[MOC REVIEW] Grove GMK6400 Mobile Crane

[Blakbird]

Congratulations, that's such a beautiful masterpiece. I'm sure your post/photos will entice many (including myself) to get on with this project and finish it. One question if I may: The thread you're using for the crane appears to be 'thicker' than the one typically found in Lego sets. Care to share the specs of such thread and where you got it from?

42009 already uses a thicker cord than normal, so that may be it. For MOCs, I just went to the fabric store and bought 100 yards of black cord so I'll never run out.

[DrJB]

Thanks. Sounds like I need to stop by JoAnn and check out their selection.

[afol1969]

Finaly i have finish the crane

And i must add, with a liitle time and very small ty-rips there is an easy way to hide the cable's from the seats.. I also want to thank Alex for his help with the vieuw problems i had..

Congratulations

So you finally arrived to place and connect all cables and all functions work.

The axle at the grille for the hook is a nice feature, I'll add it in the instructions for the MKIII Carrier version

Yesterday i began to build it, I've finished the front axle.

And I've a question to gerger: Is there a reason that for the 1st axle there are 4L black axles used instead of the tan axles with middle cylindrical stop? (so the 3713 bushs are not needed)

Greetings

Alex

Edited February 5, 2015 by afol1969

[Rygar]

Wow, this is impressive! sorry for my ignorance (maybe you have already answered me), but is it possible to see all the parts on rebrickable?

[afol1969]

Wow, this is impressive! sorry for my ignorance (maybe you have already answered me), but is it possible to see all the parts on rebrickable?

Edit: The MOC is not on Rebrickable. So I've added it there. So it's pending for approval. The part list I've controlled and have correct some errors, now they are all correct.

Greetings

Alex

Edited February 5, 2015 by afol1969

[jantjeuh]

Which version did you submit?

[afol1969]

Which version did you submit?

The first version with suspensions. Ah yes, see now you're the admin from Rebrickable, I first should ask for permission.....

[Mestari]

So the version submitted on Rebrickable is the one with Lego LAs?

[jantjeuh]

I first should ask for permission.....

You don't need permission to submit anything As long as the MOC has an accurate parts list and decent instructions, it will be approved soon. Looking forward to seeing how many 'hits' it will get. I bet it will be popular.

[afol1969]

So the version submitted on Rebrickable is the one with Lego LAs?

Yes, it is.

@jantjeuh: I take worth on a correct part list. Some parts I had selfmade for the instructions, but I could all correct them or find alternate parts.

Greetings

Alex

[gerger]

And I've a question to gerger: Is there a reason that for the 1st axle there are 4L black axles used instead of the tan axles with middle cylindrical stop? (so the 3713 bushs are not needed)

Greetings

Alex

Good question! I used tan axle with middle stop for all axle modules but I changed the 1st axle with 4L axle with bush after some driving tests. It's because the wheel hub from 42000 is a bit wobble (but I like the fact that the hub can hold the wheel firmly). Once the CV joint is attached to the hub, its 'click and stick' tendency causing the CV joint wobble as well. A tan axle with middle stop will have chance for some displacement that is enough to cause a half thick tan bevel gear from the differentials to misplace under extreme loading. The 6th axle doesn't have this problem because it has less driving force as compared to 1st axle and therefore I just keep it the same as the rest of axles.

This is also why I use 8T gear for first and sixth axle steering, instead of more simple 12T gear + 7L gear rack, just to reduce a bit of steering angle for a silk smooth turning.

I'm glad that someone do pick up this minor changes.

[gerger]

@jantjeuh: I take worth on a correct part list. Some parts I had selfmade for the instructions, but I could all correct them or find alternate parts.

Greetings

Alex

I spotted some color change on parts and it's fine. But I also found the number of blue 3L pin is now 341 pieces, instead of 333 pieces. Same for 7L LBG liftarm is now 20 pieces instead of 19 pieces. Just to double confirm if there are some changes.

[JDL1967]

Congratulations, that's such a beautiful masterpiece. I'm sure your post/photos will entice many (including myself) to get on with this project and finish it. One question if I may: The thread you're using for the crane appears to be 'thicker' than the one typically found in Lego sets. Care to share the specs of such thread and where you got it from?

Thanks

Its an original lego thread from the set 42009. The lego nr. is 6043879. Maybe you can but it there. If not try www.bricklink.com

Gr.

Congratulations

So you finally arrived to place and connect all cables and all functions work.

The axle at the grille for the hook is a nice feature, I'll add it in the instructions for the MKIII Carrier version

Yesterday i began to build it, I've finished the front axle.

