[TC26] Arctic Walker

[Seasider]

So I wanted to do something different and with this competition Jim and Milan have given me the opportunity to try a build I’ve been longing to do for a while. So I let my brain go nuts !

Firstly I built this …

That soon progressed to this …

Which yesterday grew into this …

And then today evolved into this …

Which moves like this …

I’d seen a 3D printed robot on YouTube (Robothut) and I’ve made a Lego interpretation of the leg mechanism.

Things to do:

1. Optimise leg geometry

2. Determine best leg sequencing

3. Steering - Do I control each set of legs individually or do I make the body bend?

4. Refine chassis construction, make the body narrower - got a plan for this already.

5. Work out what the rest of the vehicle looks like!

6. Ponder what to do with other functions

 

Next update won’t be for a while as my parents are visiting next weekend.

[gyenesvi]

I really like walking mechanisms, and it already looks interesting, but are you sure it fits the vehicle category required by the contest rules? Or is that something you have confirmed with the jury already?

[LEGO Train 12 Volts]

Wow it looks like the movement of a spider's legs ...great start for your project!

[Seasider]

8 minutes ago, gyenesvi said:

I really like walking mechanisms, and it already looks interesting, but are you sure it fits the vehicle category required by the contest rules? Or is that something you have confirmed with the jury already?

To quote @Jim from the discussion thread …

On 10/26/2023 at 8:17 AM, Jim said:

Basically everything that moves and can be steered/controlled will qualify .

Edited November 5, 2023 by Seasider

[Maaboo the Witch]

When wheels and tracks fail, use legs! Looks cool, gonna follow this build.

[2GodBDGlory]

Looks unique and fun!

[MangaNOID]

I was also going to do a walker as per ‘empire strikes back’  arctic theme 😅 but luckily for me I won’t have time to build anything so complex to try and compete.

look forward to the finished build!

[Mikdun]

Neat!

[Davidz90]

Wow, this is super cool!

Edited November 6, 2023 by Davidz90

[howitzer]

22 hours ago, gyenesvi said:

I really like walking mechanisms, and it already looks interesting, but are you sure it fits the vehicle category required by the contest rules? Or is that something you have confirmed with the jury already?

Walking vehicles exist in real life, for example this tree harvester: https://blog.machinefinder.com/3255/john-deere-walking-harvester

Not that they're common, but I see no reason why walkers should be excluded from this contest.

I'll be watching this entry with interest, walkers are really hard to do well especially when no third party parts are allowed!

[Seasider]

Minor update from me, some evolution…

firstly a tweak of the leg geometry 

then I went digital to refine the chassis as it was too wide …

and also to properly mount the motors

 

So next it’s wait for some Bricklink / TLG orders and also have a think about bodywork

Edited November 19, 2023 by Seasider

[Thirdwigg]

Such a fun project. Keep it up...

[SaperPL]

The prototype looks a bit structurally messy, but the new design feels really solid in contrast to that. Can't wait to see it in action as well.

Are you planning to increase the speed of movement though between the motors placed in the middle and those axles with worm gears?

[Seasider]

On 11/20/2023 at 2:46 PM, Thirdwigg said:

Such a fun project. Keep it up...

Thanks, I trust/hope you’re got a model being built too?

2 hours ago, SaperPL said:

The prototype looks a bit structurally messy, but the new design feels really solid in contrast to that. Can't wait to see it in action as well.

Are you planning to increase the speed of movement though between the motors placed in the middle and those axles with worm gears?

Yes the first chassis was a mess, I often build like this to work out where I need connections and support and then refine as I go on. Version 2 of the chassis is 6 studs narrower and should be better in terms of solidity.

As to the gearing at the moment the new chassis will be effectively direct drive onto the axle with the worm gears. I wasn’t planning on trying to speed it up as I think this should be more of a crawler (literally) rather than a vehicle who’s legs move quickly.

Hope to physically build (at least some of) this revised chassis this weekend. Also been working on the body in the digital model.

[Thirdwigg]

On 11/22/2023 at 11:24 AM, Seasider said:

Thanks, I trust/hope you’re got a model being built too?

I hope to, but I need to put out some other fires first. Maybe over the holiday break.....

[Seasider]

A minor update from me …

Mk2 Chassis built …

And it looked good …

In fact it’s a CRACKING model … ARGH!

Put the problem down to here …

Where the large gear can lift away from the worm gear as it’s only attached via a frictionless 2L axle pin.

So …

Mk3 Chassis … where I sandwich the large gears and worm gear between 2 5x7 Frames.

Makes it 2 studs wider but I think I can work with that.

Hopefully more progress at the weekend, and another test if this has fixed the cracking of the gears. I’m hoping the motors will be able to cope with the weight!

[Seasider]

So this is how I held the large gear in place …

With both the large gear and worm gear held between 2 frames. This meant the position the legs are mounted on the body moved 2 studs up relative to the gears. So I gave it a “smooth” belly to remove some visual weight and get the best ground clearance I could.

