[MOC] LEGO Technic 8868 Air Tech Claw Rig MKII (2022)

[@BrickTechnology]

Amazing project. Love how you made the initial 1993 truck 10 times better.

[@McCatty_TECH]

Thank you!

[@andreasbenning]

I guess it's been nearly 30 years since I built the 8868 truck. Then I didn't build any Lego at all until I bought the Ghostbusters ambulance a little over a year ago, and since then I've become an AFOL. I'm in the process of building another Ghostbusters Cadillac as a regular hearse, and I aspire to come up with some more advanced mocs in the future. People like you really inspire me! Thanks for uploading! Greetings from Sweden

[@tristanwegner]

Wow such an impressively functional build. I especially love the pressure regulation system and the switches to manual! And so many controls remotely! And so compact and neat looking and a great presenting video.

[@poemes]

Absolutely amazing build so many cool mechanisms like the pneumatic pressure switch and the shock absorbers on the arm (i should really use those on my robot arms) and it all drives too, just amazing, looking forward to seeing more on this channel

[@McCatty_TECH]

Thank you for the kind words! After building the first few prototypes, I understood the "crashing boom" phenomenon that is typical with pneumatic crane arms. With the shock absorbers & hose configuration I was able to eliminate that effect, even with the switches fully open. That means the servos don't need proportional control, which lends itself well to 3rd party electronics. I'm happy with the way the pressure switch turned out. It's a neat little failsafe. Others include the use of rubber bands on the crane slew function to protect the motor at the range limits. Also, the drivetrain is set up in a way so that the motor will stall at failure instead of breaking any of the gears. All these considerations are meant to preserve the parts, increase playability, & reduce maintenance.

[@poemes]

@@McCatty_TECH you’ve thought of everything 😀

[@bami2]

Amazing design, really cool.

[@McCatty_TECH]

Thank you! Glad you like it 😊

[@pierreroblin8231]

Excellent upgrade of this famous lego set. Very great video and explaination, excellent job !

[@McCatty_TECH]

Thank you! Much appreciated 🙂

[@fabricationfun1509]

This the bomb !

[@levyroth]

This is a work of art and wonder 🎉

[@nolamccatty2713]

Love this!!❤️😊🤗💯

[@BatteryPoweredBricks]

Absolutely amazing! I do a little bit of everything when it comes to Lego but coming around to Lego RC. This is truly inspiring! How long would you say you've worked on this project? Everything looks so polished and well thought out it must have taken forever 😅

[@McCatty_TECH]

Thank you! This is one of the "ones that got away" for me & so I was really aiming to do it justice. I actually made an earlier version last year, but I really wanted to push the performance even further, especially for outdoor locomotion & heavy duty lifting applications. Admittedly I spent far too long on it. The design-build-test is the most fun part of any project. Doing instructions, imagery + video editing, not so much. That presentation element probably takes half the time.

[@BatteryPoweredBricks]

@@McCatty_TECH Yeah personally I have no desire to get into digital building / instructions. But it is much appreciated by the community. I really enjoy video editing (for the most part some videos take FOREVER), but I've never really done a video in the style that you've done. Honestly fantastic work on the video / presentation as well! I really think you've succeeded with doing the set justice, I love the shock absorbers in tandem with the pneumatics, a real stroke of genius!

[@OldCarsAreFun]

This is great, I just build the set from 1992 and wondered if there was an updated version. Where do you get the lego to design, try and test these builds?

[@McCatty_TECH]

During the entire design & testing stages, parts were sourced primarily from Bricklink.

[@Bric_workshop]

Nifty!

[@Pales27]

Amazing build! The pneumatics are really fluent! However the gap above the front wheel is huge (1-2 stud less could be better look) and this model maybe needs a little bit bigger wheels i think.

[@McCatty_TECH]

Thank you! Pneumatics are tricky to get right. Yes I agree, the gap is a touch bigger than I'd like. It blends in with the main body underneath the driver's cab which is shaped like that to cover the Pneumatic Servo Motors. That's the lowest I could get it 😔. At maximum suspension flex, there is a 2 stud clearance. However, it is sized for bigger wheels like you mentioned. I used RC4WD 70mm Dirt Grabber tires with custom inserts (0:07) & I think it is an overall nicer look. It might be worth experimenting with some panels to see if I can shape it a bit better. I wish more of them were available in black.

[@donmosetto1540]

Great MOC! Has anyone tried if the original wheels (part 4267) would also fit? The wheels in the moc are good but somewhat expensive.

[@McCatty_TECH]

Good question. I think they will work because they have the same pinned connections required for the planetary hubs. And of course they're virtually the same size. I've seen them used in the dual-wheel orientation as well. I dont have them on hand but I will use Studio to check if there are any interferences later today.

[@donmosetto1540]

@@McCatty_TECH Thank you very much 😀

[@McCatty_TECH]

@@donmosetto1540 I just did a prototype in Studio with collision turned on. Part 4266 (older rim) will fit over the 46490 planetary hubs. However, the concave side won't engage the pins because the center axle stem is too long, so it has to be flipped around. The end result is that the outer edge of the older wheel protrudes an additional 1.2 studs on each side. Let me know if this helps.

[@donmosetto1540]

@@McCatty_TECH not sure if I understand....can I use the old wheels or will they get stick when the wheels turn for example by steering?

[@McCatty_TECH]

@@donmosetto1540 yes, the old wheels will fit on the planetary hubs. They will just be a bit wider overall. I did another test where I replaced them in the Studio model & engaged the steering. I can confirm that they clear the fenders. The spacing at the back is pretty tight though - I'd say 2 or 3 mm between the wheel & the edge. This can be easily increased by replacing the 1 x 3 liftarm with a bionicle 1 x 3 tooth (41669) for example.

[@legohivemind]

Is there a way to change out the M motor for the rotation of the crane to a L motor?

[@McCatty_TECH]

There may be a way. The L Motor is 7L & there is enough room for an extra stud because of a cavity behind the Buggy Motor. Also, it is mounted from the front where the axle exits, so the attachment point would be the same. The Steering Motor cables (with the extension) rest on top, so there is some flexibility there. At the bottom, there is a bridge right underneath the Slew (M) Motor that connects the Air Tanks. This is done by using rigid hoses. Due to the extra space taken up by the L Motor, these may have to be sacrificed in favor of running straight hoses. There are mounting points on the 5 x 7 frames on each side to secure them if this method is used. Let me know if this helps. Great idea actually. If I do a partial tear-down at some point I may have a look at this.

[@legohivemind]

@@McCatty_TECH thank you for taking the time out of your day to look at my comment. I’m on book 3 of your instructions and honestly I love how complex but easy your model is to put together. And I appreciate you liking my idea.

[@McCatty_TECH]

@@legohivemind thanks for the kind words. I'm glad to hear that the build is coming along great. Would love to hear your thoughts on the performance once complete! And yes, in hindsight I'm certain the L Motor would work, & if anything it would make the turntable stronger too! Edit: I just did a quick check. There is a cross beam (11L I think) that would also have to go. It's not absolutely necessary. I just put it in for lateral bracing to hold together the 5 x 7 frames, but they are pinned in so many places that it should be fine.

[@BrickOil-dh8ri]

8868 на стеройдах