STUG III Asiatam Heng long

[xrad]

Found a small IC that is a micro relay , operates at very low amps and volts ...MOC3012. Kind of a neat package ..an LED switch.

I think that I can get this to fire the flash unit off the #3 pin of HL rx18 main chip.....we.will see. This would eliminate one microswitch on the side of the recoil unit. Other one still necessary to run the gun motor.

Built up the frontal armor with thick brass sheet. This will be trimmed to look like the one piece late war thick armor. Upper deck bolt will be removed. Used brass fuel fittings parts that come with nuts from local hobby shop and soldered on at appropriate length and location.

[xrad]

The more you build the better you get:

Recoil action operational!

1) found a new and better way to mount the mini switch. Two 2.5mm 8mm long screws into small drill hole. They go into housing wall at perfect depth. Drop of Ca to hold them in place. This switch runs the 'extra' power needed to continue recoil action after 'up-stick' motion.
2) four diodes control current direction as two pos and two neg wires need to go to motor from different sources.

works like a champ! Now to decide if I want flash or IR led in the muzzle......hmmmmm..put the IR in the right spot where machine gun in mantlet is supposed to go....

Does anyone know if the IR LED fires with the 'up-stick' motion or does it fire with the 'K' button???

Never mind..it does not matter BECAUSE when I wire the trigger (third pin on RX18 chip) to the ARM recoil AND to the MOC3012(micro relay controller..because I can;t fit two relays on the recoil due to the mount), this will cause the flash to fire AND the sound AND the track recoil AND i am guessing that it will also cause the IR to fire!?! we shall see...

ANYONE build an IR test rig??? so you can sight in the IR and test distance??

[xrad]

Don't go by the above pics for wiring diagram. In fact, don;t use my JP wiring diagram either! reason is that my JP has a bad board and for some reason, my original schematics worked, but two new HL rx18 boards i use now, it won't work.

If you want the recoil mod to function, you have to use the setup by RCCommand. I have drawn a simple schematic for you below. In addition to RCCOmmand setup, I added the low voltage adjustable regulator( any 2-12 volt lm317 type adjustable regulator will work..ebay 6$..see my jagdpanther build for more info). This is to isolate the power supply as a seperate supply instead of adding the 22ohm resistor and using board power. Basically, pull to ground(yellow or brown wires..depends on which day your 8 pin HL harness was wired) fires gun from HL board and micro switch grounds for gun 'return to battery' and 'hold position.' Also, i set up the mechanics of the microswitch and spring a little differently as in above posts (rear spring screw runs ALL THE WAY ACROSS the housing). you can do it either way.

Next is the RCCommand flash combination mod. Bridging the 5pin and 8pin connectors on the board does in effect what my second microswitch does on my jagdpanther mod. this is so that you can 'upstick' fire the flash and IR at the same time. NICE! (PS: i could not wait for the IC micro relay in the mail any longer...so I went with this setup)

Next is pic of the repositioning of the IR led. Some Stugs had parallel mg port in mantlet (some of the cast and plate mantlet types had these holes) Perfect spot for IR. However, the mantlet bolts are not in scal location so drill hole is not exactly in right spot (should be below and slightly lateral to bolt) Takes a little effort to get led in right position. Other hole plugged with old led filed down and then filled with puty. No bolt here either.

I added the cooling fan from RCCommand..inexpensive and works well. I use just one 3mm allen head bolt and lock nut to secure to rx18 (in case i need to change it later)

I added a video of the recoil and firing for you to enjoy:

http://www.youtube.com/watch?v=hNDbGHcwupA

Looking good.

