RC Tanks Australia Forum

Hey All

Everyone knows the Heng Long recoil system in it's factory supplied condition is just horrible. Modifying the recoil to operate properly is not that hard to do but it is a real pain. Plus spring loaded recoil units (Heng Long & Asiatam) snap back quite hard and the micro switch operation can be unreliable and confusing. With that in mind I set about to find a super simple way to mod the Heng Long recoil. The result is a servo controlled recoil system that operates in conjuction with an ATRC MKII circuit. If you can use a saw and drill then you can do this mod. Here it is.....

Step 1. Get your Heng Long Recoil Unit




Step 2. Unscrew and take apart


Step 3. Take out all of the insides, motor and gears


Step 4. With a hobby saw cut off the bottom of the unit along the line as shown.


The recoil should now look like this.


Step 5. Take the barrel and unscrew the teeth


Step 6. Grab a PCB spacer (from old computer)


Step 7. Screw the spacer into the hole that held the teeth


Step 8. Grab a servo (We have these servos and servo mounts for sale in the shop but you can use your own)


Step 9. Postion the mount as shown and screw into place


Step 10. Attach servo as shown. All that is left is to connect a linkage rod from the servo arm to the PCB spacer. The servo lead is then connected to an ATRC MK II board.


To be continued....... Well all the hard stuff is done but I'll post the rest of the mod as I get the time.
Cheers...

Nice 2 know Admin.... Now for the rest of the mod.

Firstly, I've missed some important photos that should go here. The shots above show a unit theat will only allow the standard Heng Long amount of travel (which isn't much). Such a mod will only require 45 degrees of servo travel. (the amount that you'll get with an ATRC MKII) To get more travel I have cut the back half off of the piece that moves back and forth inside the unit. Doing so will give you nearly an extra 10mm of recoil and will require about 45 degrees of servo arm rotation.

Step 11. I don't know anyone who hasn't bought and destroyed one of those little RC 'copters or a small RC car. If you have check them out for any small control arms land put them to good use.
Barrel in ready to fire position (RTF)


Barrel at full recoil (approximately 90 degrees of arm travel)


Side view


Next up I guess I should show some video and maybe how to set up your 9X for a beautifully recoiling main gun........

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rctanksaustralia.com

Hi there,

I am new to this forum and was browsing to try and get some idea of how things work.
I came across this posting and had a thought could i make this mod work on the T34/85,i have an ATRC II board which i've installed along with the HL boards and that works a treat, Great bit of kit that board Also how to wire the flash unit up I see the board has flash connection but is that a direct plug in for HL flash Not sure on that and don't want to make a mistake at this point.

Any Thoughts would be greatly appreciated

Best Regards,

Ace

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Smoke me a kipper....I'll be back for breakfast!

HI Ace

Sorry I have not written an ATRC MKII manual yet but I hear that Gra helped you out.

Did you want to use the high tension Xenon flash unit or are you wanting to use the LED flash output on the ATRC II? The pins on the ATRC are for you to wire up your own 3 or 5 mm LED they are not to be used for the hight tension Xenon flash.

Cheers
Kevin G

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rctanksaustralia.com

Hi Kevin,

I had some assistance from Gra, which was very helpful. I do have a high intensity flash unit so i take it that can't be used with the ATRCII board. I have a new barrel which has been drilled through to take the flash but on reflection is there a better alternative to this, and ideas would be greatly appreciated.

Thanks for the quick response,

Ace

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Smoke me a kipper....I'll be back for breakfast!

Hey Ace

The high intensity flash connects to the RX18 board all by itself and operates with or without an ATRC. However if you modify the recoil you will remove the microswitch that triggers the flash.

You can get around this with the old diode on the back of the RX18 as shown at RC Command. Or a new microswitch or a relay or....

Thats why I put on the pins for a LED - so much simpler. Also a 3 or 5 mm led will fit down scale barrels for the Pz III and IVs. The big bulky flash unit won't. Which it appears you have found out by yourself.

Get a nice bright white LED 3 or 5 mm and solder some wires to it and connect it up to the LED pins on the ATRC. There already is a current limiting resistor on the ATRC so you can wire the led up 'as is'.

Cheers
Kevin G

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rctanksaustralia.com

Cheers Kevin,

I'm on it mate,
Your right,LED is the way to go with this. Just waiting for the metal barrel to come back from my mate.

Cheers,

Ace

_________________
Smoke me a kipper....I'll be back for breakfast!

Hey Ace

Why the servo is going to be a bit better than the stock WSN gears.....
crappywsngear.jpg
Cheers

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rctanksaustralia.com

_________________
Smoke me a kipper....I'll be back for breakfast!

Hey All

OK here is the video of the recoil mod in action. The servo is being controlled by the Turnigy 9X running tankER9X version of the firmware.



Cheers

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rctanksaustralia.com

Very nice P-Fish

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Gra's Heavy Tank Regiment
HL Tiger 1 - El Mod, Tiger 1, K T Porsche turret, Panzer III & IV, Stug G & E, Panther D,
Matorro KT, Jagdtiger and Sturmtiger, HL Sherman and T - 34, A7V (WIP)
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