Footwear for F-Toys 1:144 AT-AT printed (update 11/8/2009)


New Member
May 6, 2009
Ok, first real post here, and ofcourse like most recent projects it's about me trying to light small models.
I have to admit, the smallest one i lit was a 2.3 cm runabout (yes, correct, 23 mm), but that was a master i made and then a mold and clear copies cast with a led inside, not spectacular small electronics, but just a nifty thing to do.

My current testing ground is an F-Toys 1:144 AT-AT, it has a huge hull in comparison of the revell pocket kits i lit up so far, so i can do some fancy stuff here.
Its not realy a kit, but a candytoy, meaning it comes assembled (mostly) and prepainted.
I want to do more with these things, so i disassembled one (pretty hard to do it without damaging the parts too much, since it is glued together with CA).
Fortunately the chinese kids who build them only put glue on 1 stub usualy, eventhough the whole thing fits together without glue pretty tight.

Now it's a snapkit :)

My plan: add a red light behind the window in the head, make the 4 cannons fire randomly and independant and have the head swing from left to right and back randomly.
I also am going to run the power through the legs, and in such a way that i can disassemble it and reposition.
To do all that i need 1 Red led, 4 whites, some fibreoptic strand a tiny electromotor with gearbox or a microservo and a microcontroller and some passive components like resistors.

First i have to make some actuators for the feet to make it more accurate.
The F-toys doesn't have them and they would be perfect for conducting electricity if i make them out of brass wire and tubing.

Then i have to mill out trenches in the lower legs to run the wire through and put a thin brass (0.25 mm thick) washer on the inside of the knee joint and a hole in the foot.
Now the actuator will fit snugly in there.

To run power through the top leg, i need to dril a hole from the outside to the inside of the leg and a trench on the inside of the leg.
In that i can fit a 1 mm brass wire that i bent to fit in the groove of the kneejoint and in the trench on the hip joint.

The thin plates on the sides of the gearbox also need some brass rings and tubing to cunduct electricity through the hipjoint and the bottom into the hull.

On the gearbox itself i replaced the formost and rearmost stubs with brass tubes.

And here are 2 pictures of a test to see if the joints will conduct the electricity.
Next on the todo list is to make the mechanical part needed to make the head swing from left to right and visa versa.
I could use an electromotor with a concentric wheel or a microservo.
An electromotor would be the easiest since that only requires powering it for random periods to make teh head move.

A microservo would be neater, but requires some more advanced programming.
I never took the time to work out how these servo's work (i think they have a very small steppermotor inside and i never even took the time to understand how they work as well).
So now might be a good time to figure out how they work, what the difference is between a analog servo and a digital servo and how i can drive these things from a program in a microcontroller.
Maybe soomeone here can give me a crashcourse in servo's :)

To be continued

Update 20/5/2009

Stll working on the feet.
Since it's gonna be posable, i want to do something about the ugly holes at the base of the feet, so it's more accurate.
And i'm gonna make it mechanicaly work too, the base will move in and out of the foot and meanwhile the tips of the toes will move.
I've started on the inner workings of the feet.
It's gonna be a bit complicated with a spring etc., so i'll have to prototype the parts.
Here's what i've got so far ( this is watertight, so i can print it any time, some interested in F-toys aftermarket parts ? )
It's not ready yet, there's gonna be a moving part in that center indent but i haven't finished that yet.
The little bolcks on top are to position the baseplate incase you want to only add the baseplate with toes.

I also uploaded 2 avifiles, because i need some help.
I cannot see clearly how the toes on the feet work in conjunction with the moving baseplate.
So i quickly made 2 renders of the 2 ways it could work.
The second one makes the most sense to me, since it mimics the way the feet of a running bird like an ostrich or the feet of a raptor work(ed).
And it also makes sense as a way to dampen the shocks when the feet stomp down
You might have to download them, since i i only use storage space, no website with a player yet.
They are 1.1 Mb each

I also started writing the programm for the leds and the moving head.
It's gonna be a cheap PIC, i only need 6 outputs so an Arduino or a PIC16F873 would be overdoing it

Update 11/8/2009

Today i received some printed parts (4 sets total), i quickly assembled one.
so here's how it looks for real,(the filenames are a pun :) )
the parts:
tucked in a foot:
Just for size:
this one is not cleaned up and painted, but it shows what it's all about.
Oh, i haven't put the spring in yet, because i haven't found the right size yet :)
Re: I'm into lighting small stuff lately: F-Toys 1:144 AT-AT

Impressive work there, don't think i've seen anyone do so much to something so small.
Re: I'm into lighting small stuff lately: F-Toys 1:144 AT-AT

Hey Kitty! Welcome to the forums. That looks really great already. I am always amazed at how small things can go in scale modeling. :D
Re: I'm into lighting small stuff lately: F-Toys 1:144 AT-AT

Hi Kitty,
Now that's cool! 8)
Really nice job your doing can't wait to see the next stage!!

Re: I'm into lighting small stuff lately: F-Toys 1:144 AT-AT

I made a mistake, forgot to put in the links to the test pictures.
Corrected now.
Re: I'm into lighting small stuff lately: F-Toys 1:144 AT-AT

That is COOL.
Re: A little more work done on the F-Toys 1:144 AT-AT (update 20/5/2009)

A little update added.
I'm gonna prototype a few parts (again).
I just love the fact that you can basicaly dream up anything at home and have it sent to you :)
Re: A little more work done on the F-Toys 1:144 AT-AT (update 20/5/2009)

Wow that's really cool. I am really looking forward to see the final parts then and compare them to the renderings.
Re: A little more work done on the F-Toys 1:144 AT-AT (update 11/8/2009)

i ammended the first post with pictures of the printed thing
8) Those parts are fabulously tiny. You're one patient individual.

What kind of additive fabrication process are you parts made by? Was there a long lead time or cost for getting them printed?
Those parts were printed on an Objet, in a acylic based photopolymer.
The method that printer uses is PolyJet Matrix™ Technology.
After i designed the thingies.i had to make it watertight, because i actualy designed it in a CGI program (solid works etc are to expensive for my budget)
I had it printed at Shapeways .com and in this particular material it costs about $ 2.80 per cc (that's including shipment).
I worked from a sequence of that foot just before it squashed a snowspeeder and the actual measurements of the F-Toys 1:144 AT-AT.
So i figured out how to actualy have the base control the movement of the toes and at the same time have that middle piece descend into the base.
In fact the middle piece is stationary and the base slides up and down around it and pulls the toes down or pushes them up.
The rest was just a lot of work making it watertight because of the weird curves.
after that was done i uploaded it to Shapeways and they print and ship it within 10 days after you payed for your order.
(Usualy it takes a week for my stuff to get printed after ordering).

BTW anyone who wants them could order them from shapeways too.
As soon as the material restictions on the shop work again, because this only works for their white detail , because of the high resolution, if you print it in the cheaper matrial it's not detailed.
They are up for sale now at shapeways if you want them

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