[MOC][WIP] Grove GSK55 trailer crane

[M5Technic]

am interested to see the results!

[aminnich]

I was hoping to give a positive today, but nope.  

I have been talking with @Beck about a possible leaf spring idea for the trailer.  I modified it for what I needed and built it, no problems and within the 6 inch width constraint.  The problem;  the outriggers are still to big  I have made 4 versions now and they keep getting smaller, but they still look massive IMO.  I might need to go with the pneumatic/manual route for the stabilizers.  Of course, I could be wrong and they are fine, Idk.  Trying scale building the first time is pretty frustrating.  

As for the suspension, the wheel base is 1 stud longer than what I wanted it be, I tried fixing that, but then you do not get the same suspension travel with the axles closer.   It is a lose lose situation.  Have to pick function over form I guess.  

[Saberwing40k]

Honestly, the outriggers being too massive is not much of a problem. For some components on certain machines, having something being too big is better than too small. For instance, tank cannons. Sariel talks about this in his book, and so I'm going to paraphrase. With a tank, everyone expects the cannon to be massive and intimidating, and in Lego, at certain scales, you can either make the cannon too large or too small. In that case, too large is better than too small. In his example, he actually explains how both solutions were reacted to, and only the small cannon elicited comments. For industrial machinery, like outriggers, I'd say having them be a little chunky is okay.

[aminnich]

4 hours ago, Saberwing40k said:

Honestly, the outriggers being too massive is not much of a problem. For some components on certain machines, having something being too big is better than too small. For instance, tank cannons. Sariel talks about this in his book, and so I'm going to paraphrase. With a tank, everyone expects the cannon to be massive and intimidating, and in Lego, at certain scales, you can either make the cannon too large or too small. In that case, too large is better than too small. In his example, he actually explains how both solutions were reacted to, and only the small cannon elicited comments. For industrial machinery, like outriggers, I'd say having them be a little chunky is okay.

Ya I guess bigger is better in this case. But the scaled width should be around 5.5 inches. I made it 6 just to give me a little extra room. The outriggers are almost 8 inches wide. So do I have the rest of the crane 6 inches wide and have th eoutriggers stick out? Or do I just make the model as wide as the outriggers? 

[Leonardo da Bricki]

Can we have a pic of the outriggers first? Without seeing the model, I would say to compromise with manual outriggers, unless you want to scale the model up to fit the larger ones.

[aminnich]

7 hours ago, Leonardo da Bricki said:

Can we have a pic of the outriggers first? Without seeing the model, I would say to compromise with manual outriggers, unless you want to scale the model up to fit the larger ones.

Here are some pictures.  I hope they do I justice.

[Saberwing40k]

I think I've found your problem. With virtually all cranes I have seen, the outriggers actually retract past the point you have them at. The back of the outrigger box is actually at the opposite side of the crane. To point you in the right direction, here's an underside view of a model crane with similar outriggers.

If you look at the outrigger box, the outrigger piston actually goes past the back of the outrigger behind it. So, your assembly will be a bit longer, but having your outriggers retract in this manner will make it narrower.

[aminnich]

24 minutes ago, Saberwing40k said:

I think I've found your problem. With virtually all cranes I have seen, the outriggers actually retract past the point you have them at. The back of the outrigger box is actually at the opposite side of the crane. To point you in the right direction, here's an underside view of a model crane with similar outriggers.

If you look at the outrigger box, the outrigger piston actually goes past the back of the outrigger behind it. So, your assembly will be a bit longer, but having your outriggers retract in this manner will make it narrower.

Ah yes!  I even looked at a model crane and totally missed that. I guess I was relying on 42043 outriggers and not realizing that isn't how crane outriggers really work. Thanks for informing me, time to start working on outrigger version 4.0? 5.0? Idk I forget 

 

[Beck]

Saberwing40k is completely correct!

On a separate note, I have begun to build custom axles that I think would suit your crane better. I looked into the crane a bit more and found that the rear axle is not steered. Although I love steered axles on trailers, I'm not completely sure you should go forward with it.

Edited October 7, 2017 by Beck

[aminnich]

Just now, Beck said:

I looked into the crane a bit more and found that the rear axle is not steered. Although I love steered axles on trailers, I'm not completely sure you should go forward with it.

I hate to correct you, but you are mistaken.  I have read through the manual (no, not all the languages ) and I know that this trailer has a rear steering axles as an option.  

The first screenshot of the manual is showing the optional equipment that you can have on your customized trailer, steering of the last axle is an option.  

