[WIP] 1:50 NASA Crawler Transporter

[OzShan]

I am getting close to the end of this long term build and it's time to share some pictures and a bit of the story. Even before I had finished putting together 10231, I decided I wanted a Crawler to go with it. Being a Technic fan it had to at least drive around and lift the launch platform and shuttle. Those two basic goals spawned a project that has lasted a little over 2 years so far. Some ideas have stuck around since their inception, others were a bit optimistic (like building a peristaltic pump and hoping I could find a way to control the pneumatics hydraulically).

February this year marked the 50th anniversary of when the two crawlers went into service, so recently there has been extra motivation to finish.

The base equipment;

- 16x M-motors (drive)

- 4x L-motors (pneumatic jacking and leveling)

- 4x IR Receivers (V1 as the V2s do not like driving multiple m-motors on a single channel)

- 4x NXT servo motors (steering)

- 4x RCX rotation sensors (measuring jacking level between truck and chassis)

- 2x NXT bricks (one master and one slave. The master communicates with the Android Tablet and coordinates itself with the slave. Programmed in LeJOS)

- 1x PF IR-Link sensor (link between master NXT and all PF motors)

- 2x PF Battery boxes (with thermal overload removed)

- 1x Android Tablet

Future add-ons

- Accelerometer (automatically detect the crawler is on a gradient and adjust the leveling to suit)

Bricksafe folder is here: http://www.bricksafe.com/pages/OzShan/Crawler

Firstly, a couple of my favorite reference pictures;

The build itself started with the trucks, thinking that the pneumatics and LAs would dictate the scale.

First proof of concept - build a coupling to give height, pitch, roll and yaw to the truck. The pneumatics need to be on their own gimbals too. The reinforced 2x2 rounds slide and rotate in the 4x4 macaroni's. It is on the limit of what will hold together without glue, but it does hold. The two 1x2 technic bricks at the base of the 2x2 column are helped a little by a string (not pictured) which runs up through the 2x2 rounds with the axle.

Initial prototype of the drivetrain. I would have liked a higher ratio but there was just no room at this scale. When the gearbox was married with the truck chassis I had to juggle positions, so you will see in later pics the crown gears are facing in not out Best laid plans....

Marry studded and studless they said. It will be easy they said...

Showing what will eventually be the steering between chassis and truck.

The guide tube and pneumatic cylinders are all on gimbals with the pneumatics coupled together. The average height is preserved during any tilting.

With prototypes sorted, it's time to bricklink some parts and quieten down the colour scheme! (thank you 42030 for providing 5L thin liftarms with axle hole in LBG color)

You can see the relationship between "guide tube" and cylinders here.

The pneumatic system was overhauled too many times to remember but this is what it arrived at. It is all controlled by the direction of the motor. Running forwards drives the pump. When running backwards, the lobes operate the pneumatic valves in series, letting small amounts of air escape each rotation. This lowers the chassis in a slow and controlled manner. The motor can be turned on or off and run in either direction at any time due to the valve timing. Early attempts with PF Servo and NXT servo just couldn't park the valve reliably and after a few operations I would hear a slow leak.

I have been trying to keep up with the LDD but it's hard to stay motivated when I know I'm just going to have to suck it up and move over to LDraw if I want to include all the motors, pneumatics and LAs

Works so far; (I'll make the files available if anybody would like them). I found LDD essential in the early days to plan ahead and simply find parts, but later on the build overtook it.

Original 'box' pump. 1x PF XL motor, 4x 6L pumps running at 90 deg to each other. Very smooth but bulky.

Flatter attempt in the same vein.

The truck itself.

The final design for the height control modules.

I hope you enjoy the build so far. More pictures to come of chassis, steering, leveling and interior details.

I'll leave it to others to decide what 'theme' it belongs to .

Edited June 28, 2015 by OzShan

[jorgeopesi]

Good luck :thumbup: .

[Tommy Styrvoky]

Great progress so far, I look forwards to seeing this beast completed. Also will you be putting a 1/50 replica of the shuttle on it ?

[Jeroen Ottens]

Wow, that is some undertaking! I love it.

I am really curious how it operates in real life. Any chance of a viedo showing the results so far?

[dr_spock]

Neat. Always nice to see others do a crawler. The real crawler operates very slowly. Not more than 1 or 2 miles per hour if I recall.( It has been years since I bought the Creator space shuttle and made crawler+launch platform for it in the classic town style.) Good luck.

[miguev]

Great progress so far, I look forwards to seeing this beast completed. Also will you be putting a 1/50 replica of the shuttle on it ?

Yes, please! Make it ultra-light, mainly flex axles, and then 3, 2, 1, BLAST OFF!!!

[GallardoLU]

good luck on this Endeavor, though I do wonder if you'll be able to gear this thing slow enough to accurately replicate a 1:50th scale speed of 2mph. I did the math and that's a 84.4 inches(2.14meters) per minute. then there is the loaded speed of half that... either way I can't wait to see this completed, good luck Challenger, we await your next Discovery!

[OzShan]

Thanks guys.

Also will you be putting a 1/50 replica of the shuttle on it ?

