Ngoc Nguyen

Given that this year is the year of F1 Cars across multiple themes, the 2359-piece flagship just might as well be another F1 car + a transporter truck... 1300 pieces for the F1, 1000 pieces for a truck + trailer. The trailer can have double deck to encourage fans to buy either the 42206 or 42207.

Despite being a tow truck, mini 42070 is a much harder challenge to solve than mini 42128. Since I want to preserve the rear pendular suspensions, the space for functions in the rear part is reduced. There's also the problem of what to do with the front axle. The most compact and legal design for an axle to be driveable and steerable involves the Mustang rim that turns its hollow side inside. In the original 42070 the wheels have yellow rings outside black dishes, but the Mustang rim is not available in yellow. Then there's the problem with the outriggers. There are no small scale equivalent of the telescopic gear racks. There are a couple of other things to be solved as well. Those reasons, together with the fact that I've just finished a tow truck, mean a mini 42070 is not gonna be finalized any time soon, or even in this year.

Thanks a lot!

Can someone with the part 2994 and part 42716 check if the former fits into the latter? Part 2994 is no longer in production so I don't have it around.

Now that some of the major sets have been revealed, time to update the plan: Sets in development - Mini 42043 - Mini 42070 - Mini 42100 - Mini 42129 - Mini 42114 - Mini 42177 - Mini 10327 - B model for 42175 - 42100 RC PF Conversion - Technic 21327 (Typewriter) - SA-2 Samson Bicopter Sets of interest - Mini 8258 - Mini 9397 - Mini 41999 - Mini 42009 - Mini 42052 - Mini 42055 - Mini 42066 - Mini 42078 A - Mini 42081 - Mini 42110 - Mini 42126 - Mini 42131 - Leonardo AW609

Technic is not doomed. In fact Technic as a building system is very much alive and evolves every year. As it get more new parts, new possibilities open up. It's just Technic as a brand feels stagnant, but that is when the Technic spirit should be found elsewhere. (Like my JCB 3CX Compact Backhoe perhaps )

As explained above, this MOC is considered done, but the quest for perfection makes me feel restless when the superstructure tilt exists. Thanks to the consultation of Milan, who has extensive experience with cranes, I had to redesign the turntable. The main reason is that the supercarriage only rests on a turntable which has a lot of slack. The superstructure design is also not optimized in two ways: the connection point with the boom is not placed far enough to the back, and the counterweight can be made bigger. As you can see be low, the connection point, which is where the yellow axle is, is rather close to the center. This creates another problem, which is that it takes a lot of force to lift the boom. Therefore, for the superstructure, I made the counterweight thicker, and moved the connection point 4 studs back. That's the furthest that it can be moved. Since the new position decreases the maximum angle of the boom, I replace the medium LA with the large LA. I also fortifed the area at the front of the superstructure, under the large LA (the black 3L connector). That is where the superstructure will lean on. A slight downside is that the boom can't rest in a position parallel with the body anymore, but that hardly matters. The fact that the boom is at a slight angle can be explained to allow the operator to see the mirror on the other side, even. For the undercarriage, I used the gear rack quarter from the set 42160 to form a ring that the superstructure can rest on. This means I had to replace the big turntable with the small turntable, and rework the gearing that drives it. The result is that the model looks better now, and doesn't show as much tilt as before. It also requires less force to raise it. I had to redo all the renders and the function sheets, and that's a huge chore, but I have to do it since the design has changed considerably. At least I can find comfort in the fact that this model has reached the best form that it can be, and I can finally feel at ease.

I love those renders too! Even though they are a pain to make, the final results are totally worth it. Thanks mate

How the two mode steering and the steering shift works:

The reel is fixed. There's no space in that area to make a functioning rotating reel. Hence the jackhammer's hose is connected to the DBG hose connector behind it. The mini LAs are connected through a 12L axle that extends only to the left side (the other side of the model) and can be driven only from there. The hose is connected to the black connector through a black 2L axle with notched.

Thanks a lot! Please try it out, it's very fun to build and play. The whole model fits perfectly into a 17 stud width. Thanks a lot!

