I'm Back

Wow... Over two years since my last post. Seems like forever ago. I've been through a lot and even though I haven't been posting here I have been working on my R2. I will try and post some pics of my progress in the next week or two to show where I am. Stay tuned...

Foot Channel

I'm going to back up a little bit here in my description of the building of the foot drive. As mentioned earlier the large aluminum tube would be used to house the wheels and the small aluminum tube would be the channel used to connect the wheel housing to the leg itself. Describing the how to cut the channel really depends on the foot shells being used. The channel is designed to fit inside the shell and be the pivot point for the leg/ankle and foot. Since the different foot shells have varying thicknesses the length of the channel would be affected by this. The channel is cut on both end of the tube at the same angle that the wheel housing would be cut and the top of the tube is cut off to make it a channel so the leg/ankle can slide in.

Foot Channel with ends cut to proper angles

I test fit the channel with the wheel housing in my styrene foot shell to make sure that everything lines up. This picture below should really show what is attempting to be done here.

Test Fit of Channel and Wheel housing

When the test fit is good and everything is where you want it to be, you need to drill the pivot holes where the leg/ankle will connect to the foot. Based on other builders plans I went with a 1/2" hole for the pivot hole and used a reducer bushing to take the size down to 3/8". Once the pivot holes were drilled, I centered the channel the best I could on the top of the wheel housing, drilled some holes, and fastened them together using some hex bolts.

Channel and wheel housing bolted together

That's about it for now. Still more to come on building the footdrive...

Foot Drives - Wheel Housing (Pt 2)

So at this point we have the basic frame for the wheel housing. The next logical part of the task is to determine the location for the wheels and drill some holes but before we can do that some work needs to be done on the wheels. I used Colson Performa 5" x 1 1/2" wheels that I found on ebay for a decent price. However instead of using the hubs which came with the wheels, I used some Derlin Keyed Reducer Hubs that I had purchased from NPC Robotics. These reducer hubs work best with the 1/2" keyed shafts which will be used as the axles.

Derlin Reducer Hubs

The hubs themselves were longer than needed so I cut them down to slightly less than 1 1/2". Also, the center area of the wheels were a little wider than the 1 1/2" of the outer part of the wheel and as a result prevented it from fitting in the housing. So I took the dremel with a sanding bit on it and sanded down the area around the hub until the thickness was reduced enough to fit in the housing. After doing that, I installed the reducer hubs.

Wheels sanded down with reducer hubs installed

Next step, determining the location of the wheels in the housing. Based on some advice from other builders, it is recommended that about 1 1/2" of the wheels stick out from the bottom (of the original tube, not the cut line) and that the wheels be far enough away from each other as possible in the housing. I played around with this and eventually found the optimal location and marked them off. I used a 3/4" bimetal hole saw bit and drilled through both sides of the housing to ensure that the holes lined up as close as possible for the axles.

Wheel Housing with axle holes cut

Having the hole saw bit go through and make pilot holes for the other side worked out great. and allowed me to drill the opposite side without much concern as to whether or not they would line up.

Wheel Housing with both sets of holes drilled

Next step was to prepare for the installation of the wheels in the housing. The axle size is 1/2" so I used some  bronze bearings for a 1/2" shaft. The bearings however were a little long so they needed to be cut down to fit with in the walls of the housing without protruding on the inside.  This meant taking the hack saw and cutting 8 of these little things down to size. Not a difficult task but very time consuming.

Full Size Bearing and one cut to size

Once the bearings were cut to size, I used some JB Weld and glued them into place using the axles to ensure that everything is aligned properly.

Fastening the bearings in place

Once that solidified, I did a test fit with the wheels and all looked good.

Test fit with wheels

Next up gears and motors!

Disney Buys Lucasfilm!!

Ok, as I'm sure everyone is aware by now, Disney has acquired Lucasfilm and in turn the Star Wars franchise for a mere $4 billion. As a result, a local website (www.rockincomics.com), asked me to participate in a Roundtable discussion about the sale. I felt honored to be asked and had a blast doing it. The podcast just made it online so here it is: http://www.rockincomics.com/podcast-rockin-comics-round-table-disneystar-wars/

Foot drives - wheels housing (pt 1)

Long time coming for this post...

Back in May, I went to work on building the foot drives for my R2. I decided to go with the Senna Drive model because it seemed to be the best drive out there I could find. Over a few months I slowly purchased all the parts needed for the drive and after watching the DVD tutorial I had several times, I finally got up the courage to get down to business.

The body of the foot drive is made out of 2 types of aluminum tube. The first tube is 4"x2" with a 3/16" wall and will house the wheels and the second tube is 2 1/2" x 1 1/4" with a 1/8" wall which will be used for the channel to connect to the legs.

I purchased some metal cutting blades for my chop saw and the first cuts I made were to get the tube ends at  the proper angle so the foot shells could fit on top of it with some clearance on each end. Now the tube was not cut so it would be flush with the inside of the foot shell but instead was cut to be slightly smaller than it so that the shell could fit over the top with plenty of room to spare.

wheel housing after ends cut to size

After cutting the sides the edges on each end were chopped off. This was to remove a sharp edge off the housing and allow for better clearance in the foot shell. That sharp pointed end would actually interfere with part of the shell so it best be removed.

Edges chopped off 

The previous 2 cuts were done fairly easily using the chop saw. The next cuts were much more difficult because I would be using a jigsaw. At this point we just have a tube still and there was no opening for the wheels. So I basically had to remove the bottom section of the tube. To do this I put the metal cutting blades on the table saw and cut a couple of starter cuts large enough to fit the jigsaw blade in.

Starter cuts to remove the bottom section

Using the jigsaw I cut the bottom section out. Due to the width of the tube, I had to make the cuts on each side of the tube individually. I couldn't just make one cut and have it go through both ends. Note that to ensure that the housing remains sturdy and keeps it's shape, a section of the bottom of the tube was left intact on each side of the tube.

Bottom section removed (Sorry the pic is blurry but you should get the point

Cutting this with the jigsaw was not easy. I ended up using 10-12 metal cutting blades for the two housings. I held the jigsaw steady but it still jumped and bucked the entire time. Besides having them go dull, several blades broke as well so this was done as carefully as possible. Safety glasses, long sleeves, and other protective gear were worn at all times.

Sorry...

Sorry about the lack of updates over the past 5 months. So much has been going on in my life that R2 had been put on the backshelf for a little bit. However, I have been getting back to him so I hope to have some updates of what I have done recently up soon.

Frame Work and Painting

I finally got back to adjusting my frame. In an earlier post I mentioned that the quarter rings in the front of the frame were causing tension in the frame and wouldn't line up correctly. I took the frame apart and compared the positions of the cuts on the quarter ring to that of the middle ring and saw what needed to be done to correct the problem. So I pulled out the band saw and made a few cuts and voila! things looked good.

Frame with corrected quarter rings

Along with fixing the frame I also primed the bottom of the bottom ring since it will be visible to the outside world.

Bottom Ring Primed

I was also able to get the ankle wedges and cylinder holders primed and painted

Ankle Wedges Painted

Cylinder Holders Painted

I can't wait to be able to start putting a lot of this stuff together. It gets to be a little frustrating to do all this work and still not be able to see anything substantial yet. Need to keep going and keep my eye on the prize.