VI Report 10 - 5/20/01

Man, I think this update will be the king of all VI updates. I just looked back over my previous ones and the trend seemed to be they nearly double in size each time I post one.

I had decided to wait till I got back from SF to do the final build report, but having it online before I compete just feels like a better idea.

Disclaimer: Any eye damage or headaches caused by reading this report are not my fault! If you decide to take on reading this mamma-jamma it would be a good idea to visit the restroom now and grab yourself a cooler filled with multiple frosty beverages to put beside the computer.





In the above image I was getting ready to grind the burs off these freshly chop-sawed 3/4" x 3/4" square steel drivetrain supports that will be welded into the frame.





After de-burring the edges it was time to make some marks with my punch. The holes that will be drilled will get tapped and used to bolt the pillow block bearings that support the 3/4" drive axles.





After running them through my uber-cheasy drill press here are the mounts with the new holes.

Next stop: Cheesy Tap Set





Yippee skipee! It works :)





All tapped up, ready to weld some of these suckers into the frame.

Pictured here are the motor mounts I made and the rear drive wheel bolted to the finished drivetrain supports.





Same setup as above from a different angle. I was really stoked that these came out well :)





Before I welded them into the frame though, I wanted to stick an EV in the mount and spin the wheel up. Here is the test set-up in the vise with chain attached and tensioned.





Up to this point I had not been using the keyed shaft in any application. Here is the groovy keyed stuff cut to the right lengths for the front and rear drivetrain axles.





Now that the shaft (Shut yo mouth!) was cut and de-burred it was time to play with the key. I purchased it in 12" sections.

In this pic I am making the mark to cut off from. The key is going through the wheel and the keyed sprocket directly on the other side of the wheel (can't see the sprocket, the wheel is in the way).





Finished cutting the key. Here it is in place, through the wheel and the sprocket directly on the other side of the wheel.





After cutting the key for the wheel/sprocket I cut the key for the outer sprocket (the ones that connect the rear wheels to the front wheels for 4WD) and tightened everything down.





I had already cut the chain for one side of the motor to wheel attachment, here is a shot of both sides finished though.

Chain was a pain at first, but I finally got a method of breaking it and it's not too bad now.





I stopped by my local metal supplier and picked up some more 3/4" x 3/4" 11 gauge steel tubing (I had ran out!). While I was there I dug around in the aluminum remnants to look for a possible wedge material.

The 1/8" thick AL plate on the right is what I found, Mr. Graves (Graves Metal Supply) himself gave the AL to me free of charge! Thank you Mr. G!





Shown here are the rear mounts freshly welded into the frame.

Careful! It's still hot!





I was still in need of something to mount the wedge plate to. I didn't want to bolt directly to the frame and anything I put on would not be supported properly at the bottom of the wedge in VI's current configuration.

Here was my solution. I had some 1/8" steel remnant material I had picked up at Graves earlier that looked like it would go nicely along the bottom of the wedge.





Lining it up and getting ready to weld it onto the frame.





Its on!





After I had it welded into place I wanted to bend the sides down and cut off the excess.





Here is a shot of the lexan side armor panel with the corner tucked behind the steel I just bent. I wanted to cut off the excess but still have it overlap the side a little as shown here.





What it looked like after the cut:





One last shot from the bottom of the new 1/8" steel strip along the front of the robot.





I was still running overweight so to cut some more pounds off I thought I would remove some more frame that ran across the center of the robot.





Out ya go 1" x 1" steel!





After I cut some of the frame out I wanted to test the motor mounts/drivetrain supports/speed controllers out in the robot with the wheels off the ground.

It was still too early to drive, as I had yet to weld in the front wheel supports.





I cut the circuit on and spun the wheels. It worked perfectly with both in forward or both in reverse, but when I tried to spin one side of the drivetrain forward and the other in reverse (simulating turning) the motors stalled.





A pic of some spiffy power distribution blocks I purchased from the local Rat-Shack. These were to be used later to distribute Village Idiot go-go juice.





Ok, back to the task of making the front wheels stick through the bottom of the robot.

I already had the drive motors mounted and I wanted to test drive the robot as soon as I got the front mounts welded in. So, I taped some paper towels over the EV's to keep metal shavings out while I made the holes for the front wheels.





Flip, mark, and drill starter holes.





CUT! CUT!





Flip-n-weld.

Here are the mounts welded into place that support the front wheels.





Woohoo! Time to make the robot roll under it's own power for the first time!

Check the Frankenstein setup. If you notice, the front left wheel only has one bolt through one of the pillow block bearings. I messed up welding them in and there was a mis alignment. I would have to revisit that side of the mounts.





Dang.

