42215 Volvo EC500 Hybrid Excavator

[Ngoc Nguyen]

8043 is often brought up as a comparison for this set. Granted, it has four motors with six functions and RC and it has good value for money, but it's not like it doesn't have problems. Its playability is not that good. I had a 8043 and rebuilt it a couple of times, and it struggled to drive and move its arm as M motors didnt provide enough power. The function switch didnt work consistenly either, as the driving rings slid on the old axle connectors with ridges, which had quite some friction. Another problem with 8043 is that the angled section of the arm is held together with pins only, and over time the pin broke apart, so the  Therefore I've always wanted a 8043 that actually works properly and is more modern.

Then comes the 42215, whose flaws have been explored quite extensively already. Given that's it provides abysmal value for money, I don't plan to buy it. I did, however, give it some thoughts. I haven't gone through the building instruction yet, but from the look of it, it does seem possible to do a PF conversion. The ideal way is to give it 7 motors for 7 functions, but I'm not sure there is enough space. I'm already working on a PF conversion for 42100, and things are quite dense there already. If not possible, then 4 motors for 6 functions in the style of 8043 while making the coupling function manual is okay too. It can also go in the direction of 42042. In this case, it is still manual, but it will have 4 motors that drive 3 functions of the arm and the hard coupled two tracks, while the coupling function becomes manual. The possibilities are quite fun to think about, but it has to start with a Studio model of this thing, which wil take a lot of time. Therefore I planned to build and mod this in Studio some time in the future.

Then things took an unexpected turn when I got an offer for this thing at a retailer's price. After some deliberation I decided to grab it. Although it still has poor value for money even at the lowered price, I can use it to implement the PF Conversion, and also to satisfy my long desire for a 8043 update. Not to mention, I do have a number of L motors around. Let's see how this will go.

Edited Monday at 04:45 PM by Ngoc Nguyen

[thekoRngear]

3 hours ago, Ngoc Nguyen said:

8043 is often brought up as a comparison for this set. Granted, it has four motors with six functions and RC and it has good value for money, but it's not like it doesn't have problems. Its playability is not that good. I had a 8043 and rebuilt it a couple of times, and it struggled to drive and move its arm as M motors didnt provide enough power. The function switch didnt work consistenly either, as the driving rings slid on the old axle connectors with ridges, which had quite some friction. Another problem with 8043 is that the angled section of the arm is held together with pins only, and over time the pin broke apart, so the  Therefore I've always wanted a 8043 that actually works properly and is more modern.

Then comes the 42215, whose flaws have been explored quite extensively already. Given that's it provides abysmal value for money, I don't plan to buy it. I did, however, give it some thoughts. I haven't gone through the building instruction yet, but from the look of it, it does seem possible to do a PF conversion. The ideal way is to give it 7 motors for 7 functions, but I'm not sure there is enough space. I'm already working on a PF conversion for 42100, and things are quite dense there already. If not possible, then 4 motors for 6 functions in the style of 8043 while making the coupling function manual is okay too. It can also go in the direction of 42042. In this case, it is still manual, but it will have 4 motors that drive 3 functions of the arm and the hard coupled two tracks, while the coupling function becomes manual. The possibilities are quite fun to think about, but it has to start with a Studio model of this thing, which wil take a lot of time. Therefore I planned to build and mod this in Studio some time in the future.

Then things took an unexpected turn when I got an offer for this thing at a retailer's price. After some deliberation I decided to grab it. Although it still has poor value for money even at the lowered price, I can use it to implement the PF Conversion, and also to satisfy my long desire for a 8043 update. Not to mention, I do have a number of L motors around. Let's see how this will go.

Good luck. I am curious to see how it turns out!

[Ngoc Nguyen]

7 minutes ago, thekoRngear said:

Good luck. I am curious to see how it turns out!

I just opened the instruction and immediately realized luck is already not on my side. The 3x13 frame blocks transmission to the sprocket from behind, so that part will have to be redesigned. For PF conversions I dont really want to stray to much from the official design to save time doing the instruction, but thére's no other way for this part.

 

[1gor]

@Ngoc Nguyen,

perhaps best way for a start is to copy idea from 8043 set with large motors and servo to operate driving rings deployment...

Edited Monday at 07:36 PM by 1gor

[Ngoc Nguyen]

If I were to go for the 7 motors for 7 functions, the chassis must accommodate the battery box and 2 IR Receivers. Since the receivers catch the infrared, they must be exposed and thus must be put as outwardly as possible. At the same time, the PF battery box needs to be removable for battery replacement. Therefore in general there are 2 arrangements.

- In the first case, the battery box and the receivers are stacked vertically, and all are exposed. This setup will require a height of at least 8 studs. The chassis of PF 42100 use this setup because its height is 10 studs.

- In the second case, the battery box is and the receivers are put on one row. The battery box will be tucked further inside, while the receivers are outside. This setup will require a length of at least 12 studs.

The chassis of 42215 cannot accomodate either of those arrangements because it doesn't have the required dimensions, as shown below in the instruction.

Not to mention, the motor that rotates the chassis cannot connect directly to the turntable and has to instead go through a series of gearing down, which will take up space in the middle portion as well as interefering with the placement of the two drive motors. The chassis for PF 42100 doesn't suffer from this problem because it already has gearing and motor placement for 3 motors.

 

Thererfore the option for full RC (7 motors for 7 functions) is now ruled out.

