Mobile Material Handler (MOC) Crawler Under Carriage DONE + Video

[Sjoemie himself]

Doug, really amazing model. It has come a long way since the first version if you ask me.

Functions have improved but I especially like the appearance of the entire crane.

[LEGO Train 12 Volts]

Beautiful machine!

[AFOLegofan66]

wonderful MOC Doug a lot of work went into this...well done!!

[doug72]

12 hours ago, Sjoemie himself said:

Doug, really amazing model. It has come a long way since the first version if you ask me.

Functions have improved but I especially like the appearance of the entire crane.

 

11 hours ago, LEGO Train 12 Volts said:

Beautiful machine!

 

4 hours ago, AFOLegofan66 said:

wonderful MOC Doug a lot of work went into this...well done!!

Many thanks for your comments which much appreciated.

My wife also likes it as it no longer resides on the dining room table !!!

Its been a long haul but its not over yet, some improvements still possible.

While making the video and when it crashed into my camera I only just managed to save it from falling off the table !!
Result the main boom became detached from the hinge connectors and dipper arm also partly came apart.

This highlighted a problem with the Main boom connection between hinge & taper panels which only had 4 pins connecting them. 

Solved by modifying as shown on photo by installing a brace so cannot pull apart.

Dipper arm - I had forgotten to add link braces between the 3 x 11 panels. Now fixed 
using 5L thin beams with 3/4 pins.

Now starting work on a tracked under carriage which will use a subtractor system for drive & steering that can be subsituted for this MOC or used for another potential MOC.

Doug

Edited March 21, 2018 by Doug72

[Andy D]

Very nice! Thanks for the video, it really shows the functions. I like the four claw "crab claw" better than the two bucket version.

This has been quite a ride!

What's next?

Andy D

Edited March 21, 2018 by Andy D

[doug72]

53 minutes ago, Andy D said:

Very nice! Thanks for the video, it really shows the functions. I like the four claw "crab claw" better than the two bucket version.

This has been quite a ride!

What's next?

Andy D

Thanks Andy glad you enjoyed the video, Took me awhile to shoot in segments and then editing it together 

The clam shell grab picks up more than the four claw (orange peel) grab which looks more impressive. Might  try and make a demolition shear attachment if I can find parts to replicate the scissors arms.

Next step is a crawler under carriage that existing upper rotating parts could be mounted on and make it also usable for another possible MOC of Dead weight pile driving machine.

I have a spare 13L turntable for this.

 

Another possible MOC is a bulldozer which has three (3) caterpillar tracks !

YouTube is a great source for unusual machines.

Doug

Edited March 21, 2018 by Doug72

[Andy D]

I can see that the bucket attachment can pick up more than the claw, but... The claw just looks so much more intimidating.

Andy D

[doug72]

3 hours ago, Andy D said:

I can see that the bucket attachment can pick up more than the claw, but... The claw just looks so much more intimidating.

Andy D

And claw grab is able to pick up small round cans that contained beverage !!!

Edited March 22, 2018 by Doug72

[BrickbyBrickTechnic]

On 3/21/2018 at 4:23 PM, Doug72 said:

YouTube is a great source for unusual machines.

Really? I haven't been able to find any videos of truly unusual machines. (sorry for the offtopic)

Anyways, truly truly amazing MOC. The functions are so nice. Everything works super well, and the MOC looks great. 

Edited March 22, 2018 by BrickbyBrickTechnic
(sorry for the offtopic)

[doug72]

6 minutes ago, BrickbyBrickTechnic said:

Really? I haven't been able to find any videos of truly unusual machines.

Anyways, truly truly amazing MOC. The functions are so nice. Everything works super well, and the MOC looks great. 

Thanks for the comments, I was pleased that when build was completed that the drive and steering worked with all the added weight etc.
Here's a video of an unusual machine & possible MOC with three caterpillar tracks !!

 

Edited March 22, 2018 by Doug72

[doug72]

Update:-

At the moment I am building a crawler under carriage upon which the existing rotating structure from the wheeled version can be mounted. 

