Project: Revell AT-AT Walker

[anamorphicWayne]

THE LEGS Part XIV


The Caps and Panels.

Being such misc parts, I found some of the caps quite challenging. The problem was how to mill the outer impression. I couldn't mill them while they were on the sheet because of the lack of clearance I had. And I prematurely cut them down too short for the clamps to hold on to. So, I had to mount them to the rotary table with screws via the inner impression and then putty the holes later. Milling each cap at a consistent depth was tricky. Overall, they didn't turn out too bad.


I milled the inner impression first by milling around the pivot pin and then shaved off the remaining core.


Pretty much I did this to all of the Caps. The Upper Leg and Body_Hip Joint and Knee Caps.


The Inner Knee Caps had to have channels for the Lower Leg Brackets. The Brackets were epoxy in position and bolts will eventually make them more secured.


The Outer Knee Caps will have 1/2 axles added to them.


The Upper Leg Caps will consist of two extra parts. The posts(right), which are added to the Upper Leg Cap and the axles(left), which run thru the Hip Plate into the Upper Leg.


The axles are epoxy to round disks and will be re-enforced with bolts.


Lastly, I milled two 3/16 channels on the inside of the Upper Leg Panels. These will line up with the Pistons.


More to Come.

 

[anamorphicWayne]

THE LEGS Part XV


The Pistons.



I'm using 3/16 square brass tubing and 5/32 brass rods for the Pistons and its Rails. Each square tube was cut to 23mm lengths and the rods to 45mm, which includes for the tapered ends.


I'd decided to mount the Rails into the Piston Channels by using pins. I filed off a bit to prep the Rails for drilling. The notches are about 11mm from the bottom. I added an extra millimeter or two so I have enough play when I file off the ends for the Knee Caps.


Next, I epoxy small pins into the holes.


The Rails will eventually be epoxy into the channels, once all the clearance issues have been worked out.

 

[anamorphicWayne]

THE LEGS


A Test Fitting.

Thanks so much for all your comments you guys. It's much appreciated.

Thought I share a test fitting with you guys, so you can get idea on how everything is coming together. It's still quite crude, but I'm surprised I got this far. I do have a lot more work to do on it. So, I'll try to update as much as I can.

Cheers,
AnamorphicWayne :rolleyes

 

[swmodelfan1977]

Wow! Wow! Wow! Impressive! Excellent work indeed.:cheers
I am redoing my drawing taking suggestions and planning how to construct it.:wacko
Plastruct STFS-4 (3.2x3.2) and 2mm Dia. rod were used for Piston of MPC AT-AT modification prototype. Might be bit over-scale but no other good choice in my environment.

 

[Junk Pilot]

I've always been fascinated by the leg mechanics and there are just no words to describe this. It's just incredible and I love it. Amazing.

THE LEGS


A Test Fitting.

Thanks so much for all your comments you guys. It's much appreciated.

Thought I share a test fitting with you guys, so you can get idea on how everything is coming together. It's still quite crude, but I'm surprised I got this far. I do have a lot more work to do on it. So, I'll try to update as much as I can.

Cheers,
AnamorphicWayne :rolleyes


View attachment 579621 View attachment 579622 View attachment 579623

 

[Sourdoh]

This is incredible. Let me get something straight, though ... This is a kit you're modifying, isn't it? Which single part are you planning to keep from the original kit? LOL!

 

[rbeach84]

I wish my modeling efforts were so "crude"!

R/ Robert

 

[anamorphicWayne]

Thanks guys.

This is incredible. Let me get something straight, though ... This is a kit you're modifying, isn't it? Which single part are you planning to keep from the original kit? LOL!

Well, my intentions were to use most of the parts, but as I went along I had to redo them. The only parts I'm using, so far, are the side walls of body, some of greeblies and the engines. Looking back, it was a waste of a model kit, but I didn't know how difficult it was going to be. Also, I could of easily made it a studio scale, but then it wouldn't of fit in my display case. LOL

 

[Sourdoh]

Well. I'm glad you went the route you did! It sure is a lot more interesting and informative than just watching someone do an out-of-the-box build!

 

[anamorphicWayne]

Well. I'm glad you went the route you did! It sure is a lot more interesting and informative than just watching someone do an out-of-the-box build!

