[MOC] Volvo excavator [video online]

[steph77]

Here I am again.

This time the subject is one of the very usual kind: one PFS IR commanded excavator.

They are many exemples of perfect excavator on the web...but I just wanted mine, of my own design.

So I study it from A to Z and I had to answer many of the questions that many people answer before.Surprisingly, I do not answer the same at some of them :)

But first this is what we are talking about:

This model as been design in one only goal : a maximum of fun to play with it. In order to match that goal, each and every motor Is directly connected to each function. No mechanics in there.

The function are ultra classical : drive, steer, rotate and the 3 movements of the arm. I make use of L motor for the tracks and lifting main arm. Other are medium size motors.

I also choose to keep it as compact as possible. The main issue I find on many creation on the web is a too big body resulting in a too big arm. Too big arm need lots of power and often be very slow to move.

I try to get what I think is the best compromise in size and use of existing motors. (No pipa I do not have RC ones :) )

The tracks gives the global scale. As you see the BB is in the lower part of the structure. This is due to compactness of the upper part but also for better design of this last spoken upper part.

As the excavator rolls only on flat surfaces, no use of any suspension in it...

view from the downside the tracks are well integrated, and even with the BB there is a good ground clearance of 3T wich is very good.

I also try to implement good action range at the arm:

 

 

And also small details that makes it looks good, like 3 sets of lights, toolbox, ...

Back view, easy acces to the BB to swictch on/off and replace (often:) ) batteries

The top part is designed so replacing M motor by Large one is easy (I do command two of them, awaiting arrival)

 

So here it is, not the Moc of the year for sure, but sometimes it's good to achieve some simple goals.

As expected and designed for, this one is very fun to play with.

Hope you'll enjoy it

Steph.

 

Edited September 14, 2017 by steph77

[BrickbyBrickTechnic]

What can I say? Another stellar model from you, @steph77 .

Is this based on a real Volvo excavator? If yes, which one?

[1gor]

It is simple excavator, but I personally would like tread spockets than gears 40 tooth...

[Leonardo da Bricki]

Cool excavator, sometimes simplicity and playability is a nice change.  I do agree with @I_Igor that the larger track links would work better here. The chain link treads are too narrow.

[steph77]

10 minutes ago, BrickbyBrickTechnic said:

What can I say? Another stellar model from you, @steph77 .

Is this based on a real Volvo excavator? If yes, which one?

Thanks!  I do not based it from a real model. I just make use of my Volvo labeled parts to give an identity to the model :)

9 minutes ago, I_Igor said:

It is simple excavator, but I personally would like tread spockets than gears 40 tooth...

Honestly I tried to do it. But I failed. My reasoning on this point is the next one: As my treads are only 20 cm long (total length, only 21t between axes) I do not have that much place to insert the drivetrain. Making use of the treat sprockets involve that I had to report to the center on the tracks the point where I could connect the motors. This meant a 5 to 6 T longer tracks witch doesn't match my goal. On the other hand it was possible to pass the drive train directly laterally. It also failed due to much to wide design.

So, even if the design impact is real, I decide to use 40T gear and old style treads. This was the best compromise as I immediately obtain a great reduction (40T/12T) and get a good power and couple in the tracks.

As the duet 40T/12t is realized with one T of vertical offset, it also fit perfectly with the L motors points of connections

Last but not least, the rotation on flat surfaces is much smoother with those 40T gears :)

It is one of the few point on witch I made different choice than what is usually the use.

Thanks for comments

[Lipko]

You are one of my favorite builders because of builds like this

[Jeroen Ottens]

Nice one. It is not RC, right? How do you operate the different motors?

[steph77]

Just now, Lipko said:

You are one of my favorite builders because of builds like this

Just now, Jeroen Ottens said:

Nice one. It is not RC, right? How do you operate the different motors?

It is RC, three IR controller. The IR receptor are installed at the back of the body, one in the left side and two in the right side. The receptor are integrated by the use of the black color for the back part of the structure. The cells are oriented to the top for a maximum quality of reception.

