Friday, April 29, 2016

Dodge Stratus Anti-Freeze Leak Repair

Our Dodge Stratus is nearing the end of its useful life.  It has over 150,000 miles on it.  The exhaust is held together with clothes hangers, the suspension is bouncy and it is leaving puddles everywhere it goes.  Recently it overheated and I discovered it was about a gallon low on antifreeze.  The next time I checked it was low again so I took it to a garage.  They estimated $450 for repairs so I said "No thanks" and took it home.

I could not find the problem at first because I was looking at the engine.  The problem was fastened to the inside of the passenger side wheel well.  You have to remove the antifreeze reservoir to get a good look at it as in this next picture.  The lines to the heater are rotted out.  They get even worse just out of the view of the camera.


So I removed the one hose as in the above picture.  Then I removed the other one where it attaches and coupled the two hoses together with a short piece of pipe and a screw tightened pipe strap.


The top hose attaches just below the thermostat and the bottom hose attaches someplace under the engine.  Taking the bottom strap off leads to a antifreeze leak so I held my thumb over the end of the hose until I could get it up to the junction.

So far so good, but I would not recommend this repair to anyone.  For one thing you no longer have any heat!

Monday, April 18, 2016

Comparing Sony Cameras DSC-h2, H10, H50 and DSLR Alpha A330

I have prefered Sony cameras for years.  I once saw a Sony camera produce a picture that was much better than what I could see with my eyes and that sold me.  I have owned several Sony cameras over the years and now I have a Sony A330 DSLR camera.

In these pictures the A330 is on the left, followed by the HC50 then the HC2.




The DSC-H2 runs off ordinary AA Cells.  It makes a great backup camera.

The DSC-H10 is a little plastic toy.  Flash quit after a couple of months.

The DSC-H50 is a GREAT camera.  Use it for most of my videos and stills.

The A330 is a nice DSLR.  However it does not do movies.  The standard lens does not do zoom. It is my first professional camera with a interchangeable lens.

Thursday, February 11, 2016

LG Optimus Fuel L34C teardown

Someone dropped a fairly new LG Optimus Fuel phone into the tub.  I had to tear it apart.  It was really amazing how easy it was to take apart.

INSTRUCTIONS:
Remove the back cover.
Remove the battery.
Remove 6 tiny screws.
Remove back gray plastic.
Unplug two connectors, they pull straight out.
Remove the circuit board.
Disconect two metal hooks and the metal shield comes off.
Insert parts in bowl or rice and wait several hours.

The two connectors to the screen are in the upper right corner of this picture.

The two screen connectors are in the lower left corner of this picture.

 These are all of the parts minus the battery and back cover.

Everything worked when I put it back together.  A little while later the screen died and has been blank ever since.....


Monday, January 25, 2016

My next Robot - the biggest Dinosaur yet.

I am making a servo based tyrannosaurus modeled after my wooden version.  Here is a picture of the two of them side by side.  The biggest disappointment is his head.


Well that problem is solved.  Now to make him longer and taller....

He just keeps growing, but I am not sure the leg servos can lift this much weight?

Here he is in his first video. Yes the servos can lift his weight.


Here is how to control over 20 servos with an Arduino uno.  The tail can have two servos attached to each servo output with this two way splitter adapter.

Wednesday, January 6, 2016

Arduino Uno Powered 13/15/17 DOF Humanoid robot revisited

I had problems with weak servos on my 13-17 DOF humanoid robots.  So I am rebuilding them with better servos (MG-958's) and with better software.  They also have "heads" now!  Here is what the new 13 DOF robot looks like.
Here is the video on YouTube:


Next up is the 17 DOF humanoid robot.  This is what he looks like.

Here is his video on YouTube:

This next picture shows the back view.

