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As shown on the Heller tub, there are support brackets under the side bars, with spaces in between for the fender supports that need to be respected. I salvage the bolt heads from the Heller tub.


Done very rapidly in 3mm brass as these are mostly hidden but help as reinforcement for the side bars. I an noticing a bolt that that could be better positioned.


The Heller upper hull now slides into place on the Taigen chassis.


I tried to respect the spacing shown between the upper hull and the back plate seen on Panzer IIIs on Prime Portal. It was not easy.


Sharing the pain of that joint. The Taigen chassis is not a natural easy fit for a Trumpeter/Heller upper hull integration. The metal hull adds some complexity. It's doable, stressful but i have gained valuable experience for future conversions. It's likely easier with a plastic HL chassis, but surely not as cool. For someone will less experience, it could be really challenging but hope this build and detailed steps will help.


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And at the same time that the heigth and lenght is determined at the back, the front should not be forgotten, here dry fitting the armor to ensure it can be positioned correctly in the next phases. Spacing looks good, unless there is something i did not think about.


That's it for now. Next step, the turret.

Regards, Louis

Hello,

The following posts are for the turret rotation, barrel and recoil mechanism.



These are the parts for the bottom of the turret coming with the Heller kit, there is not much to play with.


The turret is holding in place by gravity... It is deposited flat against the upper hull, and the rotation wheel does not really turn on its own unless some scraping is done to the inside of the hull ring, which i did.


Looking at my old HL Panzer III, we can see that it is built in with a large space between the turret bottom and upper hull. Without going overboard like this, there is a way to at least raise the turret a bit so that it will not scrape and risk ruining the paint job with scratches on the upper hull.


A thin 0.2mm plasticard roundel is made to fit at the bottom of the turret ring to raise it a bit.


While it raised the turret, i am noticing it is not completely horizontal during dry fitting, it sinks on the left side... In the picture below, you can see that the turret bottom is being positioned with the help of very tiny stoppers at the 4 corners. There is probably a problem with them when the turret is raised a bit. These require attention for a flat turret later on when its time for final assembly.


Dry fitting the turret bottom. Glad to see that the joint is good, no gaps.


As seen during dry fit, the turret was raised a bit more than expected. It will be adjusted a bit lower, just enough for them not to touch.


In terms of helping me with turret rotation, there is no structure provided.


Needed to create a roundel, i think it was in 0.75mm plasticard, to make the turret ring just a little bit lower than the roof plate.


Then a larger plasticard ring is put on top on the previous turret ring, integrated with a HL small rotation wheel added above it. After a lot of dry fitting with a couple of drops of superglue to find the rotation center, and many rotation tests to validate it, three bolts are inserted all the way to a plasticard plate added to the inside of the turret... The turret turns freely. Then a HL rotation unit is added at the back.


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I added a plasticard structure on top of the interior bottom of the turret. I needed to beef it up and give it some weight in order to support the rotation wheel bolts coming from below. It also reinforce the turret bottom, ensuring it is stable and kept flat as all the kit parts are pretty thin.


And here we have turret rotation on the Heller kit.


Let's take a look of the vehicle with the turret deposited on top, looking good. It is the first time that i see a Panzer III being built without the usual HL style upper hull. It definitely gives a different look and feel to the build.


These are the kit parts for the mantlet, turret front plate and elevation pivot. The elevation pivot is great, a bit too tight but was loosen a bit.


The gun barrels

On top is the L45 metal barrel coming with the Heller kit, it is not hollow. Not needed.
In the middle is the L60 plastic barrel coming with the Heller kit, it is not hollow and is molded in a single part, it's rare to see that. Not needed.
At the bottom is a Mato Panzer III L60 metal barrel from eBay China, a scale replacement for the large BB gun barrel, quite cheap and it looks good, is hollow and comes with flash LED. A bit longer than the Heller plastic one. Not sure which one is accurate but i prefer it too long than too short. It can be cut as required. It's exactly what i needed.


I found in my tube stash a thick brass barrel that can serve as recoil unit with the HL barrel. The fit is prefect.


I am reusing the Heller kit plastic barrel support, not the metal one coming with the HL barrel.


The bottom of the barrel support is reworked to hold the tip of the recoil unit tube.


Checking out the barrel support connection with the recoil unit tube and the barrel, making plans and taking dimensions. It's obviously critical that it is strait inside and out.