I realized it didnt actually take much time so I actually went back and redid all the renders. Thank you! Thanks a lot! Thanks for the support! What do you mean similar breathing

Shoot you're right... Thanks for pointing that out. I've just updated the instruction. As for the renders they took too much time to do so I'll just leave them there.

I know right, the jackhammer is very fun to play with The steering is actually very smooth. It's just that my hand is big while the opening is small, and I can only use one hand as the other hand is holding the phone. It is possible to route it to under the rotating seat to transfer motion to the HOG on the roof, but doing so will requires making the seat rotation manual, which is not very desirable as it's hard to reach inside, or removing the seat rotation altogether, which doesn't make sense for a backhoe. So I decided that routing it to the steering wheel is the best solution.

Thanks a lot for the support!

WOW I got frontpaged I've never thought I could get frontpaged yeahhhhh (Actually I got frontpaged once already but that was for the 42113 Review, not for any MOC)

INTRODUCTION The collective interest in a Technic backhoe has been around since as far as when I first joined this forum, which was 10 years ago. Such intense interest is understandable: a backhoe is one of the most complex, if not the most complex vehicle for a Technic model, since it has a lot of functions while its main body is rather compact. Hence, as I see it, a backhoe is like an apex of Technic or at least Technic construction machines. Yet there are not many official Technic backhoe. Before this year the most recent iterations were 8069, a medium sized backhoe set released in 2011, and 42004, a mini version released in 2013. That means there was a whole interval of 11 years with no new backhoe. Then this year a backhoe appeared in the lineup, but it turned out to be a mini version, an arguably worse iteration even, given that it has less pieces and functions than the 42003. Even though the full 2025 lineup is not revealed, since there's already a mini backhoe, it's unlikely that there will be another medium sized or flagship sized of the same subject. Therefore I decided to publish my own backhoe this year. DEVELOPMENT The design process for this model actually started in late 2021. Back then I wanted to build a road construction playset that contains a backhoe, a trailer, and a truck from the Heavy duty Tow Truck 42128. I don't have the file for that model with me anymore, but here's a custom digging bucket I built from 42128 parts. At that point I already finalized the digging arms. Its design stay unchanged in the final model. But then for some reasons I lost interest along the way so I stopped working on it. Then last summer there was a Technic Contest that involves building models around the 49.5 tyre. That was when I took that backhoe out of the freezer and combined it with features from my 42157 alternate model. Then I encountered two problems. The first problem is that I've always wanted to build the JCB 3CX Compact. It has to be the 3CX Compact and not 3CX or 4CX because the 3CX Compact has 4 small wheels, which allows more space in the body. In real life there are versions of JCB 3CX Compact that use truck tires like the 49.5, but I think it just looks stupid. I want it to have proper tractor tires. The second problem is that I was stuck at the rear wheel arch. In the real vehicle the arch is yellow with a thin black line. I struggled to recreate that in the small scale. So even though I made quite some progress, I lost interest in the summer and left the model in the freezer again. By that time I got most of the main body done. You can also see an attempt at the wheel arch. Then in November I happened to open this file again, and I felt that I can finish it. I spent a couple of weeks in November on it to finish the preliminary design, then wait for the parts. When I did the test build, most functions turn out fine, except the front loader arms. There will always be something that looks nice on Studio but doesn't actually work and require a redesign. This is how the prelim looks like. I already revealed it in my Technic corner. You can compare it with the first image to see how the front loader arms have changed. In the end I managed to make everything work flawlessly! DESIGN HIGHLIGHTS Since it's a small scale backhoe, most functions are directly driven through knobs, so there's nothing fancy in that regard. However there are other nice things I want to share. Chassis: The whole chassis is nested in side a pair of 3x19 yellow frame. This piece is very usefull as you can form a chassis right away without having to extending it with beams. It is only 5L wide, so I have only 3L in the middle to squeeze 3 functions: drive train, steering, and rotating seat. This is how everything is arranged. Inline 4-engine: I managed to make everything black while giving the piston heads yellow half bushes, so it looks very cool and luxurious. Two-piece hood. In the real 3CX, the lid together with side walls can be lifted up separately from the front grill. In my model I made them openable separately too. I managed to put a fan behind the grill as well. Cabin interior: I managed to replicate some details. In the real cabin there are 3 pedals, two gray ones on the left and one black one on the right. The seat is only rotatable counter clockwise, because there's a control panel on the right side. There are 3 joysticks, and the two in the back are adjustable once you turn the seat around. Sliding digging arm: This is the function I like the most and want to incorporate into the model at all costs. For a compact backhoe, it's very important that it can slide the digging arm to one side to fold it up stay compact while travelling on the road. The sliding is designed like this. You use a long axle to spin the axle connectors on both sides to move the arm. Jackhammer and hose reel: On the right side of the model I put a reel, a pneumatic connector, and a jackhammer. If you have a spare pneumatic tube you can connect the jackhammer to the vehicle. This setup is based on this real life variation of the JCB 3CX Compact. FUNCTIONS I had a lot of fun designing and playing with this model. Most importantly, this model satisfies my burning long-held desire to have a functional Technic backhoe. So if you're like me, you can gather the parts yourself and build this model too! According to Rebrickable, the total costs for the parts are around 150 EUR. I'd say it's a fair price for a 1100 piece Technic set with full of functions and playablity. I tried to minimize the use of rare parts so that it's easy to gather the parts for this. The only uncommon parts that are used are the 3x19 frame in yellow, which can be substituted with the more common 3x19 frame in black if you don't mind the color, and the Bionicle tooth in yellow, which will be available later in 2025 in the Chevrolet set. INSTRUCTION: https://reb.li/m/207516