Look closely at the first image of the post and search the new curved black panels 3/5 at the back and search inside the curved side on the top, you'll find them ;)

[1gor]

2 hours ago, steph77 said:

Honestly I tried to do it. But I failed. My reasoning on this point is the next one: As my treads are only 20 cm long (total length, only 21t between axes) I do not have that much place to insert the drivetrain. Making use of the treat sprockets involve that I had to report to the center on the tracks the point where I could connect the motors. This meant a 5 to 6 T longer tracks witch doesn't match my goal. On the other hand it was possible to pass the drive train directly laterally. It also failed due to much to wide design.

So, even if the design impact is real, I decide to use 40T gear and old style treads. This was the best compromise as I immediately obtain a great reduction (40T/12T) and get a good power and couple in the tracks.

As the duet 40T/12t is realized with one T of vertical offset, it also fit perfectly with the L motors points of connections

Last but not least, the rotation on flat surfaces is much smoother with those 40T gears :)

It is one of the few point on witch I made different choice than what is usually the use.

Thanks for comments

Important is that you managed to find solution which is acceptable compromise and you are satisfied with this. This could be easily LEGO official set which should enable LEGO fans to buy lot of pf elements in relatively small and affordable set (similar idea like this year's tracked racer set...)

[Jeroen Ottens]

3 hours ago, steph77 said:

It is RC, three IR controller. The IR receptor are installed at the back of the body, one in the left side and two in the right side. The receptor are integrated by the use of the black color for the back part of the structure. The cells are oriented to the top for a maximum quality of reception.

Look closely at the first image of the post and search the new curved black panels 3/5 at the back and search inside the curved side on the top, you'll find them ;)

Ah, very clever. I should have known better

[ginger-snapped]

Another spectacular model. Amazing functions for a MOC of this size. There are very creative solutions in this excavator, and it looks like you will have a ton of run playing with it.

[TechnicSummse]

Really nice model, i like it :)

How did you manage the tower rotating+ roation limiting? Did you use a servo for the rotation? Or a m-motor+clutchgear?

[jorgeopesi]

I see some good ideas on very nice excavator  .

[steph77]

8 hours ago, TechnicSummse said:

How did you manage the tower rotating+ roation limiting? Did you use a servo for the rotation? Or a m-motor+clutchgear?

The upper part rotation is achieved by one medium motor. Here is the kinematic sequence:

M motor/worm gear / clutch / 12T / turntable.

Although I have 3 wires passing through the turntable I didn't install specific rotation limiter, but I had better to do so.

I'll try to see how I could realize this limitation. Thanks for comments!

 

[mocbuild101]

Great work! I like that you built it mainly for fun, rather than trying to replicate something specific.

[Thirdwigg]

Again, very well done. I like the 40 tooth sprockets, and the old bucket.

[steph77]

Here is a video of the model in action:

Enjoy!

 

[jorgeopesi]

NIce working, I like the bucket it will be one of my next purchases.

[Aleh]

Nice looking building equipment!

[steph77]

Thanks!

15 hours ago, jorgeopesi said:

NIce working, I like the bucket it will be one of my next purchases.

Could be hard to find and be very expensive. I just had mine from the dark age. Personnaly i would preffer @efferman custom part....

[jorgeopesi]

4 minutes ago, steph77 said:

Thanks!

Could be hard to find and be very expensive. I just had mine from the dark age. Personnaly i would preffer @efferman custom part....

No thanks I am a big purist my friend.

[steph77]

.

Anyway it'a good choice!

Just be carefull. This piece is quiet fragile at the articulation point 

[jaffrry]

On 2017/9/10 at 0:09 AM, steph77 said:

 

I also choose to keep it as compact as possible. The main issue I find on many creation on the web is a too big body resulting in a too big arm. Too big arm need lots of power and often be very slow to move.

 

 

 

 

 

 

 

I agree,but 42006 looks smaller.

https://www.youtube.com/watch?v=-wqGbeyVY04