1/35 M4 Halftrack(s) to RRC Tamiya, Testors
1/35 M4 Halftrack(s) to RRC Tamiya, Testors
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
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
- Attachments
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- This is an Escapement stye steering box that has been converted to proportional steering box with Ultra micro servo.
- IMG_8419.jpg (83.58 KiB) Viewed 33007 times
Last edited by modler on Sat Jan 06, 2024 4:28 pm, edited 7 times in total.
- Herr Dr. Professor
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Re: 1/35 M4 Halftrack to radio remote control with MTM gearb
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?
Re: 1/35 M4 Halftrack to radio remote control with MTM gearb
Why certainly Herr DR.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?
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
- Attachments
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- This steering Escapement has been converted to a Digital promotional steering box. Not scale looking but very robust and will last for decades. Scale steering looks better of course but is very delicate and hard to repair but has its place on a nice scale model that runs on a smooth surface.
- IMG_8419 (1).jpg (83.58 KiB) Viewed 32960 times
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- "Escapement" Elevator actuator from a Toy radio control plane.
- IMG_8441.JPG (84.9 KiB) Viewed 32964 times
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- "Escapement" Rudder actuator from a Toy radio control plane that flew very well.
- IMG_8439.JPG (76.42 KiB) Viewed 32964 times
Last edited by modler on Fri Aug 12, 2022 12:38 am, edited 3 times in total.
- Herr Dr. Professor
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Re: 1/35 M4 Halftrack to radio remote control with MTM gearb
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.
I recommend Modler's explanation, immediately-above, to anyone checking this thread. It's well-done.
- Captain Morgan
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Re: 1/35 M4 Halftrack to radio remote control with MTM gearb
Great job!
I'm starting to try myself in the "animation" of models in 1:35 scale:
https://youtube.com/shorts/V3WQe5LtYMs
I'm starting to try myself in the "animation" of models in 1:35 scale:
https://youtube.com/shorts/V3WQe5LtYMs
Re: 1/35 M4 Halftrack to radio remote control with MTM gearb
I like that Caption Morgan, I will be using that short phrase to describe what I do with these modelsCaptain Morgan wrote:Great job!
I'm starting to try myself in the "animation" of models in 1:35 scale:
https://youtube.com/shorts/V3WQe5LtYMs
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
- Attachments
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- oh look, upper complete (unibody mount no frame) drive line removed with 3 screws. This is a feature I perfected along the way to 1/35 model work. They have to come apart like a real machine as apposed to being glued in place like a "static" model
- IMG_8462 (1).JPG (94.17 KiB) Viewed 32908 times
Last edited by modler on Mon Jun 27, 2022 3:43 pm, edited 1 time in total.
Re: 1/35 M4 Halftrack to radio remote control with MTM gearb
RIP escapement steering. Lol yes may they rest in pieces.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.
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
- Attachments
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- Now to fit the body back on the frame. The front wheels are too wide apart and will be made to fit the fender wells.
- IMG_8473 (1).jpg (89.52 KiB) Viewed 32905 times
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- These elements will be replaced with updated versions
- IMG_8468.jpg (68.19 KiB) Viewed 32905 times
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- Here is the old drive line making its last appearance.
- IMG_8466.jpg (48.66 KiB) Viewed 32905 times
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- these two assemblies will be reunited at last after 23 years.
- IMG_8464 (1).JPG (98.68 KiB) Viewed 32905 times
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- Transformation in progress
- IMG_8463.JPG (87.82 KiB) Viewed 32905 times
- Captain Morgan
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Re: 1/35 M4 Halftrack to radio remote control with MTM gearb
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.
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.
Re: 1/35 M4 Halftrack to radio remote control with MTM gearb
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.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.
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.
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Re: 1/35 M4 Halftrack to radio remote control with MTM gearb
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
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