Tuesday, May 31, 2011

Center Ankle Redo

Had some free time this holiday weekend so I decided to get some "corrections" made.

First up is the center foot and ankle lock. I decided to completely remake the center ankle due to some minor imperfections and needing to make some changes for the ankle lock. Using the leg template I used before I made two new 1/2" pieces and glued them together. Next I'll make the outer 3/4" pieces and glue them one at a time to the sides, but it may be awhile before I can do that because of having to spend a lot of time at my new job. In the mean time I'll do what I can at home.

Other changes I'm making will be moving the head motor to the right side of the body so I have room to install the battery. The motor was getting in the way during Droid-Con so I had to install the battery through the side, which won't be possible to due once I put the skins on.
Also all the feet need to be repainted again in certain areas. One of these days I'll be done with that.

John

Sunday, May 22, 2011

Droid-Con: Before, During and After

First I'd like to say I'm sorry for taking a whole week to post updates about last weekend. I started a new job last Monday and I've been very busy with that.

So, to start, on Thursday, May 12, I assembled R6-C9 for a test run of the foot drive and to check all the other parts and electronics.
Photobucket Photobucket Photobucket

Here's the new mounting bolts I mentioned in the previous post.
Mounting bolt Mounting bolt New mounting hole

Here's a video of R6's first time trying to move.




Now the Director's Commentary:
Part 1:
Funny how few things work the very first time the way you thought it would. What's that noise? A loose belt in the right-foot. Easy fix. But here's where I make my first mistake which I'll regret later on. I started out with the wheels in the front of the foot shells but while I was fixing the loose belt I flip-flopped them so the wheels were in the back of the foot shells. I had reasoned that having the wheels in the back would give better weight support. More on that later.

Part 2:
OK, bigger problem here. If you look closely at the outer feet you'll see the front of them touching the floor. That's why R6 couldn't move. The feet were dragging into the carpet. I had forgotten I needed to lock the ankles (center foot included) so the foot shells don't rotate on the ankle onto the floor. Now here's where I went brain dead. Normally I would have waited until I could get to the shop to study the problem and make some wooden blocks to hold the foot shells in place. But because the Droid-Con was the next day I decided to cut some metal blocks in my apartment and J.B. Weld them to the foot shells. In order to J.B. Weld I needed to sand the paint off a spot on each foot shell where I would place the blocks. Clamp the pieces in and let dry over night.
Photobucket

Part 3:
Friday Morning, First day of Droid-Con.
OK. So it didn't work. Except for the center foot, the blocks held in place, however, the wood is too soft and so was bending around the blocks, or the blocks where digging into the wood. I had to think fast. Only a couple of hours until Droid-Con starts. I decided to drill a whole through the foot shells and the ankles on the outer feet and use a bolt to hold them in place. I placed blocks under the feet to hold them in the position I wanted and drilled away.
Ankle Lock

Part 4:
It works!!! OK, disassemble, load up and head out. Next stop DROID-CON!

One problem I was still having was with the center foot. While going forward it works fine. But if I go backwards the foot tilts up and R6 gets stuck. During the 'Con I got several ideas on how to fix this (bolts, ankle blocks, different ankle design) which I'll deal with later.

So I get to the Hotel, assemble R6 in the parking lot and as luck would have it....more problems. Because I flip-flopped the motor brackets the steering was backwards. Left was right and Right was left. A simple wire flip-flop corrected this. But then the power went out. Turned out to be a loose wire between the main switch and the PCB tray. I did a temporary fix and off he went.

Here's some photos and video I took while there.






Now notice how R6 has trouble turning. This is mostly because the wheels are far from the center of the body. So if I switch them around again I'll be able to perform tighter and better controlled turns. Locking the center ankle and foot will also help.

Had a great time at Droid-Con. I met several people who live in other parts of Indiana. There were several panels with someone talking about a particular aspect of droid building such as weathering, dome building, electronics, etc.. The Hotel staff was also very friendly and let us get away with things like using the droids to "floor-ski" in the hallways. Some of the guys are a little crazy, LOL. There's already talk about the next one and it very well may be back at the same Hotel.

So post 'Con work. First is to put the drive wheels in the front of the feet as I originally had it, and which I have already done, although this required drilling new ankle locking bolt holes in the foot shells.
Second is to buy the styrene I need to finish the head. I had an idea about getting a cone shape on the top which would negate having to make a new head....if it works. I'll explain that when I try it.
Third, the center foot is a half-inch higher than the outer feet. To solve this I'll just remove that much off the bottom of the center foot wheel mount.
Forth, everything else.

I'm going to take a little break (about a month maybe) so I can settle into my new job. Then back to building.

John

Tuesday, May 10, 2011

Scooter Foot Drive Complete....and other stuff

At long last the foot drive is assembled and working. I tell you I've had more setbacks with this one component than with the rest of the droid put together. Here's hoping it stays that way.


When I first placed the new wheel on the bracket I noticed a problem. The hole I drilled near the wheel to mount the bracket to the foot was in the way of the wheel. Oops. Drilled that sucker a little too high. So back to the shop to re-drill. This time I decided it would be easier if a longer bolt went all the way through the bracket. So I also drilled matching holes on the other side. Another problem I found was the motor being 3/16" too long preventing the bracket to rest against that side of the foot shell. I solved this by adding a nut between the bracket and the inside of the foot shell. Hopefully this will work without any problems.
Mounting bolt Mounting bolt New mounting hole

All that's left now is to clear coat the foot shells and then I can fully assemble R6-C9 and make him walk for the first time. I've already clear coated the center foot and will clear coat the two outer feet tomorrow.

Droid-Con starts this Friday. Be there!

John

Friday, May 6, 2011

Wheel Bearings Arrive

Got the bearings for the wheels Wednesday. Fortunately they fit.
Ball Bearing Wheel with bearing Wheel with bearing

Right now I'm working on finding the best way to mount wheels onto the drive bracket. This involves trying out different pieces of hardware (nuts, bolts, washers. spacers) to obtain the best free movement of the wheel. I have an idea on how I'm going to do it, but I need to do one or two modifications to the bracket at the shop this weekend. I'll explain the details of this once I'm done.
I'm also still repainting the foot shells. They're just about done. One more coat and then I can clearcoat them.

John

Sunday, May 1, 2011

Received New Wheel....but......

Quicker than I was expecting, the new scooter wheels from China have arrived....buuuuut there's a problem. When the eBay description said "fresh from the factory" they meant it. The wheels do not have any bearings. Why is this important you ask? Allow me to explain. [Takes deep breath] Two bearings go inside the center hole of the wheel so a. the wheel will sit level on the axle and b. so despite the weight on the axle, the wheel can still rotate smoothly. As soon as I realized my problem I sent out an S.O.S. to the Club asking for advice hoping for a fix. Luckily someone was able to direct to where I could purchase the bearings needed. So all's well that ends well. The bearings are on order and should arrive shortly. Need to be more careful when buying on eBay. Especially when the item is coming from China.

Anyway, pictures of the bearing-less wheels below. Enjoy.
New Wheel New Wheel New Wheel

In other news, today I gave a fresh coat of paint to the feet. Over the past year they've been knocked around a bit from transporting them to and from the shop so chipped paint has occurred and exposure to the light has dulled the color a bit. This time I'm going to try finishing up with some clearcoat to help protect the paint and give it a bit of a shine. I'm also thinking about painting some of the chipped paint spots an aluminum color for a weathering effect.

Laters,

John