How to make your first robot

Let's Make Robots Tutorials
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801

Jax thanks a lot for the

Jax thanks a lot for the useful information that you have given me in your last post.

I am going to New York tomorrow if God consents. Please can you tell me from what shop there can I buy the robot parts (please I do not want to order it online)

Please can you tell me which servo is the best and why for this application from the following list:

GWS Standard SO3T STD Servo Motor

GWS Standard SO3N STD Servo Motor

GWS Standard SO3TXF 2BB Servo Motor

GWS Pico STD Servo Motor

Please if you find that there is an another servo motor which is a better one from those listed above for this application, can you write its name to me.

I will get for this application a GM9 (Gear Motor 9) 90 degree shaft, is it the best option to choose for this application or there is another one which is better to work with in this application.

Please, sorry for disturbance but about the wheels which one is better:

GMW plastic wheel

BaneBots Wheel, 3-7 / 8" x 0.8", Unfinished Mount: (which colour)

Green Rubber tread:

30 Shore A

(soft and “semi flexible”)

Orange Rubber tread:

40 Shore A

(medium)

Blue Rubber tread:

50 Shore A

(hard and “stiff”)

Outside diameter [in]: 3.875

Inside diameter [in]: 0.5 / 0.75 / 0.375 / 0.875 / 0.393

Connection 1: Round / Hex

BaneBots Wheel, 4-7 / 8" x 0.8":

Outside diameter [in]: 4.875

Inside diameter [in]: 0.393 / 0.75 / 0.375 / 0.5

Connection 1: Round / Hex

BaneBots Wheel, 1-3 / 8" x 0.4", 1 / 2" Hex Mount:

Outside diameter [in]: 2.375 / 1.625 / 2.875 / 1.375 / 1.875

Inside diameter [in]: 0.5

Connection 1: Hex

BaneBots Wheel, 2-7 / 8" x 0.8", Unfinished Mount:

Outside diameter [in] : 2.875

Inside diameter [in]: 0.75 / 0.375 / 0.5 / 0.393

Connection 1: Round / Hex

Lynxmotion Off Road Robot Tire - 4.75"D x 2.375"W (pair)

Lynxmotion Ant / Beetle Robot Tire - 2.125"D x 0.8"W (pair)
8" Molded Plastic Omni-wheel

8" Aluminum Omni Wheel

6" Plaction Wheel

6" Aluminum Omni Wheel

If there is a better kind of wheels than those listed above, can you write its name to me.

Sorry but the last question is the Shorting Blocks, Top Closed the same as mini jumper (10 pack)
 (Product code: RB-Cyt-60)

What are the Shorting Blocks, Top closed? Why are we going to use it?

Is the L293D 2A 5V-12V Secret Motor Driver Kit (Product code: RB-Sbo-25) the same as L293D Motor Driver IC?

Thanks a lot for your great help that you have offered me the last time. Sorry for any disturbance.



 

802

Jax thanks a lot for the

Jax thanks a lot for the useful information that you have given me in your last post.

I am going to New York tomorrow if God consents. Please can you tell me from what shop there can I buy the robot parts (please I do not want to order it online)

Please can you tell me which servo is the best and why for this application from the following list:

GWS Standard SO3T STD Servo Motor

GWS Standard SO3N STD Servo Motor

GWS Standard SO3TXF 2BB Servo Motor

GWS Pico STD Servo Motor

Please if you find that there is an another servo motor which is a better one from those listed above for this application, can you write its name to me.

I will get for this application a GM9 (Gear Motor 9) 90 degree shaft, is it the best option to choose for this application or there is another one which is better to work with in this application.

Please, sorry for disturbance but about the wheels which one is better:

GMW plastic wheel

BaneBots Wheel, 3-7 / 8" x 0.8", Unfinished Mount: (which colour)

Green Rubber tread:

30 Shore A

(soft and “semi flexible”)

Orange Rubber tread:

40 Shore A

(medium)

Blue Rubber tread:

50 Shore A

(hard and “stiff”)

Outside diameter [in]: 3.875

Inside diameter [in]: 0.5 / 0.75 / 0.375 / 0.875 / 0.393

Connection 1: Round / Hex

BaneBots Wheel, 4-7 / 8" x 0.8":

