Introducing the STALKER! (project ended)

Hi Innerbreed,

There are a few different ways to get the legs to the position like in your drawing. But I doubt that changing the init position isn’t really what you want. Looking at the picture I think you want to create a start position for walking. It’s a good thing when you start working on the gait but at the end you want to start (and change) the gait dynamic. This way you don’t need to step in position first and then start to walk. This even makes it possible to change direction while walking.

Don’t underestimate it; this was one of the hardest things to do. I suggest you use the XXGaitPos variables to get the legs in the correct position so you get the gait right. Check one of my first vids where I did some walking tests. At 0:30 You will see that I place the legs in the init position first, then lower all legs and start walking.

I also saw Zenta’s reaction in the code topic. This defiantly is a great way to change the init positions without the legs snapping in to position. But if you only gonna use it for tests to get the gait started I should lift the bot when the legs snap. And just focus on the gait for now and get a dynamic starting position in the future. :wink:

I hope this gets you starting.

Xan

After a few weeks of thoughts, i “you could say” give in 'and Rebuilt the stalker!

i started thinking about Chassis designs and came up with a few but nothing that suited it.

anyway i started looking back at some of the other ways id designed the chassis in the past…

Remember this:
http://i531.photobucket.com/albums/dd355/innerbreed/Contructone-1.jpg

Well iv taken the SES Chassis construct and replaced the legs with the current ones from Stalker V1.0.

i remember from the old design that the femur couldnt rise up as much due to the “C” bracket for the Coxa, so i had to mod the bracket for that extra room:
http://i531.photobucket.com/albums/dd355/innerbreed/100_1236.jpg

All is not lost from SV1.0. i have also used the Chassis (upsidedown)
as seen here:
http://i531.photobucket.com/albums/dd355/innerbreed/100_1232.jpghttp://i531.photobucket.com/albums/dd355/innerbreed/100_1235.jpg
this gives me more area to add parts.

With SV2 the 9v battery clips have been moved to each side of the inverted chassis, giving better weight distribution.

Although personally i feel the make over doesnt look as good, im still happy with the result “of a two hour rebuild”! once i get more time on it i will hopfully tidy up the wiring and loose ends. :wink:
http://i531.photobucket.com/albums/dd355/innerbreed/100_1238-1.jpg
http://i531.photobucket.com/albums/dd355/innerbreed/100_1239-1.jpg

Yes i got beaten by the tilted coxa design but SV2 has a stronger configuration and a better chance of walking! :smiley:
*
all thoughts welcome:…*

Another improvement!

You are getting there :slight_smile:

I think the latest design you have there looks more rigid. That one design with the bent 45° bracket looked very “springy”.

The evoloution of robotics 8)

To make the new design look similar to the older design, you could flip the hip servos 180° so that the servo horn is on top instead of the bottom. Or leave the servos the way they are and just flip the “C” brackets, then reattach the legs. The body would then be lower like the first design. Unless having the body lower causes problems with the IK, you could look about trying that configuration.

I like this. It’s a relatively easy mod. Nice idea!

http://i531.photobucket.com/albums/dd355/innerbreed/100_1236.jpg

On the PC boards. You may be able to reduce the height of the stack by turning the SSC-32 over. Then you can stack the Bot Board on it with a 1/4" spacer. There should be ample room for the wires with the “H” design of the carrier. You may need to flip it so the DB9 is facing the away from the Sharp sensor.

http://i531.photobucket.com/albums/dd355/innerbreed/100_1235.jpg

Nice, as good as the old design, except for the towering electronics. :smiley: If you can reduce the stack of electronics, it would look perfect.

You also seems to have endless supply of SES bracket, how many did you actually bought?

Hi,

This design are going to make the leg stronger, espescially when the coxa servo are far from its center position. To be honest I liked the previous design a little better, but your new design looked great too and you did a great job making Stalker look similar to what you want. I also liked the detail Jim pointed out with the brackets! A smart and easy mod.

I’m sorry for not beeing able to help you out with the IK. Good thing the IK isn’t any trouble anymore though. :wink:

hi guys, thanks for your comments.

very good idea i will try this to see how it looks. thanks for the idea.
i wouldnt have thought it would be a problem for the ik and if anything having low body would help with the COG. :wink:

yeah i actually went to do this but am going to order your carrier to do
this with. the one i made didnt really give enough room for the wires. so you’ve sold another one there! :wink:

i have plenty of SES. collected over the years. iv got enough to build a hexapod completly out of SES plus a few other parts but not as much as jim! :laughing:

http://i531.photobucket.com/albums/dd355/innerbreed/Ant1-1.jpg

thanks, i wouldnt worry bout that, im happy with it anyway and my be sometime in the futre we can work on a robot with tilted servos for experiments or so. :wink:

thanks for your help on this anyway.
**
thanks guys.**

update:

i have flipped the SSC b2b with the ABB reducing the stack. but i have also used the old Chassis plate again on the top.
here includes:
*PS2 receiver,
ABB 9v clip,
SSC 9v clip,
servo power switch,
head directional servo.
*

http://i531.photobucket.com/albums/dd355/innerbreed/100_1305.jpg
http://i531.photobucket.com/albums/dd355/innerbreed/100_1306.jpg
http://i531.photobucket.com/albums/dd355/innerbreed/100_1302.jpg

the poses:>
http://i531.photobucket.com/albums/dd355/innerbreed/100_1300.jpg
http://i531.photobucket.com/albums/dd355/innerbreed/100_1301.jpg
http://i531.photobucket.com/albums/dd355/innerbreed/100_1303.jpg
http://i531.photobucket.com/albums/dd355/innerbreed/100_1304.jpg
i have kept the Leg config the same.

SWEET! :open_mouth:

thanks jim. i will update my contest page soon.

Great pics and modifications!

btw, whats the total weight including all batteries?

i will borrow some scales and get the total weight.
i would think its about 4-5lb but i will check this! :arrow_right:

Lookn’ great!

Outdoor pics really look nice. So much better then indoor lighting.

Can you climb that flagstone pile yet?

Alan KM6VV

Did you ever try flipping the C bracket to see if it will lower the COG?

http://i531.photobucket.com/albums/dd355/innerbreed/100_1236.jpg

i havent been able to get it walking yet due to a problem either with my atom or connections. im workingon this.

i did on one leg to see how it would look and cosmeticaly it didnt look right. the body looked to low. may think about putting it on the face of the “C” bracket but only once iv sorted my small problem.

lynxmotion.net/phpbb/viewtopic.php?t=5205

Any progress man? You were one of my inspirations and I’m really excited to see how it’s going.

hi sorry for the late reply.
thanks for your comment. :wink:

here is the latest picture:
http://i531.photobucket.com/albums/dd355/innerbreed/100_1300.jpg

you will see there had be a few altarations to the design.
you can find the latest info on the contest page:

lynxmotion.net/phpbb/viewtopic.php?t=5047

Hello. I agree that this project is excellent.