Here is the array for walking forward:
int walkf[8][10] = {
// 0    1    2    3    4    5    6    7    8    9
{ 95, 105, 105, 105, 105,  95,  90,  90,  85,  85}, // Left Ankle
{ 90,  90,  90,  85,  80,  75,  70,  70,  75,  80}, // Knee
{ 90,  90,  90,  85,  80,  75,  70,  70,  75,  80}, // Hip
{ 95, 100, 100, 100, 100,  95,  90,  90,  85,  90}, // Hip
{ 95, 105, 105, 105, 105,  95,  90,  90,  85,  90}, // Right Ankle
{ 90,  90,  90,  85,  80,  75,  70,  70,  75,  80}, // Knee
{ 90,  90,  90,  85,  80,  75,  70,  70,  75,  80}, // Hip
{ 95, 100, 100, 100, 100,  95,  90,  90,  85,  90}, // Hip
};

This is the code to execute that array:
      case 'f': // forward key
        for (int i=0; i<10 i="" o:p="">
          servo1.write(walkf[0][i]); 
          servo2.write(walkf[1][i]); 
          servo3.write(walkf[2][i]); 
          servo4.write(walkf[3][i]); 
          servo5.write(walkf[4][i]); 
          servo6.write(walkf[5][i]);
          servo7.write(walkf[6][i]); 
          servo8.write(walkf[7][i]);
          delay(twait);
        }
        break;        

I have also added some more commands as seen in this video.

Saturday, January 2, 2016

Dell 2300MP repairs part 3 - Replacing capacitors in the power supply

I spent some time fixing Dell 2300MP projectors for Africa once again. As usual I replaced the 22 uF at 50 volt capacitors (see previous posts).  This time I also replaced another capacitor.  The new capacitor is rated at 1500 uF at 16 volts.  Here is a picture showing the new capacitor to change.  The capacitor is oozing goo so the problem is rather obvious!

Here is a pile of Dell 2300MP power supplies to try to fix.  I needed to fix four power supplies for the current pile of projectors.

Here is the pile of projectors, I managed to fix three of them.  I only had two bulbs so that is more than what I have all of the parts for.  I still have three projectors that are parts piles.

Wednesday, December 23, 2015

Samsung LN-T4069 and LN-T4071 40 inch LCD repair.

Someone gave me a 40 inch TV that they found in the garbage.  It actually worked at first but after about 15 minutes the picture started jumping.  The first thing I did was to replace all the capacitors in the power supply.  They are located in the upper right corner of the next picture.  I used 1000 uF at 16 volt caps.  Be careful the polarity of one cap is the opposite of all of the others.  That did not help.


I discovered that if I plug in a computer the picture jumps non stop.  So I replaced the input board as shown below.  This fixed the problem but introduced another problem.  The new board had the V-Chip programmed to block some shows.  Now I have to get a remote control so I can wipe out the memory and hence delete the V-Chip programming.
I suspect the problem is in the power supply section located in the upper left corner.  The regulators have been so hot that the metal is purple in color.  I think I will start by replacing the 100 uF at 25 volt caps.

Replacing the capacitors was a complete flop.  I tried carefully wiggling the caps from side to side to remove them but in every case I removed the runs from the board.  I guess I am staying with the new board as it mostly works.  I was able to wipe out the V Chip programming with the remote control.

Ramsa WR-S208 Mixer Power Supply Repair

Over the weekend I finally got around to repairing this Ramsa Mixer.  The symptoms included that the solo light was on in one place and not on at another and that the overload LED's were lit with no input.  I opened it up to look inside and then everything started working correctly.


I started wiggling things and when I touched the power supply the mixer stopped working.  So I removed it and examined it for bad connections.  Sure enough one of the voltage regulators was no longer soldered in.

Here is a closer look at the problem.

Wednesday, December 16, 2015

Designing a DIY "Head" for your 15/17 DOF Servo Robot

There are many robot kits on eBay.  They all lack a "head".  So to get ahead you need to make your own.  I used a "Make your own Christmas tree Ornament".  They sell these 2.5 inch diameter clear plastic balls that you can use to make Christmas tree ornaments.  They can also make a head for your robot. Here is a picture of a robot without a head, just a servo motor.

He looks better with the clear ball over the servo.


You can also paint it and add a circuit board with some LED's for eyes and a mouth like in this picture.

Here is another DIY robot head this time it is made out of a 3.2 inch Christmas tree bulb.


