

 

[Bartybum]

1 hour ago, Yevhen said:

Sorry, but what's the reason to waste time on such work?

Because obviously he doesn't see it as a waste?

[Yevhen]

Just now, Zerobricks said:

Because it's fun to see how things are made?

Also a day before pictures of 42099 popped up, I posted my creation:

 

Wow! I have seen your tiger on YouTube and YES, it's great!

Normally I don't pay attention on buggies, because it's not my favourite genre, but something made me watch your video and I was pleasantly surprised how you improved a basic (at the first glance) model!

[1gor]

On 6/4/2019 at 12:11 AM, JonathanM said:

I reckon it's an XL, placed 1 stud higher than you originally placed the old XL. The L will be used for steering in the middle of the chassis is my guess.

There's 2 XL's for drive, so it makes sense for one per axle as per 9398.

Sorry for late support, but since 2 XL motors are on image posted by @Ngoc Nguyen and later by @Zerobricks in 42099 topic, I assume that is most logical explanation 

[Zerobricks]

Thanks to the new photos, I could make a rough estimation of the rear axle:

It seems the drive from XL motor is geared up two times using 20 and 12 tooth gears before going into the differential, which is very odd.

[Void_S]

20 minutes ago, Zerobricks said:

It seems the drive from XL motor is geared up two times using 20 and 12 tooth gears before going into the differential, which is very odd.

I think it's for transmission saving: PF's XL-Motor easily brakes the axles and gears, so it was a rick that PU's one may chew the diff as well...

So, taking into account this gearing, the full (known) ratio is as the following:

• 20:12 > x1.666667
• 20:12 > x1.666667 (2.777778 subtotal)
• <Differential + CV joints>
• 1:4 (new wheel hubs?) > 0.25 (0.6944444 total)

In other words, it's in 1.44 slower than motor output.

Edited June 6, 2019 by Void_S

[allanp]

I know this is based on our best guesses, but why do they insist on putting so much gear reduction in the motors 

[Zerobricks]

Here's a IRL build of the rear axle:

I made my own planetary hubs using the new pieces and old turntable:

 

[Saberwing40k]

Hey Zblj, did you notice that the front pendular axle actually extends for like 2/3rds the length of the model? Because it does.

[Zerobricks]

2 hours ago, Saberwing40k said:

Hey Zblj, did you notice that the front pendular axle actually extends for like 2/3rds the length of the model? Because it does.

Yes, see here:

 

[Void_S]

I took Zerobricks's drawings and added my interpretation of the parts that I was able to recognize. Here is a skeleton version that shows the size and proportions of the model:

https://bricksafe.com/files/Void_s/42099/42099.lxf  I have separated it to the groups: chassis (frame+front pendular subframe), body and pins and axles used to secure the body. Hopefully, it shouldn't be a big deal to mount 41999's body here 

Edited June 26, 2019 by Void_S

[Void_S]

And.. Here is about 95% accurate replica: https://bricksafe.com/files/Void_s/42099/42099 New.lxf