The second screenshot shows the angles (I am not particularly paying attention to getting the angles exact for the build) but as you can see, the picture shows the angles of the steering for the rear axle. 

Sure, you could say that it is an optional part of the trailer and that I do not need it, but I like having a rear steering axle on a trailer.  And I think it adds to the build.  

I am working on modifying the axle you sent me to fix the wheel base being too big.  Thanks for helping me out!

[Beck]

I stand corrected as I did not read the optional extras; however, I also found that the trailer uses air suspension instead of leaf springs. 

[aminnich]

Just now, Beck said:

I stand corrected as I did not read the optional extras; however, I also found that the trailer uses air suspension instead of leaf springs. 

You are correct there, but I think leaf springs will be a better option in this case if I go with suspended axles.  If I go with air suspension, I will need to buy more pneumatic cylinders and hoses, and I really did not want to have to buy more for this build.  Plus, I do not think it will matter. Leaf springs instead of air suspension on a LEGO model is not going to be the end of the world.  

[Beck]

I think you should try leaf springs, but if you find them to be too problematic I would simply use shock absorbers. Since you want to incorporate steering, do you know how you are going to control it: either by remote control or some type of forced steering system. You don't have to tell me, but just make sure you know what you want to do.

[aminnich]

I like when my models are 100% remote control, so the steering will be motorized.  

This also goes for the outriggers, I would rather the stabilizes not be manually operated.  I know that sometimes manual functions are easier, but I have a bunch of PF motors, so why not use them, right?

[aminnich]

I fixed the small wheelbase issue, maintaining the same flex in the suspension.  

[Beck]

19 hours ago, aminnich said:

the small wheelbase issue

Just curious, what was this?

[aminnich]

1 hour ago, Beck said:

Just curious, what was this?

The only problem was that I was looking for a 10L wheelbase, the one you sent me was 11L. 

[aminnich]

No progress, I have been too busy with homework and work that I don't have the time to build for a set amount of time. 

I did recently buy a lot of wheels and tires. I now have enough Unimog size tires to make the trailer and a truck. What do you think? Go with bigger tires or stick with what I got? 

[mocbuild101]

I would stick with the tires you've already got, just think of how big it would be if you used the Unimog tires!

[1gor]

13 hours ago, aminnich said:

No progress, I have been too busy with homework and work that I don't have the time to build for a set amount of time. 

I did recently buy a lot of wheels and tires. I now have enough Unimog size tires to make the trailer and a truck. What do you think? Go with bigger tires or stick with what I got? 

Stick to 62.4 tires, otherwise outriggers could be to small

[aminnich]

I will stick to the more doable size then  

[aminnich]

Ok so with the release on the MACK pictures I need to do some rethinking.  The plan was to use the MACK as the truck of this MOC, but it has different size tires than anticipated, so I need to build smaller, no pf.... will be a first completely non-motorized MOC for me of decent quality (hopefully) 

this means going back to the drawing board and redoing everything. But I can add lego bricks to get better curvature since the MACK has them included. 

[BrickbyBrickTechnic]

1 hour ago, aminnich said:

this means going back to the drawing board and redoing everything. But I can add lego bricks to get better curvature since the MACK has them included. 

I am happy to hear this. Your trailer will look great with the MACK.

[aminnich]

Just now, BrickbyBrickTechnic said:

I am happy to hear this. Your trailer will look great with the MACK.

That's what I'm hoping 

[aminnich]

Update:

With the most recent news about the MACK truck, I decided to scale down my build so that my crane could be used with the MACK truck once it is officially released and I have a copy.  So this meant building a scale I have never done before, so I decided to do some research on Google and brickshelf.  There I found @Erik Leppen's mini version of the 42009 crane in the same scale I was going to be building.  I highly recommend this build, I learned a lot from this model and you can see it influenced my build quite a bit.  Here is a link to this awesome model.

I have the majority of the chassis completed and I figured I would show some progress on the build.  

I can not believe how "on scale" this is turning out to be.  The only thing that is a little off is the rear outriggers, but I had to do that to keep the length of the model accurate.  I only have to figure out the turntable mechanism and then I can move onto the superstructure of the crane.  

The functions that I have right now are: extending outriggers and raising the outrigger.  The knobs to operate the functions are removable, I only had them installed to show where I operate things from.  I had planned for the rear steering axle, but I was running out of room to have the steering mechanism run to the fifth wheel so that the steering was controlled by the steering of the truck.  

 

Let me know what you think, the good, the bad, the ugly, I want to hear it.  Also, if you think that using Eriks model as inspiration I much as I did was bad, let me know. 

Thanks for looking, I hope you like the progress!