Hello all, I am just getting back into Technic after a 20? year break (wife, kids, job, the usual...) and I went a bought a 8043 Motorized Excavator since I am a sucker for tracked anything. I have read about a few problems so I didn't want to get too far into the build if I needed to change something. Are there any recommendations that I need to know before I start? I have read about too much friction on the changeover but I am no sure if that was just one guy having problems and i also saw the recall of the linear actuators but that seems to have been addressed.

Any help is appreciated and my next purchase will be the Unimog.

Thanks,

Tom

Welcome to Eurobricks! As hoeij noted on this Eurobricks post, there is a problem with some of the 8043's pins:

"This long friction pin is the gray pin that is inserted on page 12, step 44, of book 2. You see a gray pin being inserted on top of the axle connected to a motor.

Then in step 46, this gray pin will go into 2 holes, and so it'll have a huge amount of friction. Function-switching will require lots of force this way, so I left it out, and it works fine.

(PS. There is of course also the blue friction pin on page 79, step 35, of book 1. This one will likely have less friction than the gray pin in book 2 because the gray pin has friction in two holes. Still, there seems to be no good reason to have friction there, so I used something without friction instead)."

If your 8043 set is relatively new, the four Linear Actuators that come with the set should be the "improved" versions. To make sure, look at the stamped number on the ends of the LAs -- if they have a number greater than 36X0 (like 42X1, 45X0, etc.), they are the improved ones.

Welcome here!

Couple of us use 100% silicone spray to grease the gears - shafts, i did as well but only for the gears. There is also one hint, take really care for the free movement of the gears - do not place them tightly - not even slightly tightly recommended here. In this amount of connections what the 8043 has, they can produce a lot of friction, which takes the fun away. As i bought a used one built-up for the parts, on the test i experienced ~50% less performance with the same battery pack. So it absolutely payed off to pay attention + use the spray. I spent maybe 2 hours more at assembly, but trust me, every single step of it really fun and lot of interesting details - solutions to discover!

Take a coffee with you, and enjoy!

agrof

Edited September 28, 201212 yr by agrof

Welcome back to a great hobby :)

As DLuders correctly mentioned, there are two parts you have to think about:

1) the grey pin withs stop bush - instead of this I swaped the whole axle to 7L grey axle but you can probably leave the 5L axle there

2) the blue axle pin that should be replaced with tan axle pin w.o.friction

I haven't tried the silicone yet, but I'll definetly do that later.

about the LA - mines have the number 08x2 and 05x2 - and as confirmed by TLG - they are okay.

Also, I remember, that there were some problems with the tracks wobbling too much - there was a thread in eurobricks here, how to solve it, but I didn't had the required spare parts, so I didn't do it. Sorry, I don't have much time, I can't find it right now - you should check the advanced search option...

I started last night and finished book 1 and had a great time doing it. I love stopping once I complete a sub-system and really play around with it and notice all the small details that go into each step and how it works together.

Thanks for all the help so far,

Tom

Edited September 29, 201212 yr by TommyL

I started last night and finished book 1 and had a great time doing it. I love stopping once I complete a sub-system and really play around with it and notice all the small details that go into each step and how it works together.

Thanks for all the help so far,

Tom

Hi Tom - it is a lot of fun doing one section at a time, I do that too just to see the wonders of a huge Technic set like the 8043, I enjoyed this with the 8285 Tow Truck, the 8421 Mobile Crane and the 8258 Crane Truck. I always went slow too, I think half the fun of Lego Technic is the build process.

Eric

I built it in half a day taking it easy. Have you seen "the ultimate 8043" topic? Now that I think I have enough pieces I'll try to do it

Edited September 29, 201212 yr by Foggy

I built it in half a day taking it easy. Have you saw "the ultimate 8043" topic? Now that I think I have enough pieces I'll try to do it

I'm a little ( ok a lot) rusty so I spent about 3 hours finishing book 1. I didn't want to make too much of a mess on the kitchen table so I was trying to just keep all the parts in their baggies but about 2 hours in realized I really needed to sort all the parts by color. I figure I'll have about 5 hours in it or so when complete.

I'll check it out that ultimate thread, thanks!

Tom

Well, I think I messed up a little. I took the advice of leaving that blue pin out and now my change-over switch comes right back out of gear. I can switch it and then manually push it into gear or try switching a bunch of times and eventually it will "stick" but I think I am going to pull it apart and putt that friction pin back in. I am going to try ordering off of BrickLink to get the parts for the "ultimate" 8043 so eventually I won't nned it to work the same anyway.

Thanks

Tom

Didn't you have a tan axle pin as a spare part in your set? As far as I remember - I used that.

Well, I think I messed up a little. I took the advice of leaving that blue pin out and now my change-over switch comes right back out of gear. I can switch it and then manually push it into gear or try switching a bunch of times and eventually it will "stick" but I think I am going to pull it apart and putt that friction pin back in. I am going to try ordering off of BrickLink to get the parts for the "ultimate" 8043 so eventually I won't nned it to work the same anyway.

Thanks

Tom

It is a quirky model, but a beautiful one if taken slow and following every step carefully, I had problems with my turntable and tracking too, but I got a lot of helpful replies here in the forum and it works flawlessly now.

