My version of LEGO's 42042 crawler crane

[ttoks]

When i was younger I played a bit with LEGO, I was given a super street sensation for christmas one year and various other set's, but since my early teen's, i have played with LEGO much.

Fast forward to this year, my daughter started walking and playing with things, and it reminded me of being a kid playing with LEGO, I ended up impulse buying a 42030 front end loader as my first LEGO set in 13 year's.

That was 4 months ago, two weeks ago, walking through my loca Big W store (Australian version of Walmart) doing the Christmas shopping I saw another set i desperatly wanted to buy, the 42042 crawler crane, at the rediculous price of $140 AUD, I bought it and took it home, and my Wife and I had an awesome night putting it together after the little one went to sleep, and with a bit of tinkering I got it to be able to lift about 750 grams at the closest possible radius, I swapping the 12 and 20t gear around on the claw winch to give it a greater mechanical advantage and adjusted the boom linkage to allow the boom to sit vertical.

But it wasn't enough, In the interim year's I've become a pipe welder and currently work construction in the oil and gas industry, so i've seen and worked with some pretty amazing cranes, and the standard 42042 just didn't do it.

So the next day I went back to Big W, and bought another 42042 set with a few idea's in mind but no real set plan, but a rough idea for what I wanted to do, I also drove to my Mother's house and picked up what was left of my LEGO from my childhood for extra bits.

Firstly, I was dissapointed how the standard set didn't allow you to turn, both track's travel in the same direction, this was the first thing i set out to fix, i ended up completly re-designing to base of the crane including a reversing gearbox for each track, to drive in through worM gear's for a more realistic travel speed, and so it's not possible to push the model along, it also ended up being 6 studs wider and 6 studs longer then the standard one.

with the larger base, I was able to get it to lift a massive 1.25KG!!

The next thing I wanted was a movable jib, this meant I was going to need to add another winch, fortunantly due to gearbox in the substructure for driving, I no longer needed all 4 of the control's at the top of the crane, first i built the third winch into the front of the crane body, using the output that previously powered to tracks to drive the third winch, i then replaced one of the 16t freewheeling gear's in the gearbox on the idler shaft with a standard 16t and a 5l axel instead of the standard 4l, and used then to drive the shaft going into the base of the crane, this shaft now spins constantly when the motor is spinning, and selecting to drive is done by a simple linkage on the cranes base for each track.

In this photo you can see the axel used to drive the third winch for the jib.

from this point I got in the zone and neglected to take many picture's until near the end, but this is what I ended up with.

Maximum radius is 99 centimeter's from the center of the turntable, overall length not including the extra counterweight's is 120 centimeter's, hight with the boom as high as possible is 105 centimeter's.

At maximum radius with two battery boxes (with batteries) as counterweight's, it will lift about 150 grams before falling over.

It will lift around 600 grams (600 ml coke bottle full of water) at a 62 centimeter radius

unfortunantly around 6-700 gram's is the maxiumum it can lift as the boom isn't ridgid enough even at a smaller radius to lift any more, but I am pretty happy with it as it is, the only other thing i might like to do is find a way to use a worm gear drive for slewing to both reduce the slewing speed to be more realistic, and to allow it to slew more reliably as it tend's to slip while lifting any weight, and an XL motor would do wonder's as the L motor is pretty slow with the functions, but it does the job.

And a few more picture's, just because.

Edited December 7, 2015 by ttoks

[syclone]

Pretty amazing version !

Really cool moveable jib.

[Victor Imaginator]

Excellent modification, much more cooler than set itself. And welcome to EB) And welcome back to Lego)

Edited December 7, 2015 by Victor Imaginator

[ttoks]

honestly, I don't see why LEGO wouldn't have done something similar to this to begin with, deleting the two battery box's used as counter weight's the model i've built will still lay the boom on the ground without tipping, and it still uses just one L motor for all functions, it mostly uses alot more 15l beams, more 16t gear's and more string, so it wouldn't have been prohibitivly expensive for LEGO to bring a model similar to mind to market as it wouldn't be to expensive, i only paid $280 AUD plus a few extra bits and pieces (and with alot of pieces left over out of the two kits) to build this one.

[nerdsforprez]

Lots of fun yeah? Welcome back to your second Lego-life

[Kaanere]

Very cool MOD!

I think that Lego didn't do something like this because there was already a flagship (biggest set) in the year, the Mercedes Arocs. There isn't enought demand for two 200€ sets, and most people would buy the pneumatic truck of a known brand with a very cool suspension.

Aslo, I think that this crane is already a good set and I have it in my wishlist.

[Jim]

Hi,

Welcome to EB! And welcome back to the club

Nice modifications. I'm impressed with the performance!

[Vectormatic]

Amazing build!

Im not a crane-fan at all, but somehow 42042 really speaks to me, im currently trying to set up a swap, some of my spare MISB sets for a 42042, i hope it works out, i need one of these mammoths

[kisper]

I was thinking of modding it to look like its previous ancestor 8288 :) but I have yet to start :D

[ttoks]

thank you for all of the comments!

last night i was able to lift the same 1.25 kg bottle i had the crane lift before the larger boom was built, i simply had to stablize it with my handv after taking the weight up, then lift, it is very close to falling sideways thought due to the boom's lack of ridgidity, it will lift 1.25 kg at 31cm!

