42009 Crane, questions and doubts...

[Quaxo76]

Hello,

I just completed the 42009 crane, it took me about 12 hours spread over a week. I'm quite "rusty" with Technic but I used to play with them a lot as a kid, so I encountered no major problems during the build, just 2-3 small mistakes, easy to fix, especially because I always check for functionality as I build, so I can detect problems soon after making the mistake... :P

Anyway, the crane is finished and looks wonderful, it's by far the best and most complex set I've ever built, but I have a couple of doubts.

All the functions work, including the outriggers (which I hear are a common problem), albeit quite slow. Here's what I'm not so sure about:

1) When fully lowered and retracted, the boom does not contact the roof of the cabin, so the crane body has to constantly support the weight of the boom. I think it should be allowed to "rest" on the roof, so that the strain on the structure and LA's can be relieved. Did I do something wrong or is it supposed to be like this?

2) Whenever the motor is on, both with the clutch disengaged, and with whatever function is selected, the wheel train for the boom extension moves. Not very fast, and with not much torque - I just have to touch the wheels and they stop, without stalling the motor - but the torque is enough to actually retract or extend the boom, very slowly, if it's not loaded. Any idea where the problem might be, without having to disassemble all the crane body?

3) When the large LA's reach the end points, both raised and lowered, they start making a scary clicking sound. I suppose it's the internal clutch, but it's not as graceful as the white clutch wheels: when this happens, the whole structure actually shakes, and the wheels driving the LA almost seem to skip (but they don't). Again, is this normal? Is it going to damage some wheels, or something?

4) The knot to secure the winch cable to the pulley... If I leave the knot outside, it rubs with the gear and stops the movement. If I leave it inside, it messes up the winding of the thread. How did you secure/tie it?

I think that's it for now... thanks in advance for any reply! :)

Cristian

[PeterF]

I can only answer Q3, but that is a well known 'problem'. Yes, it sounds horrible, and I think TLG should change the LA design if only for this reason, but functionally it is fine. This is how it is supposed to work and sound.

[cehtunger]

1. Check if the boom is connected properly to superstructure. Mine is disassembled at the moment so i'm not sure if it's possible to connect it wrong.

I guess this would be effect if the 12 axle is connected one stud higher than should be.

Also check if LAs are connected properly to the boom. You can see on the slide 55 of the manual how they should be connected.

2.If i have to guess i would say you have some unwanted friction in the gearbox. Maybe some gear was connected too tight, or something like this.

3. It is internal clutch mechanism. Yes, the sound is very disturbing, but i decided to trust it since building 42025, where it is required to pull them out without rotating, altough that were small LA, but in my experience it should be safe.

4.I have my inside. Cable is pretty long so it covers the knot pretty good.

I would also suggest that you rotate your cable on the other side, so that it goes on the lower side of the pulley. This would only reverse the lifting function, but that way it is more

consistent with other functions. So lowering boom, than switch to lowering cable would require only gearbox change, without reversing the direction on the battery box.

[Freekysch]

Looking at my model I can tell you that the boom sits on the cab.

[Josephiah]

Mine doesn't quite sit down onto the cab either, unless pulled down slightly. It seems there's enough slack in the structure, mainly at the turntable joint, for it to cope.

[Quaxo76]

Thank you all for your replies.

The boom and LA's are connected properly, I double checked, so that can't be the problem. And the boom does actually touch the roof, but only because the crane body is "bent" forwards, and it can't be "at rest". It's not a whole stud gap, just a few millimetres more would do. I might add a small plate to the roof of the cabin, where the boom contacts, to relieve the strain to the body at rest.

Another thing I just noticed: when the boom is completely retracted, the wire loop that moves the inner part is "slack" and not tight, so that I can manually move the inner portion in and out slightly more than a stud. The wire loop becomes tight after the boom is extended at least partially. Is this normal?

For the "frictioning" wheel train, I partially disassembled the crane to get access to part of the drive train, and "moved" the wheels around a bit, but I only made it worse... I suppose I'll have to rebuild the whole crane body. Good project for a rainy afternoon!

Also... I see that everybody refers to a 6-booklet instruction set. I have a single book, of 424 pages. And I didn't get a spare 32 axle. Is this a new revision? Are there other differences?

