One of the single greatest factors in making a combat robot successful is durability.
With this in mind, I decided to do some testing on Event Horizon. I spent some time looking for large and relatively solid objects to hit, and finally settled on the EH 1.0 carcass with a large chunk of scrap aluminum in it to make it heavier.
I found that running into EH 1.0 slowly with the weapon at full speed produced only small impacts, which would not be sufficient in an actual match, so I rammed it at full speed. The EH 1.0 frame flew three to four feet, which is much more in line with the power that I want from the EH 2 weapon (Sorry, no video, I can't drive and take video at the same time).
Upon initial inspection, EH 2 appeared not to have sustained damage in the impact, but after looking closer, I noticed that one of the teeth (1/4-20 flat head cap screws) had been completely ripped out of the 1/4" thick aluminum drum. Also, the drum did not spin freely anymore, and the wires for the motor had been partly sucked inside of the drum.
I took apart the drum.
... and was confronted with a scene of absolute destruction. The motor mounting plate was completely deformed, and the wires for the motor (all three of them) had been completely sheared off. Interestingly, all of the screws that hold the motor mounting plate to the hub were missing, and the threads on the hub were completely intact, showing no signs of an impact. Thus, we reach the title of this post: As far as I can tell, the screws fell out at some earlier point, meaning that the drum motor had been solely held in place by its wires. When the drum hit the EH 1.0 frame, it seems that the motor flexed somewhat and the mounting plate caught on the inside of the drum somehow, bending the plate and shearing the wires. Using loctite and/ or jam nuts might have prevented this failure. Thankfully, this is an easy fix since I have another motor.
Yes, that hole was round once.
As a backup, I am also going to start development of a hub motor using the parts from the broken motor. More on this later.
A few weeks ago, one of my father's co-workers, Dave, decided to sell his 12" Hendy Lathe. I had been wanting a larger lathe for a robotics project, and at only $400, this was a superb deal.
After doing a bit of research, I determined that the lathe was made between 1887 and 1917, making it over 100 years old. Mostly due to the price, we decided to go to look at it.
We made the 45 minute drive to Groton, Mass and were immediately struck by the size. I had been expecting a large machine, but this basically took up the entire back of a garage bay. Upon inspection, everything appeared to be in remarkably good condition. Most importantly, all of the ways and bearings looked to be un-damaged. It also came with two four jaw chucks, a three jaw chuck, and two plates, which appear to attach to the spindle in place of a chuck (my father theorizes that these have largely been replaced by rotary tables/ CNC machines). One plate and one chuck appeared to be from a larger lathe, perhaps an 18" machine. We attempted to try turning a piece, however, the ancient flat belt snapped almost immediately, so we headed home to make a final decision. From looking around the shop, I determined that we did, in fact have space, as long as we relegated my father's crap to the attic made some organizational changes. We decided to buy the lathe.
I spent the remainder of the weekend rearranging everything in the shop, which was something I had been intending to do for a while, but never got around to.
Transportation:
Transporting a 1500 lb. piece of steel is not exactly an easy task.
We left around 10:00 and rented a UHaul trailer, which was rated for a few thousand pounds. We towed the trailer with my mother's Honda CRV to Dave's father's house, which was we were picking up the lathe and arrived around 12:00.
Disassembly commenced immediately and everything that could be easily removed (motor, tailstock, etc.) without moving the machine was taken off and put outside for the time being. We then used a jack to lift one of the legs and a pry bar to rotate the machine so that it was facing out the garage door. Pete, a friend of Dave's showed up with a pickup truck, and he backed the trailer into the garage. Next, we jacked up the lathe under the bed and removed the leg closest to the door, backed the trailer partly under it and used two 6x6's as a set of rails on which to roll steel pipes. We tied straps from the bed to the rails of the trailer to prevent the machine from tipping and I used a come along to pull it into the trailer. Once it got close to the end, we removed the other leg and finished pulling it in. We tied from several points on the bed to the (somewhat under-sized) tie down points in the trailer with straps to prevent sliding during transit.
Pete towed the trailer with his truck (the CRV trailer hitch is only rated to tow the trailer empty...) and we drove to my house. We backed the trailer under the car lift that we have in our shop and using a large strap and a 2x4 wedged between the rails of the bed, we lifted from the center of mass and pulled the trailer out.
It was now around 10:00 pm and after 10 hours of moving, we lowered the lathe down on the 6x6's and called it a night.
Lathe in the position we used to lift it out of the trailer
In the morning, my father and I lifted the lathe up, set it down on a pair of blocks (actually, the stand for the drill press), and re-attached the legs.
Lathe with legs on, still attached to car lift and on blocks.
We lifted it up slightly again, pulled the blocks out and lowered the entire machine down onto a set of carpet sliders, which were a last minute purchase. The carpet sliders turned out to be a great idea and it was fairly simple to just push the lathe into position. We used a bottle jack to prop up the legs side at a time when it was in place in order to pull the carpet pieces and sliders out from underneath it.
Lathe while removing carpet sliders.
Cleaning/ Reassembly
The rest of the day was dedicated to cleaning/ reassembly.
Lathe at the end of the day.
We cleaned the ways and rods, and removed the thick layer of grime on all of the handles.
The lathe makes the Bridgeport mill look small... This was kind of a disturbing effect after having the mill dominate the corner since we got it a couple of years ago.
Later in the week, we got the pulley on. There was still quite a bit more cleaning to go, however, and we were waiting on a McMaster order to come in with alligator lacing for joining the flat belt so that we could actually run it.
After getting the alligator lacing, we finally got it running. I fixed the tailstock locking mechanism, too. It seems that the cam that locks the bottom piece was slightly out of alignment.
This will be an ongoing project as there are lots of small improvements that can be made, such as attaching the extra quick change tool post that we have lying around. For the moment, however, my focus is going to shift to a few other projects that I have been neglecting, such as my new beetle weight combat robot, Event Horizon (Actually, Event Horizon V2, but more on that later).
