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 Technic / 12400
    Re: SSClagorpion —Kevin L. Clague
   (...) Yes. (...) No. (...) No (...) No. Ignoring side walking for a moment..... 1) One motor to turn a single switch on/off. This allows or prevents walking. 2) One motor to flip 8 switches. This one controls walking vs. turning. 3) One motor to (...) (21 years ago, 14-Apr-04, to lugnet.technic)
   
        Re: SSClagorpion —Steve Hassenplug
   (...) That was my second choice. Ok, three motors. If it can be worked out, we COULD combine #1 and #3, right? Leaving: 1) Function (walk/turn) 2) Direction (forward/backward/stop) I assume both of these groups are controlled only by motors, and at (...) (21 years ago, 14-Apr-04, to lugnet.technic)
   
        Re: SSClagorpion —Kevin L. Clague
     (...) Nope, but we could just eliminate #1 by just turning of the compressors. (...) It is still on the list, I was just leaving it out of the equation for a moment. (...) Yes, slow, more pressure, or more force. Shall I assume four pistons per leg? (...) (21 years ago, 14-Apr-04, to lugnet.technic)
    
         Re: SSClagorpion —Steve Hassenplug
      (...) That's up to you. I'd like to see it move as fast as possible, but I think even if we make it as small as possible, it's going to weigh at least 10 pounds. 3 or 4 pounds will be the RCXs, battey box, Spybot, and motors. So, what will it take (...) (21 years ago, 15-Apr-04, to lugnet.technic)
     
          Re: SSClagorpion —Kevin L. Clague
      (...) Hmmmm.... interesting question. I don't know much pneumatic theory, but..... Pressure is in pounds per square inch. So if we know the area of the face of a piston, and we know the pressure we can determine how many pounds a single piston can (...) (21 years ago, 15-Apr-04, to lugnet.technic)
     
          Re: SSClagorpion —Kevin L. Clague
      (...) Mark Riley was nice enought to point out the errors in my math. The area of the piston care is pi * r^2 = 0.2 Four times that is 0.8. So the minimal pressure needed is 10 pounds / 0.8 square inches or, 12.5 pounds per square inch. Still well (...) (21 years ago, 15-Apr-04, to lugnet.technic)
     
          Re: SSClagorpion —Steve Hassenplug
       (...) ... (...) With twice the pistons, the pressure is not as great, but the volume of air would be doubled, right? Using logic, not physics, I think once the pressure is built up (to 13 psi) the compressor may have to do less work to keep it (...) (21 years ago, 15-Apr-04, to lugnet.technic)
      
           Re: SSClagorpion —Kevin L. Clague
       (...) <snip> (...) Well, I know of situations where LEGO has asked some people to recreate their MOCs for them. You know you have arrived if that happens. (...) Kevin (21 years ago, 15-Apr-04, to lugnet.technic)
     
          Re: SSClagorpion —Mark Bellis
      (...) A few things spring to mind about this: 1. I usually run robots from a car tyre air compressor at 25PSI. This gives good performance with 1-2 large cylinders moving at a time. Using 6 large pump cylinders as the air source, performance is half (...) (21 years ago, 15-Apr-04, to lugnet.technic)
     
          Re: SSClagorpion —Steve Hassenplug
      (...) That makes sense, but you may want to take a look at the video of Kevin's walkers: (URL) you see, at the end of each stride, all four legs are at the bottom of their travel. So while it is true that half the legs will have to support all the (...) (21 years ago, 16-Apr-04, to lugnet.technic)
     
          Re: SSClagorpion —Kevin L. Clague
      (...) Funny! My presentation at Brickest (classic?) was named Pneumatic Magic. When I started on quad242 I thought the cool thing was going to be the ability to make it modify its behavior to go backwards and turn, but the hardest part was the "no (...) (21 years ago, 16-Apr-04, to lugnet.technic)
     
          Re: SSClagorpion —Mark Bellis
      (...) I can see the good sense in putting the hip switches on their own sets of levers, as your pics show. That way, the force required for them and for the legs is independent, so there's no extra load on the switches. I am used to mounting the (...) (21 years ago, 16-Apr-04, to lugnet.technic)
    
         Re: SSClagorpion —Steve Hassenplug
     (...) Ok, so what's required for walking sideways? One switch (= single set of switches, all activated at once) to switch from forward/back/turn to side-to-side? I'm sure that comes to about 16 reverser switches, or something. :) I just happened to (...) (21 years ago, 19-Apr-04, to lugnet.technic)
    
         Re: SSClagorpion —Kevin L. Clague
      (...) It is my belief that sideways walking will require a third degree of articulation in the leg/hip structure. It will cause the legs to swing towards and away from the body. By replacing the forward/backward part of the leg sweep with the side (...) (21 years ago, 19-Apr-04, to lugnet.technic)
     
