Hi tank fiends,
I did think to start a new thread for this but thought it might be better tacked on here.
I have been busy further updating the KT, instead of getting on with my M36 build, as I felt inclined to finish this project first (at least in so much as they are ever really finished I think
).
So I return to the turret again and the recoil and elevation mechanism in particular. This, you will recall, has the Asiatam unit fitted as stock - not a bad unit but also not great. I have found it quite unreliable at times and there are a few other shortcoming with this installation besides. As well as reliability issues the gun pivotal is set far too far back in the turret, giving incorrect elevation movement of the barrel. Additionally the elevation and recoil are quite short (only around 17mm recoil where, really, it needs something around 30mm or more). The Clark TK24 I have installed supports servo driven 'real recoil' and elevation so I set about conversion to this as follows:
First I remove and disassemble the turret. Here you can see the old Asiatam unit and arrangement, notice the position of the gun pivot relative to the turret in particular,
And here now completely disassembled. The plastic pivot post simply unscrews to remove but the other I removed with a grinder later,
Next I start making some parts for the gun/servo mount assembly. Here I start with the gun carriage - the pivot plate in 10x20x10mm aluminum and what will be the carriage for the breach and barrel (on the right) in 15x15x15mm section aluminium,
Here the two are brought together with further fabrication to form the new pivot point which will be fixed to the turret front armor. The pivot screws are set with locktite applied to prevent loosening in the future. The slot that can just be made out at the bottom back of the carriage is for adjustable fixing of the breach, as are the two (one each side) retaining screws just behind the pivots,
Further work can be seen below on the mantlet which now has a new aluminum (12.5mm OD) round section breach with a cutaway section for the barrel slide and fixing (to servo), To the right of the the carriage assemble is the barrel with the final fixing for the servo connection (this changed a few times as will be seen in following picture,
Assembly of the carriage, breach, and barrel seen here was with an earlier servo pivot design that was changed when I realised it would protrude too much and foul the turret base plate,
This (below) is the control arm I made for the elevation servo to connect to turret,
Next is one of very many test fits of the carriage assemble, now with the servo base plate fitted (reinforced styrene), servo fixing and servos in place. The servos I used are Fusonic 9g metal gear (all gears) digital, these very strong from my 450 3D helis - the horns shatter long before gears are damaged. (notice cutaway on right side of carriage for servo horn to keep it clear of turret base also),
And here fitted with control arm, breach, and barrel, etc,
More parts are made, this time a barrel lock/clamp as the retaining screws are fine for adjusting for optimum breach/barrel position but not strong enough for permanent fixing,
An led coaxial machine gun (of sorts
) was now needed. Output of the second machine gun flash of my Clark TK24 was running at about 3.5 volts so, with a little experimentation, I plumbed for 5mm red led with a 100R resistor which works pretty well, very bright in the aluminum tube with a faux MG34 barrel end (well thats my claim anyway
),
And here is the completed assembly with the coaxial machine gun in place. The is fixed to its own bottom plate connected directly to the gun carriage so, like the real one, it follows the elevation movement of the barrel. In the second picture I have also installed a 10mm long tube for the IR emitter so as to be battle compatible, etc.,
This is what the coaxial MG looks like outside.
It took quite a while to get the coaxial gun level with the mantlet opening through the elevation range but now works quite well. Clark also provide a different sound for the second machine gun which adds to the realism. The range of movement of the elevation is now more than I need so i still need to fiddle with that a little. I now have around 28-29mm of smooth, realistic, servo recoil (previously about 17mm) and this is fine, to get more I would have needed to modify the barrel and mantlet more than I wanted too.
Lastly, I had to reinforce the turret bottom plate as necessary grinding and sanding of certain areas to make room for the new gun carriage assembly had weakened it quite a bit,
Frankly I could have avoided this by retro-fitting a larger turret traverse gear ring and motor but i decided to put off this added pleasure/hassle(?) for another day!
Hope this is of some interest/help to some - it has certainly been a learning curve for me (great fun though).
I will try to get a video up, when I figure out how you do it!