[2LegoOrNot2Lego...]

Very well done, you have increased playability so much...

[Cumulonimbus]

Seems you have learnt to build studless in a short time, impressive. I like your crane very much, there is something similar waiting on my desk to be finished.

Edited December 7, 2015 by Cumulonimbus

[cheeze]

Looks ace. This is the workings in use for my crane for counterweight etc

So if you have a load of 1kg measure from the centre of load to the base of the boom (say 50cm) so 1000gx50cm =50'000g then measure from the boom base to the rear of the counterweight (say 25cm) 50'000÷25=2000g so to lift 1kg at 50cm you'll need 2kg of counterweight. Hope this helps

[ttoks]

So I have been playing around with my crane for the last few day's, I decided to abandon the luffing jib for now until i accumulate enough parts to build a more ridged boom, instead I've simply greatly increased the overall size of my model.

With the new boom the major dimension's are now:

Maximum radius: 160 centimeters.

Overall length (including counterweight): 206 centimeters

Maximum height: 164 centimeters

Obviously lifting capacity is far less then it was, with the standard 42042 boom and my driving base the crane could easily lift 1.25kg, with the luffing jib at a maximum height of 99 centimeters a maximum of around 600 grams at 62 centimeters radius (far more if i stabalize the boom with my hand while lifting, now it is around 300 grams at 1 meter radius.

Anyway, i hope you enjoy the pictures, please excuse the hodge podge of colour's, i don't have many parts to work with so have to use what i have.

[ctx1769]

Holy smoke, that is a mental reach on the boom. I will stick to the standard set for now, but well one on your mad creation

[Vectormatic]

Holy crap, that is really pushing the limits on that base, quite the accomplishment!

[BusterHaus]

Wow, that's quite some reach! It looks like the attachment point for the boom lifting string could be closer to the superstructure, it may help with the bowing.

[Lego Dino 500]

It looks like the turntable is really stressed, the body's tilting and bending a lot. Maybe you could make some stabilizers on the front and back, to supplement the counterweight? That shouldn't require too many pieces.

[ttoks]

Thank you for the positive comments!

Wow, that's quite some reach! It looks like the attachment point for the boom lifting string could be closer to the superstructure, it may help with the bowing.

I fixed thing problem today, I reinforced the joint between each boom section, previously each section had just 4 3L beams to connects it to the next, i have used 8 7-3l beams (depending how far up the boom it is) to join each section of boom now, so the sag in the boom is now 3mm overall, where as it was around 15mm before.

It looks like the turntable is really stressed, the body's tilting and bending a lot. Maybe you could make some stabilizers on the front and back, to supplement the counterweight? That shouldn't require too many pieces.

yes the turntable is indeed very stressed, this is my next project to fix this problem, I am looking at a few options to build a more ridged turntable, incorporating a more ridged turtable will obviously mean a complete re-design of the entire sub structure and super structure, so while I'm at it, I plan to buy 1 more L motor and another M motor and another RX/TX combo so i can convert the entire model to full RC, I plan to have 2 M motor's for driving (one for each track), and L for the main hoist, L for the boom, and an M for the luffing jib, abviously i will need to buy many more parts for this, so I need a few more sets to buy

[Vectormatic]

yes the turntable is indeed very stressed, this is my next project to fix this problem, I am looking at a few options to build a more ridged turntable, incorporating a more ridged turtable will obviously mean a complete re-design of the entire sub structure and super structure, so while I'm at it, I plan to buy 1 more L motor and another M motor and another RX/TX combo so i can convert the entire model to full RC, I plan to have 2 M motor's for driving (one for each track), and L for the main hoist, L for the boom, and an M for the luffing jib, abviously i will need to buy many more parts for this, so I need a few more sets to buy

Just an idea here, how about a mechanism that swings the counterweight further out, depending on how far the lifting boom is lowered? for a crane with a large range of well... range, having the counterweight in a fixed position is always going to put stress on the turntable

[GBC Master]

yes the turntable is indeed very stressed, this is my next project to fix this problem, I am looking at a few options to build a more ridged turntable, incorporating a more ridged turtable will obviously mean a complete re-design of the entire sub structure and super structure, so while I'm at it, I plan to buy 1 more L motor and another M motor and another RX/TX combo so i can convert the entire model to full RC, I plan to have 2 M motor's for driving (one for each track), and L for the main hoist, L for the boom, and an M for the luffing jib, abviously i will need to buy many more parts for this, so I need a few more sets to buy

For this crane, I think it would be better if the 12t gear drives the turntable at the side, not at the back. This way the gear wouldn't slip as easy when the weight is shifted to the front and wouldn't be stressed when the weight is shifted to the back.

[Omikron]

The dust on your PC made my eyes bleed a little =(

[ttoks]

The dust on your PC made my eyes bleed a little =(

don't be too stressed, my PC was built in 2005, she's had a good run, but is delegated to internet browsing duties now, i'm surprised it's still going.

[2LegoOrNot2Lego...]

This one surly stands tall!!! :thumbup: