3DOF Leg Kit Assembly Guide VERSION 1.0

Transcription

1 3DOF Leg Kit Assembly Guide VERSION 1.0

2 WARRANTY CrustCrawler warrants its products against defects in materials and workmanship for a period of 30 days. If you discover a defect, CrustCrawler will, at its option, repair, replace, or refund the purchase price. Simply call for a Return Merchandise Authorization (RMA) number, write the number on the outside of the box and send it back to CrustCrawler. Please include your name, telephone number, shipping address, and a description of the problem. We will return your product, or its replacement, using the same shipping method used to ship the product to CrustCrawler. 14-DAY MONEY BACK GUARANTEE If, within 14 days of having received your product, you find that it does not suit your needs, you may return it for a full refund. CrustCrawler will refund the purchase price of the product, excluding shipping / handling costs. This does not apply if the product has been altered or damaged. Please refer to our web site for the latest warranty information. COPYRIGHTS AND TRADEMARKS This documentation is copyright 2004 by CrustCrawler, Inc. BASIC Stamp is a registered trademark of Parallax, Inc. If you decided to use the name BASIC Stamp on your web page or in printed material, you must state that "BASIC Stamp is a registered trademark of Parallax, Inc." Other brand and product names are trademarks or registered trademarks of their respective holders. DISCLAIMER OF LIABILITY CrustCrawler, Inc. is not responsible for special, incidental, or consequential damages resulting from any breach of warranty, or under any legal theory, including lost profits, downtime, goodwill, damage to or replacement of equipment or property, and any costs or recovering, reprogramming, or reproducing any data stored in or used with CrustCrawler products. CrustCrawler is also not responsible for any personal damage, including that to life and health, resulting from use of any of our products. You take full responsibility for your BASIC Stamp and robotic application, no matter how life-threatening it may be. INTERNET ACCESS We maintain internet systems for your use. These may be used to obtain software, communicate with members of CrustCrawler, and communicate with other customers. Access information is shown below: Support@CrustCrawler.com Web:

3 REQUIRED TOOLS The following tools will be required to build your Hexcrawler HDATS: Phillips screwdriver Drill 1/8 drill bit Small adjustable crescent wrench or socket set Wire cutters A small amount of white grease or equivalent 3DOF INVENTORY The 3DOF kit contains the following components: Wiring: Servo Wire Extensions (1) 12 Aluminum Parts: (1) Servo Hinge Bracket (1) Servo holder (1) Front leg brace (1) Back leg brace (1) Front foot (1) Back foot (1) Servo pivot brace Nuts, Bolts, Washers Screws & Spacers (2) #2-5/16 screws (4) #4 1/4 screws (4) #4 5/16 screws (6) #4 nuts (2) #4 lock nuts (6) #4 lock washers (2) #4 washers (6) #6 3/8 screws (6) #6 nuts (6) #6 lock washers (1) #6 1/2 screw (2) #6 washers (1) #6 lock nuts (1) #6 nut (5) ¼ SAE flat washers (1) # screw (1) #8 Lock nut (2) #8 washers (1) #8 - ½ nylon spacer (1) #8 ¼ nylon spacer (1) Mounting kit

4 Miscellaneous (1) 3DOF leg construction manual (6) Cable Ties (1) Rubber Foot Bumper (2) Tie rod coupler (2) Brass balls (2) #4 hex screws (1) 4/40 threaded rod

5 SERVO SELECTION AND CONSIDERATIONS FOR THE 3DOF LEG KIT Several factors have to be considered when selecting the servos for your 3DOF leg kit: Servo selection is critical for optimum performance of your 3DOF legs. The higher the torque rating, the higher the performance that can be obtained. The overall weight of your robot. The heavier the robot, the higher the torque that is required for the legs to perform properly. Servo size - Any standard size servo (1.6 L X.80 W X 1.5 H) will fit the 3DOF kit. At CrustCrawler we use HiTec servos as they are the best for robotic applications. Hitec servos have karbonite, metal gear and titanium geared servos which make them ultra tough for demanding robotic applications. The list below displays the part number and the torque rating for the Hitec servos that are compatible with the 3DOF leg kit: HiTec Analog Servos HS-475HB (61 in. oz.) HS-635BB (83 in. oz.) HS-625MG (93 in. oz.) HS-645MG (133 in. oz.) HS-925MG (103 in. oz.) HS-945MG (153 in. oz.) HiTec Karbonite Gear Digital Servos HS-6635HB (83 in. oz.) HS-6965HB (111 in. oz.) HS-6975HB (144 in. oz.) HS-6985HB (172 in. oz.) HiTec Titanium Gear Digital Servos HSC-5996TG (111 in. oz.) HSC-5997TG (180 in. oz.) HSC-5998TG (250 in. oz.) HSC-5955TG (333 in. oz.) HSC-5995TG Robot (250 in. oz.)

