Project Update 05-31-04
Here is an update after weeks of slacking.
Sorry for the delay.
Here is the video version:
http://www.pasqualy.com/landraider/...31-04update.wmv
Last time I posted any kind of update I think I was installing a cooling fan for the speed controller. Well the fan worked great but I managed to get some wires crossed when putting the controller back on the bot and fried it. Thankfully the guys at vantec had mercy on me and fixed it for $70.
Chain Drive v2.0
I also have gotten a second 12V battery for the bot and at 24V total with the two batts. it has some pretty awesome power. However more power just showed how terrable my chain drive was. So I set about making some changes in the way things worked. I came up with what basically amounts to a double sprocket system. I don't know why I just didn't do it this way from the get go. It has several advantages. Gearing up/down doesnt require that I replace all 4 sprockets for each spindle. Just the ones on either the drive motor or drive spindle or both if needed. Chain tension is not nearly the problem it used to be either.
Here is a concept image of the new design. Notice the Motor sprocket drives the 1st sprocket on the spindle. The second sprocket on the spindle in turn drives the sprocket on the other spindle for that side of the vehicle. So its still 4 wheel drive.
Because there had to be two sets of chains side by side, I had to move the motors further in. This required a bit of wood work to make room for them.
You can get an idea of how things are going to work from this picture. The motor sprocket is 10Teeth. It drives a 24 tooth sprocket on the spindle. Thus its geared down 2.4:1. There is a second 16T sprocket on the spindle that drives a 16T sprocket on the other spindle for that side.
Now because my town is small and crappy, I couldn't find any keyed shaft. So I had to dremel my own keyway. It was annoying but setscrews alone just wont cut it for the amount of power we are dealing with.
If you don't know, keyway is like a channel running along the length of a rod. The sprocket also has a Notch of the same size inside of its hole. These notches are half as deep as they are wide so you can fit a little piece of keystock inside them and it fits halfway in the shaft and halfway in the sprocket. Then you tighten down on this with a set screw and it assures that your sprocket holds fast to the rod. I didn't bother to keyway the hole shaft, just the places where I needed it. Here is a closeup of the sprocket, keyway, keystock, and setscrew hole.
These two images show the final layout of the new chain drive. You can see that I also removed the old PVC roller on the tension bar and replaced with a small sprocket. This will also change with the final version. Toejam sent me some sweet tension products from his company that I plan to make use of, thanks!
Here she is in all her glory, with the speed controller and two batteries. I gave here a test run at this point and let me tell you she kicks ASS. Un freeking stopable. Compared to the previous version she now has almost 5 times as much torque. You can drive it up to a wall and it will just crawl up the wall till it flips. I can STAND on the forward edge and it will still crawl up the wall with me on it!!!!! Check out the pimping lighted power switch too.
Adding a Top Deck and Device Mounts
As stated some time ago, I had already realized that I didn't have enough real estate on the top deck to put everything I needed. So I decided to add a second level. I figured the camera would do well to hang in between the bottom floor and the top deck . This keeps it from getting smashed to pieces.
First I put down some 2x4 blocks for the top deck to sit on.
Then I slapped on the top deck.
Next I cut a hole out for the speed controller fan to pull air through. I also mounted the gun base.
Here is the view from the under side.
Next I started working on the camera mount. At this point my fabrication skills have grown by leaps and bounds and I have much better tools backing me up. So the mount came out much better than the old way of just sticking two servos tegether with tape and ticky tacky!
I used old pieces of sheet metal from broken power supplies and old computer cases. Thats why you see "BAD" marked on some parts. Its how I know a part has been tested and isn't any good.
I'll spare you guys the details and just give you the final product.
Here it is mounted under the top deck. It turned out pretty sweet.
Video:
http://www.pasqualy.com/landraider/...31-04update.wmv
Sorry for the delay.
Here is the video version:
http://www.pasqualy.com/landraider/...31-04update.wmv
Last time I posted any kind of update I think I was installing a cooling fan for the speed controller. Well the fan worked great but I managed to get some wires crossed when putting the controller back on the bot and fried it. Thankfully the guys at vantec had mercy on me and fixed it for $70.
Chain Drive v2.0
I also have gotten a second 12V battery for the bot and at 24V total with the two batts. it has some pretty awesome power. However more power just showed how terrable my chain drive was. So I set about making some changes in the way things worked. I came up with what basically amounts to a double sprocket system. I don't know why I just didn't do it this way from the get go. It has several advantages. Gearing up/down doesnt require that I replace all 4 sprockets for each spindle. Just the ones on either the drive motor or drive spindle or both if needed. Chain tension is not nearly the problem it used to be either.
Here is a concept image of the new design. Notice the Motor sprocket drives the 1st sprocket on the spindle. The second sprocket on the spindle in turn drives the sprocket on the other spindle for that side of the vehicle. So its still 4 wheel drive.
Because there had to be two sets of chains side by side, I had to move the motors further in. This required a bit of wood work to make room for them.
You can get an idea of how things are going to work from this picture. The motor sprocket is 10Teeth. It drives a 24 tooth sprocket on the spindle. Thus its geared down 2.4:1. There is a second 16T sprocket on the spindle that drives a 16T sprocket on the other spindle for that side.
Now because my town is small and crappy, I couldn't find any keyed shaft. So I had to dremel my own keyway. It was annoying but setscrews alone just wont cut it for the amount of power we are dealing with.
If you don't know, keyway is like a channel running along the length of a rod. The sprocket also has a Notch of the same size inside of its hole. These notches are half as deep as they are wide so you can fit a little piece of keystock inside them and it fits halfway in the shaft and halfway in the sprocket. Then you tighten down on this with a set screw and it assures that your sprocket holds fast to the rod. I didn't bother to keyway the hole shaft, just the places where I needed it. Here is a closeup of the sprocket, keyway, keystock, and setscrew hole.
These two images show the final layout of the new chain drive. You can see that I also removed the old PVC roller on the tension bar and replaced with a small sprocket. This will also change with the final version. Toejam sent me some sweet tension products from his company that I plan to make use of, thanks!
Here she is in all her glory, with the speed controller and two batteries. I gave here a test run at this point and let me tell you she kicks ASS. Un freeking stopable. Compared to the previous version she now has almost 5 times as much torque. You can drive it up to a wall and it will just crawl up the wall till it flips. I can STAND on the forward edge and it will still crawl up the wall with me on it!!!!! Check out the pimping lighted power switch too.
Adding a Top Deck and Device Mounts
As stated some time ago, I had already realized that I didn't have enough real estate on the top deck to put everything I needed. So I decided to add a second level. I figured the camera would do well to hang in between the bottom floor and the top deck . This keeps it from getting smashed to pieces.
First I put down some 2x4 blocks for the top deck to sit on.
Then I slapped on the top deck.
Next I cut a hole out for the speed controller fan to pull air through. I also mounted the gun base.
Here is the view from the under side.
Next I started working on the camera mount. At this point my fabrication skills have grown by leaps and bounds and I have much better tools backing me up. So the mount came out much better than the old way of just sticking two servos tegether with tape and ticky tacky!
I used old pieces of sheet metal from broken power supplies and old computer cases. Thats why you see "BAD" marked on some parts. Its how I know a part has been tested and isn't any good.
I'll spare you guys the details and just give you the final product.
Here it is mounted under the top deck. It turned out pretty sweet.
Video:
http://www.pasqualy.com/landraider/...31-04update.wmv
