Uncategorized – Page 2 – Grassroots Mechanic Movement

PIETECH Page 13, PIE 4.6 Is Now PIE 4.7 With Addition Of A “DSC”

The integration of an external control circuit known as “Differential Speed Control” (or DSC) on the PIE 4.6 is such an important component that the PIE revision level is now PIE 4.7!

This latest test design is a “Differential Speed Control” (DSC) circuit added to the DC speed controller and actuated by a micro switch. When the micro switch is actuated via an adjustable cam the motor speed increases by an adjustable amount. The amount of increase is adjusted using a potentiometer (“pot”) using just 2 connections, effectively making it a rheostat or adjustable resistor. The pot and switch are in parallel with the adjustable pot on the motor speed controller, and simply lower the resistance in the control circuit of the motor controller.

Because the dc motor has more than enough power necessary to run the PIE, the speed change is nearly instant. The difference between the set speed and the higher speed is the “differential”, and this differential is acting in concert with the planetary gear set to effectively put more control over the weight’s velocity. It is the change of the weight’s velocity (including the changes when contacting the stops) which is responsible for the PIE’s propulsion!

I took a completely hand-held video (no tripod) of the new circuit in operation and it is now posted to YouTube and BitChute, the next video will be using the tripod.

The video can be seen here:

Page 14, Phase 2 – Outer Stops Cont…

April 14, 2020

The revised outer stop (os2) seems to be the most effective, however, it should be noted that it also puts the heaviest strain on the gears. The strain tends to change the timing of the sun gear(s). I am thinking that I should fasten the sun gear(s) to the axle shafts and change the axle shaft mountings to enable “on the fly” timing adjustments.

I have also added the stop tab (which contacts os2) to one of the 1” square weights. The result was a dramatic improvement over the original trials with that weight and I also had to add an extra stop tab to the 1” square to keep it from “backfiring” or spinning itself around to the wrong side of os2.

This all showed me that the os2 is really absorbing a tremendous amount of torque from the weight, and as the timing of the sun, planet and weight are becoming much more critical it is also having a harder time maintaining adjustment.

Note: After multiple, successful tests the forward thrust would suddenly be very diminished. Sometimes it would seem like the whole thing had been a joke on me & I would get very discouraged.

This has been found to be the effect of the timing slowly slipping while test running. This illustrates the need for an improved locking mechanism for the sun gears, with an allowance for adjustment as needed.

Page 13, Phase 2 – Outer Stop

April 8, 2020

The outer weight stop is the device that stops the outer weight from swinging past the apex position of the planet gear. It stops the swing, absorbing the energy being imparted by the inertia of the weight, transferring that energy into forward motion and allowing the weight to stay at apex until it returns to the center of the sun gear and contacts the inner stop. The inner stop holds the weight until it is in position to be swung outward/forward where it contacts the outer stop again.

This illustrates how important the stops are and it begins to illustrate the stress imparted upon the gear teeth and the locks that keep the sun gears timed properly.

The outer stop seems to be where a large part of the stress is, so that is where I am concentrating my refinement efforts.

I have now tried several stops, and the 2 most successful will be called os1 and os2. Os1 is fastened directly to the planet gear and extends outward toward the weight where id stops the swing by contacting the weight’s connecting rod. Os2 is fastened to the planet gear but is inboard of the weight’s pivot. Os2 requires an extension coming from the inboard side of the weight’s pivot which contacts the stop. Intuitively, this seems to be a better idea. We shall see.

April 9, 2020

The outer stop version 2 (os2) seems to be much improved over os1 and I have changed 2 planet gears to utilize this improved design.

One of the (hopefully) benefits of this design is a change in the timing which directs much more of the generated force toward the forward direction. So much so, that I “might” be able to eliminate the counter rotating assembly. If I can, this will greatly improve efficiency!! I am hopeful.