quick BT-7 [TANKS]

["Chrysanthos Kanellopoulos" <xchrysk-at-otenet.gr>]

Thanks Paul.  I understand the relationship between speed and torque and gears ratio, I just don't seem able to implement it. MOre axles, more ball bearings to secure everything so things don't go wobbly, a tensioner for the roller chain, trouble of opening and locking roller chains.... Have never done it.

 

I will see how you do the drive shaft and perhaps will copy ideas from your systems.  As I said , in a year or two from now.  I need to spend more money on batteries for both my tanks and more markers. And, it will be a white BT-5, after Chris's suggestion!.  WIll dry brush it with olive green to enhance the edges and give it a weathered, veteran look, so she's not like Snowhite in the field. White is stained very easily and dust, grease and mud will do the rest.  Actually,  during these 2 years I could take the difference in temperature between a hull or just a large tin box painted white and dark olive. More research. That's the beauty of this forum!

 

I was also thinking of a spray can of compressed air - teh kind you use for cleaning computers- that sprays the motors everynow and then at will, from an extra channel on the RC. It should cost more than batteries on teh fans, but it's effective, cool and gives instant freezing temperatures. Don't know if teh latter is good for the motors....

 

Chrys 

 

 

Chrys,

 

I simply can not let this stand.  Let's look at .25 pitch chain drive first.  If you use two 14 tooth sprockets you get a 1:1 ratio, meaning that if you turn the input gear one time, the output gear also turns one time and torque remains the same.  If you use one 7 tooth sprocket and one 14 tooth you get either a 2:1 ratio or a 1:2 ratio depending on which sprocket is used as the input. So, if you use the 7 tooth sprocket as the input (2:1 ratio) the output speed is reduced by half and torque is increased X2.  If you use the 14 tooth sprocket as the input, speed is increased X2 and the torque is reduced by half.  The length of chain doesn't matter.  This is the simple version by far, but as you gain a bit more confidence, you can delve a bit deeper.

 

Paul Hilton.

----- Original Message -----

From: Chrysanthos Kanellopoulos

To: tanks-at-rctankcombat.com

Sent: Monday, October 22, 2007 12:08 PM

Subject: quick BT-7 [TANKS]

 

I know Paul, only pulleys and gears are above my skills level.

 

Chrys

 

OK, that's better.  So, as you can see there isn't any room for a direct drive.  the gears for the final drive shafts are housed in those disk shaped housings.  The final drive shafts are mounted in the tube that connects the two housings.  The relationship between the tube, housings and drive cog are such that it isn't really possible to "fake" the rear of the vehicle and move the drive cog forward.  I would think that it would resemble a pickup truck with the rear wheels right behind the cab.  Just not quite right.  I've decided to simply accept the structure and use it pretty much as it was originally, with sprockets for chain drives inside the two housings and either a pair of live shafts or a long continuous dead shaft inside the tube.  The dead shaft would offer more stability, the live shafts are simpler to construct.

 

Paul Hilton