Friday, December 4, 2015

Arduino Powered Hexapod/Spider 18 DOF Robot Part 2

Its time for an update on the spider robot.  So far I have repaired the sensor shield twice, replaced the power cable and now replaced two of the servos.  I have changed two of the MG996's to the more powerful MG958's.  That made a huge difference!  The spider can now get up completely off the floor!  The new servos also made the spider a lot quieter as the other servos do not have to work as hard.

Here is a picture of the spider folded in.

 Here is a picture of him walking.

Here is video one before replacing the two servos with MG958's.


This is the next video with the better servos.


And now the latest video with better software.

Monday, November 30, 2015

Fix for adding Servos on the Arduino Analog Port/Pins of Servo/Sensor Shield

Over the weekend I found and fixed the design bug that prevents servos from working properly when they are connected to the analog port connectors of the standard servo/sensor shield.  The problem is that the logic five volts is always used to power those servos.  If there is any load on the servos they will overload and shut down the logic five volt voltage regulator.  The fix involves cutting two runs and adding two jumpers.  This change is needed to route the five volts around the servo connectors.
The problem showed up with my spider robot project.  Some servos tried to come to life without the six volt power supply being turned on.  It took a while to figure out where they were getting their power from.  The logic five volts was being pulled down to about two volts!

Also do not forget to remove the green jumper near the six volt power input screws.  It will also short the five volt logic power into powering the servos.  That could seriously damage the Arduino!

Another thing you might need to do to use more than 12 servos is to change a line in servo.h.  This limit gets mistaken as to why servos do not work on the analog pins.  There are usually 12 servos already on the digital pins and when you try to use the analog pins you have exceeded the 12 servo limit.  The line says something like "Maximum servos per timer = 12" and you will need to change it to 18 or even 20 if you want.  I have made the change months ago and it does not hurt anything to increase the maximum servos per timer.  Servo.h can be found in your Arduino/libraries/servo folder.

While working on my "Spider" smoke rolled off the Servo/Sensor shield.  This time a run had burned off the board!  I never had these problems with my home made servo shield!  Here is a picture of the burned run in the top left corner:
Here is the cure for the burnt run as well as a cure for the power distribution issues.  basically you take power from the screw terminal and distribute it to the top and middle of the 16 digital pin servo connectors as well as to the top of the 6 analog pin servo connectors.  With this change the spider worked perfectly.

While I am showing fried stuff, here is what happens when you buy a cheap servo on eBay:

Get real servos that say "Tower Pro" not "TowardPro".  Do not buy them if the seller intentionally hides the manufacturer name.  There are a lot of junk servos on eBay!

Another issue I just confirmed is that all HiTec servos work in the opposite direction of all other servos.  I now have five HiTec servos!  There are two options: Sell them or figure out how to reverse them internally.  I might do that and then post on how to reverse them.


Friday, November 20, 2015

Arduino Powered Hexapod/Spider 18 DOF Robot

My next project is a six legged robot.  I look at these projects that are all using an Arduino Uno and servos like they are a modern day version of the "erector set" that I played with as a kid.  This is a more economical way to build these various projects instead of buying several expensive kits.  Basically I am using the same parts to make all of the following projects:
5,9,13,17 DOF Humanoid robots
14 DOF Dog robot
17 DOF Dinosaur robot
18 DOF Spider robot

I have looked at several hexapod designs and so far I have been able to reproduce the body using standard parts.  The other designs use two custom plates spaced about two inches apart.  My design uses:
4 - Angled "U" brackets
2 - Straight "U" brackets
2 - Waist brackets
4 - Straight brackets
2 - "L" Shaped brackets.

Here is a top view of my design for the hexapod body.

This next picture is a side view of the hexapod body: 

So now to collect at least 18 servos to make it work.

I decided to make my own lower legs.  I used a picture from a kit on ebay and blew it up to the actual size.  Then I cut it out and used it as a model.  These legs were cut out with a hand held jig saw.  They did not look that good in clear plastic so I painted them black.

This is after two coats of paint.

This is what they look like on the assembled spider.  They are still a little rough.

 Here is how I assembled the servo mounting brackets.  Then I added the servos and then mounted them on the robot.

 The Arduino mounted real nicely using some of the existing holes in the bracket.

Here is the completed spider as far as the mechanical assembly.


