Sign out

Mega Scout

#21

Mega Scout’s legs can be put closer together using the Multipod leg segments (the first three joints connected to the body) to swing the legs around towards the front. The legs can be kept facing forward at all times using the hip rotate of the biped leg (the fourth joint from the body). :smiley:

Each leg is 8DOF - three segments for the Multipod part and five segments for the biped part. :smiley: I won’t know if any modifications will be required for walking until I build it and start working on making it walk. I have many ideas on this already and these legs are very flexible.

I have already created four different configurations for the legs in my CAD software - three for the biped walking setup and one for the multipod walking setup (so far).

8-Dale

#22

8DOF…lol…you’re nuts.
:laughing:

#23

Ummm, no, I don’t think so, but I could be wrong. :stuck_out_tongue: I wasn’t sleeping when I designed most of the leg… It just didn’t have hip rotate in the first design, then I figured out how to do it. I finally think I understand the Scout leg design fully.

There is a place where I could add another joint… :smiley::smiley:

8-Dale

#24

I have decided how I am going to go about building Mega Scout. I am going to start with the 3" U channel and then work my way down both legs equally. Eventually I will get to the end of each leg. :smiley:

When I get the first three joints of each leg constructed, I could construct one more set with the same three joints and have a working quadraped. :smiley: I don’t know if I will do that or not, but it’s a possibility.

8-Dale

#25

I still think you’re nuts. :slight_smile:

That does sound like a great way to start it. That way you can see it slowly come together. I wish I had some SES brackets I could give you but I gave them all to Jester in our trade for his heli.

I can’t wait to see this.

#26

I am used to it, and I may be! :smiley: Most creative folks are often accused of similar… :stuck_out_tongue: Hee hee, Muahahahahahaa…

I can at least test parts of the legs as I build it, which will help as I will often have to wait until I can add more to it.

I’ll be happy to get those HS475’s which I will find use for on WALTER or Junior (My BRAT). :smiley:

Me too! :smiley:

8-Dale

#27

HS-475’s are packed up for you. I gave 8 of them to Jester in our trade but I saved the other 4 that I promised you. Just haven’t got around to shipping them yet. I’ll get it done this weekend and send you the info.

#28

Cool and thanks! :smiley:

I have identified at least two joints I will probably have to use HS-5955’s on for Mega Scout. It’s the 2nd and 3rd joints from the chassis. Those joints will take serious beating in many of the movements of the legs because they are keys to tilting from one leg to the other…

8-Dale

#29

Here are some updated pictures of Mega Scout and Mega Scout X2. I have changed the normal biped style walking stance to be a lower crouch. This will make a much better starting stance for forward stepping, since the foot can be moved forward easier without as much change in the over all height of the bot. I also have the first picture showing the multipod walking stance for Mega Scout X2, meaning it walks like a regular quadraped or hexapod would walk, with much additional height adjustment potential.

Mega Scout (New Biped Walking Stance)
http://www.thedynaplex.org/robotics/bipeds/megascout/img/megascout-front-new-biped-stance.jpg

Mega Scout X2 (New Upright Stance)
http://www.thedynaplex.org/robotics/bipeds/megascout/img/megascout-x2-upright-stance.jpg

Mega Scout X2 (Multi-Pod Stance)
http://www.thedynaplex.org/robotics/bipeds/megascout/img/megascout-x2-multipod-stance.jpg

I am calling this a multipod stance because these legs could, theoretically at least, be used on anything from a quadraped (pictured) on through an octapod (and would use two full SSC-32’s to controll the legs).

8-Dale

#30

I have been doing a lot of thinking about the leg design for Mega Scout and Mega Scout X2, and I have come up with a new design. This new leg is slightly smaller, a bit lighter, and still retains almost all the range of motion the current design has. In fact, the bit of range of motion lost with the new leg design would not be used anyway, so there is no real loss.

New leg (front):
http://www.thedynaplex.org/robotics/bipeds/megascout/img/hybrid-walker-leg2-left-front.jpg

New leg (side):
http://www.thedynaplex.org/robotics/bipeds/megascout/img/hybrid-walker-leg2-left-side.jpg

I’ve removed all the tubes, reoriented two servos, and replaced the ASB-10 long C brackets with ASB-9 short C brackets where I can.

These changes will:
Reduces the weight of the leg
Brings the leg a bit closer to the center of the robot
Strengthens the critical 2nd and 3rd lifting joints
Shortens the leg a bit.What do you all think?

8-Dale

#31

I have to say Alibre Design is a lot easier to use vs. Solid Works.

I have the Free version and it’s easy to learn. I have not spent the time
I need on it like I should.

#32

I have revised both legs to be a bit shorter, not quite so wide, and a bit closer to the body. I don’t think any loss of range of motion is going to be significant enough to make a difference for moving. This should be the last revision of the legs.

This is Mega Scout v2.0 in normal walking stance.

Front:
http://www.thedynaplex.org/robotics/bipeds/megascout/img/megascout-v2-front.jpg

Right Side:
http://www.thedynaplex.org/robotics/bipeds/megascout/img/megascout-v2-right-side.jpg

Back:
http://www.thedynaplex.org/robotics/bipeds/megascout/img/megascout-v2-back.jpg

Top:
http://www.thedynaplex.org/robotics/bipeds/megascout/img/megascout-v2-top.jpg

These changes also reduce the weight by removing the tubes that made Mega Scout stand taller and potentially over balance when walking. I’ve also replaced several ASB-10’s with ASB-09’s.

8-Dale

#33

looks better. 8)

#34

Thanks. I think this slightly smaller and narrower design will be much better and be easier to balance when taking steps. :smiley:

8-Dale

#35

I agree, the overall design may seem like overkill but I deffinately think its neccessary to provide complete control of balance over very rouch terraine. What you have done to this biped is bassically made a suspension system keeping the biped walking smoothly over rough terraine. Its a great improvement to any kind of biped leg design I have seen. Keep it up, I would like to see this design become a real robot.

#36

I agree. The tubed I had in the leg before made Mega Scout too unweildy and too tall.

I originally set out to design a leg that could walk any way I wanted it to - as a multipod or humanoid. I can indeed use the upper segmet of the leg (the multipod segment) as a suspension for the humanoid segment of the leg.

Thanks.

I didn’t set out to improve biped the leg design, but if that’s what I end up doing, so be it. :smiley:

Mega Scout will become a real robot. Version 2.o will be easier and less expensive to build as far as brackets go.

8-Dale

#37

Sounds good to me!

#38

How about a drawing showing the bot appropriately blanced on one foot as it would be when taking a step.

#39

Yes, it certainly is, and less than half the price for Alibre Design Expert (which I am purchasing). Alibre will let you pay in 12 installments - no credit checks.

You’ve seen what I have been able to do with Alibre Design… :smiley::smiley: I have not been using it that long - just a couple months to learn what I have learned so far without anything but the four training CDs.

8-Dale

#40

I’d like to do that, but my computer is not fast enough and doesn’t have enough memory to allow me to position the model the way I want to.

I would have Mega Scout go into a full crouch, lean towards the opposite leg, use the multipod mode to rotate the stepping leg forward, and then extend the biped segment to finish the step. This would allow a longer extension of the leg and therefore a longer step. Repeat with other leg, and there you have Mega Scout walking. :smiley::smiley: The key is for Mega Scout to get as low to the ground as possible before taking a step.

8-Dale