6 This construction guide uses Hitec HS-645MG (133 oz. in.) and HS-475HB (61 oz. in.) servos as an example. Use Figure A below as a guide for servo placement as it relates to its torque value for each of the 3DOF leg joints. At CrustCrawler, we have tested the performance of the legs based on servo selection and their related torque value. Always use at least the minimum torque value specified below or more to obtain the optimum performance from the 3DOF leg design. Be sure to adjust your legs using the (4) fulcrum points if you find that your not obtaining enough torque from the vertical lift servo. Horizontal Servo 133+ oz. in Foot Servo 61+ oz. in Vertical Servo 61+ oz. in Figure A Servo Selection and Placement

7 Adjustable Fulcrum Points There are (4) adjustable fulcrum points built into the 3DOF leg kit. Move the fulcrum point based on the weight and requirements of your robotic project. Use the figure B as a guide when selecting the fulcrum point of the legs for your project. Maximum leg lift least amount of torque Minimum leg lift most amount of torque

8 PREPARING THE SERVOS Remove the aluminum body parts from their protective bags and lay them loosely in their respective groups on your work surface. Remove the riser tabs from both sides of your servos as shown in figure. The removal of this plastic riser will allow the servo to sit flush against the 3DOF leg hardware later in the construction process. Place these servos to the side of your work area. Figure 1 - Servo Tab Removal

9 Leg Configurations Prior to the construction of your leg kit, determine how the legs are going to mount to your robot body. The servo hinge bracket was designed with slots and holes on all sides to accommodate multiple mounting configurations. Use figures 2A, 2B and 2C as a guide for determining the mounting configuration of your legs kits. Figure 2a Top/bottom deck mount bolts to and upper / lower deck of your robot Figure 2b Side mount bolts to the side of your robot Figure 2c Servo hinge bracket mount - connect this assembly to your robots upper and/ or lower decks

10

11 Assembling the Servo Hinge Bracket 1. Using a 1/8 drill bit, drill out the hole of the round servo horn from the servo as shown in figure 2. Tip: Drill the holes with the servo arm still mounted on the servo. After completing the holes, remove the round servo arm and temporarily place the servo screw back onto the servo. Figure 2 - Servo Arm Modification 2. Using (2) #4 5/16 screws and lock nuts, install the servo horn to the servo hinge bracket as shown in figure 3 and figure 4. Ensure that the servo horns center hole is centered in the servo hinge bracket hole before tightening the lock nuts. Figure 3 - Servo Horn Installation

12 Figure 4 - Servo Horn Installation 3. Grease the bottom of the pem spacer as shown in figure 5. Figure 5 Greasing the pem spacer

13 4. Install (2) 1/4 SAE flat washers to the pem spacer as shown in figure 6. The flat sides of the washers should be mounted flush with each other. Grease the top of the pem spacer and place the assembly to the side of your work area. Figure 6 Washer Grease Application To make leg assembly easier, bolt the servo hinge bracket to your robot assembly before going to the next step. 5. Using (2) #6-3/8 screws, lock washers and nuts, install the HiTec HS-645MG servo to the top of the 2 tabs on the servo holder with the servo oriented as shown in figure 7.

14 Figure 7 - Horizontal Servo Installation 6. Install the servo holder onto the pem spacer and the round servo arm of the servo hinge bracket as shown in figure 8. Ensure that the servo can rotate 90 degrees in either direction from a centered position before installing the servo screw as shown in figure 9. Figure 8 Servo Holder Installation

15 90 Degrees 90 Degrees Figure 9 7. Place (1) ¼ SAE flat washer (flat side up) onto the pem spacer as shown in figure 10.

16 ¼ SAE Flat Washer Figure 10 - Washer Installation

17 8. Install (1) #6-1/2 screw, (2) washers and a lock nut as shown in figures 11 and 12. #6 Flat Washer Figure 11 #6 ½ Screw #6 Flat Washer #6 Lock Nut Figure 12

18 9. Using (2) #6-3/8 screws, lock washers and nuts, install the vertical, leg lift servo to the servo holder as shown in figure 13. Ensure that the servo is positioned as shown in figure 13. Use (1) tie wrap to secure the servo wires to the servo holder. Tie Wrap Figure 13 - Vertical Servo Installation Front View Figure 13B 10. Repeat steps 1-9 for each leg in your kit

19 Leg Assembly 11. Apply a small amount of grease to the pem spacer on the back leg as shown in figure 14. Figure 14 Grease Application 12. Install (2) ¼ SAE flat washers (flat side towards the back leg) onto the pem spacer and apply a small amount of white grease to the top of the second washer as shown in figure 15. Figure 15 Washer Installation and Grease Application

20 13. Using (2) #4 5/16 screws, washers, lock washers and nuts, install the back foot to the servo pivot brace as shown in figure 16. Ensure that the large, pem spacer hole of the servo brace is aligned with the pem spacer hole of the back foot before tightening the #4 screws. Pem Spacer Hole Servo Pivot Brace Back Foot Figure Using (1) #6 1/2 screw, (2) washers and (1) lock nut, attach the servo pivot brace and foot assembly from figure 16 to the back leg as shown in figure 17 and 17b. Do not tighten the lock nut completely! Tighten the lock nut just enough so the back leg can swing freely with little resistance. #6 ½ Screw #6 Washer Figure 17

