42215 Mods Improvements Alternative builds And Attachments

[Ngoc Nguyen]

Let's start the PF conversion.

 

[Ngoc Nguyen]

Plenty of space for 4 L motors + 1 battery box + 2 IR receivers after the original gearbox is removed.

[Ngoc Nguyen]

The PF RC Conversion mod is finished.

 

https://reb.li/m/231183

 

[mpj]

Have you tested it in real life to check everything works fine? What is the speed of the arm?

[Glaysche]

I started with an RC PoweredUp mod.  I think I have something pretty good for the tracks and rotation.

 

 

 

I haven't started on converting the top functions yet.  The motors and hub are pretty well hidden when in this position.  When the top rotates, it becomes more visible.

The lower section is very height constrained.  I ended up with the support for the gears on the bottom being 2L lower than the rest of the chassis, reducing ground clearance.  It might be possible to put those gears inside but that would require much more major changes to the structure.  I might revisit after converting the top functions.

[Saruzeufel]

On 8/6/2025 at 10:34 PM, SNIPE said:

1.PTO1 (e.g. drill rotation)

2.PTO2 (e.g. drill hammering)

3.attachment latch/unlatch

I'm really looking forward to your progress on this, please keep us updated with what you come up for the quick coupler. I tried building one with those 3 functions a while ago but it ended up being way to big and bulky, so I am really interested ins seeing your approach

[SNIPE]

15 hours ago, Saruzeufel said:

I'm really looking forward to your progress on this, please keep us updated with what you come up for the quick coupler. I tried building one with those 3 functions a while ago but it ended up being way to big and bulky, so I am really interested ins seeing your approach

I'll try, but I have a tendency to half finish things

[Ngoc Nguyen]

After quite a number of trials and errors I finally found a gear combination that strikes an acceptable balance between playability and speed.

The biggest bottleneck is determining the speed for the base XL LAs. They can definitely be geared to move faster, and I did try some gearing combos that make them move faster, but past a certain point they struggle to lift the arm with an empty bucket. Since the movements of all 3 stages are too slow to actually play digging, I instead optimize the speed that at least permit a tool swap play. 

Video and instruction for 42215 Playability Mod coming soon.

Edited September 4 by Ngoc Nguyen

[Ngoc Nguyen]

Deleted

Edited September 23 by Ngoc Nguyen

[Ngoc Nguyen]

On 8/2/2025 at 3:03 AM, Zerobricks said:

Quickly looking at the instructions, it shuld be possible to center the battery box and add another motor. This would allow faster gearing ratio and perhaps ability to control 2 functions at once.

I managed to add another motor and hard couple two motors together. The sad news is that their performance is only slightly better than that of one single motor. Video is coming soon. This set is truly unfixable.

Edited September 11 by Ngoc Nguyen

[Bartybum]

7 hours ago, Ngoc Nguyen said:

I managed to add another motor and hard couple two motors together. The sad news is that their performance is only slightly better than that of one single motor. Video is coming soon. This set is truly unfixable.

Uh oh... looking forward to it

[SNIPE]

one possibility might be to replace the bevel gears with just a 12 tooth single bevel gear, but then we do something I've never seen before, that is: use just the red 28 tooth idler gears  then have another  single tooth bevel gear on the other side. Its kinda big to fit in though but you can put half beams inside of the 28 tooth idler gear at least.

I also have every spike prime motor (x1L,x4M and x6 small) + other lego motors so l can test stuff out if needed. sadly no buwizz 3.0 , only 2.0

[Ngoc Nguyen]

Deleted

Edited September 23 by Ngoc Nguyen

[Ngoc Nguyen]

On 8/11/2025 at 7:27 PM, mpj said:

Have you tested it in real life to check everything works fine? What is the speed of the arm?

Here's the demonstration.

 

The transmission can always be modified for more torque through some gear swaps, but that would come at the expense of speed, which is what I'd rather avoid. The setup I used in the video is a careful balance between acceptable speed and sufficient torque for bucket coupling/decoupling. I haven't tested, but I don't think there's enough torque to play digging.

[Ngoc Nguyen]

Guys, a winner is found!

I finally found an arrangement that makes the 42215 playble. I define playable as having the arm move at decent speed with decent torque. And the solution is just one extra L motor. I actually did try hard-coupled motors in my previous iteration, but because I put a linear clutch in the transmission for the base LAs, they don't work reliably. Fortunately @gyenesvi pointed it out. I removed it and the whole thing works flawlessly. Honestly at 430$ this is what should have been sold in the beginning.

Demonstration.

 

[ZippyUK]

Hi all new to this site, although a member off Rebrickable for a while. Ive got into Technic late in life and have amassed a large collection in a short space of time. Further more I was introduced to Rebrickable and then the Moc building started. Ive also had the pleasure of working with a Moc builder as regards a test build.  The latest Moc I've built is the RC EC500 by WW Bricks Studio, defiantly what Lego should off done, and I'm glad I bit the bullet to build this one. So now I've entered the world of RC.

 

[Ngoc Nguyen]

1 hour ago, ZippyUK said:

Hi all new to this site, although a member off Rebrickable for a while. Ive got into Technic late in life and have amassed a large collection in a short space of time. Further more I was introduced to Rebrickable and then the Moc building started. Ive also had the pleasure of working with a Moc builder as regards a test build.  The latest Moc I've built is the RC EC500 by WW Bricks Studio, defiantly what Lego should off done, and I'm glad I bit the bullet to build this one. So now I've entered the world of RC.

Does Buwizz provide more power to the motor? I can't really figure out how direct drive L motors have enough torque to drive the model at that speed. In my RC mod I have to gear it down by the ratio of 1:20.

 

[ZippyUK]

56 minutes ago, Ngoc Nguyen said:

Does Buwizz provide more power to the motor? I can't really figure out how direct drive L motors have enough torque to drive the model at that speed. In my RC mod I have to gear it down by the ratio of 1:20.

 

The Moc uses 7 motors and 2 power boxes, I used Mould King 6L Power Function and 1M Power Function, 2 x 4.0 Power Modules, that's all I can divulged. The instructions are well worth purchasing. Note!!!! the video is not sped up.

https://rebrickable.com/mocs/MOC-233006/WW Bricks Studio/full-rc-lego-technic-42215-volvo-ec500-hybrid-excavator/#details

[efferman]

I have done a small gearbox mod with the gears included in the set

The 12/24 step in the main drivetrain is removed, and the 12/20 in the mainboom drivetrain is replaced by a 16/16 combination.

Replace the 16/20 by the 12/24 and replace the red bush with a 12z and the 12z will mesh with the 20Z above and the 24Z.

[efferman]

Has anyone an io file of the unmodified EC500? I have discovered a problem in the drivetrain and would try out something before i disassemble the set.

Does anyone else noticed this?

 

Edited Friday at 07:02 PM by efferman

[SNIPE]

1 hour ago, efferman said:

Has anyone an io file of the unmodified EC500? I have discovered a problem in the drivetrain and would try out something before i disassemble the set.

Does anyone else noticed this?

Here you go: https://fogeyman.tistory.com/1644

[efferman]

Thank you very much.

 

edit:

i think this will work. Should be even easier when the quick coupler is removed.

Edited yesterday at 09:50 AM by efferman