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Planned barrel position looks good. Making plans for the recoil unit. The turret interior is very small, so i am designing a home made recoil unit that can fit inside it, servo operated, that can provide great servo elevation and depression, and also that cost almost nothing. After the $55 bucks i spent on the unsatisfactory HL metal recoil unit used on the M4A3E8 build, i decided i could do better myself in a couple of hours.


After calculating its position, a slot will be cut on both sides using a Dremel reinforced cutting wheel. The two slots need to be exactly parallel.


Making the recoil bolt slot was easy enough, but the interior of the tube gave me trouble afterwards. The barrel would no longer slide in it despite all my attempts to make it smooth inside the tube. Everything looked perfect inside and i could not find out what was preventing the barrel from sliding through it like before. I had to create a special sanding drum (a 400 grain flexible sanding foam rolled around a drill bit) and re-polish the inside of the tube for 10 minutes with the drill. It somehow cleaned up whatever was preventing the recoil inside the barrel and only this allowed me to move on.


The recoil arm is put in place, thoroughly adjusted to find the perfect configuration, find out any imperfection and resolve any resistance, and tested for a hour. Now it slides perfectly.



The tube is glued to the barrel support, with a plasticard ring added as reinforcement.



The mantlet with front plate and elevation pivot are then put on and the tube is glued to it at the back, with a plasticard ring added as reinforcement.


A plasticard platform is added below the commander's hatch and an e-Max servo is connected to the push rod arm. On a small gun like this, it’s ok for the servo not to be attached to the barrel, it makes the whole thing simpler and less cumbersome. But a strong elevation servo and mechanism is needed to keep the barrel stable.


Recoil tests were done with all elevation levels, working well in all cases. I expected that i might have to limit the elevation because the recoil servo is not connected to the recoil unit, but no, it works even at maximum elevation. In any case, i will likely reduce the max elevation in order to protect the servo.


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Barrel support with gun at rest


Barrel support and barrel at maximum recoil, looking good and centered. It’s important to me that the barrel does not go sideways while recoiling. Having the barrel recoil into a tight fitting tube allows for that.


The model as it stands today.


Next step, barrel elevation.

After that, the most critical technical components will have been built, the rest will mostly be plastic structures from the Heller kit. I am realizing that this build is going quite fast, specially without having to build the kit suspension, road wheels and tracks.

Happy New Year 2024

Regards, Louis

Looking great. Happy New Year

Happy new year and thank you for your interest.


This is the gun elevation.

A thick and re-inforced plasticard arm is glued to the kit elevation pivot.


A regular size powerful servo is installed on a platform under the rotation wheel in the hull, outside the main turret. There was no room for it inside the turret and i did not want to install a smaller servo that are usually struggling for anything else than light work. After finding the optimal position for it, it is simply glued in place with a few drops of superglue. In case it is ever required to replace it, it can just be snapped out with a tool.



Testing; Max lower depression


Max elevation. On a Panzer III there is no mantlet canvas cover to worry about with the elevation.


There is a built in mount for the coax MG, like the real thing actually. I love these kits with realistic interior parts, the kit comes with a complete gun breech. its more interesting to work with such design than simple plates or holes. My Aber MG34 have not arrived yet.


Finishing up the hull. The suspension stops were built, they come in 5 parts... This is the center roadwheel Heller suspension stop part compared to the Taigen. A nice touch is the black plastic part to simulate the rubber bushing. It will certainly ease painting and look good. These will be permanently installed later in the painting phase.


After validation with the Heller hull, all the pre-cut holes on the Taigen chassis that to be filled with a 2mm plasticard block and sanded smooth. They were all positioned too close to the suspension shaft. I took calculations the best i could from the Heller hull and positioned all the suspension stops accordingly, or very close to it considering the difference in design.


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The rubber stops will be added after painting.


For reference and comparison, these are the equivalent parts on a Heng Long plastic chassis.


Close up on the Taigen roadwheels and Continental rubber band markings.


The Impact Panzer III metal tracks, sprockets and idler wheel are installed, strait but a bit stiff. I'll see how they run during upcoming tests. The Taigen idler adjusters are great but installing the idler wheel was a struggle because i did not have the mounting bolts. I had to use M3 hex bolts with some inner tubing to adjust the hole size.


The model as it stands today.


Regards, Louis

Such a big difference with the oversized Heng Long turret.