Outside diameter [in]: 4.875

Inside diameter [in]: 0.393 / 0.75 / 0.375 / 0.5

Connection 1: Round / Hex

BaneBots Wheel, 1-3 / 8" x 0.4", 1 / 2" Hex Mount:

Outside diameter [in]: 2.375 / 1.625 / 2.875 / 1.375 / 1.875

Inside diameter [in]: 0.5

Connection 1: Hex

BaneBots Wheel, 2-7 / 8" x 0.8", Unfinished Mount:

Outside diameter [in] : 2.875

Inside diameter [in]: 0.75 / 0.375 / 0.5 / 0.393

Connection 1: Round / Hex

Lynxmotion Off Road Robot Tire - 4.75"D x 2.375"W (pair)

Lynxmotion Ant / Beetle Robot Tire - 2.125"D x 0.8"W (pair)
8" Molded Plastic Omni-wheel

8" Aluminum Omni Wheel

6" Plaction Wheel

6" Aluminum Omni Wheel

If there is a better kind of wheels than those listed above, can you write its name to me.

Sorry but the last question is the Shorting Blocks, Top Closed the same as mini jumper (10 pack)
 (Product code: RB-Cyt-60)

What are the Shorting Blocks, Top closed? Why are we going to use it?

Is the L293D 2A 5V-12V Secret Motor Driver Kit (Product code: RB-Sbo-25) the same as L293D Motor Driver IC?

Thanks a lot for your great help that you have offered me the last time. Sorry for any disturbance.



 

803

Which book is the best to

Which book is the best to buy to learn basic robotics?

804

resistor 330x8 array

Im trying to be exact, but the 330x8 resistor array is now black, instead of yellow. Does that change anything?

805

Wow. Lots of questions, and

Wow. Lots of questions, and a triple post. I don’t think you can delete your repeat posts, but you can go in and edit them to replace all the text with something like ‘repeat post’. That will clean up the comments a bit.

All the parts in the Start Here kit are the recommended parts, but substitutions for some of them are acceptable.  

For example, you don’t have to get that specific servo. Just about any standard sized analog servo will be fine. Avoid digital servos and servos that are for continous rotation.

If you need an alternative for the GM9 motors, review the specifications. You want something with a simiar gear ratio (143:1). If you have a lower gear ratio (e.g., 100:1), then the robot will move faster and have less power (torque). If you choose a higher gear ratio (e.g., 200:1) then your robot will be very powerful (able to climb steep ramps), but will be very slow. Also important for the motor is the voltage it will run on (you want 3V) and how much current it will take. You need it to be less than 600 mA stall current, which is the maximum current you will get if the motor is stuck but still trying to run.

Get wheels that will match the motor. Sometimes the motor will have wheels that are nicely designed to fit. You need to be able to attach the wheels to the motor shafts. The diameter of the wheels will affect your robot’s speed and power, just like the gear ratio. So if you choose wheels much smaller than the ones in the kit, your robot will be slower, because the wheel needs to turn more to go the same distance. Much bigger wheels will go faster, but will deliver less power. You don’t want an omniwheel for this application. You can even make your own wheels from jar caps with rubber band tires, or old CDs or anything round.

If that mini jumper pack you listed is from robotshop.com, it is fine. You can also find those shorting blocks on old hard drives and old computer motherboards. They simply make a connection (a short) from one pin to another. Top closed or not closed does not really matter.

The Secret Motor Driver Kit will not do. You are looking for the L293D chip itself, because it can be inserted into the Picaxe 28-pin Project Board. There is a pin-for-pin compatible chip that will also work. It is the Texas Instruments SN754410. So if you can’t find the L293D, try that one.

For shopping in NYC, I don’t know if you will find everything in one place. A hobby shop for RC airplanes and cars will have servos. An electronics shop might have some of the chips, but they are not that common, so maybe not. Chances of finding the Picaxe board and chip are really slim. For the resistor pack, you can actually substitute a single 330 ohm resistor, if needed. You would just stick the resistor across the leads for the output pin where the servo is connected. One side gets inserted into one side of the chip socket, and the other side of the resistor goes into the socket hole directly across from it. 

806

It changes nothing. Just be

It changes nothing. Just be sure to insert the correct chip into each socket. People have made the mistake of confusing the resistor array with the l293d chip, since they are both black with 16 pins. 

Also be sure to insert the l239d so it is oriented the right way. The resistor pack can be inserted in any direction.

