[MOC] Forklift 42128 B-Model

[Mr Jos]

As soon as I saw the new set coming out, 42128 Heavy-Duty Tow Truck, I knew I wanted it. For his pneumatic cylinders and valves it was something I already wanted a long time, but they were to expensive (1x11 @50€/piece).

My initial plan was to make something with my EV3 bricks, and program movements with the cylinders as in MOC Perforating Press. But I thought, I'll give an alternate build a try.

I came up with this forklift with many functions. As cylinders have a fixed size, it was impossible to make the front end (mast with forks) bigger, so had to keep the forklift itselve in scale with it small.

The start, after breaking down the A model, thankfully had some bins left over as I normally only build with LBG/Yellow/Black.

I tried to make a triple stage mast to get more height, as 2 sets of cylinders only extend 2x6 studs, now it goes 18 studs high without tilting.

Meanwhile making the cabin with all functions+leftover pneumatic hose inside whilst keeping the floor low wasn't easy.

The instructions (Rebrickable) also were not easy as Stud.io is not a good tool for routing the pneumatic lines, and string doesn't even exist. The smaller ones I did manage to make. Here a few examples of how I kept the complete PDF at 101pages.

Might make some renderings later with Stud.io but my computer is getting old (~10years) and it goes sloooow.

 

I hope you like my first B Model for a Technic set. No idea if I will ever make some again, depends on feedback I will get. If you like it, leave a message, if you don't like it, certainly leave a message as well so I know what can be improved, or what not to do.

Edited August 9, 2021 by Mr Jos
Added HD rendering with white background

[Mr Jos]

First HD rendering is in, it's sooo hard to get hoses connected 100% in the middle with Studio..

[Pattspatt]

Very cool! I’ve always been interested in trying to MOC a proper pneumatic forklift. Your parts are well-chosen here; looks and functions are great, especially for a B-model. I like how you’ve increased the mast extension using the rope. I wonder if the mast extension could be even more increased, if the same string were looped a couple more times on a few more rollers - including one at the base of the mast section, I think. Of course, that would require a serious rebuild of the mast, but I guess real-life masts are fairly modular 

[Mr Jos]

1 hour ago, Pattspatt said:

Very cool! I’ve always been interested in trying to MOC a proper pneumatic forklift. Your parts are well-chosen here; looks and functions are great, especially for a B-model. I like how you’ve increased the mast extension using the rope. I wonder if the mast extension could be even more increased, if the same string were looped a couple more times on a few more rollers - including one at the base of the mast section, I think. Of course, that would require a serious rebuild of the mast, but I guess real-life masts are fairly modular 

Thanks, the mast can be taken out easily modified, just the 4 hinge points need to stay the same. The only problem is the pneumatic connections, in real forklifts pneumatic lines are small compared to the mast. In lego they are huge, and cant make short 90° bends. This makes that you can't brace the mast easily as these lines move everywhere in front of.

Second problem to this set making it hard to get a bigger then 18stud height difference for the forks; There are no long axles to make guides. Plenty of 9 long, but only 2x 10L axle, where one is used in the motor already.. No 11L/12L. Take into account that you need to brace a 9L axle at both ends and you only have 7L left, then your guidepoint removes 1more and there you have my 6L movement (3x). That is also what the long cylinders move 6L. So unless you go to a 4 stage mast you won't be able to get higher.

For reference, here are some of the forklifts I have driven this year, this one with a 3stage mast. You can clearly see that the real cylinders extend waaaay more compared to their size(thickness). Lego cylinders should be 1x30 instead of 1x11.

The model I made is better to be compared with this big boy.

I still want to make one like this next one, but the extension is here increased by the chain looping over the cylinder, and this set doesn't have any (I have 1200 in stock, but can't call it a B model then). But I do plan to make a bigger forklift, but then freestyle with all my elements.

Edited August 10, 2021 by Mr Jos

[Pattspatt]

9 minutes ago, Mr Jos said:

The only problem is the pneumatic connections, in real forklifts pneumatic lines are small compared to the mast. In lego they are huge, and cant make short 90° bends. This makes that you can't brace the mast easily as these lines move everywhere in front of.

