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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Well, I had hoped to have a robot page up today, but I'm not feeling to well and my robot seems to like problems.

First, I noticed yesterday that if my robot drives straight for any length of time it would turn to the right and go in circles. I noticed my right track was turning a lot slower then the left. I tried switching the A and B connections to see if maybe one wasn't getting enough current, but that didn't help. Then I tried loosening the front axle, because I thought maybe one side had more resistance then the other, that didn't help either. So I took the tracks off and just watched the wheels turn on the motor and I could definitely see that the right was turning slower (almost like the gears were set different). So I did the unthinkable and stole a motor from my first robot. Switching motors helped and last night my robot was driving in perfectly straight lines. Then I woke up this morning, turned my robot on and it proceeded to drive in circles to the left, why oh why? I think it hates me, lol.

Second, tuning the drumsticks is a lot harder then I had hoped it would be. Partly because I don't have a "musical bone" in my body, lol. So it's taking a lot of testing to get it right. But I'm sure I will get it close enough (it may never be as good as the YDM, but I kind of expected that anyways).

Anyways, if I am feeling better tomorrow, I will try and get a robot page up with videos (hopefully tomorrow, but maybe the day after).

DC gear motors almost always turn a slightly different speeds. Sometimes it is your motor connections, but usually it is something you just have to live with.

If you can use PWM to control the motors, you can try to adjust the speeds. Or, take apart the slow motor, look carefully at all the gears. See if there are little burrs on the gears that can be carefully shaved off. Then re-grease and assemble the motor. It might improve the speed, but it is a lot of work and may not even help.

Another approach is... don't worry about it. So what if your robot doesn't drive straight? As long as he finds something to drum on, it is cool.



It still needs some more tuning. The white and black drumstick (Hihat) will sometimes miss because it is short, but I think I can bend it a little bit forward to fix that.

I also need to work on the code that makes the robot "snake" into position, because it takes it forever to get there.

But I'm happy it's finally working. Thanks to everyone that helped me get this far!!!

Careful with that high hat drum stick. It is very hard to bend tube without crimping it. There are tools to do it. Or try feeding a spring inside the tube that is just a little less than the inner diameter. It will help it bend without crimping.

Bettery yet, forget bending it. Add a thumb tack or something to the top to give it wider diameter there and it will hit more often. The extra weight at the top may also help.

Congratulations! The video looks good (despite the lighting). I'm sure the tracks work better on a hard wood floor.

It has been fun watching you work towards this. I'm really glad you stuck it out!

I wouldn't have got here without your help, I really do appreciate it! :)

I don't have very much hard wood floors in my home (that's why my rear drumstick doesn't hit the floor), but I'll try to get some video of it in the kitchen once the code is better tuned.

In the Picaxe manual, Section 1, Tutorial 4 - Making Sounds, it states:

"Note that on the project boards (supplied in the
PICAXE-14, 18 and 28 starter packs) fitted with a Darlington driver the piezo
must be connected directly to the PICAXE output pin (not the buffered output

I assume this would apply to both Piezos and speakers(?) and my speaker does work if it is not connected to the buffered output.

So if the above is correct (I don't know how I missed that before), then I just have to find out why my drum motors aren't working.

Looking into this...

When a digital output is set HIGH, the corresponding darlington output is connected to ground. So I would agree with you that you need to wire from Darlington output to +V.

You mean with the darlington, I would connect my drum motors to an output and +5V correct?

Just want to make sure you aren't talking about the speaker?

Yah. I would try that for the motors.

For the speaker, see Picaxe Manual 3. If it is a piezo, you can connect direction the the Picaxe output (not the Darlington output).

If it is a regular speaker, a 10uF capacitor is recommended. Though I've seen it work fine without it.