It is based on this design as used on the real machine. 
Turntable unit will connect to the 5 x 7 frame with the 8 blue pins.
 No changes are required to rotating structure.


This could also be used for any future crane MOCs.



Actual crawler  side track unit:



So far have sorted out the drive to the tracks which uses two L motors and a subtractor unit.
 Track speed is a too slow so gearing changes are required.

Had thoughts of a 2 speed solution but space tight so it will be single speed only.

Yellow sprockets to change to black & I may the use the smaller size sprockets along with ten small track wheels.



My biggest struggle is getting the track units to look OK like the real machine without too much slack in the tracks - its something I always have trouble getting right.

Have tried a track tensioner but makes the track units too wide. 
Suggests & comments welcome.

I have made two versions of the track units - see photos.

Both use five track support wheels plus two return wheels.

The real machine uses ten smaller support wheels & I will also try a version to see how it performs.

Under carriage will have its own battery & PF Rx.

Underside view:



Overhead view:



Track unit without side covers:



Track unit with side covers:

Edited March 30, 2018 by Doug72

[Sjoemie himself]

Interesting video you've posted above, never seen something like that before.

About the tracked undercarriage, imo with more slack and sidecovers looks better. Mostly because of flat underside of the track and tensioning wheels on top. Perhaps raise the upper tension wheels or replace them with bigger wheels to get the track a little tighter? 

[doug72]

27 minutes ago, Sjoemie himself said:

Interesting video you've posted above, never seen something like that before.

Yes found it on YouTube.
It's a very fast earth mover. May rebuild the first ever Lego Technic 8275 set i got for Xmas some years ago, which got me into Technic builds and adapt it with the power dozor blade, will make a nice challange to get it working.

27 minutes ago, Sjoemie himself said:

About the tracked undercarriage, imo with more slack and sidecovers looks better. Mostly because of flat underside of the track and tensioning wheels on top. Perhaps raise the upper tension wheels or replace them with bigger wheels to get the track a little tighter? 

Thanks for the comments:
Just tried using small sprockets with 8 small track support wheels and 2 larger return wheels - result a very jerky track.
I will revert to the large sprockets and try some form of sprung return rollers, trying not to let the top run of the track get too high so it doesn't foul the rotating structure.
Could try tires on the return wheels to take up some slack.

If at first you don't succeed try try again !

Edited March 30, 2018 by Doug72

[doug72]

Now fitted six rollers (without tires) for track return and is much flatter with only slight sag.

Rollers with tires are better but I don’t have enough for both sides.

Tested and looks OK when in motion.

Next step add battery box & PF Receiver.

View with covers removed:



View with side covers.



Now tried without any return rollers and beam substituted for the track to slide along which performs OK without any sag.

 

View without return rollers and side covers in place:


Clearance between track & underside of rotating structure is 2L.

Edited March 31, 2018 by Doug72
Added image

[Andy D]

@Doug72 I like where this is going. Very good looking track unit.  On your subtractor I noticed that you use 2 L motors.  I thought many subtractors used one L one XL motor for drive and an M motor for steering. 

Is there a reason you used 2 L motors?

Andy D

 

[doug72]

8 hours ago, Andy D said:

@Doug72 I like where this is going. Very good looking track unit.  On your subtractor I noticed that you use 2 L motors.  I thought many subtractors used one L one XL motor for drive and an M motor for steering. 

Is there a reason you used 2 L motors?

Andy D

Thanks for comments & observation.
I used two L motors as with the multiple pin holes make it easy to build into the undercarriage structure.
Used gearing to get desired speeds for travel & steering.

Tested yesterday usings PF speed controller and OK when moving forward and backward and able to do steer between large to small radius turns.

However it refuses to turn on the spot other than on a very smooth surface when it is very jerky.
This is due to the white 24T clutch gear between L motor and the 16/24T Differential slipping intermittantly.

