Sunday, April 24, 2011

Turning Heads

The wheel I ordered for the head motor arrived Friday and I wasted no time installing it.

I got the wheel from ServoCity.com. They actually send you two wheels. In addition I had to order a 1/4" wheel hub to attach it to the motor shaft plus screws.
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Video shows the wheel working without and with the head on. Another long awaited mile-stone reached.


It's a good thing I got a stronger tension spring. I tried it with the first one I got and it wasn't pulling the bracket hard enough for the wheel to get good traction on the Rockler bearing. Using a shorter and stronger spring fixed that.

I also received shipping conformation for the belt wheels with am estimated arrival time of "varies." God willing the wheels will arrive in time for me to install them before Droid-Con.

John

Friday, April 22, 2011

Got a few more things done yesterday. I got the hole drilled for the head motor and adjusted its tension spring so it's tighter, finished the center foot's caster wheel, added a quick disconnect for the battery so I don't have to keep using a wrench and screwdriver to remove the wiring, and I ordered the wheels for the foot drive. Sadly the wheel for the head motor hasn't arrived yet.

Photobucket Photobucket Photobucket Center Foot Caster Mount Photobucket Photobucket Photobucket Photobucket Photobucket Batt. Quick Disconnect Batt. Quick Disconnect

About the foot drive wheels. The source for better wheels I was given was out of stock. So after searching and searching the Internet I eventually checked ebay. There I found the original Razor E100 belt driven rear wheels I was told can't be found. And for only about $17.00. Just one thing. They're in China. I bought two of these wheels but because of them coming from China, I don't know if they'll make it here on time for the Droid-Con. I tried working with those "other" wheels I have but there's just no way. So here's hoping they get here with time to spare.

John

Monday, April 18, 2011

Center Foot & Head Motor

Yesterday I continued work on the Center Foot's caster mount. After test fitting the block I made I discovered I had miscalculated and ended up being a full one inch short. So I had to make two more half-inch blocks and glue them on.

Next I started work on the mounting bracket for the head rotation motor. Using scrap aluminum from the foot drive brackets, I made a flat piece measuring 1-1/2" x 4-1/2" x 1/8". I then drilled two holes to mount the motor, one hole for the motor shaft, one hole to mount the bracket to the body frame, and one more to connect a tension spring to. The tension spring's purpose is to pull the wheel (that will be on the Pittman motor) snug against the inside of the Rockler bearing. The other end of the spring simply connects to a hook of some sort on the body frame. To secure the motor to the bracket the motor is pre-tapped for #10-32 machine screws. To secure the bracket to the frame I'm using a 5/16" x 1" hex-bolt with 2 metal washers and three nylon washers. The nylon washers go right above and below the bracket. They help the bracket move while the bolt is tight. For the spring I used spare screws I had laying around.
Head motor bracket Head motor parts layout Motor on bracket Tension spring 5/16" bolt w/ hardware Mounting hole in body frame Bracket installed Extra room needed

Two things. One, I feel the spring I got is too long to give the amount of pull I want so I'm going to get a shorter one. Two, in the last photo you can see a half-circle drawn where the motor shaft is touching. This is where I need to remove some material so the motor can be close enough so the wheel will touch (I'm just a few fractions of an inch off). This Thursday I will take the body to the shop and carefully remove that spot. Hopefully the wheel will arrive by then so I can do a full test fit and then a powered test run.

John

Friday, April 15, 2011

Outer & Center Foot Prep

Yesterday I drilled the holes needed for the wiring in the top of the outer feet and started work on mounting the caster wheel in the center foot.

Before and after. Used a half-inch drill bit.
Drilling Wire Hole Drilling Wire Hole

For the center foot, I needed to make a block big enough to secure the caster to and extend it enough to get the proper height from the ground. Most builders extend the wheels out about 1.5 inches so I'm doing the same. To obtain this, I made a wood block out of 3 half-inch thick pieces of plywood. The top block I made to fit the inside of the foot while the next two blocks are the same size as the caster wheel's mounting footplate. I have two more pieces to make which will provide a way to secure the main block within the foot.
Center Foot Caster Mount Center Foot Caste Mount Center Foot Caster Mount Center Foot Caster Mount

I'll share the measurements and other details once I prove this setup will work.