It still didn't turn and the 2.5:1 one stage reduction to the 5" Colsons left a LOT to be desired. It would go straight fine and in reverse fine, but if you tried to turn it the robot just spazzed out. Lots of jittering and no turning. I did manage to ride it though, that was pretty cool :)

I couldn't figure out why it wouldn't turn, I thought perhaps it was something wrong with my radio setup or the 2.5:1 reduction was stalling the motors from the friction in tank style steering. I figured I would look into it later, lots of building yet to do!





After welding with the plate on and driving the robot some of the plate was in bad need of a cleaning.





I had to take it off anyway to cut some more material out of the frame, so I figured I would take it outside and hose it down.





Back to the frame.

I re-did the front left mounts when I took the plate off and cut out the rest of that 1" x 1" support I had running across the center of the frame.





Cutting the remaining 1" x 1" stuff out of the middle was going to make it much easier to get adjustable mounting holes in the supports anyway. Show in this pic are the new weapon motor mounts I made before welding them into the frame.





And here they are actually welded into place.

Groovy!





I wanted to weld in a battery holder that fit the SLA's good while I was working on the new weapon motor mounts. I figured I would use some more of the 1/8" steel I had shaped to wrap around the batteries.





Ready to weld it into place.





Welded in.





With the plate off again, I welded in more support for the drivetrain mounts.





Bookoo weld grinding later:





Cool, everything bolted up great now. I went ahead and cut the chain to make the 4WD connection and hooked all the drivetrain up.





Noooo!

I re-hooked up my test setup using Evelon mixing in my radio this time. I ran across the floor a little with the same problems, straight ok, back ok, turn = nogo.

This time though, after a couple minutes of trying the left speed controller burst into flames. Literally. Turns out the self-resetting fuses help some but they can't protect you from what my problem was...





It turns out the EV warriors are grounded to the motor housing (See tab in pic).

What was happening was when I had both motors in FWD they were both using the frame as a ground, no problem. When they were both in reverse the frame was shared as positive, no problem. When I tried to TURN the robot, one motor was using the frame as ground while the other was trying to make it positive.

Direct short. Very bad.





I needed to kill that ground to the motor housing, so I dremeled the tab off.

No touch for you!





To make SURE that I didn't have a short again I used some double sided sticky tape in various placed on the back of the motor leads. I didn't want to take any kind of chance on smoking additional speed controllers. Those suckers are expensive!

I borrowed the tape idea from Terry Morris of Team Wizard.





After I finished properly performing the motor isolation I hooked everything back up and tried to have a go with the one good ESC and the bad one (the bad one still worked a little).

As soon as I hit forward on both sticks the second 883 burst into flames. I was disgusted. All this crap happening less than two weeks from the event made it feel like, "There is no way I can make it!!". It didn't take very long for any notions to drop out left my head though. I was going to do everything in my power to make this hunk-o-steel roll.

So I got on the phone with Innovation First and they had two more 24V 883s overnighted my way. Ricky (the tech support dude I talked to) even cut one of the two to half price, even though it was my stupidity that fried them both. Thank you Ricky!

I did feel like I had fixed the isolation problem though, and that the damage had been done when I was throwing all those direct shorts into the mix. Reason being, the robot did turn some after the second ESC blew up. It was weird, they would make more smoke as I rolled and sent power through them but they continued to work for two or three minutes. Go figure. I look at the experience as it was better to happen in my garage a week and a couple of days before I ship than the day before I ship.

I still wasn't making any headway on being overweight either, so I called Steve of HillTop Batteries and asked if there was any way that I could still jump on the Nicad BattlePack bandwagon. Much to my surprise, he said he would fill my order for three 24V 3AH BattlePacks (it was almost a week past their cut-off deadline to order). Three days later I had the BattlePacks in hand, and the chargers came the next day. Steve is an awesome guy, if you need Nicads GO TO HillTop BATTERIES! They saved my tail at the last minute.





With the extra weight savings I would have going with Nicad from the SLA's I had (from about 30lbs to less than 12lbs) I felt I needed to make another go at that two stage 5:1 reduction I had originally planned. The 2.5:1 just scared me that I would draw too many amps and fry additional ESC's. Frying ESC's is a very bad thing, if I could avoid it, it's what I should do.

So, here is an image of the four supports being made to hold up the reduction material. It was going to be a tall order getting it all the materials needed for the two stage reduction in and staying under weight.





In the interests of weight, I decided to buy some 1/2" shaft and sprockets to compete the reduction setup. The fat cog in this pic is obviously a little TOO fat to use, but it did work nicely to help me weld the thin sprocket on.





I used the fat sprocket with the thick collar to clamp the skinny one to. It made the skinny one straight on the shaft, then when I was finished welding I removed the fat one and all that was left on the shaft was the skinny 20T sprocket.





Smokin!!





Here are the two finished 20T sprockets welded onto the shaft.





This is a shot of the supports welded into the frame after I finished the adjusting slots. Finishing slots = Lots-o-dremel/file action later.

