Asiatam StuG IV conversion kit...

[PainlessWolf]

Good morning, sir,
I was successful in getting both recoil and elevation. I bonded the unit to the roof of the StuG III casemate which allowed full movement of the gun using the provided trunnions. The only real problem that I ran into was shortening up the mounts to allow recoil. The Taigen unit has a 'snappy' recoil to say the least and it has to have full clearance or you stand the chance of it slamming into the rear casemate wall. I also had to make an alternate short main gun barrel but that was due to the original metal barrel not having enough inner diameter to seat the xenon flash units bulb. Following along as your ideas for mounts already look cleaner than the design I came up with.
regards,
Painless

[43rdRecceReg]

Good morning, sir,
I was successful in getting both recoil and elevation. I bonded the unit to the roof of the StuG III casemate which allowed full movement of the gun using the provided trunnions. The only real problem that I ran into was shortening up the mounts to allow recoil. The Taigen unit has a 'snappy' recoil to say the least and it has to have full clearance or you stand the chance of it slamming into the rear casemate wall. I also had to make an alternate short main gun barrel but that was due to the original metal barrel not having enough inner diameter to seat the xenon flash units bulb. Following along as your ideas for mounts already look cleaner than the design I came up with.
regards,
Painless

Many thanks, Maestro! I should have checked your Pz 111 thread before citing your involvement with this fiddly unit. That was uncharacteristically lazy of me! The Pz IV Barrel here should easily accommodate the xenon cable. I have yet to calculate the optimum position for the mounts, although i know from previous experience, that the gun travels around 19mm on this unit, and need to leave around 2mm at the back of the casemate to allow for unimpeded recoil

[43rdRecceReg]

I still think a Clark recoil with elevation is one of the best units. However you do need an aftermarket board.

Good job so far

I'm sure you're right, Adam. The problem is that I'd opted to buy the new Taigen V2 kit for the StuG, as much to try it out as much as anything. This recoil unit is meant to be plug and play compatible with it...
Ah well, it seemed good idea at the time. Don't they always?

[Arnie_DK]

Actually... Painless was a great help for me as well, when I installed the recoil

And yes. My casemate is completely closed and the recoil is attached to the roof with a single screw in a fitting i had removed from an old top hull and ten glued in to the stug.

[43rdRecceReg]

Actually... Painless was a great help for me as well, when I installed the recoil

And yes. My casemate is completely closed and the recoil is attached to the roof with a single screw in a fitting i had removed from an old top hull and ten glued in to the stug.

Thanks, Arnie, and for the link to your own unique setup. Again, it's such a pity that the pictorial reference aspect of the Forum, has been so blighted by Photobucket.
The reason I'm opting to keep the Casemate roof detachable, is that I don't trust the unit to work properly, or- if fully functional- not work for very long. The recoil units trunnions looked promising to begin with, but I shall only use the elevation arm that came with it, but remove the run-on from it.
If this all works, it will be a minor miracle. Still, as they say, nothing ventured...
Yes, Painless' solution looks immaculate and well worked out; but we expect anything less? I don't think so...

[Raminator]

I'm impressed you managed to shoehorn that unwieldy Asiatam unit into the StuG casemate, Roy. You've done well, I hope it works out.

If you stick with the Taigen electronics, I think the RC5HL lets you use servo recoil. If you've got the option, a servo-driven unit would take up a lot less space and provide the ability for traverse (if you're feeling brave!) if you upgraded to a similar-sized Clark board.

[43rdRecceReg]

I'm impressed you managed to shoehorn that unwieldy Asiatam unit into the StuG casemate, Roy. You've done well, I hope it works out.

If you stick with the Taigen electronics, I think the RC5HL lets you use servo recoil. If you've got the option, a servo-driven unit would take up a lot less space and provide the ability for traverse (if you're feeling brave!) if you upgraded to a similar-sized Clark board.

Thanks, Dan. There's room enough to secure the unit in place; It's a pity that the design has not been streamlined, or made less bulky. The real problem is finding sufficient room for the recoil mechanism to move unhindered.
The first thing to do, is to shorten the clamp that holds the barrel in place. The longer the clamp, the further in needs to intrude into breech space.

StuG IV - barrel clamp recoil lever.

Here I've already removed a centimetre from the clamp. If you look at the same fitment in Painless' Pz 111 installation, he's paired the clamp down the bare minimum, and bonded the barrel to it with glue. Normally, two screws tighten the sides of the clamp to grip the barrel. I may have to do the same later...
Next it's necessary to calculate the maximum travel of the recoil arm, in order to determine how much more of the breech will have to be cut away to accommodate it..

Recoil clamp starting point- maximum retraction

The red line indicates the maximum retraction point the arm reaches.

Recoil clamp end point- maximum extension

The distance travelled is roughly 19mm. This means I shall need at least 19mm gap between the end of the breech and the end of the white clamp. Failing that, I shall have to ream the breech out further to allow the clamp to enter it, and move the breech/trunnion (gun pivots) assembly outside the casemate to maximise the operating arm space.

[43rdRecceReg]

After looking at the results, I've decided to open the breech out more. The should allow the clamp to move forward (with the barrel) without hindrance, or limit.
Time for the Dread Dremel....

Barrel clamp access limited by tight breech...

Clearly, there's not enough room for the gun clamp to move smoothly. More reaming necessary..no jests about tight breeches please

Breech opened out with a Dremel to allow clamp to move

[43rdRecceReg]

Still not enough room, after tests. The trunnion pivot arms that came with the Kit will be relegated to my burgeoning rc spares box. I'm going to mount the gun outside the casemate in the Saukopf section.
This will reuse fabricating some pivots/ trunnion housings with brass tubing and styrene.

Making a trunnion pivot housing Pic A

And the finished units:

Finished trunnion housings/ gun pivots

[43rdRecceReg]

Here's what the assembly now looks like, with the revised trunnion pivots bonded in place with epoxy. Believe it, or not, quite a few measurements were taken and checks made, prior to fitting this unit in place..

Gun assembly in place pic A

Gun assembly pivot points outwith the Casemate

This is what the interior looks like now, after the move. There's more room now to fit the Recoil unit now. More to the point, there's more room for fingers to get in there to connect the barrel to the recoil arm, and then fit the elevation arm.

Interior view of gun breech assembly..

I'm going to bond the elevation arm to the breech housing...
But..that's for another day..
I'm very pleased with today's efforts, though!