Lifting will be fine, but yet to see if it can drive fully loaded. If it can, then I'll worry about lack of inventory for a 1m high shuttle!

I am really curious how it operates in real life.

Any chance of a viedo showing the results so far?

What would you like to know? There are two 16 cylinder diesel generators which in turn provide electric power to the drive motors down in the trucks. The trucks are mechanically independant and it can be steered in crab, circular or independant mode. There are a number of smaller generators which then drive other hydraulic and auxiliary systems. Economy is in gallons/mile not the other way around! The laser docking system guides them onto the launch site to the millimetre now but the original piano wire and mechanical sights got them to within 2" if I recall correctly, which was close enough in the 60s :)

I will be youtubing some progress soon. My 4yr old son is becoming a solid operator so I'll let him drive and I'll record :)

good luck on this Endeavor, though I do wonder if you'll be able to gear this thing slow enough to accurately replicate a 1:50th scale speed of 2mph. I did the math and that's a 84.4 inches(2.14meters) per minute. then there is the loaded speed of half that... either way I can't wait to see this completed, good luck Challenger, we await your next Discovery!

You wonder correctly. It isn't geared low enough but there just isn't room for extra ratios. i settled on the higher speed anyway because it is a lot of fun to drive when it's not so slow :)

[Tommy Styrvoky]

Another thought, put a plate of sheet metal on the top of it and mount a Estes rocket launchpad on it( even though it wasn't launched from it), you could then launch model rockets from the crawler.

[GallardoLU]

Another thought, put a plate of sheet metal on the top of it and mount a Estes rocket launchpad on it( even though it wasn't launched from it), you could then launch model rockets from the crawler.

hmm now that you mention rockets... it did carry the Saturn V rocket too! and a 7foot 3inch tall scale model of that on the crawler would be a sight worth seeing! (not to mention the support tower would take the model over 8 feet tall easily)

Sorry, our goals for your build are getting a little carried away

[Graydingo]

Wow this is epic! What an awesome project! Really great attention to detail and functionality on the trucks.

[OzShan]

Thanks for the feedback guys :)

hmm now that you mention rockets... it did carry the Saturn V rocket too! and a 7foot 3inch tall scale model of that on the crawler would be a sight worth seeing! (not to mention the support tower would take the model over 8 feet tall easily)

Sorry, our goals for your build are getting a little carried away

A tube like rocket is probably the easiest to achieve for me and the most likely option.

No problem getting carried away :) that's the point of sharing. Go ahead, throw the ideas in.

That picture of the crawler leaving the assembly building sums up the situation really well for me. The crawler was their chosen solution after considering so many options, including digging a channel and using floating barges. In itself it is huge and uses clever and reliable technology, but is dwawfed by the scale of everything else going on and they don't receive a lot of attention.

Edited April 24, 2015 by OzShan

[guandul]

Looks amazing. It seems like a big and complex project. I hope you meet your own expectation.

Hope to see the final model soon :)

[KirTech LAB]

Huge thing! Good luck in further progress - it wouldn't be easy!

[veryrusty]

I like this project immensely. You can't like it any other way!

[OzShan]

The chassis developed slowly and it took a long time and lots of tear downs to decide on studfull or studless structure.

Layouts tying the trucks together

The height control valves and NXT got moved back leaving the front section open for Cooling fans and motors.

Early days of the full chassis tied together at all four corners and current progress after ripping the whole thing apart to shrink it by 1 stud laterally. The 45s just would not work with a double beam down the centre. There is now a single stud at the centre of the whole machine

[aminnich]

Wow, that is impressive!!!! Are you going to add a tower or just leave it as a platform?

[Tommy Styrvoky]

That's definitely a beast, can't wait to see more progress.

[Splat]

Looking good.

I recently got my hands on 8480 Space Shuttle, and thought that it would be cool to build the fuel tank and rockets, and a crawler, but that is about as far as my plans went - just thinking about it.

I'm looking forward to seeing more of this creation.

[Foggy]

hat off mate!!!! Simply Amazing!

@ Splat: Got your same thoughts about fuel tank and rockets but remained thoughts....

[bonox]

someone please build him a tank and some boosters for an 8480

[OzShan]

Thanks for the kind comments everyone.

Wow, that is impressive!!!! Are you going to add a tower or just leave it as a platform?

The MLP and support tower would be awesome, but I'm going to take it easy for a bit after this is finished so that might take a while.

Looking good.

I recently got my hands on 8480 Space Shuttle, and thought that it would be cool to build the fuel tank and rockets, and a crawler, but that is about as far as my plans went - just thinking about it.

I'm looking forward to seeing more of this creation.

What's its scale?

someone please build him a tank and some boosters for an 8480

Haha

[Blakbird]

I recently got my hands on 8480 Space Shuttle, and thought that it would be cool to build the fuel tank and rockets, and a crawler, but that is about as far as my plans went - just thinking about it.

I have dreamed of exactly that for many years. The shuttle is still my favorite Technic model and I'd love to "complete the set" with the tank, SRBs, and crawler.

[kieran]

The site of a 8480 with tank and boosters would be amazing i agree

[allanp]

I think 8480 works out to roughly 70:1 scale.