[zux]

Also... I see that everybody refers to a 6-booklet instruction set. I have a single book, of 424 pages. And I didn't get a spare 32 axle. Is this a new revision? Are there other differences?

Yes, it has been reported this set has slightly different number of extra parts, some got extra 32L axle, some not. Later versions have single booklet instead of multiple.

[bonox]

If it's built correctly and the LA's are fully retracted, then the expression "they all do that" applies. It will probably rock on the turntable enough to touch at the front if you take the batteries out.

[allanp]

A photo would help us see why the boom isn't sitting low enough.

[rollermonkey]

My boom rests on the roof nicely, both as originally built, and as Juergen's Ultimate.

[Kumbbl]

Mine too

[Gnac]

I got one of these behemoths yesterday - finally finished [speed]building and testing, so I'll chime in.

When fully lowered and retracted, the boom does not contact the roof of the cabin, so the crane body has to constantly support the weight of the boom. I think it should be allowed to "rest" on the roof, so that the strain on the structure and LA's can be relieved. Did I do something wrong or is it supposed to be like this?

I had this before I powered everything up, but after raising and lowering the boom a few times, it now fits snug. Maybe there's just a bit of "slack" somewhere in the drivetrain which needs to be worked out through use.

The knot to secure the winch cable to the pulley... If I leave the knot outside, it rubs with the gear and stops the movement. If I leave it inside, it messes up the winding of the thread. How did you secure/tie it?

I used a bobbin for this. It's a bit narrower than the gap between the yellow pulley wheels (and a slightly greater diameter than the axle) but there's enough room to hold all the string. I initially had a problem with the string getting caught inbetween the edge of the bobbin and the pulley wheel when winding the string onto it for the first time, but it hasn't happened again while using the crane's functions.

Another thing I just noticed: when the boom is completely retracted, the wire loop that moves the inner part is "slack" and not tight, so that I can manually move the inner portion in and out slightly more than a stud. The wire loop becomes tight after the boom is extended at least partially. Is this normal?

I believe this is a normal quirk of those string pieces - I remember someone mentioned a while ago that they're slightly too long. 10226 Sopwith Camel uses a load of them to move the control surfaces, and the stud ends often need to be twisted to make the stings taut enough to make everything work properly.

For the "frictioning" wheel train, I partially disassembled the crane to get access to part of the drive train, and "moved" the wheels around a bit, but I only made it worse... I suppose I'll have to rebuild the whole crane body. Good project for a rainy afternoon!

Get this: I must have spent about ten minutes watching those outrigger feet lower before I decided to see if my rechargeable batteries were dying (they were). There's now an ugly situation going on at the back where I've bodged a LiPo battery box into it. I'm not going to go messing about with making it faster because 30 seconds is a vast improvement for me!

Also... I see that everybody refers to a 6-booklet instruction set. I have a single book, of 424 pages. And I didn't get a spare 32 axle. Is this a new revision? Are there other differences?

6 booklets and no spare 32M axle. I was prepared to be denied the spare axle, but I dont know how to feel about not having a spanky new all-in-one booklet.

[niknarjc]

I just bought the set and am in the process of putting it together. I realized I am missing the string with the plastic on the end. I have put in a request for a replacement part with LEGO. Anyone else have this issue?

[Victor Imaginator]

My set had one more string with studs as spare...

[Gnac]

[...] I realized I am missing the string with the plastic on the end [...]

Those come loose in the box, i.e. not inside an other bags. It's possible that they may have dropped onto the floor and got kicked under a cabinet or something; also they may still be inside the box itself, caught on one of the flaps.

[niknarjc]

Those come loose in the box, i.e. not inside an other bags. It's possible that they may have dropped onto the floor and got kicked under a cabinet or something; also they may still be inside the box itself, caught on one of the flaps.

I've looked everywhere. even other rooms just in case the cats got it. The box was bit bit beat up from the store, last in stock I assume, but it wasn't opened. I didn't even look in the instructions, how many are used? I did see the set comes with two.

Also interestingly the ID number in the instructions is not the same on the LEGO Bricks and Pieces website.