I used this as a normal 24T gear rubs against the side frame where as the white 24T gear doesn't as it appears to have slightly smaller o.d.

So I have to change the gearing and might see if M motor strong enough to turn on the spot and use that if it does.
An XL motor to large to replace  the L motor without it touching the ground.

Re Track unit - I have space to raise the track return run by 1L and make it look more like the actual machine and will also improve track tension.

Odd Problem:
I always seem to be short of 1 piece when trying to build to a uniform colour scheme when building MOCs and have to substitute another colour !!!!
e.g, I only have 3 dark tan # 1 connectors when I require 4  etc. !!

Edited April 1, 2018 by Doug72

[Andy D]

5 hours ago, Doug72 said:

 

Odd Problem:
I always seem to be short of 1 piece when trying to build to a uniform colour scheme when building MOCs and have to substitute another colour !!!!
e.g, I only have 3 dark tan # 1 connectors when I require 4  etc. !!

Edited 5 hours ago by Doug72

Yeah, I have the same color problem. I have for the most part given up. For me it is all about the build anyway, so I just try to use colors that go together or in one case I used one color on one side and another on the other side. My reasoning was that no one can see both sides at the same time. Works for me. When rebuilding my 8258 I had to substitute colors because I did not have all the right colors... I still enjoyed th build anyway.

Andy D

[doug72]

Update:

With the existing under carriage I found I was unable to install a battery box AND a PF receiver, this due to extra space used by L motors and the double gear reductions in the subtractor unit, so had to completely rebuild the unit, using XL & M motors with single stage gearing.
Only way to install the  battery box was to install it upright to allow Pf Rx to go behind it with enough space for cable connections.

However the battery switch and cable plug now fouled the underside of the turntable rotating base frame so had to raise the turntable mounting 5 x 7 frame by 1L to get clearance.
Ground clearance below battery box & XL motor only 1L.

Side track units:

Getting the track tension just right has proved awkward do the due to track link wear after many others usage on MOCs.
I had to carefully match track links to take account of this wear.


Now devised two versions:  track return flat and track raised return as per real machine.
 Both use 16mm wedge wheels for track support. 

Which looks better ?

Flat track return:



Raised track return:



Subtractor unit revised and now uses  XL motor for drive and M motor for steering.

Tested and OK on carpet with turn on the spot and full range of turns.



Topside showing battery box and PF receiver:

Next mount existing rotating unit from the wheeled mobile material handler.

Edited April 3, 2018 by Doug72

[jotta93]

For me it's the raised version 

[Aventador2004]

Raised, absolute! 

[Sjoemie himself]

Raised has my vote

[ColletArrow]

I prefer the raised track return version for construction equipment. Also, I like the neatly tucked away exposed PF on top, although I'm not so sure about the trans-orange 1x2 tiles myself. 

[doug72]

Thanks  @jotta93  @Aventador2004 @Sjoemie himself @ColletArrow
Raised track version it is - both now changed and functions well.
Still looking to see if can locate the battery box better or use an AAA batterey in its place.

5 hours ago, ColletArrow said:

Also, I like the neatly tucked away exposed PF on top, although I'm not so sure about the trans-orange 1x2 tiles myself. 

The two trans-orange 1 x 2 tiles act as IR collectors !!!

Edited April 3, 2018 by Doug72

[doug72]

Material Handler now mounted onto the crawler under carriage, it was not a direct exchange as I had hoped for.
Had to add an extra 5 x 7 frame and adjust slightly the connections to slewing ring.

Tested and performs OK on a hard surface with sharp turns possible while in motion forwards or backwards but reluctant to turn on the spot. 

Probably due increased weight, a run down battery and an M motor for steering not powerful enough, L motor to substitute.

I will return Material handler back onto the wheeled under carriage and use the crawler under carriage for another MOC I have in mind.

Side View:



End View:


 

Oblique View:



Video:

 

Edited April 4, 2018 by Doug72
Embedded video / duplicate image replaced.

[AFOLegofan66]

Good video Doug. Nice track system overall and great looking moc!!