Lifting the droid into my pickup solved

As my lift design wasn't sound and downright dangerous, I decided to look into what commercial options were available. And there were many different solutions and most had drawbacks. However, there was one design very similar to what I did but much more efficient. It's a hitch mounted boom crane that will lift up to 700 pounds. Just right for my needs. And this one has an arm so you can swing it into the middle of the bed. Much more efficient. The only downside is it's not cheap. I was considering buying a trailer but the expense of storage for the trailer, upkeep, license plates, tires etc. I was able to justify this purchase and even convinced the wife. Plus I can see other benefits of having a crane to lift heavy items into the truck. For more information about this lift kit, see http://www.spitzlift.net/

Stressing steel and a robot builders limits

After spending weeks building the escape pod, I added nice trim and some paint. I reinforced all the joints and I was confident that it could support 500 pounds without any problems. Plus it looks pretty cool too.

The crane assembly however was another issue. Today was stress test day. The day I would load a lot of weight into the escape pod and "attempt" to get it into my truck. The first test was a relatively simple one where I attached the chain hoist to the escape pod and quickly whisked it into the back of my truck. Ahhh this will be a piece of cake I thought.

The next test, I took several 40 pound buckets of paint, several full 5 gallon gas cans (leftover from hurricane supplies), my floor jack and a couple pieces of junk and load it all into the escape pod. I estimated it was about 175 pounds give or take 20 pounds.

I knew I was in trouble when shortly after cranking on the chain hoist I started hearing some strange noises. At first I thought the hitch pieces were just getting ready for the load and it would be ok. But after a few more cranks and a few more unsettling noises I noticed now deformed the hitch piece that the pole that was attached to the crane was. By this time the pod was only a few feet off the ground but that was as far as I was willing to go. The deformity of the steel bars was pretty scary. I didn't think that would happen with steel. But that's because I'm no engineer and just a garage hack. At least I figured this out taking my time and didn't have this stressing of the metal happen outside of my home. Could have been dangerous.

So what does this mean boys and girls ? Once again I'm "back to the drawing board". C3PO was right - This droid is sure going to cause me a lot of trouble.

Getting R2 into the pickup truck

This week was spent coming up with a way to get a (very heavy) crated R2 into the back of my GMC Pickup truck without destroying my back.

I looked at many options. The truck cranes at Harbor Freight, Motorcycle lifts, Jacks, and winches. Each option had it's drawbacks. Whatever I did had to be able to be set up and ready to go in 5 minutes. Plus I wanted nothing permanently mounted to my truck as I also use it to carry my kayak/sailboat. And the Kayak setup I used is what actually gave me my ideas. Using a bed extender ($39.00 at harbor freight) I was able to come up with a bracket that would hold a 8.5 foot square steel tube with a chain winch attached to the top. I had to cut the bed extender down to snug up closer to the end of the tailgate I then turned it on it's side and cut one side of the T piece that came with the extender. The T piece turns into an L piece and only serves as a long tube to hold the 8.5 foot steel tube. The steel tube actually rests directly on the ground so as not to stress any of the hitch extender welds. So most of the stress and weight is transferred directly to the concrete.

When I hooked it all up tonight, I wasn't sure how the crate / escape pod would lift with the chain winch but it was a piece of cake. In 5 minutes I had the crate in the truck and then back out. Temporarily I had straps on the escape pod that I was attaching the chain winch hooks to. Tomorrow I may add some O hooks (or whatever you call them) to the sides and then weight the escape pod down with several hundred pounds and try it again.

The actual chain hoist is a piece of engineering genius. This was my first time using one. It takes a little longer than a regular winch but you can literally operate it with 2 fingers. And once it's in position it is locked in. There's no way it (I hope) can slip. To raise or lower you just pull the chain clockwise or counterclockwise. I got this tip from my genius insanely crazy robot building friend in New Hampshire who lives on the side of his mountain and pulls down giant trees with these chain hoists to build giant robot laboratories by hand. If you haven't see his website, check out http://www.jamius.com and click on "The Giant Robot Project". He is the most talented genius builder on planet earth. And very down to earth cool. Last year he came down and went sailing with me. He built his own sawmill to make lumber to construct a giant dome home and even hand built a road up the mountain through the forest. Sorry for getting off the subject at hand but just thinking about Jamie's projects inspires me.

After I do a few successful tests lifting a heavily loaded escape pod then I'll finish covering the structure and check this todo off my list. And I can take my droid anywhere and in any weather. $39.00 for the extender, $16.00 square steel tube, $44.00 for Harbor freight chain hoist = $99.00 total.
As Hannibal the leader of the "A" team says
"I love it when a plan comes together".

More droid escape pod and battery boxes

Tweaked the escape pod design more today and added a bumper that will be padded with foam to hold the center wheel. I plan on putting a door in the front so I can access the droid from that area to adjust the straps and check the padding. I found four casters I had and attached them to the bottom of the escape pod and it now rolls nicely. Two of the casters had brakes on them.

