[WIP] Volvo EC750E

[cloud]

The Lego set 42030 Volvo L350F is one of my favorite sets. I love the playability, but I wish there were more Volvo vehicles from the same series of earth moving vehicles that were equally playable.

I happen to have a second L350F bucket kicking around from a second set purchase to make a A40 dump truck. I wish I had the Lego motorized excavator, but I have parts and this is Lego after all, I'll just make one.

The first check in my mind is the bucket size. The L350F bucket is a spade nose rock bucket with teeth and segments. In real life this bucket is 13 feet wide and holds about 9 to 10 cubic yards.

The EC750E's largest bucket is a general purpose earth moving bucket with a capacity of 9.34 cubic yards. It's width is unspecified(in the EC750E brochure), and while it will not be a spade nose bucket, the volume is close enough that maybe this could work.

The first thing I've done is to figure out if/how the loader bucket could be used as a digger bucket. My initial scale is 1 stud width = 6 inches based on the 750mm grouser being 30" (2.5') or 6" x 5 being a good match for the Lego track being 5 studs wide. We'll see if I stick to this roughly 1:30 scale in the end.

I'm going to document the build here: http://cloudslego.blogspot.ca/2017/  and discuss the problems that come up in this forum.

Here is the first proof of concept on the bucket/arm/boom.

Edited July 20, 2017 by cloud

[1gor]

Interesting project , but there is one thing that interests me; which thred spocket wheels will you use (it is a tracked excavator), because biggest ones (from 42069 set this year) look to small IMHO 

[evortigosa]

Hope to see the progress :)

[mocbuild101]

If you manage to make the rest of it to the same scale, it will be amazing!

[Jurss]

Huge project with some big challenges.

[Jeroen Ottens]

Interesting start for sure. Any idea what the size of the sprocketwheels will be?

[Dafgek81]

This will be a monster when finished. The EW160E model looks like a HO model next to this.

[cloud]

21 hours ago, I_Igor said:

Interesting project , but there is one thing that interests me; which thred spocket wheels will you use (it is a tracked excavator), because biggest ones (from 42069 set this year) look to small IMHO 

True, but there are only two sprocket options and that is the biggest one. Scale wise it is one stud too short on the diameter, but that is ok. I will probably try other gear options to see if I can get a more accurately sized sprocket look, but driving the tracks from any point other than either end has ended in poor performance.

 

12 hours ago, Jurss said:

Huge project with some big challenges.

Indeed, the wrong sized LAs  and turntable come to mind immediately.

 

11 hours ago, Jeroen Ottens said:

Interesting start for sure. Any idea what the size of the sprocketwheels will be?

There is only one choice, the biggest sprocket available - also a bit too small, but not terrible.

 

7 hours ago, Dafgek81 said:

This will be a monster when finished. The EW160E model looks like a HO model next to this.

Max stud length with biggest arm fully stretched out will be 138 studs. This is adding max digging reach on ground (106 studs) to tail swing radius (32 studs).

 

I have gone through the Volvo brochure and converted all of the diagrams and measurements to studs instead of m/ft. You can see this here: http://cloudslego.blogspot.ca/2017/06/ec750e-dimensions.html

 

 

[1gor]

1 hour ago, cloud said:

True, but there are only two sprocket options and that is the biggest one. Scale wise it is one stud too short on the diameter, but that is ok. I will probably try other gear options to see if I can get a more accurately sized sprocket look, but driving the tracks from any point other than either end has ended in poor performance.

 

There is only one choice, the biggest sprocket available - also a bit too small, but not terrible.

 

Max stud length with biggest arm fully stretched out will be 138 studs. This is adding max digging reach on ground (106 studs) to tail swing radius (32 studs).

 

I have gone through the Volvo brochure and converted all of the diagrams and measurements to studs instead of m/ft. You can see this here: http://cloudslego.blogspot.ca/2017/06/ec750e-dimensions.html

 

 

Perhaps my solution on Case IH STX 530 quadtrac can help you (using turntables and smaller treads, but 42069 treads are much stronger...)

http://www.brickshelf.com/cgi-bin/gallery.cgi?f=365319

I was looking also Volvo brochure and tracks are some 1,3meters high - for me to high for current spockets...

