Please excuse my excitement. A very simple project.

[Robo_Pi]

Today I did a very simple project, but it took me several hours just the same. I'm building a robot base and I needed to make up some special axles. I also didn't want to spend any money on this project. Well, actually I already bought the wheels and tires, but I didn't want to put anymore money in it than I need to. So I went out in the field today and cut a couple pieces of steel rod off an old hay rake to make the axles from. The rods were bent so it took a while to try to get them straightened out as best as possible. I did that in a large vice with a hand-held sledge. Then I cut the axles to length, faced off the ends in the lathe and drilled center holes in the ends of them.

Then I had to turn down the ends ever so slightly to make them fit through the bearing races of my wheels. Finally I had to drill 8 cotter pin holes Two for each wheel so I could mount the wheels between the cotter pins with washer. This was the fun part. I needed to figure out a convenient way to drill these holes centered on the shaft. I came up with the following plan. I have a lathe/mill combo machine. So I figured that if I put the axles in the lathe chuck with the mill drill lined up on center this should do it. I could use the lathe chuck as the vice to hold the rods. So that's what I did. On the very first hole I also discovered that the chuck needs to be locked into place. There's no way to lock the lathe spindle so I had to hold the lathe chuck in the milling vice.

Notice in the following picture the mill vice is not holding the workpiece. It's just holding the lathe chuck.



I was then able to drill the axle with a center drill as shown above.

And finally with the cotter-pin drill shown below:



I had to drill two cotter pin holes for each wheel. One on either side of the wheel.

This is a photo of the finished axles with wheels attached.



This is going to be the base for a robot. And they are laid out here pretty much the way they are going to be on the robot.

Next I'll be making a wooden base as the main frame that will hold the batteries and motors. Once I get those mounted I'll need to make some bicycle chain sprockets. I've decided to use chain drive on all four wheels. One motor driving two wheels on each side of the chassis. There is no steering mechanism. Turning will be accomplished by running the right and left motors at different speeds. Or running one forward and one in reverse, which should allow this thing to turn around on a dime.

I'm excited about building this robot, but it's a project that can only be worked on during "free time". Which doesn't come up too often. Today I wasn't feeling very well so I decided not to do any "work". Then I said to myself, "Well go do something on the robot then". Who am I to argue with myself.

So I'm one tiny step further toward having a robot now.

But yeah, I really enjoyed doing the machine work on the lathe/mill. And yeah, I know I could have gotten by doing it on a drill press, but that wouldn't have been nearly as much fun.

 

[mmcmdl]

Why's your key in the chuck ? You plan on making projectiles also ?

 

[Robo_Pi]

Why's your key in the chuck ? You plan on making projectiles also ?

Actually I'm so safety-minded that I have been removing the key from the chuck before turning on the machine. However, in this particular situation removing the key from the chuck is overkill since the chuck is locked down from turning with the mill vice. The machine is configured for running the mill/drill head. So the lathe chuck is disengaged. It better not turn.

But if it did turn it would be an extreme disaster since the milling vice is in the way of the chuck jaws preventing the chuck from turning. Something else would need to give. Probably the belt drive would slip. I don't keep my drive belts real tight anyway specifically to allow them to slip in the case of an accidental crash of some sort.

But yeah, I've actually been removing the chuck key before turning on the machines anyway. Just force of habit. What happened in this case is that I was putting in the very LAST axle and thought to myself, "Hey I should take some photos and share this silliness with the guys on Hobby Machinist". So I stopped in the middle of that operation and grabbed the camera. Even I noticed the chuck key in the photo afterward and thought to myself, "Ought-oh! Owl be getting comments on that", and sure enough it was the first comment I got.

 

[eugene13]

Keep the pictures coming, I want to see your robot.

 

[ezduzit]

... I have been removing the key from the chuck before turning on the machine...

Extremely bad habit and unsafe to leave the key in the chuck.

 

[Robo_Pi]

Keep the pictures coming, I want to see your robot.

It's going to be a much larger version of this one.


This was the original prototype. Much of the electronics is going to be identical.

There are four computers running this robot. Three onboard computers, and it's also connected to my laptop via WiFi.

The Onboard Computers:

1. On the "top shelf" there is an Arduino Mega. This controls the motors and monitors sensors.

2. On top of the Mega is a prototyping shield that contains a ESP 8266 WiFi module.
The ESP 8266 is actually a powerful computer in its own right. It's fully programmable and can be programmed using the Arduino IDE.

3. On the front lower shelf is a Raspberry Pi. This will become the automaton brain of the robot.
I program the Raspberry Pi using Python.

