RC Tank Warfare community hobby forum

Good one Kaczor, i like it. I'll have to put something funny like that somewhere on all my builds.


The following two posts are for the turret rotation. This build is going rather fast. Its faster when we do not have to undo anything, or scratch build everything.


As this is a Tamiya M4 restoration project, the plan is to reuse anything good from the available material, make it as simple as possible so that anyone can replicate, and also as cheap as possible.


This is the bottom of the Tamiya and Takom turrets. The Tamiya rotation unit and wheel are good, and offer 360 degrees continuous rotation. There is no reason to develop something new. However, the Takom turret ring is much larger. It is not possible to reuse everything exactly as is, some adaptation is required.


I also need to think ahead and plan for the recoil unit, so i cannot have the elevation unit too close to the middle of the turret with a metal bar going across it.



The Takom turret is a little bit loose on the upper ring. To keep it from going sideways by 0.5mmm, i added a thin plasticard section on the four corners to keep it in the centre and reduce friction. There is also no retention mechanism to lock the turret on the upper hull, but there is a deep extension rim that is much appreciated.


I needed to find a simple way to restrain the turret on the upper hull so a roundel the size of the turret ring and 2mm thick is made using my very practical roundel maker, a little tool that can be purchased on Amazon for a few dollars. Because the plasticard is thick, the roundel is not made by cutting it with the sharp side of the blade, it is made using a counterclock mouvement, slowly scraping the plasticard with the tip rear of the blade. It takes a few minutes, starting with the outside ring. The middle point is important.


It goes around the turret ring extension and holds in place without any screws, glue or else. With this retention method, the turret can be installed on the upper hull, and removed as required. The roundel rotates with the turret, and is flat against the inside of the upper hull, with some buffer for free mouvement.


The bottom of the turret is perfectly round. A roundel is made to give a floor to the turret bottom, and it is glued in place.


On the reverse side which has the center hole of the roundel maker, i make a mark the size of the rotation gear with a compass to mark the required position and ensure it will be perfectly centered in the middle, without any wobble. This is critical.


The rotation gear is glued in place with a long cure glue, allowing it to be perfectly positioned with the marks, finetuned, and then rechecked twice with a compas. Any wobble will create dramatic problems with the turret rotation.

There is no need to install screws in the two screw holders. The center of the turret bottom is likely to be completely made hollow later to allow for the gun recoil unit to work freely.


Need to create a stand for the Tamiya rotation unit, why not reuse the one from the Tamiya upper hull...


Continuing on following post

A rotation unit stand is made by cutting the Tamiya hull with the Dremel and sanding the edges, done in a few minutes and exactly what i needed. The Tamiya upper hull was going in the garbage anyway, glad it could be of some use.


Re-installing the Tamiya rotation unit where it used to be with same screws.


Of course, the cable connector need to be changed to match the type on the Heng Long board.


After searching for the ultimate position through much rotation tests, the rotation unit is installed at the front, pretty much where it used to be. It is glued direcgtly against the upper hull side without any ceremonies and it's quite strong. It's positioned a bit higher to clear the rotation wheel but not too high because it would then hit the fender supports when the upper hull is put back on the chassis. Inner beauty is not the highlight of this build...


Having this little guy at the front allows for the interior of the rear deck area to remain clear so that the Tamiya speaker can be reused.


It works smoothly and flawlesly with 360 rotations, very good. The whole thing took about 2.5 hours to do.


The upper section of the turret is deposited on top, just for the look.


If i decide to install a figure at the front, the mount can be trimmed.


The model as it stands today.

Notice how perfect and sharp the joint between the two turret halves is, it is one of the main reason i selected the takom kit for this build. It will be possible to create a method to close the two turret halves with a way to keep it removable if need be, allowing for easy access to the sensitive electronics that will be in there. The joint on the Trumpeter model was not that great.


Next step, the gun barrel and recoil.

Regards, Louis

Hello,

This post is for the bun barrel.


The Takom kit comes with two barrels, the plastic one in a sprue in two halves and a beautiful aluminum barrel, well turned and smooth, the problem is that it is not hollow for the gun flash and the tubes connecting to the barrel smoke unit. It is undetermined at this time how the root of the barrel will end up in the recoil unit, this is something that will be dealt with later.


Instead of buying a lathe, or sending it somewhere to get it hollowed, i decided to at least try to save $50 with shipping by doing it myself with my very basic tools. I have done it before, i know it can be done. The trick is to start absolutely strait from the tip, adjust as required in the first 10mm, then drill through the whole 19.5 cm of solid aluminum, 0.25mm at a time, and hope for the best. It is better to position the drill in a downward slope to apply more pressure, constantly cleaning up the tube of residues. At one point, if it is determined that it goes sideways and that the drill bit will exit from the sides, then there is no hope to salvage it and the drilling must stop, but it's worth a try. At about 2/3, it is good to restart the process from the other side and for the tubes to meet. It derisks the outcome. It does not matter if it is perfectly strait inside but the two end points need to be perfectly centered.

There are after market hollow 76mm Sherman metal barrels available on the market. Be aware that they are not necessarily well shaped or accurate. I had some bad experience with them in the pasts, but also good ones.


Banzai !

Here is a hollow Takom Sherman aluminum gun barrel after two hours of drilling. I probably got lucky one more time.


The Takom plastic muzzle comes molded in one piece and looks great with visible barrel rifling.


