[TC25] Air Tech Claw Rig 8868

[lcvisser]

This was my all time favourite set as a kid (still is, maybe), so when TC25 was announced, I was determined to shrink this set. I was worried that someone else would choose this famous set as well, but when I started last night to plan the build, I was convinced there was no other build yet. I overlooked @howitzer's topic. I'm looking forward to see their build and see how our builds compare. Mine is sized about 56% of the original

Progress so far:

[SaperPL]

Wow, this is going to be interesting with multiple builds going down to this scale.

[lcvisser]

More progress:

It was a pain to connect the fake engine to the rear, and have the HOG steering in the same general area, but I managed. Rims, front bumper, etc. need to be white.

I'm not going to fit differentials and I think I will only make the two arm actuators pneumatic: I doubt I will get the slewing to fit inside the space I have, plus there'll be so many hoses... However, if @2GodBDGlory can manage it in the Arocs, then I need to step up my game too ;-)

 

[SaperPL]

Can you show more angles of the mechanism you got there?

Good luck with pneumatic, can't wait to see how it'll work.

[lcvisser]

I’ll try, but maybe it’ll be easier if I  make a quick stud.io model. 

[SaperPL]

13 minutes ago, lcvisser said:

I’ll try, but maybe it’ll be easier if I  make a quick stud.io model. 

I do recommend going back and forth between stud.io and physical model. Sometimes it's faster to figure out what you need to do, without physically disassembling what you already have, and also when you disassemble, having a point of reference in 3D, a backup of how it's supposed to go together, is good.

[Paul B Technic]

This is coming along really well.

[howitzer]

Looks great so far! It'll be interesting to compare our entries, I aim to keep all functionality and make them as close to the original as possible, which forces somewhat larger scale than you. I've been busy for the past few days and I'm itching to get back to the build, hopefully tomorrow I'll have something more to show...

[lcvisser]

Final progress after a weekend of building:

I've started also a digital model. I was trying to avoid it as my day job involves already too much screen time, but my fingers started to hurt ;-)

This is where I'm going to:

 

For @SaperPL: here is the underside, showing the steering mechanism. Was this what you were asking for? There's a pin that slides the construction with the thin liftarms left and right, which transfers to the steering arm. The blue pin that is barely showing in the steering arm slides in and out of the DBG pinhole-with-two-axle-connector to account for the parallelogram motion.

Larger versions of all images are on Bricksafe. 

[2GodBDGlory]

Looking nice! That is a real classic set, and those tires look very nice for it! I don't know if I've seen them used in Technic before, but they look handy!

[SaperPL]

1 hour ago, lcvisser said:

For @SaperPL: here is the underside, showing the steering mechanism. Was this what you were asking for? There's a pin that slides the construction with the thin liftarms left and right, which transfers to the steering arm. The blue pin that is barely showing in the steering arm slides in and out of the DBG pinhole-with-two-axle-connector to account for the parallelogram motion.

Thanks. I didn't understand what was happening there in the middle with that pass-through 20T gear, but now I get it, it was for steering there.

Also interesting approach to steering, It took me a moment to get what you're doing there. It's understandable though - no other way to pass another input for steering if you have engine above. Very clever approach for this scale.

[lcvisser]

Quick virtual update:

I redesigned the chassis entirely in order to fit in the drive shaft, routing of pneumatic hoses and improve general sturdiness. Also fixed some impossible builds. To do this weekend is to build it for real and see if it works out as intended.

I'm not too happy with the white connectors above the chairs holding the "exhaust": they're too obvious. Also undecided on what to do for HoG steering control: the 2x2 beacon is too big, but I don't yet have a good alternative. Suggestions welcome!

 

[lcvisser]

Solved exhaust issue. The HoG I'm still undecided, but for now I'm going with the "standard" 12z double bevel gear.

Actual build, in all its rainbow warrior glory, is also done:

I'm really happy with where this is going. Now the crane!

 

[lcvisser]

Done? What do you think?

 

[mpj]

I like the turret and the arm. And also pneumatic hoses placement doesn't look bad at all.

I feel that the bonnet on the truck is a little too long?

[lcvisser]

Thanks!

i agree that the hood is a bit long. Probably should be one stud shorter. But the front bumper can’t move any closer to the wheel or it would rub against it, so not sure how to achieve a shorter hood without an awkward gap between the hood and bumper. I still have time, I’ll think about it.

Edited July 10, 2023 by lcvisser
Good hood… stupid auto correct

[MangaNOID]

Hey this is looking good!

curious about the grabber as I just spent so many hours finishing mine for my crane and it looks similar in principle but yours looks very simpler. I can’t really see how it operates. Does it lock together? 
 

don’t worry I finished mine so Im not wanting to copy it, just really curious as the grabber busted my brain 🤪
 

[lcvisser]

3 hours ago, MangaNOID said:

curious about the grabber as I just spent so many hours finishing mine for my crane and it looks similar in principle but yours looks very simpler. I can’t really see how it operates. Does it lock together? 

 

Thanks!

 The grabber is just a 2x4 L-beam. On the “short leg” are the two axles with the grabber (3x3 thin lift arm), synchronized with 8z gears. Just above it is a third 8z on a friction pin to keep it open. The12z is a knob to operate it. 
 

 I doubt it will hold much weight, but the small pneumatic actuators can’t lift much anyway. I’ll make a “log” to test it. 

[lcvisser]

Final tinkering. I didn't manage to make the hood shorter in a way that was satisfactory, so I'm going to keep it like this:

 

I'm not convinced I am going to keep the trans-orange cone for steering, but I guess that it represents best the original.

While I wait for parts to come in, I'm building 8868. I don't have all the parts anymore (with space constraints one has to make choices...), so it is a virtual build... Don't they look good together?

 

Edited July 27, 2023 by lcvisser
Add render of big and small

[vascolp]

This looks very cool!

Maybe, in the front,  using white or LBG lights instead of transparent ones would look better?

[lcvisser]

Thanks @vascolp!

I started with white, as you may see in the first post. At some point I changed my mind, but maybe it is more faithful to the original indeed:

Still waiting for parts to come in... Hope everything arrives on time.

Edited July 27, 2023 by lcvisser

[lcvisser]

Finally. Parts arrived, rebuilding done, photo's, video. So much work ;-) But I'm happy with the end result:

If anyone is interested, I made instructions as a stepped .io file. Pneumatic hoses not included. I prepared a Rebrickable MOC with some additional info (click), but you can also find the .io model here (link to .io file). In my Bricksafe you can find some photo's to help with the routing of the hoses, if needed. There are also high-res photos.

I made some comparison renders too - I forgot from whom I go t the idea to make the original "trans clear" as a substitute for wire frame, but it looks cool. Thanks for the idea!

Edited August 12, 2023 by lcvisser
Added link to instructions

[Akassin]

You did a great job with this set! I especially like the crane boom. Even on the large scale of official sets it often doesn't look very good due to the large size of the pieces and their technical limitations. Your version looks very neat along with the operator's cab.

[lcvisser]

Thanks @Akassin! The boom took me way more effort than expected, even though it’s only a handful of pieces. The original is already quite slender and to be accurate the shrunken version should only be one module wide, but that is not feasible. But even only 2 wide  was a challenge, especially the mounting point for the second pneumatic cilinder was difficult to get right. And then the hoses… 

 

[Thirdwigg]

Well done. This turned out great, and the pneumatic tubes are well integrated.