And I've a question to gerger: Is there a reason that for the 1st axle there are 4L black axles used instead of the tan axles with middle cylindrical stop? (so the 3713 bushs are not needed)

Greetings

Alex

I was thinking a way to fix the hook on the crane, and this option was the one.

Gr. Jesser

The front and the back.

Front with axle to place the hook.

The rear with my version of the rear lights.

[Zimix]

That said, do we know of a package that calculates the total mass + CG location of a given assembly?

This should be asked more in the

LEGO Digital Designer and other digital tools forum

but as far as I know the ldraw parts have no weight value or density nor volume. So you would have to use a professional cad and build up your part catalog.

Edited February 6, 2015 by Zimix

[JDL1967]

[Karle]

I've down loaded efferman's drawings. LDD was able to open and create step drawings for 4 of the files. For some reason it could not "open" the gesamtmodell or teileliste files. Would one of the experts take a look and see what the problem is. I know it's a lot of work but "we" really need a pdf for this crane.

[afol1969]

I've down loaded efferman's drawings. LDD was able to open and create step drawings for 4 of the files. For some reason it could not "open" the gesamtmodell or teileliste files. Would one of the experts take a look and see what the problem is. I know it's a lot of work but "we" really need a pdf for this crane.

I've converted effermans' LDD file in MLCAD, but didn't have made the building steps nor made instructions. But I've planned to make instructions at a later time - if there's no volunteer to make this task

I too had big problems with the files, for ex. big models I couldn't rotate. So there is no garantee that the part list in the MLCAD file is correct.

For information: I'll soon finish the superstructure modification that two Firgelli actuators can be mounted (a second one I've ordered from France and just had arrived) The place where I took out the boom lift L-motor I've filled it with a construction which makes the superstructure more stable and stiffer. And the boom modification I've prepared too, just have to build it now. Some photos will follow next time.

Greetings

Alex

[DrJB]

I've seen the discussion back-and-forth few times about the "options". I know some of the answers are buried deep in this thread, but anyone with enough 'patience' to answer these questions once and for all?

1. Figelli vs. Lego LA's to lift the boom

2. Technic vs. Studded (heavy) counter-weight

3. Wheels with suspension vs. none

Where are we today and which options were the 'best' and which versions do we have instructions for?

[Blakbird]

I've seen the discussion back-and-forth few times about the "options". I know some of the answers are buried deep in this thread, but anyone with enough 'patience' to answer these questions once and for all?

1. Figelli vs. Lego LA's to lift the boom

2. Technic vs. Studded (heavy) counter-weight

3. Wheels with suspension vs. none

Where are we today and which options were the 'best' and which versions do we have instructions for?

All good questions.

1. The LEGO actuators work just fine to lift the boom, but the scale and attachment points are totally wrong. Also the stroke is too short for a proper final boom angle. The Firgelli should improve on both of these, but my money is on the third option: Efferman's custom linear actuator. It looks more scale, but also requires more mods to integrate. So far, full instructions are only available for the first option, but LDD files are out there for the other 2.
   
2. The model is in dire need of a counterweight. The poor turntable is loaded very unevenly and has a hard time staying together. If you end up going with Efferman's superstructure, it already has a much larger counterweight.
   
3. The suspended version is what I have built and has some problems. I haven't built the newer version but probably will. Consensus seems to be that it is better. Instructions are available for both.
   

[DrJB]

Thank you for the comprehensive reply.

Edited February 20, 2015 by DrJB

[Fyredog]

Hi,

Read through the Thread - Impressive stuff. Made some mods on my own Crane, but love eveything here. I was curious to know What I needed to do to get parts list and building instructions for the suspension version on MAC?

[Karle]

Look at http://www.bricksafe...69/Instructions the file you want is GMK6400_1.1.pdf. Keep in mind that there are 3 parts graphics, carriage, superstructure, and controller.

Edited February 20, 2015 by Karle

[DrJB]

Here are few options for a counter-weight

1. A box made with lego panels, but filled with sand (in a plastic bag of course)

2. Many stacked heavy parts 73090b from BrickLink

Option #1 it clearly is for those adventurous amongst us, not bound by 'purist' edicts. Though, cost-wise, option #2 might be a viable altenative than to fill the counterweight with regular bricks.

[Fyredog]

Thank you kindly Karle.

[Saberwing40k]

I've got a better idea than sand. Either one could use decorative stones from Ikea or Michaels, or steel ball bearings. i have a large number of the latter from various Magnetix building sets. I'm sure you could get some in bulk online. I'd also suggest some small free weights, but those are much harder to incorporate.