Stug III RECOIL unit

[971wright]

Hi guys just taken the recoil apart to see if its posible to get it working correctly and the answer is I think it is the recoil unit motors back then springs forward well Have a look at photos the gear that winds the barrel forward needs a slight modifiction one is to stop it going all the way back so the gear can engage the other is to modifie it so it moves a little further forward so the gear will disengage this will allow the gun to recoil then reverse the motor conection so its running backwards so when you hit the fire button the motor will turn to disengage the barrel the spring will pull the gun backwards then the motor will engage and push the barrel forward


its finished and tested works fine the only filing to do is the internal stops pointed out with screwdriver on early post you have to file about 1,5 mm off 4 stops to allow the barrel to move forward to disengage the drive gear,glue the clutch so it will disengage at end of stoke from a stationary postion when testing found the cluch would slip rather than disengage , after this swop over motor wires to reverse the motor move spring 180 degrees so it pulls the barrel backwards and fit limit switch to stop barrel when it is driven forward with the motor.The hardest part is setting the limit switch its alot of trial&error to get it just right

the wiring should be like this
Batt Positive connected directly to motor as per stock.
Batt Negative connected to NC on microswitch
COM on microswitch connected to motor
Recoil start/supply (negative) from RX18 board connected to NO on microswitch


if its worked you should see the new gearbox from Heng long its only the right one they have changed

regards pete

[tankman]

Now that's what I call clever. If you have no objection Peter I would like to PM you when I get round to doing this mod on my Stug for a spot more advice on this upgrade. All the best for now
Alan

[971wright]

Hi Alan no problem will help all I can .

        regards pete

[971wright]

bump

[YHR]

I hope 971 wright doesn't mind if I use this thread for a discovery.

I run the bbl through the back of the gun and no modification is necessary.  Have a look at the pictures,  and see how easy it is to do.  You then just have to trim off the plastic ridge, and use the new Heng long elevation unit. 

Not much point doing a how too thead as 971wright has already done one for those that want to use the recoil unit with the old elevation cam.  And if you are using the new elevation cam you don't need that ridge of plastic and can run the bbl through the back as I have mentioned..

[Gigantohawk]

Hi Pete, you alright mate. Still trying to get the house in one piece so I can do some Tank modding. You're probably thinking why I don't use my workshop in the garage. Well it's quite simple...I can't get through the door. Better get another skip ordered and sort things out.
Anyway back to the recoil unit. Using YHR's gun reversal mod and a contact switch I should be able to leave most of the wiring untouched including the gun flash. What do you think ?. Am I on the right track ?.

[971wright]

Hi Nick I didnt touch the flash in mine But I did move the I.R. led a little bit I fitted a brass tube and set the I.R.LED about 10mm down the tube but it is the original one havnt changed it going to try it out you might have to add a microswitch and one extra earth wire direct to the negative on the battery this is to make the gun return to normal position when you fire it.

regards pete

[Gigantohawk]

On the subject of microswitches. Maplins have a N95AQ. Do you think that would be suitable ?. Whilst on the subject of Maplins I didn't realise that they had a shop in Wakefield. That's only about 15/20 minutes away from me. I'll have to pop over and buy lot's of supplies.

[BREL]

I am spoilt for choice on Maplins store because there is one in Stoke on Trent and one in Stafford both are a couple of bus ride away and take about half an hour to reach either one. but if I am buying small items that are one off's and the total is lower than the minimum order level for free postage, I buy on line because the postage is cheaper than the bus fare at £4 for a return ticket

[YHR]

Hi Pete, you alright mate. Still trying to get the house in one piece so I can do some Tank modding. You're probably thinking why I don't use my workshop in the garage. Well it's quite simple...I can't get through the door. Better get another skip ordered and sort things out.
Anyway back to the recoil unit. Using YHR's gun reversal mod and a contact switch I should be able to leave most of the wiring untouched including the gun flash. What do you think ?. Am I on the right track ?.

I think you will have to remove the gun flash contact.  I think you will find it will stay on except when the bbl recoils.  Just wire it up on the same circuit as the trigger wire(yellow) with a 68 ohm resistor.  When you move the left joystick up, it will light.