          Re: SSClagorpion —Steve Hassenplug
      (...) Ok, we [plan to] have a sensor on the front foot, and can detect when that is down. So, no more sensors are required. So you said, the forward/backward must be changed while the feet are in the air. We've been thinking of having a touch sensor (...) (21 years ago, 19-Apr-04, to lugnet.technic)
     
          Re: SSClagorpion —Kevin L. Clague
       (...) Actualy we need to sense when it is *up*. (...) As soon as you figure out that a foot is up, you can reverse directions. I'll have to study the state sequence, because there are two non-weight bearing pistons that control the feet, so it might (...) (21 years ago, 19-Apr-04, to lugnet.technic)
      
           Re: SSClagorpion —Steve Hassenplug
       (...) Is *up* the same as "not down"? I was thinking it was, but that may not be the case. (...) This sounds like we can NOT do the table edge detection stuff, using it's feet. Imagine you're crawling around on your hands and knees, with your eyes (...) (21 years ago, 19-Apr-04, to lugnet.technic)
      
           Re: SSClagorpion —Kevin L. Clague
        (...) I think that you are right, that they are the same thing. (...) Hmmm.... We would need to know two things to determine we'd hit the edge of the table. 1. The foot is down as far as it will go. 2. The down foot is not touching anything. We (...) (21 years ago, 20-Apr-04, to lugnet.technic)
       
            Re: SSClagorpion —Steve Hassenplug
        (...) Right. That's listed somewhere in my prior ramblings. It should work fine with 2 inputs (one for each foot) (...) ... (...) We may need to figure something out, here. I think it WILL be a problem. At any given time, he will (could) have only (...) (21 years ago, 20-Apr-04, to lugnet.technic)
       
            Re: SSClagorpion —Kevin L. Clague
        (...) OK. You are going to put two touch sensors on one port? I thought you needed to know that the leg is fully extended, but not touching. How will you do that with one sensor port? (...) You are right, he needs to balance on the three feet that (...) (21 years ago, 20-Apr-04, to lugnet.technic)
       
            Re: SSClagorpion —Brian Davis
         (...) I can think of two was: use two touch sensors, and be able to read the state of both of them (you can do this with a 3rd party multiplex, or cybermaster sensors (which are kinda rare... right, Steve?), or use touch sensors stacked with (...) (21 years ago, 20-Apr-04, to lugnet.technic)
        
             Re: SSClagorpion —Steve Hassenplug
         (...) Again, the main goal is to know when the leg is extended, and the foot isn't touching the ground. So, you can mount the foot sensor so it's normally closed (pressed) except when the foot is on the ground and mount the leg sensor so it is (...) (21 years ago, 20-Apr-04, to lugnet.technic)
       
            Re: SSClagorpion —Steve Hassenplug
        (...) There are a couple ways that come to mind. If you don't want to know the details, skip ahead... We want to know when the leg is extended, and the foot is not touching the ground. There will be four possible states: 1) Leg up, foot not touching (...) (21 years ago, 20-Apr-04, to lugnet.technic)
       
            Re: SSClagorpion —Kevin L. Clague
         In lugnet.technic, Steve Hassenplug wrote: <snip> (...) Nope. The sequence is: 1. All feet down. 2. Lift one foot group 3. Sweep legs 4. put feet down 5. Lift other foot group 6. Sweep legs So it does not need to walk forward to lift the feet. (...) (...) (21 years ago, 20-Apr-04, to lugnet.technic)
        
             Re: SSClagorpion —Kevin L. Clague
          In lugnet.technic, Kevin L. Clague wrote: <snip> (...) Oops: B expand = ~C & ~D & E & F (...) Kevin (21 years ago, 21-Apr-04, to lugnet.technic)
        
             Re: SSClagorpion —Steve Hassenplug
          (...) I keep thinking about a rotary type walker, where the feet more or less go in a circle and the body is always moving forward. Please forgive me. :) So, when it lifts one leg group, and someone switches it into reverse, will it put those legs (...) (21 years ago, 21-Apr-04, to lugnet.technic)
         
              Re: SSClagorpion —Kevin L. Clague
          (...) Nope. It will force the legs to the correct position for walking backwards, and then drop the feet. Kevin (21 years ago, 21-Apr-04, to lugnet.technic)
         
              Re: SSClagorpion —Steve Hassenplug
          (...) I could be wrong (missing something) but I think if the switch is flipped immediatly after they raise up, then the legs are in the correct position. If you're walking forward, and switch to reverse right as your foot comes off the ground, you (...) (21 years ago, 21-Apr-04, to lugnet.technic)
         
              Re: SSClagorpion —Kevin L. Clague
          (...) Probably not. Kevin (...) (21 years ago, 21-Apr-04, to lugnet.technic)
        
