Let's Make Robots!

Jinnarin's third robot (YDM clone). (Updated: 9-1-11)

Hi all. I have been away for some time (health reasons), but I am finally back and starting on my third robot. You can see my first robot here and here, I never made a page for my second robot, as it was just a remake of the start here robot (maybe it will make a special appearance).

Anyways, I am making a Yellow Drum Machine clone, it is the reason I made my first and second robot. I have had the parts for it for over a year, I just was never able to start working on it and almost gave up that it would ever be made. It seems like everything is coming together at just the right time though, I noticed yesterday that instructions to make a YDM were posted on makeprojects.com last month, those will come in handy, Thanks Fritsl!

I will be using this blog to document my build process and will transition to a robot page once I feel I can actually call it a robot.

I started working on the head today, I will post pics as soon as my camera charges.

Pictures of the head (SRF05) mounted to a GM10 motor and pressure mounted into a Lynxmotion Ant-style electronics carrier (used as chassis).

I started with the head first because I will have limited room for everything to fit inside and the head needs to be in the right place. I was able to stack a standard servo horn on top of the GM10 motor horn and secure it using a bigger screw. At first it wasn't very secure, but I added a small washer between the horns and that tightened it up. It appears to be really strong now.

Tomorrow I will work on mounting the motors and tracks, I have to figure out how to make a bracket for the front axle.




Today I started mounting the drive motors.

I had to make a board to mount the motors onto because the Ant-style chassis I am using has cut-outs right where the motor brackets sets (As seen below).

The board I am using to mount the motors is just some thin plastic material that you can get here. It's really easy to cut and work with (it's actually what I used to make my second robot).

Here are the motors test fitted into the chassis,

And with the tracks set on it,

(It's starting to look like a robot!)

That's all for right now. I have to go figure out how to make a bracket to mount the front wheel for the tracks. :)


Well, I started making the front axle. I'm using a small brass tube I had lying around. I went to my local hardware store and picked upped some brass nuts for the ends. Unfortunately, I couldn't thread the brass tube (I tried), so I went ahead and soldered the end nut to one end of the tube, using a torch to heat it up and solder. It worked really well, and it looks nice!

The front axle is complete.

Front axle

My goal for today is complete! I have the drive motors, front axle, and tracks mounted. I did a small test and ran each motor, the tracks move smoothly, I was afraid they wouldn't. Overall, I am happy with today's work!

If I have time tomorrow, I plan on working on the second stack (chassis above the motors) where the electronics will be mounted.


Hooray for design flaws (or lack of a design lol)! Looking at my robot I have noticed a potential problem. My tracks are too far apart, making my robot wide (fat) like my first robot is. On my first robot that created a lot of problems. I think I may have to redesign the tracks position and make the motors closer together. Thankfully, because of the way I am building my robot it shouldn't be too much of a problem. I am using stacked units to build up the robot, so fixing one stack does not require fixing all the stacks.

Unfortunately, I will not have time to work on it today.



Today I rebuit the base for my robot, to make the tracks closer together (make the robot less wide). I used a square aluminium tube as a main support to mount the motors and front axle to. I have never used aluminium before, I wished I had discovered it sooner. It is very easy to work with. Overall, I think the this base is a lot stronger, and it looks a lot better. Here is a pic.

new base

It looks a lot different and is about one and a half inches less wide.

Tomorrow, I hope to get back on track and start mounting the electronics. Hopefully there won't be too many problems.



I finally got the PICAXE in it's mounted postion and started soldering headers on.




Well, I've been working on my robot some more finally (I have too many projects going at once), here is how it looks now.

I have a lot of wires to still hook up. I also found out one of my GM10 motors is defective, it just spins like one of the gears is stripped but they are all fine. I though maybe the gear on the motor pinion wasn't tight enough so I glued it on, but that didn't work either. So I guess I have to get another one.

Tomorrow I hope to get everything wired (minus one GM10) and install the sound board.



I finally received my new GM10 motor today, so I can start working on my robot again.

I still have to mount the rear drum stick motor, make and mount all the drum sticks and mount the soundboard.

I still haven't decided what the drum sticks are going to be made out of, but I have a few various materials I will be trying out.

Also, because my house is fully carpeted, my rear drum stick will not be able to "play" on the floor like the YDM, so I have a different idea for that one, hopefully I can get it to work. 

(And now I can't find my programming cable to start testing connections, grrr.) 


I found my programming cable and started testing individual components. Everything is working except for my small speaker, it won't beep. Why is it always the simple things that go horribly wrong! I'm not sure whats wrong with it, I mean it's a speaker, how hard is that.



He finally has drumsticks!!!!

The white/black drumstick is made out of a piece of lightweight metal and the yellow/black drumstick is made out of a plastic mechanical pencil that was broke.

I have successfully tested both and they work perfectly!

Also, the small speaker is working now, it was off by one pin lol. Actually, everything is working now, except for the rear drumstick, I haven't even started on that :)

This robot is taking a lot longer to build then I thought it was going to, but I am having a lot of fun!!

I made a video of it, kind of a teaser trailer! I tried to make it like a toy commercial, but I'm not very good with videos, so don't take it too seriously. http://www.youtube.com/watch?v=okvDab2EAcM



Tested the front set of drumsticks. http://www.youtube.com/watch?v=hMr2fdgOWW4

Also, finally started work on the rear drumsticks!