21 #6 Lock Nut #6 Washer Figure 17b

22 15. Place (1) HiTec 475 HB servo to the top of the servo pivot brace with the servo spindle oriented toward the bottom of the foot as shown in figure 18. Figure Using (2) #6 3/8 screws, lock washers and nuts, install the front foot to the servo as shown in figure 19 and 19b. #6 3/8 Screw Figure 19

23 #6 Lock Washer #6 Nut Figure 19b

24 17. Figure 19c depicts the leg assembly completed to this point. Figure 19c 18. Using (1) #6 nut, and lock washer, install the rubber foot to the bottom of the foot assembly as shown in figure 20. #6 Nut #6 Lock Washer Figure 20

25 19. Using (2) #4 - ¼ screws, lock washers and nuts, install the round servo arm to the front foot as shown in figure 21. The servo arm should be mounted to the inside of the bend of the front foot. Figure 21

26 20. Install the leg assembly to the front leg assembly as shown in figure 22. Before securing the front foot to the front leg assembly with the servo horn screw, hold the front leg in parallel with the back leg and be sure that the foot can rotate freely to the points illustrated in figure 22 and figure 22b. Figure 22 Figure 22b

27 21. Using (2) #4 ¼ screws, lock washers and nuts, connect the front leg to the back leg as shown in figure 23 and 23b. Figure 23 The front of the leg Figure 23b The back of the leg Repeat steps for the remaining legs in your kit.

28 The completed leg assembly

29 22. Obtain (2) round brass balls from the servo coupler bag. With your thumb, press each brass ball into each of (2) tie rod couplers as shown in figure 24. Secure the brass ball in the tie rod couplers using (1) #2 5/16 screw. Note: Insert the #2 screw to the tie rod coupler hole that is slightly larger than the #2 screw first. Brass Ball #2 5/16 Screw Tie Rod Couplers Figure Partially thread (1) 4/40 threaded rod into (1) end of the tie rod coupler assembly as shown in figure 25. 4/40 Threaded Rod Figure Thread the other tie rod assembly onto the 4/40 threaded rod to complete the assembly as shown in figure 26. Be sure that the heads of the #2 5/16 screws are facing in the same direction as shown in figure 26. Repeat steps for the remaining tie rod couplers. Figure 26

30 25. Using (1) #4 ½ hex screw, brass spacer and lock nut, install the tie rod coupler to the completed leg assembly as shown in figure 27. Note the orientation of the brass spacer and the #2-5/16 screws as it relates to the leg assembly. The flat end of the brass spacer should be mounted against the aluminum leg assembly. Be sure that the #2 screws are facing towards the outside of the leg for easy access to and adjustment of the #2 5/16 screws when the entire leg assembly is completed (figure 27b). #4 1/2 Hex Screw Brass Spacer #4 Lock Nut Figure 27 #2-5/16 screws facing the outside of the leg Figure 27b Repeat step 25 for the remaining tie rod couplers.

31 26. Obtain a servo arm from your servo box (The one depicted in figure 28 is from a Hitec 645MG servo) as shown in figure 28 from your servo. Using a 1/8 drill bit, drill out the second hole from the top of the servo arms. Drill Here Figure Place the servo arm on the vertical lift servo of the servo holder and rotate the servo counterclockwise until the servo stops rotating as shown in figure 29. Remove the servo arm and repeat this step for the remaining vertical lift servos in your kits. Figure 29

32 28. Using (1) #4 ½ black hex screw, brass spacer and lock nut, install the servo arm to the other end of the tie rod coupler as shown in figure 30. Repeat this step for the remaining servo arms in the kit. Figure 30

33 29. Using (1) # screw (2) washers, (1) lock nut, (1) ½ nylon spacer, (1) ¼ nylon spacer, install the leg assembly to the servo holder assembly as shown in figure 31. Tighten the #8 lock nut to the point of which there is no play in the leg but not too tight in that it would be difficult for the servo to lift the leg assembly Figure # Screw 5 #8 ¼ Nylon Spacer 2 #8 Washer 6 Back Leg 3 Front Leg 7 #8 - Washer 4 #8 1/2 Nylon Spacer 8 #8 Lock Nut

34 30. Using the servo arm screw for the Hi-Tec 475 HB servo, install the servo horn to the vertical lift servo in the 11:00 o clock position as shown in figure 32. Figure 32 Repeat steps 29 and 30 for each leg in your kit. Note: If you are using another servo arm other than the one depicted in this construction guide, ensure the following: 1. The arm is stiff and will not bend when your robot is completely loaded. 2. The servo arm does not hit the front leg as it swings throughout its range of motion. If you find that your servo arm does hit the front leg, add (1) #6 lock washers between the servo and the aluminum servo holder to provide more clearance.

35 Using (2) tie wraps, secure each of the (6) foot servo wires to the back leg as shown in figure 33. Ensure that you can rotate the foot freely through it s entire rotation before securing the tie wrap. Tie Wrap Figure 33