Definitely buy the parts to do the ultimate model, it is very well worth it, having to change gears between the boom functions and moving/turning functions is a royal pain. Luckily I had everything I needed from my vast spare parts collection. The smaller bucket size too makes it look more realistic, Lego really shouldn't have put the standard huge loader bucket on an excavator. I don't recall if the ultimate version gave you tips on the 'sagging butt' because of the weight of the battery box and 4 m-motors weighing down the rear end, but the 'lift' mod on the crossmembers in front of the 8043 are well worth and require very few parts. Also make absolute sure you have the set with the updated linear actuators, I believe from what I have read, I wrote it down in my spare instructions box about the numbering on the newer more lubed and better functioning LA's, I think if I recall it says 36x0 or something to that effect on the LA's itself, not on the outer plastic wrap they are in, the updated LA's have a new Lego part no on the package they come in too, but I'd have to go out to my garage and check as I saved a few extra when I built the alternate tracked loader model, I just used the older LA's on that and it works great and really is the best alternate model I've ever built, the functionality is really cool and its fast moving too. I'm going to try and remove the bucket and somehow modify it to be a bulldozer instead of a loader, but haven't worked out the plans yet.

As far as sorting your parts in a small place to build, I bought some fabric covered craft bins with sorters from Bed Bath and Beyond, a chain in my city that sells, well, just like the name of the store. They are perfect and allow you to sort parts before the build. They came in 2 different sizes, a larger one which I use for less piece count sets and a bit smaller ones with a large compartment and 3 smaller open sorters and use 2 of them for the larger sets. I never sort by color alone, but everybody has different ideas on how they sort parts, I put gears, racks(for steering and such) and engine parts in one bin, pins in another, axles in another, liftarms and plates in another, smaller parts like lights, etc in another, and connecting pieces like axle joiners, etc in another. Takes a bit of time to open the poly bags and sort out all the parts, but its well worth it rather than trying to 'find a needle in a haystack' for smaller parts.

Eric

Well, pulled it apart in 5 minutes, put the friction pin back in, rebuilt it in 30 minutes and it works flawlessly. I won't disagree with the advice that was given but with my 8043 the friction pin was needed to keep the change over switch from flipping back into neutral. Other peoples models may be different.

I am going to use the Ultimate model as a way to get the hang of Bricklink but it is looking like it might cost me $100 in spare parts to build it so it might have to wait until after Christmas.

Thanks to all for the help and wish me luck on the Unimog.

Tom

Edited September 30, 201212 yr by TommyL

I think they originally made some corrections to the manual, but any recent copy of the set should have those in them (as well as the newer LAs). I made no changes beyond what the corrected manual had and mine works great. I actually like the original model better than that "ultimate" version. The function switching mechanism is quirky but that whole concept is the coolest part of the set for me.

I think they originally made some corrections to the manual, but any recent copy of the set should have those in them (as well as the newer LAs). I made no changes beyond what the corrected manual had and mine works great. I actually like the original model better than that "ultimate" version. The function switching mechanism is quirky but that whole concept is the coolest part of the set for me.

+1 absolutely!

p.s.:I also didn't experience the problem with that pin, neither the one with the track.

Welcome to Eurobricks! As hoeij noted on this Eurobricks post, there is a problem with some of the 8043's pins:

"This long friction pin is the gray pin that is inserted on page 12, step 44, of book 2. You see a gray pin being inserted on top of the axle connected to a motor.

Then in step 46, this gray pin will go into 2 holes, and so it'll have a huge amount of friction. Function-switching will require lots of force this way, so I left it out, and it works fine.

I was using fairly old batteries when I wrote this. In a later post in that sequence I wrote that with fresh batteries, some friction is useful because

with full batteries, the switching is so fast that it can bounce back.

Initially I was also planning to build the ultimate 8043, but actually (unless you have the LA's from the first version of 8043 that was only sold for

about a month or so) it works fine just as it is. Mine also works fine without lubrication (I am not against lubrication, have used it for other things).

The only thing I think is worth changing is to hide the gears in the undercarriage a bit more (there was a post on that of someone that had hidden those

gears very nicely).

Actually, now that I think of it, the undercarriage could use some other changes too. The excavator is riding on top of those small wheels at the bottom,

these wheels go through the grooves in the track, but the wheels are round and don't go smoothly through the grooves in the track, leading to a bumpy ride.

There are other small wheels that fit better and should lead to smoother driving, but I don't know if it'll look as good.

All in all, I think 8043 is the best technic set. I'd recommend building the B-model first (and also the C-model that someone posted instructions for a

little while ago). The reason is that if you build the main model first, it's so nice that you don't want to take it apart, and that would be a pity because the B

and C models are definitely worth building too.

I made this one a while ago,but it is costly.

Zorex-220 Orange Motorized Excavator

Quick question, has anyone ever measured the percentage of mechanical energy that gets lost for each gear in the gear-train?

For instance, say the maximal torque of the M-motor is K.

Now I insert a sequence of 10 gear-connections (say using only 16 tooth-gears). What would then be the maximal torque on the

axle of the last gear?

Did you try philo's site?