[MOC] PF JCB 3CX Backhoe

[dhc6twinotter]

Hey all,

So, this is a project I've been working on for the past 10 months or so. This is a remote control backhoe based on the JCB 3CX. I know there are a few pictures of this floating around the forum, but I wanted to go ahead and post up a thread about it.

There are 9 motors, and 12 functions (11 if you don't count the gearbox selector as a function).

Functions:

Drive | 2 XL motors

Steer | 1 m motor

Boom | 1 XL motor

Gearbox Mode Switch | 1 m motor

Dipperstick | 1 m motor*

Dipper | 1 m motor*

Dipperstick Extension | 1 m motor*

Boom Slew | 1 m motor*

Right Stabilizer | 1 m motor*

Left Stabilizer | 1 m motor*

Loader | 1 m motor*

Loader Scoop | 1 m motor*

Working steering wheel

Fake I4 engine with moving pistons and fan

*Functions operated through gearbox

Specifications:

3 XL motors

6 m motors

2 battery boxes

5 IR receivers

3 extension wires

1 set LED lights

10 linear actuators

1 mini linear actuator

4 wheel drive with center differential

8 output gearbox

Pendular front axle

8.4 pounds

25x140 studs (approximate)

5500 pieces (approximate)

Pictures:

LEGO didn't make a wheel large enough, so I had to piece together my own. For each of the rear wheels, I built an internal frame and each wheel has 32 smaller LEGO tires stretched around the frame. This took forever to do.

If you've been to BrickFair or BrickCon, you may have seen this on display at those events. Since BrickFair, I've rebuilt the front axle, built the battery boxe enclosures, added a 2nd LA on the boom, and geared down the LA that operates the dipperstick. After BrickCon, I rebuilt the front axle again, removed one level of gear reduction on the boom LAs (it moves quicker now), and redesigned the boom gearing that operates the LA on the dipper scoop.

All in all, I'm really happy with how it turned out. Some of the motors are straining a bit, and knowing what I know now, I think I'd do one or two things differently.

In the future, I'd like to build a pneumatic version with a few more functions. That will be in a while, and I have a list of mocs I'd like to build prior to another backhoe.

Anyways, just thought I'd show you all my project.

More pictures on my Brickshelf

And on my Flickr

Thanks!

Daniel

Edited October 16, 2011 by dhc6twinotter

[Alasdair Ryan]

I like your backhoe You have found a clever way of making bigger wheels ,i am not to sure on the rear backacter it seems a bit to long and thin (the first part of the boom).

Your video is blocked on copyright terms.

[dhc6twinotter]

I like your backhoe You have found a clever way of making bigger wheels ,i am not to sure on the rear backacter it seems a bit to long and thin (the first part of the boom).

Your video is blocked on copyright terms.

Thanks! Yeah, now that you mention it, it may be a bit thin.

I'm not sure what to do about the video. It works fine here, but I got an email saying it may not work in a bunch of different contries. The music is copyrighted. Youtube does list the artist and a link to purchase the song on amazon, so I figured it would be ok. This is why I don't like adding music to my videos. Any ideas?

Edited October 16, 2011 by dhc6twinotter

[DLuders]

Your JCB backhoe is really fantastic! :thumbup: I don't believe I've seen a better solution to creating a large rear wheel. In regards to your video, perhaps you could post another one (without music) so that the Europeans can see your creation in action. If folks cannot see the music version, they can revert to the non-music version.

[Alasdair Ryan]

I just noticed that you listed 5 receivers how did you set up the 5th one does this run of the gearbox via a switch?.

[dhc6twinotter]

I just noticed that you listed 5 receivers how did you set up the 5th one does this run of the gearbox via a switch?.

I'm using 2 XL motors for the drive. Each motor is run off separate battery boxes and receivers. I basically have two separate circuits, and each motor can run at 100%. Two of the receivers are set on the same channel.

As for the video, I'm just going to re-upload another one later today. Youtube is lame.

Edited October 16, 2011 by dhc6twinotter

[Alasdair Ryan]

Sorry how do you control the 5th one? Given you can only control 4 receivers.

Edited October 16, 2011 by Alasdair Ryan

[dhc6twinotter]

Sorry how do you control the 5th one? Given you can only control 4 receivers.

The 5th receiver is set on the same channel as one of the other receivers, and receives the same signal from the remote control. In other words, the 4th and 5th receiver both have an XL motor plugged into the blue port and are set on channel number 1. Both XL motors run when I push the single blue lever on my remote control that is set to channel 1. The 5th receiver has nothing plugged into the red port.

Edited October 16, 2011 by dhc6twinotter

[Alasdair Ryan]

Thanks for that i get you now.