 Second problem to this set making it hard to get a bigger then 18stud height difference for the forks; There are no long axles to make guides. Plenty of 9 long, but only 2x 10L axle, where one is used in the motor already.. No 11L/12L. Take into account that you need to brace a 9L axle at both ends and you only have 7L left, then your guidepoint removes 1more and there you have my 6L movement (3x). That is also what the long cylinders move 6L. So unless you go to a 4 stage mast you won't be able to get higher.

Not sure what can be done about that first problem, especially for the free lift cylinder. But for the second problem, I’ve had success using beams as the guide. (My forklift is posted on here somewhere). My mast design was heavily inspired by set 8416, although I did extend its overall reach and made it all connected/activated by a single string. There’s certainly some slop when the mast is fully extended, but it’s good enough for me. This beam-guide solution doesn’t scale easily for a many-stage mast, but 8416 suggests a lot of creative ways around this.

[Mr Jos]

33 minutes ago, Pattspatt said:

Not sure what can be done about that first problem, especially for the free lift cylinder. But for the second problem, I’ve had success using beams as the guide. (My forklift is posted on here somewhere). My mast design was heavily inspired by set 8416, although I did extend its overall reach and made it all connected/activated by a single string. There’s certainly some slop when the mast is fully extended, but it’s good enough for me. This beam-guide solution doesn’t scale easily for a many-stage mast, but 8416 suggests a lot of creative ways around this.

Well that's the difference with 8416, it uses gear racks as I mentioned before, you can make them as long as you want. In that set it's 2stages, one looong gear rack second with the string. With pneumatics you're limited to 6L extension for the cilinder. Maybe I'll give it a try later to make a bigger one, but as you said beam guides are good for 1-2stages max, then it gets really big. And the bigger/heavyer, the more chance it will grind to a stop by the pivoting weight. I had this problem in my High Bay Crane MOC. It has a really long (can scale up easily) beam guide allowing it to go up in 1stage. The forks for taking pallets is 2stage, and really big/heavy because it uses brick-stacking as guides + chains. It is pulled up with a string, down is gravity doing its job. But without a good beam-stack it will just stop midway, string still loosening, and bam crash.

Here it should be possible to see these stages (if the video starts where I want it should @90sec)

 

Edited August 10, 2021 by Mr Jos

[Pattspatt]

4 hours ago, Mr Jos said:

I had this problem in my High Bay Crane MOC. It has a really long (can scale up easily) beam guide allowing it to go up in 1stage. The forks for taking pallets is 2stage, and really big/heavy because it uses brick-stacking as guides + chains. It is pulled up with a string, down is gravity doing its job. But without a good beam-stack it will just stop midway, string still loosening, and bam crash.

Very cool video! Satisfyingly smooth operation. 
 

For me, 8416 inspired a few creative ways to do beam guiding, without needing a gear rack - here are some screenshots from my forklift MOC (ForelockMocs is to thank for the great instructions). I bet the setup below could be modified easily enough to fit one more stage within the same dimensions. Might add to my list of projects 

[Mr Jos]

For that mast a 1x30 pneumatic cylinder I mentioned before would be awesome to go with the 2x15 liftarms in series.  

I'm nearly finished with my C-Model, it's just a small fairground attraction, but I made it just to try some special technics with the turntable from the set combined with the 1x11 cylinders. Mechanically finished, it works, no idea if I will make instructions, depends on feedback, don't want to waste time on it to much. Tomorrow I want to add one of my EV3's with 2 motors to make it work like in a real fair just for fun.

[Pattspatt]

1 hour ago, Mr Jos said:

I'm nearly finished with my C-Model, it's just a small fairground attraction, but I made it just to try some special technics with the turntable from the set combined with the 1x11 cylinders.

Sounds cool, looking forward to it!

1 hour ago, Mr Jos said:

For that mast a 1x30 pneumatic cylinder I mentioned before would be awesome to go with the 2x15 liftarms in series. 

A guy can dream…