[cloud]

23 minutes ago, I_Igor said:

Perhaps my solution on Case IH STX 530 quadtrac can help you (using turntables and smaller treads, but 42069 treads are much stronger...)

http://www.brickshelf.com/cgi-bin/gallery.cgi?f=365319

I was looking also Volvo brochure and tracks are some 1,3meters high - for me to high for current spockets...

A pair of system tracks is a nice functional idea. Certainly gets around the problem of only being able to drive the wide technic link tread with either the small or large tread sprocket. The skeleton chasis currently weighs 2.4Kg so I will probably stick with the bigger track pieces. That and I have a second 42055 for spare parts so lots of wide track pieces. I will probably first look at inventive ways to drive the tracks using different track sprocket placement.

For the moment I'm only just past the stage of proving to myself that a model this large with as much dynamic weight movement is possible.

Actually, I'm no certain about the central turntable. I had the v2 turntable in there to use the 8 tooth gear, but decided that it was too wobbly so it got replaced with the v3 turntable. Less give, but different teeth. Even with better lack of flex it is too small. I need an 11L or 13L turntable and that doesn't exist. The BWE round ring is just too big. I'm looking at using the v3 turntable as the center pin with fore and aft weight support rollers and/or wheels/tires on hopefully a 3L thick stiff/flat chassis between the shoes.

[cloud]

This page has more discussion and images: http://cloudslego.blogspot.ca/2017/06/cylinder-linear-actuators-pistons-etc.html

This is my solution to the cylinder problem of Lego linear actuators being too short.

Driven either by gear or by axle:

So this is what the MOC currently looks like:

The scale on the arm and boom were changed to 1:26 from 1:30. The arm is now a replica of the 3.55m arm and it fits a double LA instead of just one. This makes it more realistic too as the Volvo has all of its cylinders the same size.

There is a problem though. In trying to drive the boom lift cylinders with one XL motor from the side there is too much torque going through this joint:

I'm going to look for an all gear drive solution for the boom lift LAs instead of the axle drive and/or a gearing down after the joint.

 

[GroundskeeperWillie]

That's a really interesting way to extend the LA's. I'm looking forward to see how it works out. It does look like there might be a friction problem with the turn table under load.

[BrickbyBrickTechnic]

That is an interesting solution to the LAs range problem. I'm excited to see what other cool solutions go into this model :)

[1gor]

22 hours ago, cloud said:

A pair of system tracks is a nice functional idea. Certainly gets around the problem of only being able to drive the wide technic link tread with either the small or large tread sprocket. The skeleton chasis currently weighs 2.4Kg so I will probably stick with the bigger track pieces. That and I have a second 42055 for spare parts so lots of wide track pieces. I will probably first look at inventive ways to drive the tracks using different track sprocket placement.

For the moment I'm only just past the stage of proving to myself that a model this large with as much dynamic weight movement is possible.

Actually, I'm no certain about the central turntable. I had the v2 turntable in there to use the 8 tooth gear, but decided that it was too wobbly so it got replaced with the v3 turntable. Less give, but different teeth. Even with better lack of flex it is too small. I need an 11L or 13L turntable and that doesn't exist. The BWE round ring is just too big. I'm looking at using the v3 turntable as the center pin with fore and aft weight support rollers and/or wheels/tires on hopefully a 3L thick stiff/flat chassis between the shoes.

Idea with turntable sounds good to me because wobbling is a last thing we want on our mocs...

About (spocket) wheels I know what you have for a problem. My models are based on tires (as precise as possible) and for years I'm trying to decide which particular measirement I'll stick for the future built - same scale for trucks, tractors and havent even try to construck excavators, so I'll follow your development to see what can I do...perhaps there will popup something extraordinary 

[cloud]

I'm thinking of something like this:

[1gor]

On 7/6/2017 at 5:51 PM, cloud said:

I'm thinking of something like this:

This is very promising idea. Do yo know that you can separate turntables to achieve more narrow construction? 

Edited July 8, 2017 by Milan
Removed quoted picture from previous post. Please do not quote them if they are on the same page.

[cloud]

4 hours ago, I_Igor said:

This is very promising idea. Do yo know that you can separate turntables to achieve more narrow construction? 

