tomacwhite

8043 Excavator - Lego update

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Thats what I meant, I just wanted to be sure that is normal because the instructions do not mention that.

If you built it to instructions and set correctty the small switch on remote to sync up tracks then it's normal.

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Thats what I meant, I just wanted to be sure that is normal because the instructions do not mention that.

I built mine and didn't need to change the little polarity switch to have the tracks work in the same direction. Are you sure you haven't made a mistake somewhere? The only place I changed the polarity was for the gear change motor because it made more logical sense to me to have it the other way around, so that from behind the excavator the remote switch operates in the same direction as the red gear change lever.

Have to say, mine seemed defect free when I first built it. Have been playing with it a fair bit* to test it out and the boom raising does seem to be getting slower and sounding more strained with time, whilst the other functions seem pretty constant. Haven't had any issues with the tracks operating at different speeds either.

*i.e. probably a lot more than I ever would have if it hadn't been for this issue.

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sometime I do see the left track a little slower than the right track, with a fresh batteries. I think it something to do with gearing in middle of turntable. I think the M motors may not be powerful enough for tracks and main boom. It would be like driving a small car pulling a 44 tonnes trailer.

I think it should have XL motors, the bulldozer has two, it is powerful, so why don't 8043 have one......

I think I shall keep it for now and wait till Lego's instruction.

Dan.

I chose to do a little investigation of my own so see if indeed the M-motors are to blame, because I simply do not believe The Lego Group would mass-produce a product that wouldn't work- if the designer of 8043 said that the M-motors should take the pressure, then they have to- that they do it less efficiently than the XL motors, that's a whole other story. So, after fighting my way through the internals of the excavator I made a discovery most sinister. Two grey 16-tooth gears transfer the power from the far left motor (if you face the excavator from the back) to the left-hand tracks. One of these gears are held by a tan pin that is not secured by the bottom, so it will slide out eventually with time. It explains why when I first built it, it ran well, and got progressively worse. What I did was basically remove the tan pin and the grey shaft from the second gear and replaced the tan pin with a size 3 shaft and the grey shaft (from the second gear) with a size 6 shaft. All is left is to secure the bottom. This mod was based on Jurgen's modifications of 8043 (see his Ultimate 8043 post, it is magnificent work). The result was fantastic performance from the left track, and the excavator's speed increased dramatically as well, since both tracks move at the same speed without any strain. This is worrying however, because this is a design flaw that can result in gear/motor damage if left unchecked.

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Yes, I noticed this after building my 8043 the second time and was easily corrected as I did in my instructions. I just didn't mention this before. It's weird that TLG didn't notice this. See instruction book 1, page 45.

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Yes, I noticed this after building my 8043 the second time and was easily corrected as I did in my instructions. I just didn't mention this before. It's weird that TLG didn't notice this. See instruction book 1, page 45.

Well, I'm surprised too, actually- and your instructions were very helpful, spared me hours of frustration, so I thank you- I think TLG should take a strong note of this.

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While I'm still glad I bought it, I'm becoming more disappointed in this being the first Technic set to hit the $200 USD mark. These problems are way different then the added instructions needed for 8455 and 8275, after customer complaints that were attributed to a difficult build.

I know the price isn't decided by the designers nor is production quality controlled by the technic team, I'm just surprised it wasnt caught somewhere in the food chain, and a bummer for it to happen on the most expensive set to date.

Edited by Dannnohhh

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I also sent an Email to Lego about the problems im having with the excavator, and they replied that the problem has to do with the LA and that they added me to the list for replacement parts. They also told me that the developers have found a solution and tested it and that the production of the new parts would be ready in 3 to 4 weeks.

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Yes, I noticed this after building my 8043 the second time and was easily corrected as I did in my instructions. I just didn't mention this before. It's weird that TLG didn't notice this. See instruction book 1, page 45.

I don't have the set now, but does this fix the slow Main Arm movement?

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I don't have the set now, but does this fix the slow Main Arm movement?

When I contacted Lego the other day they told me they are simply replacing the current LAs with the updated ones (someone here raised a good question as to if they will look the same as the current ones or not)- and they put me on the list to receive the parts as well (4 LAs)

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This is similar to the answer I was about to type. The further the actuator is extended, the shorter the couple between the end gland and the thread. In a real actuator, the end gland has hydraulic seals in it and you don't really want those seals supporting much side load or they will wear prematurely. You want the structural members to carry that load as much as practical. The LA doesn't have any seals, and I don't know how tight the gland fit is compared to the threads. In any case, side loading can't be helpful.

I wonder how much advice Firgelli are able to give Lego? maybe they could outsource supply of some internal components to a specialist?

I still hope for metal sleeve and metal screw, finer thread (same pitch) and double the length of thread maybe about 8mm so about 8-10 threads (maybe not as much as the Outside Diameter) but I'm going to have to wait and see... a tighter collar/gland might help with side loading but I think supporting the internal sleeve at both ends would help more, am I right that it is only supported at the base input shaft end? it seems to have a large amount of play inside the case when the actuator is retracted (shortest).

P.