I've also started designing the head rotation motor bracket and have ordered the wheel for this motor. Basically the wheel will rest against the inside of the Rockler bearing and make it spin. I'll be using the scrap aluminum from the foot drive.

Soon I'll be able to order the main wheels for the foot drive and then R6-C9 will be able to walk for the first time. It will be a true milestone for this project. I can't wait.

John

Monday, April 11, 2011

Drive Bracket ready

Yesterday I continued work on the foot drive bracket. To make it fit properly in the foot shell I had to cut off about half an inch from the top corner on the wheel side.
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With the corner cut off I can position the bracket so the motor has clearance.
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To secure the bracket inside the foot shell, I decided to use two 1/4" x 1/2" hex bolts through the side. Using the horizontal drill press, I slowly drilled two holes through the foot shell and drive bracket.
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All that's left now is to get the new wheels and install the motors.

While I was at the shop, I finally remembered to get the 1/4" spacers on each side of the center ankle so it will fit without sliding from side to side. As you may remember, I accidentally made the mounting rails too far apart.

One thing I did forgot to do was drill a hole in the top of the foot shell for the wiring from the motors to the leg wiring to pass through. Will just have to wait until Thursday to do that.

One more thing I was able to do at home was finish painting the two blue panels. Now I can start on the remaining pieces.

John

Friday, April 8, 2011

Painting and Wiring

It was a nice day today so I was able to get a little more painting done. The three panels I've been working on are finally done and I put a third coat on the two blue panels.

I also started to wire up the legs for the foot drive but ran short of those Anderson Power Pole (APP) connectors. More are on order. Since I'll have to remove the wiring later when I'm ready to paint the legs, I'll be using temporary connectors on one end of the leg wiring so I don't waste any of the APP connectors.

Still saving up for new wheels for the foot drive. Hope to be able to have them in time for the Droid-Con.

I need to make one final adjustment to the foot drive brackets before I install them. For some reason they don't line up right inside the foot shell for the motor to fit. I've determined if I cut off one corner on the wheel end then I can make it fit. Will try to do this on Sunday. I also need to get a caster wheel for the center foot.

So much to do, so little money.

John

Monday, April 4, 2011

Made Motor Brackets

Friday I received the aluminum tubes for the foot drive motor brackets and Sunday I started work on cutting and drilling. To cut the aluminum I used metal cutting drill bits and my Dremel. I started by cutting the tubes to the desired length of 8-1/2" long. Then I taped the drilling patterns to each side of the tubes. Using a drill press I slowly drilled the holes needed for the wheel axle, the motor and the motor's mounting screws. Once that was done I used the Dremel and about two packs of cutting wheels to cut the wheel axle slots and half of the bottom to give the wheel clearance.
Drilling Patterns Drilling Complete Bottom Cut Out

Tada! All done.
Completed Motor Bracket Completed Motor Bracket

There is, however, one problem. The wheels do not fit. I tried everything but they will not fit inside and spin. The fit is just too tight to work. So that's $80 bucks down the drain. Luckily I have been shown another wheel that will work. They're half the price too. Wish I found them earlier. So other than the wheel problem the foot drive is nearly ready to install. Only thing left to do is devise a method to secure them inside the foot shell in such a way as to be able to remove them.

In the meantime I will either start work on the new head or start mounting the skins.

John

Friday, April 1, 2011

Some Foot Shell Work

When I was assembling R6 at Celebration V, I discovered the bolts which hold the ankles to the feet wouldn't fit through the holes in the feet. The bolts were the correct size, but the holes were just a bit small. So yesterday I fixed that by using my Dremel with a small sanding drum to widen the holes a bit. Now the bolts will fit so the legs and feet can be securely connected.

While I was at the shop I started working on a new head for R6. The main problem with the current one is the crown, or lack there of. I had thought I could add it on later but my attempts to do so have fallen short in good results. So my new design for the head will be to made the vertical ribs one whole piece, including the crown. I'll be making 6 ribs (fewer than the current head has) mounted to a base that will sit on the rockler bearing. My first attempt at making the first rib leaves some room for improvement but with a few adjustments it should work this way. Once assembled I will continue as originally planned and wrap the head with styrene or sintra (both are similar types of PVC based plastic). Can I get all that done before Droid-Con? Maybe, but I'm more eager to get the foot drive system finished first.

Speaking of the foot drive, I ordered the aluminum tubing and it should be here any day. Maybe Sunday I can start on that.

John