I know that they can be separated, but I don't know how I would use them separated. In the photo above the turntables are used as hubs as well as driven wheel. 

Do you have examples of how a separated turntable would be used? 

[1gor]

15 hours ago, cloud said:

I know that they can be separated, but I don't know how I would use them separated. In the photo above the turntables are used as hubs as well as driven wheel. 

Do you have examples of how a separated turntable would be used? 

I'll take photos in few days, and put them in your topics if you allow to do that - it is easier to see picture than to talk about it... separated turntable it used at the outer end - it could be seen in my Brickshelf gallery several posts before. Of course there is a gear 24 tooth inside separated turntable which perfectly fits inside "ring gear" on black turntable part...

Edited July 7, 2017 by I_Igor

[TechnicRCRacer]

Interesting LA solution! Looking forward to the finished result!

[1gor]

On 7. srpnja 2017. at 2:34 AM, cloud said:

I know that they can be separated, but I don't know how I would use them separated. In the photo above the turntables are used as hubs as well as driven wheel.

Do you have examples of how a separated turntable would be used?

Hi Cloud,

I hope that this "pictorial" example will be of some use for you...

 

 

[cloud]

On 7/8/2017 at 5:38 PM, I_Igor said:

Hi Cloud,

I hope that this "pictorial" example will be of some use for you...

 

Interesting use, but I'm still not sure where the non-moving structure would connect and where the "wheel" or moving part would be. The gear in the middle of the grey half unfortunately has an axle hole in the middle not a pin hole.

In the diagram I added above, the green drive axle drives the black half of the turntable directly. Which is a mistake on my part in the drawing, but assuming it was ok, one can push the pieces together and the outer wheel almost touches the black half of  the turntable and the inner space between the turntables is two studs.

The mistake is that the planets in the gearset need to be anchored to the sun gear in the middle, not the ring gear(black half of the turntable).

It should be like this: Where the carriage does not spin(an unused input into the planetary system).

I think I have a solution for that, but haven't put it together yet because I'm waiting on the "ring gear" (wheel with inner gear) from a bricklink order. I'll try to put together an ldd sample of what I'm thinking about.

Edited July 10, 2017 by cloud

[cloud]

Here is the above idea I was talking about in ldd from the blog.

Note the pink half of the turntable will be removed.

Power comes in from the red axle. The blue carriage on the turntable side will spin based on the planetary gear set of the turntable. This will increase the final drive ratio of the ring wheel driving the track by counter rotating the carriage of the drive wheel gear set. Finally the paired drive wheel will continue to transfer power along the green drive axle and power a sprocket somewhere along the track.

[1gor]

2 hours ago, cloud said:

Interesting use, but I'm still not sure where the non-moving structure would connect and where the "wheel" or moving part would be. The gear in the middle of the grey half unfortunately has an axle hole in the middle not a pin hole.

In the diagram I added above, the green drive axle drives the black half of the turntable directly. Which is a mistake on my part in the drawing, but assuming it was ok, one can push the pieces together and the outer wheel almost touches the black half of  the turntable and the inner space between the turntables is two studs.

The mistake is that the planets in the gearset need to be anchored to the sun gear in the middle, not the ring gear(black half of the turntable).

It should be like this: Where the carriage does not spin(an unused input into the planetary system).

I think I have a solution for that, but haven't put it together yet because I'm waiting on the "ring gear" (wheel with inner gear) from a bricklink order. I'll try to put together an ldd sample of what I'm thinking about.

For carriage that does not spin you can use this

https://www.bricklink.com/v2/catalog/catalogitem.page?P=2711#T=C

And new beam 1 x 5 thin with axlehole at the ends to make beam 1 x 5 with axleholes at both ends and in the center 

[cloud]

2 hours ago, I_Igor said:

For carriage that does not spin you can use this

https://www.bricklink.com/v2/catalog/catalogitem.page?P=2711#T=C

And new beam 1 x 5 thin with axlehole at the ends to make beam 1 x 5 with axleholes at both ends and in the center 

I was thinking that maybe the new bean could not hold the pins. I'll have to play with the idea and see where it goes, thanks.

[fritz4783]

That is quite the unique approach to having short Linear Actuators. I eagerly await completion of this project.