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).



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Great job on the head. I am really looking forward to following this build because I am wanting to build a YDM also. Keep up the good work!

The only thing I would be concerned with when using the Aluminum Tubes is that its going to add weight and will add drain to your power source. Perhaps you could look for a lighter weight alternative such as carbon fiber? McMaster-Carr should have something lighter.

I was also afraid of it being too heavy, but my first robot is a lot heavier and it uses the same motors, so I should be ok. If not, I can always remove some of the aluminum tube. I test ran it on the carpet and it sounds fine, the tracks move freely so we will have to wait and see once I add everything else.

I'm posting this as a comment so that hopefully someone will see it.

In the directions for building a YDM found on makeprojects.com (PDF file) under Section 9 - Connections it says:

"Small speaker (under chassis): O0, Ground."

My problem is if I connect the speaker to O0 and ground, my speaker does not work.

It also says:

"Drum motors: Snare drum motor to O1 and Ground, hihat
motor to O2 and Ground, bass drum motor to O3
and Ground."

If I do what it says for the drumsticks, then they will not work either.

So, I have the speaker and drumsticks connected to their respective output pin and to +5V, not ground. In this connection they work perfectly.

Am I doing something wrong, or are the instructions messed up?

Here is a picture of how I have it connected (notice a ground pin is NOT connected.)

Also, one more question. Does having a speaker magnet right above a battery pack negatively affect either the batteries or speaker?



Have you tried out the test programs Frits provided? They should work with the speaker and motors wired as stated.

Basically, if you wire a motor to a digital output and ground, then to turn on the motor you set the output HIGH. This is what the instructions are having you do.

If you wire a motor to a digital output and +5V, then to turn the motor on you set the output LOW. So it sounds like your programming is backwards.


I have used the test programs and I am actually running his full program code (not writing my own, which is part of the problem, but I am still trying to learn) I really don't like coding, building is more fun.

Weird. The Picaxe 28-pin Project Board for Dummies post is a good resource that may be valuable to you.

I don't know what is causing what you are seeing, but maybe another source of info on that board will help you figure it out.

This is the code that Frits provided.

'This program is testing the speaker connected to the main board
'If all is well, after you run this, you will hear a single beep
Symbol pinSC_beep = 0
sound pinSC_beep,(120,10) low pinSC_beep

So, from your first comment, then is it correct that since the code says, "low" that the speaker would be connected to a digital output and +5V?

So, then the instruction to build a YDM that says, "Small speaker (under chassis): O0, Ground." are incorrect?

The "low pinSC_beep" command is there to force the speaker signal off at the end of the tone - a "low" pin will be grounded.  So his code is consistent with the instructions for connecting the speaker between the Picaxe pin and ground.  Frits gives an explanation for why he includes that command in this post. 

Conceptually the "sound" command could work with the other lead on the speaker connected to +V or to ground, but in practice you should probably work with the Piacaxe as a source of the signal rather than as a sink.

Oh ok. That makes sense now. Now I think I burnt my little speaker, it sounds weird now too. Lesson learned.