             Re: SSClagorpion —Eric Sophie
         (...) I'm back I'm back. What can I do? I want to build something. I'm gonna make a concept moc moc up. Pun intended. e (21 years ago, 21-Apr-04, to lugnet.technic)
        
             Re: SSClagorpion —Benton Jackson
         (...) MOC-up! I love it! (21 years ago, 21-Apr-04, to lugnet.technic)
       
            Re: SSClagorpion —Eric Sophie
        (...) Ahem, (...) So we can incorporate the tail's funtionality and weight to help aid the robot by swinging or uncurling the tail so it faces away from the body and is extended back. This shifts the center of gravity away from the front of the (...) (21 years ago, 21-Apr-04, to lugnet.technic)
      
           Re: SSClagorpion —Eric Sophie
       (...) Ahh now we are getting somewhere. (...) Hmmm, indeed, or perhaps if we monitor the time it takes for a Leg to hit the ground and then install a logic command that will take action if the leg does not hit the ground in a predetermined amount of (...) (21 years ago, 21-Apr-04, to lugnet.technic)
      
           Re: SSClagorpion —Steve Hassenplug
       (...) Detecting the table edge is not the problem. We can do that with a sensor in the hip/leg in addition to one in the foot. Then, when the leg is extended, and the foot is not touching, there is an error. The problem (as I see it) is that it must (...) (21 years ago, 21-Apr-04, to lugnet.technic)
     
          Re: SSClagorpion - robotic update —Steve Hassenplug
       The latest robotic update: As it stands now, SSClagorpion will: 1) Move: (one of these at a time) A) Walk forward & backward, B) Turn right & left C) Step right & left (move sideways) D) Stop 2) Open & close two claws on it's arms (via pneumatics) (...) (21 years ago, 21-Apr-04, to lugnet.technic)
     
          Re: SSClagorpion —Eric Sophie
      (...) Hey that is interesting. How would the robot actually behave in this circumstance? We'll have to build it and teach it and build as necc. e (...) (21 years ago, 21-Apr-04, to lugnet.technic)
    
         Re: SSClagorpion —Eric Sophie
     (...) -snip- Good Read. (...) Question please. The Spybot. That's for Directional Control. Can you eloborate? I find this interesting. I have conceived of possible contrivences, I'm interested in dicussing a method. What would the Spybot's two (...) (21 years ago, 21-Apr-04, to lugnet.technic)
    
         Re: SSClagorpion —Steve Hassenplug
     (...) Ok, so first of all, the Spybots, although limited, have one VERY cool feature. It's their IR capability. They have three IR sensors, so they can detect the direction of an IR signal from a controller, and/or another Spybot. So, if you set a (...) (21 years ago, 21-Apr-04, to lugnet.technic)
    
         Re: SSClagorpion —Eric Sophie
     (...) Oh! That's cool, I get it. (...) Right! Right! I get it, that answers the questions. I see. So the Spybots (oh course doi!) wouldn't be in the claws. The motors of the Spybot (located in the head or body or where ever) could trigger the Claw's (...) (21 years ago, 21-Apr-04, to lugnet.technic)
   
        Re: SSClagorpion —Kevin L. Clague
     (...) This is a reality given large LEGO pneumatic pistons, but I knew this when I started this project by inviting Eric to join me. (...) Kevin (21 years ago, 15-Apr-04, to lugnet.technic)
   
        Re: SSClagorpion —Kevin L. Clague
   (...) Thinking about this more....... One of the reasons that makes this slow is the inherent piston friction which combined with pressure defines the rate of expansion and contraction. So the rate is not very negotiable. But using rate * time = (...) (21 years ago, 15-Apr-04, to lugnet.technic)
   
        Re: SSClagorpion —Kevin L. Clague
   In lugnet.technic, Kevin L. Clague wrote: <snip> (...) So using #1 axle connectors as the linkage, we get a reduced piston expansion, down to 86% of maximum. Using technic axle joiner perpendicular, we can reduce the range to 70% of maximum. I can't (...) (21 years ago, 15-Apr-04, to lugnet.technic)
   
        Re: SSClagorpion —Steve Hassenplug
   (...) Yes, I'd rather see a solid, strong, slow robot over a fast robot that succeeds in tearing itself apart. :) (...) That's the throw of the switches, right? Not the throw of the cylinders on the legs. So the legs will "move" at the same speed, (...) (21 years ago, 15-Apr-04, to lugnet.technic)
   
        Re: SSClagorpion —Kevin L. Clague
   (...) Well Steve, it might and it might not. Given 18 bits of state (two bits/pistons per leg plus two extra), we could have a total of 256K possible combinations of leg positions. We only want about about 10 of them. If we start out the pistons in (...) (21 years ago, 16-Apr-04, to lugnet.technic)
 

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