RC Tank Warfare community hobby forum

The 1/35 Testors Half Track model with 3 channel Track assist steering mod starts here.
viewtopic.php?p=347810#p347810

Latest Video here
viewtopic.php?p=347810#p347810

After working with the MTM gearbox in another project here viewtopic.php?f=33&t=33341I decided this gearbox was the answer for an M4 Halftrack and so I continue that build here separate from the Crusader build.

After the MTM gearbox is up and working with both poly tracks, I will upgrade the model to "Hobby Grade" DP radio remote control. As it is now, it is "Toy Grade" radio remote control with crude "Escapement" steering.

Here are some videos for this build...

MTM gearbox re-build and test
https://www.youtube.com/watch?v=kBy7XCbifjY

Gearbox mounted to M4 Chassis and test
https://www.youtube.com/shorts/1d_Wy4AniIY

Left track\chassis test
https://www.youtube.com/watch?v=ufJjediYq38

Steering assembly mounted and test
https://www.youtube.com/watch?v=0FOamfHicPA

I can make a rather good guess at "proportional steering box,' but "escapement stye steering box" puzzles me. Both seem to use a tie-rod (rather than, say, trailing arms as on some 1950s Ford tractors). Can you explain please?

Herr Dr. Professor wrote:I can make a rather good guess at "proportional steering box,' but "escapement stye steering box" puzzles me. Both seem to use a tie-rod (rather than, say, trailing arms as on some 1950s Ford tractors). Can you explain please?

Why certainly Herr DR.
The earliest form of sequential (although not proportional) actuator for radio control was the escapement. Like the device used in clocks, this escapement controls the release of stored energy from a spring or rubber band.

An "Escarpment servo actuator" is a linear device (not proportional) that was used in early radio control planes to move the Rudder Left\Right in both extremes of movement and when not called to actuate the Rudder (or elevator, ailerons), will return to center or neutral position. These were used before digital proportional servos were available.

Back in 1977, when China mass produced radio control cars became available at the malls, They were elaborate, well made Toys that featured "Digital Proportional" speed and steering and were expensive. As time went by, They figured out how to make them less expensive with "Bang Bang" steering using a new form of steering "Escapement actuator". Suddenly most Toy grade cars had this style of steering actuator and to make them even cheaper, no more proportional speed control as now they went "full on\off and reverse.
Full on\off is also called "Bang Bang or escapement style speed control as well as BANG BANG steering which is full left or right when steering command is issued then returns to center position when steering command ends with a center position adjustment lever.

So basically, a R\C Escapement actuator is similar to a servo in its function. It has a few drawbacks compared to a digital servo but has one major advantage, it is cheap to manufacture compared to a digital servo. These are very common in
toy grade radio control vehicles.

For years, I would cut the Escarpment steering out of Toy Cars and use them in models like Half Tracks. I am now converting those steering actuators to "Digital proportional" servo steering boxes.

M4 Escapement steering box bottom view with "return to center" motion
https://www.youtube.com/shorts/N05PaKAiBXU

M4 Halftrack with Escapement steering and simple on\off speed control still works after ~2.5 decades.
https://www.youtube.com/watch?v=DQxX4auE9jI

Thank you! I clearly understand--and memory confirms---the "escapement" steering. In the late '70s, Ertl sold two RC toy tractors (JD 4430 and IH 1486) with such steering. It was painful to watch, the all-or-nothing movement causing some tricky handling. RIP escapement steering.

I recommend Modler's explanation, immediately-above, to anyone checking this thread. It's well-done.

Great job!

I'm starting to try myself in the "animation" of models in 1:35 scale:



https://youtube.com/shorts/V3WQe5LtYMs

Captain Morgan wrote:Great job!

I'm starting to try myself in the "animation" of models in 1:35 scale:



https://youtube.com/shorts/V3WQe5LtYMs

I like that Caption Morgan, I will be using that short phrase to describe what I do with these models

Suspension really is difficult @ this scale but I see it getting implemented more in the future.
The variety of models available in this scale (1/35) is impressive and the cost of entry is reasonable. The workspace required to work on these models is less as well not to mention storage and display. Interested in seeing more progress on your model. And as they say in France, Make Them Move

Herr Dr. Professor wrote:Thank you! I clearly understand--and memory confirms---the "escapement" steering. In the late '70s, Ertl sold two RC toy tractors (JD 4430 and IH 1486) with such steering. It was painful to watch, the all-or-nothing movement causing some tricky handling. RIP escapement steering.

I recommend Modler's explanation, immediately-above, to anyone checking this thread. It's well-done.

RIP escapement steering. Lol yes may they rest in pieces.

As you can see the old M4 Is going to get an update I can no longer stand to looks at it in its present form

This update will reunite the well used frame to the well used body and will re-join the ranks of my favorite models Arizona patina as an extra bonus

To manage the models, I have developed a smaller version of TCB (parent project - Open Panzer):



I have not yet received the mini-ESCs for commutator propulsion motors to begin assembly.
Initially, I assumed that I would control the propulsion motors (geared N20) through the DRV8833 drivers, but this does not seem to work. I ordered small ESCs from aliexpress.

Captain Morgan wrote:To manage the models, I have developed a smaller version of TCB (parent project - Open Panzer):



I have not yet received the mini-ESCs for commutator propulsion motors to begin assembly.
Initially, I assumed that I would control the propulsion motors (geared N20) through the DRV8833 drivers, but this does not seem to work. I ordered small ESCs from aliexpress.

Very interesting. I am an electrical designer (retired) and my specialty is in micro electronics. I am curious as to why it did not work. The impedance of the N20 cored motors may be too low (3v). Put a 22 ohm resistor in series with the motor and try again. Oh course this will limit the current to the motor as well as increasing the impedance of the N20.

Oh, you could try a coreless motor as they are higher impedance than cored motors and take way less current to operate. If you provide a link to the ESC you ordered, I will give you my opinion on them.

It didn't work because the parent project, which has an L298 chip, needs PWM, inA, inB signals for each motor.
I am not particularly strong in electronics, more precisely, it is often difficult to read the datasheet (English is not my native language). I think DRV8833 will not fit, what do you think?
So far, I have only learned how to design boards in EasyEDA, and then with the help of an autorouter.

I ordered these ESCs to control the RC outputs from the board:



https://aliexpress.ru/item/1005003152945927.html