R2server

[crazybillybob]

I got a little more done this weekend.

Both feet are bolted the legs and R2 is standing on his own now.

Now Everyone wants to get into the Action!!

I also realized that I needed to stiffen the open side of the outer feet, I'll also try and give you a better Ides as to how I've done all the sheet metal work so far.

I started out by making a pattern.

The Pattern is transferred to sheet steel (this is 22guage steel), then it is cut out, I used "Tin Snips" (also called Aviation shears) to do this.

Once that is finished we move to the bending. On these pieces there will be a smaller bend about 1/2" up from the bottom then a hard 90degree bend about an inch up from that. There should be an inch or so flat then arch up into 90.
I start with the hard 90, then the slight angle, and finish off with the arch.

Being a home shop I don't have a sheet metal brake, but I do have a nice piece of angle Iron, and some clamps.

Then Apply Pressure and smooth out the high spots with a ball peen hammer.

Once both angles are bent you get something that looks like this.

To add the Arch I used a piece of Iron gas pipe instead of the angle Iron.

Just apply gentle pressure till the metal is in the shape you want. Smooth the high spots (they look a bit like bubbles) with light taps from the ball peen.

I'll be posting pics of the finished pieces tonight, I seem to have forgot to bring them with me this morning. oops

Thanks For Stopping in!

Crazybillybob

[hxcguitarist]

great work CBB! i have enjoyed following your work log! keep it coming!

hxcguitarist

[crazybillybob]

great work CBB! i have enjoyed following your work log! keep it coming!

hxcguitarist

Thanks, HX ....I'll be here till he's done.....Then I'll still be here just with a diffrent mod



Crazybillybob

[crazybillybob]

Good Day R2 Fans.....Welcome to another Fun filled update.....

After all that bending and shaping this is what you get.

I've got the piece dry fitted into the foot where it will be. It needs a hole cut out for the end of the scooter motor and a little more adjustment on the gaps but most of that will be taken care of when I clamp it up to weld it all together.

I was also able to get the center ankle cut out. The main part of the ankle is 1/4" (6.35mm). The tip that the bolt will go through is reinforces with a piece of 1/4" and 1/8"(3.175mm) on each side.

The Center foot shell also got the channel path cut out of it.

Now I just need to get the channel cut correctly, and weld it in place.

Moving to the other end of the Droid. I've been asked about how I'm going to get R2's head to spin....
Here's my choice.

It's a 12"(30.4cm) round Lazy Susan (picked up at Lowe’s). I'm still thinking about weather it's going to be driven by a gear or, friction drive type assembly. Both have their pros and cons. One thing for sure I need to have a way to get power up into the dome that still allows 360degree rotation. I've got a few Ideas but they all depend on how I turn it. Let me know if you've got a great Idea (or even a good one...) for these problems....

Thanks for dropping in...I'll be back soon with more from the Backwoods Lab.

Crazybillybob

[wingman358]

Lookin' good, crazybillybob!

[Rankenphile]

You know, the thing I love about this worklog the most is that you really get down into the nitty-gritty of a fabrication job like this. It's not just "I'm polishing the heat sink for my fancy new $600 video card", it's "This is how I bent the metal that supports the cam that turns the gear that spins the doodadd I fashioned out of duct tape, aluminum scrap and hillbilly gumption".

Keep up the great work, CBB.

edit: About your drive mechanism - I'd still recommend a gear drive. You can control the speed and accuracy a lot more, at least the way I've got it figured out in my head. If you can build a right-angle lip inside the dome to run a toothed track - such as a flexible drive belt securely attached to the angle lip - and have an appropriately sized gear (you can get very good precision gears at RC shops, but I'm sure you already know that), then you should be good to go. One thing to consider is properly shielding the motor away from any computer components with some sort of Faraday Cage (spelling?) to prevent the electric motor's electromagnetic pulses from interfering with the operation of the system - I've got a great horror story of a friend of mine using an electric screw gun on the inside of his computer and pretty much destroying the data on one of his hard drives.

I'm still stumped on preventing the wiring from tangling or pulling out, especially after repeated turns back and forth, putting stress on your solders.

I'm sure you've got a lot of this down, though - like I said before, you're one hell of a better engineer than I am.

[crazybillybob]

I've been musing about slip rings lately.

The down side is that with the slip ring in the middle I have to work out a gear set that would run around the out side of the bearing. The larger gear would have to attach to the bottom of the plywood and the whole thing can't be to thick (about 1/2" max (1.27cm)). Anyone have software to design a 16"(40.64cm) gear? and a 2" (5.08cm) matching gear? OR a plug-in for AutoCAD that will do it. As I don't know how to calculate all the things needed for a gear (I'm sure they taught use the basics in collage physics...but I don't remember anymore).

Better yet anyone have a 16" -18" (40-45cm) Gear laying around? (that is light weight less then 5 lbs (2.26Kg))...

More or less Thinking out loud here....If you've got Ideas....Join in..!


Also Started looking into Prices on the PC Parts I need. Between Mini-box.com and newegg.com I should be able to get all the parts I need shipped for about $600US. Now I just need to get my Tax info so I can Get my return and order these pieces!!!

Crazybillybob

[chris_kalan]

An idea I had would be to run gear tracking around the lower edge of the head. Then you would just need a motor and a single gear to be able to spin the head as you needed to.

[crazybillybob]

That's the basic Idea with the Gear. I was just going to mount it to the plywood as it's easier to find gears smaller then 18" around. Which is what I'd need to mount it to the dome.

Thanks for the Idea...

Crazybillybob

[Rankenphile]

You know, I've been mulling this thing over all day at work, because I love puzzles like this. I want to work something out on paper when I get some time to actually fiddle with it but one thing I realized is that I'm pretty sure faraday cages don't work for elecrtomagnetic waves, only radio waves and such.

Hmmmm..... how do they do shielding for speakers to prevent damage to CRT screens?