[WIP] 1:50 NASA Crawler Transporter

[Tommy Styrvoky]

you could always swap out the M motors for L motors, it would have twice the torque with slightly reduced speed

[MaxSupercars]

I thing it's impressive when it does not move or level itself... It comes me like in times of space race... It's like development in that days... They made also a lot of tryes to be sucessful...

I like it very very much... HoF...

Max...

P.S.: Someone make him Overstructure, Tank, Busters and Shuttle please... :P

Edited June 24, 2015 by MaxSupercars

[Werlu Ulcur]

Awesome!

How would it look with Shuttle Expedition (#10231) on top ?

[dr_spock]

Maybe a MLP (mobiile launch platform) on top. It could be made mostly hollow inside to save on weight.

[sm1995]

I am simply lost for words. Amazing just doesn't cut it.

Eagerly waiting for more updates. Good luck with sorting out the drive train issues!

[OzShan]

Thanks for the encouragement, I guess it really isn't finished yet .

I can't really swap out all the m-motors but I have another plan. After having a good look around the truck I can see a little flex in a few places and the 8t mounted straight on the m-motor with just a 2l axle is just not going to last the distance. It wasn't something I wanted but the area is so tight.

Overall ratio would drop from 1:6 to 1:24 which I'm looking forward to. Pity about the friction and backlash but lets see how it goes. It might even get me out of another problem where at full steering lock the speed difference between the inside track and outside was too high and the inside track power dropped below the minimum required to keep it moving.

The irony is that during the test runs of the first real crawler they had massive drive and bearing issues and were picking up pieces of melted and fused bearings off the crawlerway after they self-destructed

Edited June 25, 2015 by OzShan

[Tommy Styrvoky]

Is there a LDD file anywhere? As I would like to see if there could be further improvements to the crawler assemblies.

[OzShan]

Is there a LDD file anywhere? As I would like to see if there could be further improvements to the crawler assemblies.

Sure, have a play around with this;

http://www.bricksafe...rTruck mkII.lxf

After trying the worm drive I have a different set of problems. It is generating a lot of Lego Dust at each end of its axle at the half bushes because of all the thrust. This is only from a few minutes testing so I'm not keen to keep going this way. Another issue is that I cannot run beams side to side and that allows just a little flex when the load comes on and the worm gear is catching on the Pole Reversers.

It generated a lot more separation pressure so rather than limit the number of holes visible and use short 1x2 bricks, full length beams keep everything from separating now. My bad for sacrificing rigidity for looks.

I had to significantly modify the steering arms to get the changes to fit and that made them a lot more flexible and the list of cons gets longer. I do like that it is so much slower but that's about it.

Going back to the original bevel gear approach (which is a little closer to reality) and making a number of modifications has helped. No more gear or part separation, right to the point where the motor stalls on a new set of batteries. The m-motor axle is now properly supported and the gear ratio ended up the same 1:6. The new bevel gears seem to hold together much better than the 24t crown gear. Even with a little play they have not skipped at all.

A productive couple of days after all .

[Tommy Styrvoky]

I see there may be a solution using XL motors, if it kept the current gear ratio there would be nearly 150% more torque produced.

[GallardoLU]

How goes the project? havnt heard any news on this in quite a while. I really hope things are still progressing on this. its a magnificent build already!

[LEGO Train 12 Volts]

Hey man this is an epic build, I can't wait to see it working without gearing issue!

This huge set is the final toy that every child would like to have in its own collection!

[OzShan]

Hi, yes it has been a while . After sorting the problems with the drive it took ~6 weeks for Bricklink to catch up.

Drivetrain is working well now. The tracks themselves have some issues where they catch and pop when cornering. It is because they are not being fed straight on and it tries to climb off them. Not much can be done there except reduce the turning angle and not turn as sharply.

Another small update:

Still lots of tweaking and minor improvements but the major parts are there now :)

For those going, it's on display at the Gold Coast Brick Event this weekend (can't be there myself unfortunately).

[mahjqa]

Good to see you're still working on it, it's a very original model, and it's been great to see all the iterations and improvements you've made.

The tracks themselves have some issues where they catch and pop when cornering. It is because they are not being fed straight on and it tries to climb off them. Not much can be done there except reduce the turning angle and not turn as sharply.

Perhaps consider giving the tracks some more support on the sides, like here:

This will guide the tracks a lot more, so they don't misalign in front of the sprockets.

[MaxSupercars]

Thanx for video... I'm a big space technology fan and this is just lovely for me... I really enjoy every detail on this MOC... Very good work... :)

Max...

[OzShan]

Thanks guys it's been a long road :)

Mahjqa, to be more specific, the drive sprocket and road wheels are not exactly riding up off the treads, but they do click against the sides. From your picture the example in the top right would show the same situation. The treads get laid on the ground at a larger radius than the actual circle. As the truck rolls over them they are pushed sideways across the ground towards the center of the turning circle, then pushed out again before leaving the ground at the rear of the truck.

A quick sketch;

It's still driving well. I'll take the tracks off after the show and see how it's all holding up (and how much Lego powder has been created in the drivetrain )

Edited September 19, 2015 by OzShan

[Mowikan]

col build!

[derpybricks]

Oh dude I just saw some pics of GC Brick Event, had no idea you were in my LUG. I'm volunteering tomorrow, I'll have to come and have a good look.

[OzShan]

Haha, I recognised the avatar :) I'm sure you'll have a lot of fun.

[Kristof]

Enormous creation. I think I saw this earlier on yourtube but somehow missed this toppic until now. It's cool to follow your progress, seing how clever engineering approach you take while solving the problems.

I'm honestly impressed with it's driving performance. I expected it to be way way slower - actually don't you think you require to high speed out of this massive contraption? Probably pushing lego (and ABS plastic) to the limmits :D

I'm looking forward to see more progress!

[OzShan]

Enormous creation. I think I saw this earlier on yourtube but somehow missed this toppic until now. It's cool to follow your progress, seing how clever engineering approach you take while solving the problems.

I'm honestly impressed with it's driving performance. I expected it to be way way slower - actually don't you think you require to high speed out of this massive contraption? Probably pushing lego (and ABS plastic) to the limmits :D

I'm looking forward to see more progress!

Thanks. There are so many competing factors going on here, it is one of the things that drew me to the project in the first place. The biggest challenge was the fact that the chassis is basically hollow, so supporting everything mechanically and keeping the look was a battle. So yes, lots of things are on the limit of what plastic can tolerate :)

In terms of speed, yes that is going to be a problem. I like that it has some good speed but it really should be slower. There is no space in the drive train for higher reduction or extra stages in the gearing. The speed it runs at is going to make locating the MLP on launch supports difficult. I will be re-visiting the worm drive because that did give a much higher reduction. The thrust of the worm gear against whatever is supporting the axle generated a lot of Lego dust though. Not really a long term solution, I'd be forever replacing bushes and beams as they get drilled out.

Glad everyone is enjoying the developments :)

[LEGO Train 12 Volts]

Wow I love this video!

I thought that in real life this model is limited to go back and forward along a straight line

[Jvishani]

Can u please send me the ldd files for the crawler

I would highly appreciate

 

[KERVAJAN daniel]

Hi, OzShan . i just discovered your Crawler transporter.

It's wonderfull.

As Jvishani asked you few months ago, do you have a ldd available and you could send me. I think it could be wonderfull with the saturn V set.

Thanks a lot

 

[Milan]

Hi @KERVAJAN daniel and welcome to EB!

Creator of this model is not active on EB for more than a two years, as seen on his profile.

I would suggest you try send him a PM or to find him on some other site where he might be still active.