----- Original Message -----
Sent: Monday, October 22, 2007 11:22
PM
Subject: quick BT-7 [TANKS]
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 -----
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