[MOC] 42151 Bugatti Monster Bolide

[mla2]

Last few days I've been working on a motorized version of the Bugatti Bolide using the .io file @Void_S posted earlier (thanks again!).

I wanted to do the motorization by adding a diff, a Buwizz 3.0 + monster motor and a PU L motor for steering, all without impacting the looks except for removing the HOG.

Adding the PU L motor was pretty straight forward. It increased the existing gap that's between the dashboard and the front hood but later I found a nice solution to close this gap again.

To add the monster motor and the diff I used the same design as in my 8865 New Jeep MOC. It's very strong and doesn't suffer from any gear skipping. Fitting this required some changes on the back side but none of those change the looks.

Adding the Buwizz 3.0 was the hardest, it's quite big and I tried to many ways to get it to fit. In the end I found a nice way to hide it well, this did require the removal of the seats and also some minor changes to the sides: the yellow door panel had to be moved one stud outward and half a stud backward. It think this looks pretty good actually, perhaps better than the original. Additionally I had to change the two bottom new panels in front of the rear wheel with a single old panel but that's it. Using an Lego Buggy motor doesn't work, there's no space for the PF connector it requires.

I don't have the set yet but I built it all using my own parts and made it so all connection points for the new panels are there again. All panels are fixed at least as well as in the original design except for the aforementioned yellow door panel which is only connected with a single pin now.

Here's 2 work in progress photos:

It drives really well and when it's fully built you don't really notice the motorization which is exactly what I was trying to achieve so I'm happy :) Especially the cabin is still nicely spacious.

I will be able to build it with the real set parts soon, I managed to order it somewhere and it has been shipped. I did already finish the virtual model and will make free instructions available once I can test the full build and instructions.

Thanks for reading and hope you like it, any feedback is welcome!

Here's some renders of the model:

 

[Void_S]

@mla2, is it possible to put the BuWizz hub upside down here, raised at 1 stud to grant some space for wires? I believe it would be easier to change and switch on it.
Nice motorization, BTW. I would only add some decorations to turn the "buggy motor" into a casing of the W16 engine (some slopes, brackets, and 16 1x1 round tiles).

[mla2]

@Void_S Thanks for your comments!

I made it so you can still reach the BuWizz switch to turn it on/off when it's fully assembled. You can even put an USB cable in for charging or keep it there all the time. The Buwizz is now actually lowered half a stud to hide it as much as possibile.

I'm not sure what you mean with decorating the buggy motor though it sounds very interesting. Do you have some example for what you're thinking about, perhaps in some other MOC? I did add some panels to hide the motor when you look into the cabin (especially when the LBG version by Buwizz is used). You can't see this very well on the images above, see below for a new one which also shows the space for turning on or charing the Buwizz. I tried various other things as well like using fence instead or thinner panels but I couldn't get those to work because the Buwizz has an odd numbers of studs.

Just in case I also added my current .io to Bricksafe: https://bricksafe.com/files/mla2/other/bugatti-monster-bolide/Bugatti Monster Bolide.io

 

Edited December 22, 2022 by mla2

[mla2]

I'm happy to report the build with the set's parts worked well. It drives great and the motorization is barely visible. Hope to be able to start creating the instructions soon.

This is a fun set BTW, there's a lot more attention to detail than I'm used to in official sets! The difference between a set like 42125 and this is like night and day.

[Zerobricks]

Well done. Are you using a 12 tooth gear to power the differential? I think you could use a 20 one with old diff to make it even faster, there should be plenty of torque available.

[mla2]

@Zerobricks

1 hour ago, Zerobricks said:

Well done. Are you using a 12 tooth gear to power the differential? I think you could use a 20 one with old diff to make it even faster, there should be plenty of torque available.

Thanks! I'm using a 12 tooth gear indeed. I tried using a 20 with the old diff on my older MOC I mentioned and couldn't get rid of skipping gears. I now tried it on this one too and have the same problem, it seems the forces are too much unfortunately. It's only ok if you accelerate more gently. Bit of a shame since it does indeed become very fast. What I don't know if it's due to my design or just fundamentally not doable.

[Zerobricks]

How about ditching the diff altogether?

[mla2]

I beleive I have to lower the buggy motor by 1 stud in that case (right? using 2 *  32198) which means it will stick out 1 stud on the bottom making very close (as in a few mm) to the ground. I'm afraid that this would give too much risk to the front side of the buggy motor. There's 2 thin beams at 1 stud below the bottom as well but those are 1) directly between the rear wheels and 2) not as precious

Edited December 23, 2022 by mla2

[mla2]

@Zerobricks I got it to work without a diff in a different way: I raised the motor by half a stud so I could use a 87408 to reinforce things. Now it's really fast, but still no skipping gears Thanks for the inspiration!

An additional nice feature of this setup is that it works with a Lego buggy motor as well: its unusable pin holes due to the curved casing are avoided.

Edited December 26, 2022 by mla2

[Zerobricks]

1 hour ago, mla2 said:

@Zerobricks I got it to work without a diff in a different way: I raised the motor by half a stud so I could use a 87408 to reinforce things. Now it's really fast, but still no skipping gears Thanks for the inspiration!

 

That's how I motorized the Mustang, but using 48496 part. Glad it works for you!

[mla2]

1 hour ago, Zerobricks said:

That's how I motorized the Mustang, but using 48496 part. Glad it works for you!

Ok, cool, thanks for letting me know!

[mla2]

The instructions are now available for free on Rebrickable at https://rebrickable.com/mocs/MOC-133111/mla2/42151-bugatti-monster-bolide-extreme-rc/

Here's a little demo video I made:

I also made instructions for a version with an upside down battery box as suggested by @Void_S requiring just a few different parts. These instructions are available at https://bricksafe.com/files/mla2/other/bugatti-monster-bolide/Bugatti Monster Bolide_udb.pdf

Comparison animation:

Final photo of the regular version:

 

 

[mla2]

I have built a version with Buwizz 3.0 + 2 large PU motors as well. It's not as fast but still quite nice. Also did a version with a small PU hub + 2 large PU motors which would be the cheapest but is pretty slow.

It's good fun to try hiding electronics in such a small model and very satisfiying when you find an elegant solution which can be built without issues!

 

[NoEXIST]

It's really cool to see motorized set with it's stock appearance!

[mla2]

Perhaps I should restore the HOG gear on top of the roof and then it would be a true Lego version of a sleeper car