PS @Allan, Race car tires are wider because for several reasons, rubber is flexible and this is key to grip, the thinner the better (more flexible) so lower pressure and wider helps, as the tire deforms onto the roughness of the road this provides 'keying' grip rather than true friction, in addition tires are 'sticky' and race tires even more so, so you want greater area for the sticky to apply, and to go further tires leave small amounts of rubber behind when loaded this rubber is torn away in a shear situation from the tire, you would loose grip faster with small contact area so a larger surface means a greater shear surface, but this is about the elasticity of the rubber and its tearing strength again not really true friction.

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I don't have the set now, but does this fix the slow Main Arm movement?

No, it refers to the right track running slower than the left track. My solution to slow arm movement was using an XL-motor, but I don't think TLG will do this. But then again I can't develop a new LA ...

Edited by Jurgen Krooshoop

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10 minutes ago i recieved a Call from lego uk. In couple of weeks lego will start sending service packs for 8043.

Edited by backbone

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TLG will just send replacement actuators... but what about ther other problems?

of course im glad they added me too and that the srvice is great

i asked them for an XL motor to modify it otherwise the problems are the same..

Edited by shimon

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These problems are way different then the added instructions needed for 8455 and 8275, after customer complaints that were attributed to a difficult build.

May I ask, what and where are these added instructions for 8455? Mine printed version (bottom left corner) is same as is on-line on service.lego.com. Sorry for little OT.

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10 minutes ago i recieved a Call from lego uk. In couple of weeks lego will start sending service packs for 8043.

How does one go about getting on the list for the service packs?

I purchased my 8043 last week and have not had a chance to start building. Now I think I would just rather wait for the corrections before I do build this model.

Thanks,

Andy D

Edited by Andy D

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1. Replace the gears shown in step 53, replace 12T bevel gear to 20T idler to 12T second idler to two 20T bevel gear, with 8T to 32T idler to two 20T bevel gears. It takes 1.5 times the motor revolutions to do the same thing, but somehow, raising the main boom seems faster.

I am impressed with this tweak. I think this simple gear change may have put the motor back into its power band, so it is no longer struggling, it seems that this gear down slows the drive and increase the power, which seems to turn more freely, hence turns faster.. so yes almost as fast but it just works better. I'd highly recomend this change, and am starting to think this may be how the model was originally designed (and tested?) before someone tweaked it (to look better?)... I think this simple 2 gear(8t+32t) change may be what Lego are intending as the fix. (no matter how much I want an imporved actuator :hmpf_bad: )

2. In step 36, replace axle 4 with stop, with 6 axle. It's the same thing Jurgens did in his MOD. This stabilized the top end of the axle and reduces friction.

I have not tried this yet (did you mean step 36? maybe my instructions are different.)

3. Used a differential instead of the stacked driving ring and clutch gears to pass power thru turn table. This removed the slight delay in one of the tracks when switching from forward to backward.

I have not tried this as it has not bugged me yet. I may try it later. I would like a long tube piece for this (new part).

Swapped the two 16T gears for a 12T and 20T for the switching function.

I do not like this change so much. it prevents manual switching (Though I dont know why you would!) and it does not cure the sticking issue (fix by pulsing all motors).

Placed both bevel gears on the same side at the LA's in the main boom.

This I see as a no brainer, it has minor cosmetic implications but it does ensure a equal actuation (I'm not sure how much it really helps though!).

anyway batteries are on charge again more testing later.

P.

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Hi everybody, I bought a 8043 excavator just a couple of days ago and the box is still unopened since I read all the stuff you are discussing here.

How can I get the service pack that TLG has scheduled for this model?

Thanks

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Use Customer Service, post form and wait to recieve call from lego.

...or email from Lego :classic:

My correspondence in UK was all by email following using the online contact form, and after my second email re-explaining the issues I was experiencing I was told they'd added me to the 'Service Pack' list. I bought from Argos and Lego didn't even ask for proof of purchase - very trusting.

.

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Lego didn't even ask for proof of purchase - very trusting.

Yep. And its very impressive what TLG is doing - replacement parts, service packs. Excellent customer support anyway.

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Just got another email from Lego UK saying the new part wont be ready until October, and it will be a new Linear Actuator part specifically for lifting heavy items such as the arm on 8043. I was offered a £10 credit if I waited for the part, or I could get a refund. Obviously this is a mail going out to all buyers of the model because mine has already been sent back.

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I emailed Lego (US) about the Excavator problem and here is what they replied with:

"First let me apologize for the difficulty you've had so far with your new 8043 Motorized Excavator. Our design team recently became aware of this issue and removed the item from our LEGO.com shop. We're now working feverishly to redesign the Linear Actuator - the source of these motor problems! We expect to have a solution up and ready within a few weeks."

They go on to say I'm now on the list to receive the replacement LAs, or that I can get a full refund. I'm holding out for the new actuators. I wish everyone had as good customer service as Lego.

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What about the sets on the shelves in regular shops? I dont want to buy this set by Shop at Home because of the shipping cost. How should I get this replacement part if I buy this set in a regular shop?

Edited by menad

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What about the sets on the shelves in regular shops? I dont want to buy this set by Shop at Home because of the shipping cost. How should I get this replacement part if I buy this set in a regular shop?

Send mail and wait for reply / call. Everything is posted above. I bought my 8043 via allegro.pl (polish equivalent for ebay).

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So if i understand, the current Las won't be change by the new?

The 2 sorts of La will cohabit?

If it's the case, do you think the new Las will be really different than the current?

And in fact, how many times does lego take to answer at a mail?

Edited by GuiliuG

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