I did some more work on the battery boxes and actually attached them to my droid by hanging them on an aluminum bracket I made. They hang pretty good but may need some tweaking. The hoses actually caused them to not hang as straight as planned. There's still a bit of a hole in the foot shells that is exposed in the back so I have to come up with a way to make a temporary patch.

Building a Droid Escape Pod

Today's big project was to build a Droid Escape Pod. This will be R2's mini garage at events where he can park and get a little downtime at busy events. As this will be on wheels, it can also be used as a cart or sag wagon to move R2 from one area to another without having to power R2 up. I got some good advice from Marc B. again who has a very similar item. His advice and measurements helped me immensely.

An important fact I had to keep in mind is you may need to go through a doorway. Most doorways are 32" and from front to back this Escape Pod measures 31.5" which will squeak through most doorways. And inside there's just enough room for R2 and some padding. And maybe a few tools. A harness will also be made to strap him in (around the shoulder hubs). I got lucky on the way to Lowes, I noticed a neighbor throwing out a pretty nice piece of 1/2" plywood that was already painted white on one side. I snatched it up and it's now the ramp and floor. Always up to do my part to recycle : )

Tomorrow I plan to enclose the exterior with 1/8" mdf fiberboard. The top and front pieces may be on hinges for access and to pad R2 before a roadtrip. I also have to change the position of the front 2x4 because in this first test, it looks like that 2x4 is too close to the front of R2. I'll also put a padded bumper right in front of the center foot.

I also worked some more on the battery boxes and they are just about ready to install. Just need to install the hanger on the feet and the hoses which should look pretty nifty. It was so nice working with wood again. I am really sick of working with aluminum with all the sparkly shavings going everywhere. Even after all the sweeping and using the shop vac, I have my trademark sparkly driveway and workshop. The smell of sawdust and working with wood is so much more enjoyable.

The next big challenge is to find a practical way to hoist that Escape Pod loaded with a droid onto my pickup truck.

The 1,001st time is a charm !

I kicked it into overdrive this long weekend and got a lot accomplished with R2. All my major problems have been solved and it looks like I'll have a solid working droid for MegaCon.

The foot drives are working beautifully and LEVEL. At last !!! I modified the motor mounts by cutting a lot of excess aluminum off them and by creating completely new brackets for hanging the foot shells. These brackets are much better than the original sets. The parts were painted and the tapped holes in the motor mounts were reused. I initially made paper templates of the brackets and when they were right, I traced them over aluminum angle iron to fabricate new foot shell brackets.

The battery boxes are almost ready to install. I painted the blue on the battery box details and drilled holes for the hoses. The battery boxes were sanded and primed after a coat of glazing putty. PLUS ... now that the foot drives are finally done and the motors are in their final positions, I could fit the battery boxes and determine what to cut out of the back of them (to accommodate the motors). My friendly rotozip made short work of those battery box cutouts.

So after redoing all these parts, I charged R2's batteries, put him back together and then took him for a test drive in the street. This was the first time R2 was taken into the street. He needed to be tested to see if the battery power stayed steady and strong. After an hour of going up and down our street (a slight hill too), R2 was strong as ever and he made a lot of friends as neighbors and people driving by stopped to see him. So my original problem was a bad battery after all.

In a matter of 4 days all the major problems on my todo list have been erased and now there's just a couple dozen minor things to finish.

Time to grab a beer and kick back. Today was a major R2 build milestone and it feels great to not have those nagging problems bouncing around in my head.

Leveling foot shells ... again

After about a thousand tries, I finally came up with an intelligent way of leveling R2's foot shells. Before I thought I could eyeball it and it would be fine which I now know is not a good idea.

Now that the motors and wheels are pretty level and the mounts are trimmed of excess aluminum, I can position the shells level using pieces of 1" wood. Since I already tapped threads into the leg/ankle motor mount, it seems to make more sense to make new shell brackets (the brackets just under the ankle) with holes that line up with the existing holes in the upper part of the motor mount. It's a bit of work but that way I won't need to retap threads and the aluminum won't look like swiss cheese with all the holes.

If this works I will be very happy and can move on to the battery boxes and figure out how to temporarily cover thoe large gaping holes in the inner foot shells. Fortunately the battery boxes will cover the majority of the hole.

When a droid SLAMS on his brakes

Ok, mystery solved. I took apart R2's drive system and foot shells to give him a wheel alignment. And I did discover that one leg was an inch or two lower than the other so I modified the one mount.

The next step was to drive the droid on the driveway (without dome or foot shells) and see if the skid marks from the wheels still appear on the driveway. I can watch the process easier without the foot shells. And sure enough new skid marks appeared on the driveway. But this time I was able to pinpoint when and why. They happened when I let off on the throttle and the speed controller applied it's version of brakes to the droid motors. And just like in a car, when your droid "slams on the brakes", skid marks will appear on the driveway. Got me thinking .... maybe if I rewired R2 to 24 volts, I could squeal the tires during acceleration and produce skid marks that way.

So the mystery of why there's skid marks on the driveway is solved. AND the wheels are better aligned. Now to balance the foot shells better. I got some good information from Marc B regarding my foot shell alignment so I'm thinking about a few alternatives I now have.