Monday, November 9, 2015

Walking "Dog" and "Dinosaur" 17 DOF robot from Humanoid robot kit.

I plan on making some more creations besides the 9, 13, and 17 DOF humanoid robots from the robot kit.  The next one is this 14 DOF "Dog" robot.  This is actually the third revision and there will be more to come.  As you can see I have had a hard time with attaching the "tail".  The "Mouth" is a robot hand or it was....

He is starting to work.  Here is the latest picture of him.  He lost his "feet" and has a more solid rear end.
And now for his first video appearance.


The next thing to do is to add a tail and make him into a dinosaur.

Here is the dinosaur video.


He has now grown to three feet long and has LED eyes.

Here is his second video with greatly improved software.


Friday, October 9, 2015

Walking "Humanoid" Robot found on eBay part 3 with 9, 13, and 17 DOF

After not having a lot of success with a more complex robot I went backwards and built a 9 DOF humanoid robot.  Here is a picture of that robot.

Here is the video of him walking.


Up next is the 13 DOF humanoid robot.

Here is his video.


Here is his servo array to make him walk forward.

int walkf[6][6] = {
// 0    1    2    3    4    5
{ 80,  80,  80,  85,  90,  90}, // Left Ankle
{ 90,  80,  70,  70,  70,  80}, // Knee
{ 90,  80,  70,  70,  70,  80}, // Hip
{100, 100, 100,  95,  90,  85}, // Right Ankle
{ 90,  90,  80,  70,  70,  80}, // Knee
{ 90,  90,  80,  70,  70,  80}, // Hip
};

I still cannot get a 17 DOF robot to work very well.  My servos are too weak for the weight! Do not buy the MG995 or MG945 servos except for the arms (or for a 9-13 DOF robot). I have burned some up trying to power the 17DOF robots legs. I am thinking of trying the MG958. Anyone know if that servo has enough power?

Here is some more Information that I have discovered about servos and robots.

Be sure the servo that you buy is not a cheap imitation.  This can be detected by the seller hiding the manufacturer name or misspelling the manufacturer name.  A common example would be “Tower Pro” (real) or “Towerd Pro” (fake).

This is my new rule of thumb for making humanoid, as in 2 legged robots.  The problem is that the more the servos (and their connecting hardware) the more the robot weighs. 

The leg servos of a 5-9 DOF Humanoid robot should handle 100 oz. inches of torque. 
The leg servos of a 10-15 DOF Humanoid robot should handle 150 oz. inches of torque.
The leg servos of a 16-20 DOF Humanoid robot should handle 200 oz. inches of torque.
Here is the video of the 17 DOF humanoid robot.


Wednesday, September 16, 2015

Walking "Humanoid" Robot found on eBay part 2

I am back to working on the walking humanoid robot after writing another book.  First I had to make an Arduino Shield to control the servo's.  Here is a video testing the servo shield.



Next is to connect it to the robot and get those servo's working.  I am using an IR remote control to test his movements.  This is a picture of the front view of the setup.

Here is the back view.  The arduino has been mounted in place for this picture.


Here is a video of me testing out the robot servo's.



Here is a second video with most of the servo's working and they are now "zeroed".



In spite of the really bad servo's he is taking his first steps.



Here is a two servo per leg version of the robot.



Here is the code for the two servo per leg robot in video 4.

void StepForward(){  //Moving Left Leg Forward
  servo1.write(75);  //shift weight to left ankle
  servo3.write(60);  //right ankle kicks weight over
  delay(200);
  servo3.write(70);  //free ankle lifts
  servo2.write(110); //left hip
  servo4.write(120); //right hip
  delay(200);
  servo1.write(90);  //level leftt ankle
  servo3.write(90);  //level right ankle
  delay(200);
  servo1.write(115);  //Shift weight to right ankle
  servo3.write(110); 
  delay(200);
  servo1.write(110);  //free ankle lifts
  servo2.write(70);  //left hip
  servo4.write(60);  //right hip
  delay(200);
  servo1.write(90);  //left ankle - back to home positions
  servo2.write(90);  //left hip
  servo3.write(90);  //right ankle
  servo4.write(90);  //right hip
  delay(200); 
}