The Forth Computer:
The forth computer is my laptop which is in direct communication with both the Arudino Mega and the Raspberry Pi. The Raspberry Pi also has its own WiFi connection.

4. On the laptop I'm running Visual C# as the main "Robot Overseer". This is so I can program the robot from my laptop live and get feedback from the robot as well.

The ultimate design is to use the laptop as a prototyping tool to write more sophisticated programs. I can then transfer these over to the Raspberry Pi to allow the robot to become fully autonomous. The Raspberry Pi is almost as powerful as a laptop in computing power.

So while this prototyping robot is physically small it has an almost infinite capability for intelligence.

The new base I'm currently building will basically be just a larger physical robot for this same original computing architecture. In other words, once the physical base is built it's just a matter of moving all the computers over to the larger robot. All the programming and intelligence will remain.

The only major difference will be the motor control board. On the small robot in the photo above you can see a small red PC board just to the right of the battery pack. That is an H-Bridge motor driver. On the larger robot I will need a much larger motor driver. But other than that, all the rest of the electronics should move over to the larger robot without any need for modification.

So in a sense the robot is already built. It just needs a larger base so I can add a larger body and arms.

 

[Robo_Pi]

Extremely bad habit and unsafe to leave the key in the chuck.

Exactly. Don't worry about it, this machine wasn't even plugged in at the time that photo was taken. Not only this, but if you read the OP you would already know that this chuck isn't about to turn anyway. It was locked down with a mill vice. There's no way this chuck could be turned. Something else would need to break first. The only thing the chuck was being used for in this operation was as a stationary vice.

But yeah, the moment I saw the chuck key in the chuck I knew that was going to spark replies. But rest assured that were no unsafe practices being done here. As I say, the lathe wasn't even plugged in when this photo was taken.

Well, technically is was. But the receptical it was plugged into had no power.

In fact, I suppose I should explain precisely how OVER SAFE my shop actually is. I went through a lot of trouble wiring this up because this is how extremely SAFE I am.

Notice in the following photo. There are two switches that must be turned on in order to run the lathe. One is a main power switch which also lights up a bulb on the wall so you can see that there is power for the lathe. The other switch is on the lathe itself.



In the next photo you can see that the power is on for the lathe because the light is lit.



Close-up of the main power switch:



I don't only do this on my lathe. I have this same set up for all the power tools in my shop. Even my drill press is set up with this.

I won't even put the chuck key in the chuck when this light is ON.

So that's how safe my shop is.

And I NEVER leave the chuck key in the chuck when the machine is set up as a lathe. In the case of the set-up I had for drilling these axles it actually wouldn't have mattered if I left the chuck key in the chuck while drilling the holes anyway. Because that chuck wasn't about to turn no matter what.

None the less, I actually removed the chuck key even before turning on the mill. A totally unnecessary safety precaution in this particular case.

If anything, I'm extremely OVER-SAFE. Which I don't mind being actually.

You can never be too safe.

But no, I NEVER leave the chuck key in the chuck. This photo was taken DURING the chuck tightening operation. I was in the middle of setting up that axle to be drilled. So it wasn't like the chuck key was left in the chuck unattended.

I knew this photo was going to spark these comments. But the photo had already been taken, and by the time I realized the chuck key was in the photo I had already closed down the shop. I wasn't about to go back out and try to set everything back up again just to take another photo without the chuck key in the chuck. The chuck was locked down. In theory there would be no danger in leaving the chuck key in the chuck throughout this entire drilling operation. That chuck was NOT going anywhere.

At the time of this photo this machine wasn't even a lathe. It was a mill/drill.

 

[ezduzit]

...Don't worry about it...rest assured that were no unsafe practices being done here...

You just don't get it.

I'm not worried about your truly unsafe practices a bit. Just trying to help you keep from hurting yourself or others.

Unsubscribed.

 

[Robo_Pi]

You just don't get it.

I'm not worried about your truly unsafe practices a bit.

There were no unsafe practices to worry about.

Safety includes having an understanding of what's going on around you. In this situation the chuck was being used as a stationary vice on a mill table. It couldn't turn no matter what.

Just because you see a photo of a chuck with a key in it doesn't mean that anything unsafe is going on.

 

[ThinWoodsman]

I tend to consider what would come up during an accident investigation, regardless of how safe things are and how improbable an accident might be. Questions like "Was alcohol present when you were discharging these firearms?" Doesn't matter if you've got the rifle in a lead sled and no bystanders to wander into the field of fire - "yes" is just a bad thing to answer.

To put it in more topical, plausible terms: "Is this a picture of a chuck key in your lathe chuck? Claim denied!"