And it works without any gear cracking

You don’t realise how relieved I was that this worked.

So time to do some bodywork which will be quite simple on this …

Sorry for the poor lighting on this.

Now I need to work out what the nose/cockpit looks like

[1gor]

Highly interesting idea, but I thought on thick layer of ice tracks are best solution for movement...it is very hard to make stability (not to get seasick) on such vehicle that uses mechanical legs. I admire your enthusiasm since you are "wheel" guy.

Cockpit / cab could be influenced by small submarine (or some space expedition vehicle) that picks samples from ground and has big curved "windshield".

Edited December 3, 2023 by 1gor

[Seasider]

So I’ve been having some very good build time on this and it’s almost complete.

First of all I played with the legs and their sequence. My model up to this point had legs 1&3 at 180 degrees on the large gear to legs 2&4. But as @1gor pointed out it rocked back and forth a lot.

I then tried each leg using the drive gear at 90deg to the next which turned out to be even worse.

It turned out the answer had been staring me in the face the whole time (as the model I used as inspiration from YouTube uses the pairings of inside and outside, so 1&4 and 2&3 with 180deg difference on the drive gear. It’s much smoother.

So what does the model look like …

I’ve got a cockpit I’m happy with …

Most of the electrics worked out …

And even done some finishing touches to borrow from the old Arctic theme (because by pure chance I bought an old technic set from a market and it actually had 3 inside the box, one being 8620 which gave me the figure and skis!)

But still some things to do …

1. Mount the linear actuator for the rear door. I’ve got the position sorted, just not mounted it yet.

2. Shorted the legs so they don’t stick above the joint. If you look you’ll see the leg design has changed where I’ve made the cranked liftarms to be the middle section, not the final section. This gave me better ground clearance but all the final beams are 2 studs too long at present.

3. Await a Bricklink order to correct some parts currently in the wrong colour.

4. Create some classic Arctic Technic stickers.

But a question … it there any way to make lights switch on/off using PF without just holding the switch in place?

 

Enjoy

[2GodBDGlory]

Looking good! Quite a unique model

18 minutes ago, Seasider said:

But a question … it there any way to make lights switch on/off using PF without just holding the switch in place?

Here's a couple options:
1. Use the train controller to keep them on. This would require you to use that controller for the other thing on that receiver as well, which might not be convenient

2. Mount a motor inside the body that flips a PF switch. That way, you can use the remote to flip the switch, and then leave it there. That would require a fair bit of complexity and weight, though
 

[Mikdun]

Looking good! 

Definitely one of the most extraordinary vehicles, and good looking too.

[msk6003]

On 12/11/2023 at 5:57 AM, 2GodBDGlory said:

2. Mount a motor inside the body that flips a PF switch. That way, you can use the remote to flip the switch, and then leave it there. That would require a fair bit of complexity and weight, though

This will work with similar but little different way.

[Seasider]

So I’m pretty much done.

thanks to @msk6003 I built this …

I added some bits to mean it can only moved the switch in one direction to stop me flicking the switch too far meaning the lights stay on.

 

Then I worked on mounting this and the tailgate mechanism. But the light mech was too long for the space I had left so as you’ll notice the IR Receivers have moved forward in the vehicle to free up some space.

This meant taking the whole thing apart to move the main drive motors 1 leg forward. Thankfully I build this in a modular fashion so it was easy to take apart and update.

And now it’s all back together and resting on a “work stand” I also made to help with assembly.

Just a few System pieces left to tidy a couple of areas and that’s it.

I’ve also been working on a Stud.io file to go with this, as I try to do with all my builds. But that’s missing the legs at the moment so no pictures at the moment from that.

Controller is quite easy …

Yellow Left = Left Legs

Black = Tailgate

Red = Lights

Yellow Right = Right Legs

 

Proper pics and video to come once I’ve added the system bits.

I’ll have to work out where to take them, we don’t get snow around Christmas here so I think it’ll indoor shots.

 

Edited December 18, 2023 by Seasider

[Bluehose]

On 12/10/2023 at 9:57 PM, 2GodBDGlory said:

Use the train controller to keep them on. This would require you to use that controller for the other thing on that receiver as well, which might not be convenient

Why would this be a matter ?

-#1 classic remote control, channel 1, you use lever right and left for two motors 

-#2 proportional train remote control, channel 2, you use only the left one for lights

-#3 classic remote control, channel 2, you use only the right lever for a motor

 

-Two receptors, channel 1 and 2

Edited December 19, 2023 by Bluehose

[MangaNOID]

20 hours ago, Seasider said:

I’ll have to work out where to take them, we don’t get snow around Christmas here 

Looks really good and I like the technical dedication for this walking but it’s probably good you can’t photo in snow as it might sink with no feet??