2009년 9월 25일 금요일
This is a practice work.
Creation date : September 26, 2009
Features : rack and pinion steering, rubber band shock absorber
Left photo shows top view. Right photo shows a wheel is lifted.
By twisting the rubber band, the strength of shock absorber can be adjusted.
2009년 9월 15일 화요일
Creation date : September 14, 2009
Adder-Subtractor with double differential gears
Essential mechanism is the same as the one by Philippe Hurbain below ;
(Image source : Philippe Hurbain's Brickshelf page)
My version is different in some aspects such as frames and the motor positions.
Top view and front view. Front view shows some extra space inside to insert the chassis beam.
Left, right, and overall view
A modification for example :
Main drive motor was changed to XL motor for more power.
Gear reduction for M motor is added on top.(12t->20t and then 12t->20t->differential)
This is a practice work. Pieces of various colors were used for demonstration.
The main photo shows the motive(starting point) of the idea.
Creation date : September 13, 2009
XL motor for drive
M motor for steer
worm gear and clutch gear used for steering
Wheel tread is similar to 8386 Ferrari
These 3 pictures show how the parallelogram works.
Overall module and close view of the gears for steering.
Video for demonstration
2009년 9월 4일 금요일
This is an experimental demonstration for a small idea.
Date of creation : Aug 23, 2009
special feature : the output shaft rotates in only one direction regardless of the input rotation
Since I saw the worm gear first, I have been wondering why the worm gear has loose axlehole unlike most gears. And during Aug of 2009, I came to this idea to utilize the loose axlehole.
The gear combination consists of a worm gear and two 16 teeth gears.
The video of internal motion explains everything, I hope.
When the input rotation reverses its direction, the worm gear scrawls along the axle
and connect to the other 16 teeth gear. A short delay of the output shaft comes from this crawl.
From the viewpoint of worm gear, crawling requires less torque than driving the wheels.
So, it crawls as far as it can, and then move the 16 teeth gear.
Date of creation : August 31, 2009
PF XL motor is used and total gear ratio is 1 : 3.9 overdrive.
Module dimension is as follows :
width = 9
length = 9
height = 8.5(including differential gear underneath)
Gear combinations A->B and C->D both have gear teeth 20->12 resulting in a very fast car.
They can be replaced as 16->16 or 12->20 according to the desired speed of the car.
Differential gear was adopted as seen in the photos.
The last photo shows a test car.
Front(steering) module is also a practice work with clutch gear, but not satisfactory in that
it is so hard to control this car to go straight because it is so fast and it does not have return-to-center mechanism.
These days, I am trying to combine clutch gear with return-to-center mechanism.