Now that I've implemented the new gearing for the rotation, the model is in its most perfect form and I can finally move on to the next one yay. But before that I would like to share some design highlights, which are the solutions that I used in this set and felt very good about. Front Mudguard: The only solution that works is two #4 connectors, but they will be off center. Therefore I offset them with cranks and the cranks are held on the other side by thin 3x3 liftarms. Bullbar + number plate: This white piece keeps the bar in place and serves as the fake number plate. Sun Visor: A full liftarm is too bulky, while a half liftarm can't be secured through one point only. Fortunately I remember the existence of this plate, very useful. Steering: Since the truck is 9L long only, the distance between two steering connectors is only 5L. Therefore usually at this scale the steering is not done with a steering rack, and at first I didnt think it was possible either. Fortunately I discovered this way of connecting it. It sticks out a little bit but since it's black it's hidden quite well. Compact rear body: In the original model the rear body is 10 studs tall. When shrunk by a factor of 3/5 the rear body of the mini model should be 6 studs tall. But the best part is that I don't even use 6 studs for all the gearing and mechanisms. Only the side walls are 6 studs tall. The middle sections are confined in a 5 stud height. And there's nothing that sticks out below the floor either. Crane design: In the real life truck that 42128 is based on, the lights are mounted on the crane and should rotate with crane. In the official 42128, the lights are mounted behind the cabin instead. I managed to put the light on the crane and got the slanted design of the body too. That's all I want to share. Overall I'm very happy with and proud of this set.

As requested by some, here's a version without the crane and front counterweight: https://reb.li/m/205443 .

Thanks a lot! It's nice to have someone who shares the same experience Actually, I'm a fool... You were right. Earlier I said this. And I realized I have not actually tested the possibility of putting the 8z gear there instead. So I opened the Studio file and messed around. I moved the pair of 8z-8z gear to the bottom, and the 20z gear to the top, and voilla, it actually worked!

Haha thanks you're not alone in seeing it wrong Are you Tuco (Breaking Bad reference) Thanks a lot! Thank you for the praise! I do think this is my best mini model so far as well, at least in terms of look. It's very fortunate that the original contain dimensions that are easy to shrink by a factor of 3/5. Unfortunately on both sides there are supporting structures of the cabin. Very tight space in there. There are only two gears that can stay directly above the worm gear and don't interfere with the blue 20z gear: a 12z gear or a 8z gear. Space constraint is a huge headache for me when I design this part.

I just learned that my total sales on Rebrickable surpassed 1000 EUR today!

Thanks a lot for the support!

Crane rotation needs quite more force than normal, indeed, as it tils heavily towards the end. Normally when I put force into the knob and rotate it slowly there is no problem.

For this mini replica I managed to achieve a new level: The proportion is so accurate that at first look quite a number of people thought it's the original 42128!