Building is finally complete :)

I still have to find the best place to mount the microphone, but that will come with testing. The SRF05 may need adjusting too, but nothing major.



My "big" speaker sounds awful :(

Time for a small redesign.

Other then that, everything is working well. I am going through the code and "learning" it, which is easy the way Fristl wrote it (thanks!).

The drumsticks are kind of hard to "tune", but I'm sure I'll figure it out.


I think I am going to move the front drumsticks back a little, and rework the rear drumstick (I don't like how it sounds). I'm also replacing the "big" speaker and also adjusting the chassis. So I guess, building is not complete :(



I'm finally back on track and getting all the problems sorted out. There is a lot of information in the picaxe manuals and it is overwhelming going through it all, but I am learning a lot (more then I did on my first two robots), so that's good. 

Currently my robot is looking a bit different, it is shorter and a bit lighter too. All I have left to do construction wise is adjust the front bumper and mount my new big speaker (which I can't do until I get a package of wires, I ran out).

I have to get my little speaker sorted out too, it's getting there slowly. The info about speakers in the picaxe manual is all over the place so it's hard going back and forth, but I'll get it. 




Building is complete (more or less, I have to add a capacitor to the small speaker and "mount" the microphone).



Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

I still can't figure out what the problem is. I ordered a new picaxe, but I doubt that will work because my other two robots only make a quiet beep too.

So I can try an amp, which I would rather not do, because I don't think I should need to.

I also read that adding a 10uf capacitor could work too.

I just wish I could use O0 and +5V without burning the speaker. (The drum motors don't work either, if they are connected to an output and ground.)

I'll wait and see what a new picaxe does. I really hope it works.

After further investigating my problem and going back and reading the manual and tutorials online, my board still isn't working.

So I went even simpler and used this code:

high 0
pause 200
low 0
pause 200
goto light

To make an LED connected to O0 and it's corresponding ground blink. It doesn't work. I've connecting it to various ground pins around the board and none of them work, except for two at the bottom of the board (these two DO make the LED blink).

I'll keep working on it!


There's a jumper that joins the two voltage supplies on the board (V1 and V2). If you are using a single power supply, you should keep this jumper in place. If you are using two separate power supplies, you should be sure that the ground from both supplies is connected to the ground on the board.

If you were using two power supplies, with the jumper removed, and had not connected the ground from one of your power supplies/batteries, then anything run from that supply won't have a path back to ground.

I'm only using one power supply (4 x 1.2V batteries) and the jumper is connected properly (that was one thing I checked).

Also, Thank You for your help so far!

Edit: Oh WTH, those aren't grounds in my above picture (or, they are with two power supplies), lol. Ok, so none of my grounds work :) I think I'm trying to hard.

-bangs head on desk-

Hang in there. I know it can be frustrating.

Did you take a look at the Picaxe 28-pin Project Board for Dummies post I mentioned earlier? It explains all the grounds and other connections.

My advice is to take a step back. Read through that post. Then verify that your board matches what is described in that post. If the grounds are really not working, you will just continue to bang your head on the desk to no result.

Do you have a multimeter to check connectivity between where the batteries connect to the board and all the ground pins?

Also, I'm assuming that the Picaxe board seems to power up OK and so you don't need to double check that the wires on your battery pack itself.

Yeah, I read that and a lot of other things. I think I'm just getting frustrated (taking in too much) and making stupid mistakes. I never had problems like this on my first two robots. I'm going to let it sit for a few days and come back to it for a fresh start, but I won't give up.


My problem is back :(

So I decided to take everything off the picaxe and make it simple. Currently all I have connected is a speaker to O0 and Ground. I wrote this code to make is beep over and over for testing,

Symbol pinSC_beep = 0
sound pinSC_beep,(120,10) low pinSC_beep
pause 200
goto playbeep

It's just the speaker test code with a pause and repeat, simple.

When I turn the board on the speaker does beep, but it is very quiet.

When I touch the voltmeter to where the positive and negative leads from the battery pack connect to the board, I get a reading of almost ~5V (4.8V). And all the +5V are getting the correct power, so it's not a power/connection issue I guess. It's also not a code issue, so I am completely lost, over something so simple.

So I thought maybe I had a bad board or I ruined it. I tested the boards from my other two robots and they do the same exact thing.


I figured out my problem.

My ground connections that are next to the output pins (O0, O1, O2, O3) are not working. I'm not sure why.

I hooked my speaker to O0 and a ground on the opposite side on the board and it works, I can hear it! I also did they same thing with my drum motors and now they work too!

Thanks for the help everyone. The problems have been solved :)

I'll have to take the picaxe out of the robot and have a look at those ground connections.


Edit: My connections look good?

Link to a bigger picture.

It could be a problem with your solder contacts. The solder on O2 looks like it might be a cold joint.

If your grounds aren't working on that side, there could be a problem with the board, or at least with the soldered header. It would be weird that the whole row of the ground header are mis-soldered.

Try putting a jumper wire between the ground connection on the other side of the board and the row that isn't working. You need to track down this ground issue.

Everything I am reading online says that to use a speaker with a picaxe, that you need some sort of amplification. But the YDM doesn't have one.

Also, I tested a piezo buzzer in place of the speaker and even it is really quiet, piezos are normally loud. I have never heard of a quiet piezo, lol.