807

There are many, but the

There are many, but the Robot Builder’s Bonanza is a fine choice.

808

I have a problem with the sensors


hi!

I have made the robot and it works perfectly well - until I connect the sensors. It stops working and the batteries get hot within a minute or two. I’ve checked all the connections and everything all over again. I’m using 3 AA non-recheargeable batteries. Can you help me out please?

809

Pictures please

It sounds like a short circuit somewhere. The biggest help would be some pictures of your setup. The connections to the sensor are of the greatest interest.

810

I agree with JAX. If the

I agree with JAX. If the batteries get hot you are almost certainly shorting power to ground somewhere.

Check and see if the batteries still get hot with the sensor disconnected. If not, look carefully at your sensor. Perhaps you have it wired with power and ground swapped or some other mis-match.

811

sensor

Hey,i got the codes and they work thanks for that,but the sensor is not working the infrared light which we can see in front of it does,nt light up and b1 does,nt change do you think its faulty piece?

812

Thanks a lot we got it


Thanks a lot we got it
 it’s damn silly the red and black wires were in contact right on the sensor’s head
 thank goodness the sensor’s not fried n the robot is dancing again :smiley:

When we write this program :


main:

readadc 0, b0

debug

goto main

some debug window opens and some counting starts which never stops on the title bar
do we need to wait? if yes, till when? and when we write the bigger program given at last (before “fun time”) in this tutorial, the head turns right, left n center (i’m not sure about the order) the robot moves a bit ahead; when i bring my hand in front of it, the head turns many times n the robot moves ahead even less n this keeps going on (shouldn’t it change it’s direction and move?). The robot does not “keep on going” forward or anywhere
 we watched the video, our robot doesn’t move like the one in the video (guess its the same program, n we kept the robot indoors with its way clear, so shouldn’t the robot move?) n what program should we write to make the robot move ahead? need your help in programming!

We (me n my friends who are working on it) are beginners and completely new to all this stuff :slight_smile:

813

Well, you cannot see

Well, you cannot see infrared light with your naked eye. You can use a digital camera and should be able to see IR light as a blue glow through the camera viewer.

Are you using the debug statement in the program in order to view the value of b1?

Please try to provide complete and clear information so we can help you better.

814

I’ve sometimes found the

I’ve sometimes found the debug statement to be a bit
 well, buggy in the Picaxe Programmer. ; j

Try putting a delay statement in your little test program. Maybe it is just going to fast to update the debug window. This is just a guess. Try inserting ‘delay 500’ above the ‘goto main’ line.

It is possible that your sensor is still giving you some problems, which might explain the weird behavior. See if you can get the debug working and confirm that the sensor detects range properly.

 

815

You can also independently

You can also independently check the operation of the motors with a simple program. Write a program to make your robot drive forward for a few seconds, then stop. Then turn right, stop. Then go forward a few seconds, stop. 

You get the idea. Make sure you can drive forward, stop, go backards, and turn in both directions on command. If all this works, you can focus on your sensor, knowing the robotic platform itself is working perfectly.

816

TY!!!

well it works fine now and though i don’t know much about programming, i tried it out n somehow understood and actually learned a lot. and delay 500 shows syntax error, but it doesn’t bother me now! the program given in this tutorial is fine, the problem was with the batteries - they drain so quickly! so sorry for bothering you :slight_smile: but your advice did help me out a lot


we got into all this because of a science exhibition held at our school
 we wanted to do something new which we were really interested in - n now we’re so happy we chose lmr! everything went flawless (except for batteries which we managed somehow
), we wooed our seniors and impressed the judges (yea we did tell them about this wonderful website - otherwise they won’t believe we made it ;D)
 sO thanKs a biG loT ignoblegnome, JAX, n i dare forget 
thank you fritsl =)

LMR rocks \m/

817

So glad it worked well at

So glad it worked well at your exhibit. I hope you’ve caught the robot building bug and continue to make cool robots!

818

yes that bug’s running


yes that bug’s running
 there’s a long way to go though :slight_smile:

819

Double check the wiring from

Double check the wiring from the sensor to the board as well. The sensor doesn’t wire up the same as a servo so it can be an easy mistake to make.

820

sound

is there a possible way to add a speaker to the project board? If so, can you please tell me the specific place to connect it? 

Thanks

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