Edited October 16, 2011 by Alasdair Ryan

[dhc6twinotter]

Thanks for that i get you know.

Cool. I'm sorry I'm not the best at explaining things.

[Jurgen Krooshoop]

Truly amazing creation. I've built Backhoe's myself, I know how difficult it can be to make everything working properly. My compliments

[dhc6twinotter]

Thank you, Jurgen.

I've re-uploaded the video with a different sound track. It should work worldwide now.

[timslegos]

Fantastic Backhoe!! that is certainly a very clever way of building back wheels. I am in the process of building a backhoe right now and i will definitely use yours as an inspiration.

tim

[dhc6twinotter]

I know this is an old thread, but If anybody is interested, I've created some CAD pictures showing the mechanical aspects of the backhoe. This is my first time using MLCAD, and it's by no means perfect, but it gives an idea of the design.

The entire backhoe:

The drive motors, gear reduction, and steering:

Half of the gearbox:

The stabilizers with associated motors:

The loader LA's with associated motor:

The loader bucket LA's with associated motor:

Boom slew with associated motor:

Boom stick LA with associated motor:

Boom stick extension with associated motor:

Dipper bucket LA and associated motor:

Boom LA's and XL motor. This does not operate though the gearbox.

[Lost_In_Noise]

Looks like you've thought this really thorough through before you started it even. Fantastic MOC, and it works so well also. It really doesn't matter how much time you spend creating something as good as this. Good work on the CADs, it must have taken you forever just to add the parts

[Carsten Svendsen]

I'm even more amazed now, especially that you were able to fit all of those mechanism in that thing. I'd still like a picture or something up close of the boom turnwheel where you have 2 or 3 axles goig through it.

[Blakbird]

Those mechanisms look amazing! Thanks for the effort. I was amazed at the functionality of this thing when I saw it at BrickCon.

FYI, you can get much better images by opening your model in LDView after you finish it in MLCAD. AN MLCAD capture looks like this:

and an LDView capture looks like this:

[cgarison]

That is a brilliant build. I love the detail and the scale of the model!

[dhc6twinotter]

Thanks all! Blackbird, thanks for the tip about using LDVIEW. I'll for sure use that next time.

Carsten Svendsen, which section of the boom are you wanting more pictures of? The base of the boom where it connects to the chassis, or where the boom and the stick connect?

[Carsten Svendsen]

Well you've got 3 functions going through the turntable, how did you solve that?

[dhc6twinotter]

Well you've got 3 functions going through the turntable, how did you solve that?

Actually, there are 4 axles going through, but I just used u-joints for all the functions. The downside to using u-joints is that they don't allow the boom to rotate 90 degrees to the chassis. My stabilizers are in the way anyways, but on my V2 of the backhoe, I'll come up with a different solution.

Here's a picture:

Let me know if you need any other pictures.

Edited September 21, 2012 by dhc6twinotter

[Dennis Bosman]

It's the first time I see this MOC. What nice piece of technique! These rear wheels are a very clever thought! I've seen more varieties of those, mostly using plates. Never thought about this, well done!

[Tji-chan]

Hoi hoi

Nice love it, for sure the back wheels

Maby a bit late nouw but for music in a youtube video this is a option

http://freemusicarchive.org/

Muddy

[jantjeuh]

How does this compare to Jurgen's PF backhoe?

[dhc6twinotter]

It's the first time I see this MOC. What nice piece of technique! These rear wheels are a very clever thought! I've seen more varieties of those, mostly using plates. Never thought about this, well done!

Thanks Dennis! The wheels were pretty difficult and took about 4 hours each. I built them at work.

Hoi hoi

Nice love it, for sure the back wheels

Maby a bit late nouw but for music in a youtube video this is a option

http://freemusicarchive.org/

Muddy

Thanks for the music tip! Saved to my bookmarks.

How does this compare to Jurgen's PF backhoe?

Jurgen's is better. My backhoe is larger with a few more functions, like the independently controlled stabilizer, extending stick, fake engine, 4WD with center diff, and dual drive motors; but all this adds weight, complexity, and takes more room. My backhoe worked ok at the first couple of shows, although I did break a couple of the old style 16t gears at Brickfair. Paul Boratko was kind enough to give me a few of the new style gears, which held up great. After those first few shows, some problems started to develop. Some of those problems were probably a result of a last minute design change that, while a good idea, wasn't implemented properly and ended up putting stress on the drivelines for a few functions. Lots of lessons learned on this moc. I'm sure Jurgen's backhoe is much better designed, and I think it has a much more efficient layout, especially placing the motors in the boom.

Someday I'd like to build a second version, and hopefully with some additional functions and a smaller package.

Edited March 14, 2014 by dhc6twinotter