Sept 11, 2005. WE WILL NEVER FORGET!
I started out wishing to construct a cab-over-engine sleeper cab, and flat bed trailer (the trailer being made mostly out of a hand dolly). When I scaled the truck originally based on hand truck tires, I was using the measurement of 4.5 inches. It simply slipped my mind that the 4.5 inches was a measurement of the RIM and not the tire assembly. With the tire being an actual 10 inches in diameter, the truck would have to be 1/4 scale for the tires to look right. After reviewing the website http://www.eastcoastminiclassics.com I see that they use 6 horse 'lawn mower' engines in similar 1/4 scale trucks. Their trucks are capable of pulling a 1200 pound trailer, and up to a 350 pound driver. My truck will not carry a passanger and at the moment I am planning on carrying a 1/4th scale model car.
Monday, September 12, 2005
WE WILL NEVER FORGET!
Monday, September 5, 2005
Radio Control Tractor Trailer, second issue
Sept 04, 2005. I am working on ideas to create a reverse gearing system that can be controlled with a push-pull motion of a servo. I havean idea but I have no clue if it will work effectively. Dad says that one of his Mother Earth News magazines has the same'linkage' that I designed in the drawings for a gocart, so I guess I did something right. The linkage requires three identical gears, and two identical pulleys, none of which are anything special. Using one smaller pulley then the the other will effectively drop the ratio for reverse. Here's a B/W of my idea..
I had another idea.. using the mobility scooter differential in place of the red axle in his picture, I can pwoer BOTH rear axles with a sngle chain on each side. I will have to add some srings to it to keep the rear 'truck' from "pulling wheelies" (back axle digging in, front axle lifting off ground). There is a slight chance that this may create a convincing "wheel hop" like big rigs sometimes do.. We'll see.
Thursday, June 2, 2005
Radio Control Tractor Trailer, the concept
R / C . T r a c t o r . T r a i l e r ! !
..I am looking to custom build a large, radio control
Tractor Trailer. I think I will use a cab-over design to have the
most engine room, and hide the fact that it will have a weed whacker
engine in it, hopefully I can make a good looking static model out of
it as well. I"m thinking 1/10 or 1/6 scale, what do you think of
that?
..I am having trouble finding people willing to help, even just advice
answers tips and things, all the websites I have found as-of-yet don't
make all that much sense or look like they were built by 12 year olds.
Most have little or no useful information to me.
..I am trying to figure out what to use for a rear differential. I'm
worried about using a straight axle. The short wheelbase, with most
weight being over the front end makes me think it may work fine, but
if I put enough weight on the trailer, it may not steer.
..I have drawn up plans (not to scale yet) to custom-build a diff with
my Dad (who is a blacksmith, and a welder-fabricator by trade) out of
six 90degree bevel gears (4 inside, one outside, one on driveshaft).
I tested my design with Lego's (Don't laugh) It worked. I don't see
why it will not work on a larger application. The draw back is that
it will be all open.
..My third idea rests with the differential out of something like a
Lark Motor Scooter.. The diff is enclosed, 4 inch Dia, 6 inch long
"tin can" shape. Considering such a wheel chair is designed to move a
person, plus the weight of their belongings, plus the weight of the
chair itself, I imagine it should be suitable for this. You?
..I had a battery toy truck when I was a kid that used a rocking
mechanism to try to keep all 4 rear tires grounded. I think I will try
the same with this, but I'll need universal joints. Weed whackers
tend to employ flexible drives housed inside the pipe-handle. Maybe I
can use that to my advantage?
..I also wonder if I might be able to find a variable, shiftable gearbox
(hopefully even radio operated?) or at least a forward-reverse. I
have no ideas on that as of yet. Do you?
..I need a radio.
..For the moment I will take a 2 channel but every time I type
anything about this truck I think of ways I could use more channels..
..I NEED throttle and steering obviously, and brakes if equipped can
be added to the throttle control easily enough I think.
..I would also like to add a kill switch since 99% of weed eaters have
them, and it would be nice to be able to immediately kill the engine if
something is wrong, and if the receiver has the right functions, kill
the engine when the signal is lost. I know there are model airplanes
that "level out make a 180" if the signal drops. If I can find one, I
want to use the Torro weed eater with the electric start option so the
truck will be really hands off operable. It would be nice at a fair
to sit back and see some kid gloat over the awesome giant model truck,
and start it from where ever I am sitting and drive it around a little
:) The start and kill functions could easily be controlled with the
same servo. Now we are up to 3 channel.
..If I find a suitable gearbox, that can be operated by servo, that
will be 4 channels.. What is your input on that?
..I'm hoping to keep the cost of this down as I haven't much money to
throw at it. Dad things he can find allot of what we might need for
the chassis in the scrap pile at work. The cab can be a simple
painted box for now, unless I find a suitable model truck to scavenge.
..I was thinking push mower wheels or old kid's wagon wheels until I
find something better. Maybe 2 or 3 side-by-side will make an
appropriate single wheel/tire. We have a mower here with a blown
engine.. Another option slightly more expensive would be pneumatic
tires from hand trucks, dollies (I just realized, a hand truck with
the bottom plate removed, a deck added, and a modified handle will
make the perfect trailer, about 5 feet long :-) )
..Any idea on adding "Diesel smoke" and making the engine sound a little
more real? It will have side-pipe of course.