MOC: IR controlled Crane Truck

[Rishab N]

I know, the instructions generated by the LDD are almost useless I wish I had 2 weeks spare time to make real instructions...

But I try to help you in your build the best I can.

Are you going to try different colors? (I hope you are, IMO the colors I HAD TO USE looked awful) And if you have lot of flat panels, build the cargo bed with them instead, might look better.

I have lot of new parts in my collection now, I might make this again some day, with better looks.

I'm going to try to make it in the color scheme of the 8258(as I am breaking it down to make this). But, I wont get around to building this till Christmas as I dont have time

[xandros]

Amazing MOC. I want to start some MOCs and was always in awe when I discovered something like this thing you built. Always wondered how do you proceed to achieve such complexity, I know the theory but in practice, you sit in front of your bricks and decide to do this thing, then what ? start building separate modules and fit them together ? do you model in LDD the gears and axles that make it tick and then tinker to add the structure to fit it in ? I would love some pointers on how to start ... sorry for the off topic

[Erik Leppen]

Lovely model, it looks good and does a lot in the functional aspect. Great job on it! Reminds of 8109.

[Tech-nick]

Thanks Erik

@xandros, Thanks for you kind words. I never though in detail that how I achieve something I want. I'm not talking LEGO Technic alone, I'm thinking this generally.

I'll try to tell you how I did this. This MOC was mostly result of inspiration. (I think inspiration is the most important thing needed, nothing can't be forced to happen) I was about to build 8258, but I was not happy with the amount of manual handling of the model. (Otherwise it's great model which I wish to own). So I decided to design my own one. I looked what parts I have/wanted to use, specially power function parts. I had plenty of LA's and some pneumatic parts. For precise control the pneumatics were out of question. I had two TX and two RX units so I knew amount of functions were limited. Manual mode change was necesary to increase number of functions but also to keep it simple. So then I knew I can get 2x4 functions in theory. But one motor had to attach to boom for the telescope function alone. So that makes it 2x3 + 1 functions. Then I desided what to do with them. Decision was of course easy: MODE1 for Steering, drive, outriggers and MODE2 for turntable, main boom, second boom. +telescope.

So seems like little planning in advance is good.

Then off building with real bricks, no LDD. Complex structures are easiest to comprehend in the most realistic 3D dimension, the reality . Much faster to build too.

I started with the most important, the gearbox. Basic structure is simple but main work was to figure out how to get motion to destination where it is needed. And off course to manage it so that the order of functions to be logical on the Trasmitter end. So on the first motor driveshaft is for steering/turn table. second drive/main boom. Third for outriggers/second boom. So, I had to deside in advance how I wanted it to work, and kept goals in mind while building.

I made so many prototypes necessary to achieve working but small and simple gearbox. I made a simple chassis, with tyres and turn table, were to mount the gear box. There I was able to see possible problems and to see were the gearbox should be. One thing I recall, the turntable was tricky to seat allmost on top of the gearbox, but still keep the hight in tolerance and lead drivetrains trough it. It took me maybe 6-8 versions until I was happy with it.

The outriggers were challenging. I wanted them to work without manual imput. out-down <-> up in. But I had only one channel/gear to use for it. I roughly figured method to do it, and started making prototypes again.

So the desinging method for me is: Build - see whats good, what is bad - distmantle - build it again, use good, redesign bad. Repeat until every things good.

If I have enough of parts, I keep previus prototype next to new one. Its easier to build good things again and not to make the mistakes again!

When I had the main functions ready, then I started to put them togethor. So I quess I used some kind of module- method. With each module, I had to keep in mind the module next to the module you are working with. I mean, make them easy to connect to each other and to chassis too.

I really don't know that did I made any sense..

All in all, designing things is more like problem solving, you have to arrange elements in a way that makes things work the way you want. It is a skill which can be learned, you just have to start learning, other words just start messing with your technic legos!

Edited August 18, 2013 by Tech-nick

[xandros]

Thanks a lot for this explanation, it does makes lots of sense, and it's very enlightening. When you did never do any MOCs, it's very hard to know how and where to start :)