SUBLIME3

Well I think it is time for another progress report since I havn't done one in a while. The robot is coming together nicley, I need drill allot of holes in it before the competition though as it is verry HEAVY.

At the end of the last report I had just finished making the gear box for the spinner weapon. After that was finished I went looking for a blade to spin on it, and this is the one I found. It is a 2.75" x .5" x 27" chunk of 6-4 titanium. I had heard titanuim was a pain to work with, and trust me it is, but I think it will be worth since it should be pretty indestructable. Here are a few snaps of the blade.

I constructed a hub to mount the blade to the 3/4" shaft by taking a chunk of round stock, drilling a hole through the center on the lathe. Then taking a chunk of 1/4" steel flat stock, drilling a 3/4" hole in the center and welding it to the newly machined round stock. To mount the hub to the 3/4" shaft I just drilled a 1/4" hole through both and pit in a steel roll pin. The whole thing is quite solid.

Now came the fun part, drilling the one 3/4" hole, and two 1/2" holes in the titanium to mount the blade to the hub on the gearbox. I drilled all three holes first with a 1/4" bit to get them started, then I went ahead and drilled the bigger holes, that 3/4" one was scarry!

Now it was time to TEST! I was a little scared to test fire it up since with the EV motor running 28.8 volts the blade would be doing over 4000 rpms! I put the whole blade set up in the vice verry tightly, then spun it up at 14.4 volts, the bevel gears whined during spin up but quieted down after it was up to speed. The test went well so I went ahead and ran it at the full 28.8 volts and it was amazing! I need to get a movie up some time soon.

I put the gear box loosly in the frame to snap these shots of what it should look like complete minus the 1/4" thick hardend steel extenders for the blade that will ride 1/2" off the ground.

Next I started to build the new gear boxes using some 16 pitch gears purchased from Mc Master. When I got the gears the big 60 tooth ones where extremely heavy so I lathed out some unecisary material, as well as trim the hub down from 3 inches to 1 inch. With the mods to the gears finished I started to build the new motor mounts, for the chain drives I just welded some bolts to the face of the motors, though strong this did not let me replace the motors easy if there was a problem. I decided to make some cradles to sort of clamp the motors to the base using hose clamps. Here is the big chunk of plastic I made the mounts from with the two motors sitting on it.

Here is a shot of the gear box test layup with the feshly made plastic motor mount (white thing under motor.) I bought 4 of these hose clamps to clamp the motors into the cradle.

Here is a shot of me cutting the hose clamps on the hydralic shear. Here they are all cut out.

Here is the motor mount before the hose clamps, here it is after. I just drilled and tapped some 1/4" holes into the plastic for the bolts securing down the hose clamps to go into.

The next thing I had to do was to mount the small 12 tooth gear on the shaft of the EV motor. The EV motor has a 5/16" shaft while the gear had a 3/8" bore so I made up and adapter on the lathe by taking a 3/8" rod and drilling a 5/16" hole in it, it was a tight fit! Here is the gear sitting on the adapter in the lathe. The EV shafts have an 1/8th inch roll pin already installed in the output shaft so I cut a slot in the gear and the adapter with my Dremel and slid it on the output shaft of the motor, it fit well but could easily slide off the end of the shaft since there was nothing securing it. My sollution was since there was still a good 1/4" of shaft sticking out past the gear I could thread that and put a nut on to keep the gear from coming off, here I am taping the end of the motor shaft.

Here is a shot of the nut on the threads I just cut into the shaft. Next I needed a way to mount the big 60 tooth gear to the base so I build a custom pillow block to do this. Here is a chunk of scrap alluminum that will become the L shaped pillow block.

Here is the pillow block that I just cut out from that chunk of scrap, I then squared it on the mill to ensure that the gears run nice and smooth. I drilled a hole in the top of the "L" pillow block for the bearings, then drilled several holes iin it to make it lighter. Here all all of the parts mounted to a scrap chunk of 1/4" alluminum to test it. Everything runs really smooth, you might also notice the 18 tooth sprocket and chain that is atached to the output shaft of the gearbox, this is what will transfer the power to the tires through a 1:1 reduction. That is all for this report, I hope to finish the robot for the next one!