Instead of a weak glued connection, i opted to install a 5mm brass tube as a joint and drill the tip of the aluminum barrel to take it.


Just great. There are 3 other parts to be added to the tip to complete the muzzle. I will be adding these once the LED is in place and the muzzle permanently installed on the barrel.


Moving to the mantlet, It looks solid. I currently plan to reuse it with the pivot and adapt the recoil unit to it.

The Takom kit comes with a detailed breech that i thought should not be wasted like this without even looking at it.


I therefore decided to spend a couple of hours to build the Sherman breech to at least examine it before discarding it. It also allows me to calculate the position of the barrel in relation to the mantlet.


Continuing on following post

Dry fitting the barrel with the mantlet to check things out. It will be a good looking Sherman.


That's the issue with tank interiors unless you put micro cameras inside, the nice gun breech does not really show from the hatches, it is a pity. So there is no point trying to make it recoil with a servo. I think it is better to keep the fragile breech out of the RC build and do a special Sherman 76mm gun exterior static display with it, including the machine gun mount.


The best view is from the pistol/rearming port.


It does recoil with difficulty and the breech can open but it is not convenient, the parts around it are fragile and easily break. No way to use this in an RC tank.


One last view of the gun breech, unless i build a static display for it. It is a cute little model by itself, and the kit provides an extra mantlet and plastic barrel so there is something more to be done with this than discarding it in the junk yard.


There is a detailed Browning machine gun mount for the left side as well. I did not build it, yet.


A Heng Long recoil unit is on the way. I will pick up the work on the turret when it arrives.


Coming with it is this gun barrel flash and smoke unit. I never tried this before so it will be amuzing. I am told to plug the heater wire in CN5 (Wifi image transmission port).


I just got my Heng Long TK 7.1. I am surprised by the quality, wow. Gone are the days when the Heng Long control board was coming in a cheap plastic box. This one is real sharp and the functionality is amazing. No need for PC apps or a TV remote interface to set it up. For the $90 that i paid for both the board and emitter, the competition will have a hard time. After my great experience with the TONGDE equivalent of the Heng Long 7.0 on the M60 and Centurion, there is no going back for me because this one has additional servo ports for DIY features, the last obstacle is gone.

What is bizarre is that it has a different battery connector. I do not understand why Heng Long is now using old Deans T plug connectors on the TK 7.1. I had to order from Amazon a set of Deans female T plug to male Tamiya converter in order to use my existing batteries.


Next step, finishing the hull while i await the turret electronics.

Regards, Louis

Well done! This barrel looks great.

Great job

Hi, Thank you !

The following posts are for the bow machine gun and the headlights.


The Takom kit comes with a complete Browning M1919A4 bow machine gun. I want to give a flash, sound and mouvement to it so i am not going to waste a nicely detailed machine gun just like that which would be completely hidden.

As usual, i use a Aber barrel replacement, i always have a few in inventory and are relatively inexpensive for the quality.


These are the assembled parts for the bow machine gun. The three Takom moving plastic parts for the mount, the Aber barrel, thin fiber optic cable, tube for the fiber optic and tube for the extension to the rear, and a 5mm LED that i later replaced by a yellow one.


The Aber barrel is not hollow. The barrel is cut at the root of the muzzld and easily hollowed at the size of the fiber optic.


The solid barrel is replaced by the brass tube and connected to the muzzle with the fiber optic inside.


The position of the mount is calculated and then glued.


The Tamiya chassis has a low gearbox, but the edge of the mount for the right motor is a bit in the way, preventing some mouvement.


A curve is therefore given to the brass extension tube to avoid hitting the motor and allow for full sideways mouvement.



A micro servo and a very simple attachment is connecting it to the machine gun.


There are two plasticard strips that helps control the movement of the machine gun. One is attached to the machine gun itself and keeps it mostly horizontal, with the curve on the outside to avoid the motor on the inside. The other strip is attached to the hull and keeps the machine gun mostly horizontal but not completely at the same level when moving sideways. It gives a more natural mouvement that goes a little bit up an down as the bow gunner mows down the North Koreans in front of the tank.


Simple, but effective.


Continuing on following post

For the $10 that it costs, the Aber M1919 is fun to work with, is resistant and provides unparalleled details.


Moving to the headlights.


I use Mato Sherman metal headlights. They need to be cleaned up, polished and the back sanded smooth and rounded with superglue putty. I like them because they are easy to connect with good thick wires, not the little tiny minuscule wires that always give me problems on naked LEDs.


The Takom plastic headlight guards would not survive long in the RC field. They need to be assembled from multiple parts, nice but fragile. Better keep these for a static model one day and use the Mato guards that come with the headlights. They just need to be cleaned up, thinned a bit and polished.



The Mato metal headlights are perfect for the Takom upper hull. They can be made to fit exactly in the Takom positioning holes of the glacis, perfect replacement with some work with a nail file. This tells me that the Mato headlight shape and dimension are pretty good.


Looking good, and solid.


Continuing on following post

The model as it stands today. Next step, the tail lights.


Regards, Louis

Hi Louis,

I am glad you decided to take on this build/conversion. You are saving me all this mental engineering work. I hope you don't mine me "stealing" as I have a Tamiya M4 and Andy's M4E8 and will do a late war build.

Excellent use of existing Tamiya parts to supplement the Takom and save where you can.

Barry