The next best option will be RC in 8043 style. In this style only 6 functions can be motorized, and only 3 can work simultaneously, so I have to choose one function to exclude.

This reminds me of another problem with 8043. Since two independent transmissions have to go through the turntable, the solution in that set is that one motor will drive a direct axle, and one motor will drive a clutch gear, which transmits motion through the driving ring and a ring extension.

 

A drawback of this setup is that the clutch transmissions has a significant degree of backlash, which causes one track to start rolling slightly later than the other one even when the motors driving both tracks start at the same time. The difference in starting time causes the model to slightly turn whenever it starts moving from its resting state instead of going in a straight line, and I don't like that.

Another problem is that in order to accomodate both of those track transmission and the drive of the lowest pair of LAs, the drive train for the LAs has to go above the drive train for the direct drive, which means there should be at least a space of 7 studs to accommodate.

 

In 42215, that space doesn't exist, because the connection point with the excavator arm is put really low into the undercarriage. And as stated above, I don't want to do any major redesign, especially structural placements.

 

Another point of consideration is that the bucket coupling function might not make sense for a manual model, but for a RC model it increases playability. Therefore I decide that in the 8043 style PF conversion for this set, 3 functions for the arm will go together, just like in the old 8043, while the other 3 will be driving, slewing, and coupling. The two tracks will be hard coupled like those in 42042, so that only one transmission needs to go down through the turntable. That will simplify the setup in the area right above the turntable, while still allows the coupling function to be RC. Also, while the excavator is digging, it doesnt really need to decouple the bucket.

[Anio]

Your RC excavator wouldn't steer ? O_o

[Ngoc Nguyen]

2 hours ago, Anio said:

Your RC excavator wouldn't steer ? O_o

Yeah what else can I do

[Bartybum]

4 hours ago, Ngoc Nguyen said:

The two tracks will be hard coupled like those in 42042, so that only one transmission needs to go down through the turntable.

Don't do this to me baby

11 minutes ago, Ngoc Nguyen said:

Yeah what else can I do

How about motorized pneumatics a la 42043? I'd imagine that should free up space a fair bit maybe?

Forgive me I'm an idiot, I forgot we don't have XL pneumatic cylinders

Edited 22 hours ago by Bartybum

[Ngoc Nguyen]

50 minutes ago, Bartybum said:

Don't do this to me baby

I think I'll try both setup once I start: slew+track+coupling, and slew+track1+track2. The second way is clearly better, but since I havent built the Studio model I dont know whether there will be space for that.

[Paul B Technic]

I wonder if TLG will see how poorly this has been received and take it in to account for future sets? It is the first time I can recall seeing a set that has been so negative...

[Ngoc Nguyen]

9 hours ago, Ngoc Nguyen said:

Thererfore the option for full RC (7 motors for 7 functions) is now ruled out.

Actually...

[1gor]

Good idea is to have one battery box in undercarriege and one in uppercarriege; I thought in first place that you want to use just one BB...silly me...looks promissing

[Stormyy]

What about using Cada battery boxes to free up some space? Wouldn't it help?

[Ngoc Nguyen]

16 minutes ago, Stormyy said:

What about using Cada battery boxes to free up some space? Wouldn't it help?

I wanna use only standard Lego PF components.

[1gor]

5 minutes ago, Ngoc Nguyen said:

I wanna use only standard Lego PF components.

Then you can only help yourself with train battery boxes to save some small percentage of space...

[mpj]

I think it should be better to move the whole @Ngoc Nguyenattempts into the mods and improvements topic

 

 

[dhc6twinotter]

20 hours ago, Ngoc Nguyen said:

This reminds me of another problem with 8043. Since two independent transmissions have to go through the turntable, the solution in that set is that one motor will drive a direct axle, and one motor will drive a clutch gear, which transmits motion through the driving ring and a ring extension.

A drawback of this setup is that the clutch transmissions has a significant degree of backlash, which causes one track to start rolling slightly later than the other one even when the motors driving both tracks start at the same time. The difference in starting time causes the model to slightly turn whenever it starts moving from its resting state instead of going in a straight line, and I don't like that.

You can use an old style differential instead of driving rings.  You won't get the backlash.   Run an axle straight through the differential instead of using the bevel gears.  That's how I've done it in the past.

[Ngoc Nguyen]

I got the functional parts done.

 

This is the exploded view for the transmissions only. There are a couple of interesting things.

 

 

1. The most ingenious part is the arm that has 3 transmissions running through it. Previously the only other set with 3 transmissions in the digging arm is 42100, but the arm in 42100 is much wider and contains motors inside. Before that, the maximum number of transmissions running through a digging arm is 2, and that only appears in 8043. 

Because the width of the digging arm in this set is mostly just 5 studs wide, only one transmission go through the mounting point (highlighted). The other two transmissions sit above the mounting point, so as the arm moves, the length of those transmissions also change, and therefore can only be done with the new long CV joint that first appears in the Zetros.

This explains why the mounting point of the digging arm is lower down and closer to the center than the arm in other Technic excavators.

 

 

2. The transmission through the last section of the digging arm is very cool too. The right one is off center.

 

 

 

3. The transmission from the motor is unusually geared down.

 

The motor's output goes through a pair of 16/20, a pair of 12/24, then another pair of 12/16 before reaching the red 16z clutch gears. That leads to a x0.3 of speed before any function is selected, while there doesn't seem to be anything that requires that much gearing down.