[Saxondog]

Hello Xrad,The diode jumper should have made left up stick function combine sound,tank recoil,and barrel recoil.Also either flash,or airsoft should also happen at same instant.Although I am using a different recoil mechanism(servo) and a VS GUN with single micro switch the key was the jumper.But at times it does hesitate to key the sound and tank recoil,Have not figured out why this happens.Sometimes I can fire 10 shots in a row with perfect timing and then it seems to become confused about the two recoil actions happening together,Shut down and restart problem goes away.Checked every connection and have no intermittent contact issues,just a ghost in the machine syndrome.I am awaiting a new paintball system from Creeping Death,had hoped for it to be released at Christmas but Shelby@C/D is still having issues of a legal nature,so for now I will leave the gun system I have in place without further adjustment,but if you discover some new information about left stick function please share,and as always you have created another quality build.Take care Saxondog

[Saxondog]

Hello Xrad,did you use a top and bottom fans,also did you open RX18 housing to allow more air flow?Just wondering about the mounting when elevated my board cooled twice as fast as the heat was easier to dissipate under the elevated unit.Also have you ever considered mounting an exhaust fan to pull inside air out of the hull? I realize the PIII may not be the best test bed for this mod,but was wondering if you had tried it with you Jagdpanther? Sax

[littletankman]

Hi , Nice build . Im also just starting my HL Stug III build however Im out of work so wont be getting a asiatam tub for this one . Have you any idea were or if you can get the pot shaped mantlet from . Or is it a case of scratch building . I have done one before but wasnt 100% . Also are you adding the skirts ?satisfied . But keep up the good work mate its a very nice build.

Littletankman

[xrad]

Thanks!
Sax: i never had a timing issue. But it is hard to tell from your dgm if a SECOND ground was added to recoil motor. I have a second power supply which supplies BOTH loops (the microswitch and the #4 pin of 8 pin harness (yellow or brown ..depending)) I DO NOT use the HL board for power to the recoil unit and I lowered the voltage going to the recoil motor. In your DGM 'EG' is my concern. Also...looks like older wiring set-up (tracer LED?).

If you hold the 'left upstick" for more than the recycle rate, timing is sometimes an issue (mechanically). If I just "left Upstick' for half a second, it works like the vid.

I leave the elevation motor as wired by HL. I am waiting for a new flash unit as my spare was cr*pped out.

Littletank: too bad about the work. It will all come to pass...eventually. As for cooling, I drilled about ten holes around the sides and top of box to allow for airflow. My JP rx18 box hauls around a VERY heavy model and has not had any problems (no cooling fan) I do use reduced gear ratios (and sometimes smaller motors) on all my tanks, and this probably helps a lot.

Sunday afternnon modelling: Added Notek light. used HL supplied parts and a 40cent radioshack yellow LED. Added 100ohm resistor in line positive side to make it dim. drilled two tiny holes behind the lamp support down which the LED leads go. You can see these in the wiring pic. LED shaved down and recess carved into Notek hood so it fits nicely.

Overhead shot shows the receiver and extra power supply which powers the recoil mechanism. Basically, you want to tuck away all wiring as the is limited room in hull and superstructure. The elevation and recoil mechanisms take up a lot of room and need to be able to move (so make sure there is some slack in the wires)

For wiring, I try to use silicone covered braided wires for remote control cars and such (local hobby shop). this stuff takes abuse and heat. It is VERY flexable and strong. wires don;t fail like the cheap copper in HL wire.

[littletankman]

Hi there thanks I will be watching this build . I have only just started my Stug III I did originaly scratch build the top before but decided to get a stock HL one from Dave . Do you know a supplyier of the ' pot ' mantlet . Although I will probaly scratch build one . Ive altered the muzel break today to a double baffel one.

All the best and keep up the good work mate Andy

[xrad]

No supplier of the cast type mantlet.

Here is what to do:
1) take the HL plate mantlet and trim it to close shape (preserving the inner structure and mounting system.
2) carve some hard foam to fit and sand to shape.
3) cover in two part epoxy and glass cloth
4) sand and finish as needed.

the overall length is the same as the barrel guide tube. Don;t mess with the inner parts so that the your cast mantlet will operate as smoothly as the original.
Plenty of pics on the net.

For a few dollars, you could get a used copy of Spielberger's German armor book (amazon shopping) on the Stug III. tons of good pics and drawings!

[xrad]

Before messing with the HL mantlet, be sure to read on this page where I describe how to take apart. Easy to break some things.