Lego 8043 Excavator Help

turtle1173

Hi all,

My son got the 8043 motorized Excavator for Christmas today. We have been at it all day and are about 3/4 of the way done. I hooked up the battery pack to see what it would do at this point. The left track seems to work fine but I get no movement from the right track. I then proceeded to take it apart back down to the gearcase and re-verify all the gears, motors, etc. Finally got it all back like it was and still no movement on the right track. The motor turns and I see some gears moving but it doesn't seem to translate down to the right track moving.

We are good lego builders but this is very frustrating. I am anticipating a finished product that will not function right and my 10 year old is going to be very devastated.

Anyone have any advice and/or suggestions?

I've done some searches and I see that many in days gone by have had trouble with this. They issued a service pack, etc., etc. This was bought 2 months ago and should be recent. Instructions were on cardboard and my manual is the same as the service updates.

Thanks!

Legoboy

I really don't know. I'm not a Technic expert although confess I get most of my enjoyment out of these types of sets over others. The Mechanical Excavator was one of my favourite builds and remains one of my favourite sets. I am reasonably thorough when building but will admit to cocking up quite significantly when building this one. I don't have any specific details to hand but do recall mistaking one particular type of small cog for an incorrect one. I didn't realise until I'd run out of one type cog sooner than I should have done and a spare couple of a different type left to use. This is the only reason I knew I'd made a mistake - I didn't get as far as starting it up. What I also remember was that they were cogs used to transfer the power in the vertical axles under the cab to the horizontal axles in the tracks.

You might have a completely separate issue but definitely worth a check nonetheless.

Good luck. J.

peterlinddk

If you arent completely done, it might not work fully yet.
Did you test the track movement as described in step 38, page 46 book 1?
Did it work? Can you test it now, and does it still work?

If not, then the problem lies with the dark grey cogs, that has to be turned the right side up.

If it works manually, then the problem lies with the gearbox! Pages 67 to 79, same book. Again those pesky cogs - or the spacers on page 70 and 71, there are two kinds, with ridges and without - it is important to not mix them around.

If can also be the red spacers and pins not being aligned - check that they all move correctly when changing "mode" (turning the yellow 4-prong cogs)

And sorry if my technic-jargon is a bit strange, neither technic nor english is my native language ;)

turtle1173

Thanks for the comment. It has been a trying day. We hit a low point when my son broke down in tears because he had been looking forward to this set so much and was so disappointed that it wasn't going to work. :-(

I ended up tearing the whole thing down. I encouraged my son to play with the cargo train and relax. Then I rebuilt the whole thing up to the point where you connect the intricate gearbox to the main body/ treads. At this point I hooked the battery up to it and my son nearly dove into my arms with joy as it drove forward/back, left/right perfectly. So it looks like the day has been salvaged, lol.

I don't know what the problem was but it was apparently big enough. When we build, usually he builds 4 pages, then I build 4 pages. Usually it goes smoothly but with this there are SO MANY things that can go wrong.

Well, thanks for listening to my troubles.

Si_UKNZ

Not sure if this is related but there was a problem with the linear actuators on early batches of these. If you tell lego the batch number they may provide a replacement.

lulwut

Didn't want to start a new thread, but I also have a few questions on this set.

I finished the set and had these spares:



Did I miss anything? I'm a little worried as I have never seen extra gear cogs before. Mine is fully functioning except for that annoying function switch, it doesn't fully engage on one go, I have to keep pushing on the receiver a few times until it engages. Is that normal?

RunSub

If you check rebrickable rebrickable.com/sets/8043-1 you can see the extra parts list.

However I'm not sure if its 100% perfect

Ardalis

I just checked my spares for that set, I have 2 black pins and no blue pins spare, the rest is the same, the important part is the gears are the same and my excavator works ok. As regards the function switch it should change straight way when the lever is pushed, I would check all the gears are the right way around, easy to make a mistake and put one of them gears in backwards with the serated edge in the wrong place causing friction.

cloud0

I'm having problems with the right track struggling to move, while the left 1 is moving smoothly!
Also, when I push both knobs forward to move, the right track goes in reverse too. Any idea whats wrong?

Ardalis

cloud0 said:

I'm having problems with the right track struggling to move, while the left 1 is moving smoothly!
Also, when I push both knobs forward to move, the right track goes in reverse too. Any idea whats wrong?

Weird it go's in reverse when both knobs are pushed forward, is the black switch below the lever in the same place on the remote? also when you try get the right track to move on its own does it try go forward or reverse?

cloud0

When i push forward on the right track by itself, it goes in reverse. It also struggles to move.
I don't get what you mean by the black switch below the lever.

ColoradoBricks

@cloud0 the switch is highlighted in the picture below. That will fix the reverse/forward issue.

cloud0

ColoradoBricks said:

@cloud0 the switch is highlighted in the picture below. That will fix the reverse/forward issue.

Yes, it is both in the same position.
Also, the crane boom takes forever to erect, is this a L.A problem?

Ardalis

cloud0 said:

ColoradoBricks said:

@cloud0 the switch is highlighted in the picture below. That will fix the reverse/forward issue.

Yes, it is both in the same position.
Also, the crane boom takes forever to erect, is this a L.A problem?

Well the reverse track sounds bad tbh, if the switchs are both set the same way then I'd suggest put the right one the opposite way and see what happens, if not a rebuild as something is not in its right place, as regards the crane boom try a fresh set of batteries, as batteries lose power the output from the motors will drop, and see if it works better if not you will need to rebuild it anyway to sort out the reverse tracks.

A good idea I find when building is attach the motor just by hand every now and again after certain sections like after you build the track base and check everything is turning. Can save you some time as you should be able to see the mechanism working and give you a idea if there is a screw up, always watch out for the 16 tooth clutch gears dark grey gears with a smooth side and a serated side, if you put them backwards they can cause issues, there are 14 of them in the set mainly in the big gear box in front of the motors.

cloud0

All right, many thanks for the advise. I'll go try