1/2" pillow block bearings will hang underneath the supports and be adjustable to tension the chain.





This picture shows the whole assembly (minus the chain) installed to make sure everything lined up correctly. The 10T sprocket on the motor will turn the 20T sprocket on the reduction assembly, the turning reduction assembly will have a 10T sprocket connected to the 25T sprocket on the drive axle, giving the robot a 5:1 reduction.





Reduction with the chain on.

I was satisfied that it would work, so next up was grinding those welds down and working on the electronics to test with my new 883's and Nicads.





I had yet to cut the wedge out of the aluminum I had picked up. Here's a shot of me cutting it out of the bigger piece of AL. Go-go Gadget Jigsaw!





Here is a pic of the beginning plans for an all lexan electronics mounting platform. The back of the lexan doubles as a battery holder.





The spiffy power distribution thinggies mounted on the lexan.





A little lexan bending action to make a mount for the Hella cut-off switch..





The Hella switch makes it's appearance on the electronics layout.





Test mounting the rig with the smoked ESC's. They turned out to be good for something after all.





Getting close to finished with the lexan electronics rig. Pictured here are the receiver in place, and the 30A self re-setting breakers.





All the goodies on the robot. You can't see it, but the Team Delta switch and receiver battery eliminator are under the platform.





CHARGE!





After getting close to having all the materials ready that would be in the final setup of the robot, I weighed again. Dang, I was still going to be a little overweight after adding the two stage reduction.





I took the cogs off the rear drive axles and drilled the heck out of those uber-beefy collars. That helped a little.





I also grinded the corners down all over the frame and drilled holes in several places to lighten it up a bit.





Ok, welds grinded, two stage installed, chains tensioned... I am ready to test drive again with my new ESC's and freshly charged batteries!





All the goodies installed (other than the power to the drive motors, don't have a pic of that :( ) and ready to test again.

It worked beautifully! I was so happy I cannot begin to convey my feelings. I rode it around, turned here and there and had a little fight with a dead box fan I had. It was such a relief that it worked!





Drilling the motor mounts out some more before I paint them to drop some additional weight.





Crazy Jon's paint shop!





When the charger that came with your drill just isn't fast enough...





Next, I welded a couple more pieces to the frame to mount the wedge to.





After I grinded the welds down on the new wedge mounts I clamped the wedge to the front of the robot. Then I drilled the mounting holes through the mounts and the wedge.





After making the holes in the wedge I punched some marks and made the holes into slots using my hand drill and a file. I wanted the wedge to be somewhat adjustable.





Pictured here is the top piece of lexan with marks to start making holes for the saws to turn through.





In this pic I have cut the holes for the blades in the top lexan and the wedge.





The saw blades still had some gunk all over the teeth. It was the way the guy I won them from on eBay shipped them. I think it was silicone? Anyway, I left it on till the last minute because it saved my hands a little through the times I was working with the blades.

To get the gunk off I used some Fast Orange to "brush the teeth".





Rinse!





I felt like I was finished with the frame, I had already made all the holes for armor attachment. So I taped off the aluminum plate and painted the frame flat black.





After the paint dried I couldn't wait to throw the armor and blades on to see what it was going to look like.

While I had the armor on I went ahead and placed the stickers too.





From the front.





I took the frame back downstairs and got ready to start putting all the goodies on for real.





First I put the electronics on and installed the solenoid and power supply to the weapon motors.





Here I have the drive motors, wheels, and chain installed.





With the lid on from the front.





All the guts in with the top armor off and the wedge off.





Same configuration from another angle.





Sorry, one more angle :) I just thought these pics were pretty cool looking.





Finished!

This was the first time I had spun the blades up too (early morning of the day I shipped the robot!). They are something, I was pretty scared of them actually. Only takes about a second or so for them to get up to full speed and they are moving.

I have a 2:1 reduction for the dual EV's that power them and the EV's are running at 24V, so I'm thinking they spin around 2500 RPMs or so. Very loud and very in your face!





Another angle of the same set up: Finished! ;)

Everything you have read about in this report took place over the course of less than two weeks. It was a roller coaster of disasters and triumphs. A HUGE thank you to anyone and everyone that said some word of encouragement that helped motivate me to spend the time and energy to finish the robot in time.





Last shot, same deal: Finished!!

I am sure that I could not have completed this robot without the answered prayers I feverishly sent in the final weeks and the support of all those around me. My wife in particular has been so supportive about the long hours and money spent that it amazes me any time I think about it. Blessings were abundant the last couple of weeks at the Autry house!





This pic is sized to 1024 x 768 for anyone goofy enough to use it as a wallpaper (i.e. ME! ;))

This has been a rewarding experience thus far, it is a great feeling of accomplishment to have something like this come together. Now I can put all my energy towards looking forward to the competition next week and meeting a lot of the people I have came to respect so much over the last few months.







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