Totally.

 

[swmodelfan1977]

Hi Wayne,

My progress is very slow. It is still in the middle of drawing as shown. And also, still wondering piston mechanism. I could not find any exact reference picture of mechanism as far as I reserch. I might be wrong and it would be somewhere. Attached picture is showing what I have done but not looking good as prototype:cry. However I am still wondering while looking at ILM photo. I am not sure how you are going to make it. This is just idle talk.

swmodlefan1977

 

[joberg]

Your work is stellar so far Wayne...I was wondering, looking at that ILM pic, if they used some kind of rubber bands to do that piston movement? You can by-pass that central hub easily by doing so. (just my two cents) Also, on the ILM pic, it seems that those square "pistons" were moved/attached behind the leg and not in front like in your mock-up.

 

[anamorphicWayne]

Hi Wayne,

My progress is very slow. It is still in the middle of drawing as shown. And also, still wondering piston mechanism. I could not find any exact reference picture of mechanism as far as I reserch. I might be wrong and it would be somewhere. Attached picture is showing what I have done but not looking good as prototype:cry. However I am still wondering while looking at ILM photo. I am not sure how you are going to make it. This is just idle talk.

swmodlefan1977

View attachment 584978View attachment 584979View attachment 584980

Thanks so much swmodelfan1977 for sharing your progress. I too, had trouble finding any info or pics on the cam/piston mechanism. I wouldn't be surprised it's on purpose. :confused

Slot B has a very short pin or tab, connected to the Hip Plate. But from what I get, it's no more than a guide track. Unless it has something to do with that 'rubber band'.

Your work is stellar so far Wayne...I was wondering, looking at that ILM pic, if they used some kind of rubber bands to do that piston movement? You can by-pass that central hub easily by doing so. (just my two cents) Also, on the ILM pic, it seems that those square "pistons" were moved/attached behind the leg and not in front like in your mock-up.

Thanks joberg. That so called 'rubber band' is connected to an 'off centered' hole at the base of the central hub. You can see the hole on the back of the Upper Leg.



It leads up and under the Upper Leg Cap, but to where???

As for the Pistons, I'll have them running behind a panel which weren't shown. Last summer, I did a crude mock up using a rubber band to see if it's possible to rotate the cam. It's hard to say if it'll work, but it does show promise.

 

[swmodelfan1977]

Hi Wayne,

Your mock up gave an assumption while reading comments on the train to come office .

Assumed as rubber band, means either giving tension or friction. Probably tension between leg and hip plate due to support whole body while making stop-mo adjustment but I am not stop-mo proffessional. However, backlash is always issue when designing gear mechanism. I thought even stop-mo model would be similar and requires something to avoid small movement while changing of pose. It means my assumption is that is not related to piston mechanism as of now. Oh I have to back office.

 

[anamorphicWayne]

It's quite possible the rubber bands add tension to the cam as it rotates.

 

[swmodelfan1977]

Yeah, possibly. Will study more deeply. ;-)

 

[joberg]

I like you pics with your rubber band display. What if (and keeping that half moon "wheel" near the hub) the square pieces, going up and down, had spring. That way, each time that half moon passes over one square piece, it springs down, and comes back up as soon as it's free again...while the same half moon is hitting the second square piece.
Maybe that half moon should have to "beaks"...a little bit like rotating the barrel of a gun.

 

[rbeach84]

I've got to watch the movie again; I can't seem to visualize the motion of the various parts. I do recall the 'steam-driven' feel to the whole thing, later triggered by that weird little romp with Will Smith, 'Wild, Wild West'.

R./ Robert

 

[joberg]

Or maybe it's just a matter of looking at the wheels of a steam locomotive

 

[anamorphicWayne]

I like you pics with your rubber band display. What if (and keeping that half moon "wheel" near the hub) the square pieces, going up and down, had spring. That way, each time that half moon passes over one square piece, it springs down, and comes back up as soon as it's free again...while the same half moon is hitting the second square piece.
Maybe that half moon should have to "beaks"...a little bit like rotating the barrel of a gun.

Are you talking about having the springs within the pistons, running along the rails?

Something like this?