Any Tanaka Launcher builders out there?

More or less ... I have a Tanaka, but it's still in it's original form. What are you looking for?

Cheers,
Stefan

I have finally successfully built the GL using original SPAS cage and Tanaka 870.

what do you need to know?

A few little testers in the build but not too daunting. However, it did help that a good friend has access to a full engineering machine shop.

UKG

I have also gone through the entire process very successfully. Ask away as I am sure I can help. She's a beauty when finished.

Some picts and videos would help.

Just haven't seen anything yet.

$$ for a tanaka, the airsoft surgeon slug shot looks and sounds
cool.

You problably know the videos on youtube - what more to say?

That thing looks and feels like the real deal.

The only difference I noticed compared to the real steel version is that the pump action is easier to operate. Actually when no shell is loaded it could have a little more friction. When you are holding the rifle upright the pump grip slides back about 5mm through gravity alone (unless a shell is loaded - then it's locked in place). It's the distance you need to unlock the bolt and before you have to work against the spring of the hammer. It's present on the real steel as well but the higher friction makes this less noteable.

Initially, I had some issues with the shells not firing, but it soon became clear that I simply have to wait some time after filling them up (this is my first gas gun!).

I can't say anything in regard to "field use", but the airsoft surgeon slugshot version looks a lot more powerful and with the buckshot shells you can fire 8BBs at once. The price however seems to double and even the original Tanaka isn't a cheapo....

Cheers,
Stefan

Funny enough it takes a lot of effort to pump mine. I really think I need to pull it apart and get the pump moving more smoothly on the cage. It's not bad but it's not "perfect"

You guys have any pictures of your Tanaka all cut down and whatnot to fit?

I too have been thinking about this for my final build, but at $400 I really don't want to mis-cut it and mess up the works.

Russ

_________________
"A writer needs a pen, a painter a brush, and a filmmaker an army." - Orson Wells.

http://www.rookscastle.com
http://www.alchemyarms.com

I will be pulling mine apart tonight to smooth out the pump grip. I will take some shots for you Rook.

I appreciate it. Thanks!

Russ

_________________
"A writer needs a pen, a painter a brush, and a filmmaker an army." - Orson Wells.

http://www.rookscastle.com
http://www.alchemyarms.com

Also, I know that the shells for the Maruzen are smaller than real 12 gauge shots or grenades. How big are the Tanaka shells? Are they undersized too?

Also, as DATA stated in my thread (http://forum.alienslegacy.com/viewtopic.php?t=3837) the Maruzen has a shorter racking action than the real thing, i.e. you can only pull the grip back 80mm instead of 100mm. How's the racking action on the Tanaka?

The Tanaka shells are also slightly (I'd say less than a millimeter in diameter) undersized. However, you'll only notice the difference when you try to load a real round (or an M40 that's based on a real round).
The travel of the pump action should be the same as on the real deal as the internals are almost identical (whereas the Maruzen only covers the shell instead of really loading it).

Cheers,
Stefan

Speaking of the internals - here an exploded view from the manual (the rest of the manual is the standard "don't look into the barrel" stuff):



Cheers,
Stefan

I took some pictures last night so I will post them when I get home.

Also, just an FYI, if you plan on having this be able to fire (which is very easy), make SURE you reinstall the inner airsoft barrel even if you just cut it down.

The shotty will fire without the barrel just fine but the O-ring in the shell itself will fly out without the added pressure of the inner barrel. And let me reassure you that when that O-Ring comes out...you won't be able to find it *Grumble*

Now that I reinstalled the cut down airsoft barrel it works perfectly. This shotty is excellent for this project. Cost be dammed. =)

Instruction Pictures

I believe the steps for cutting a spas-12 has been well documented before. Let me know if you have any questions.

One thing to be very careful of, is to make sure the screws you use to secure the metal plate to the cocking handle do not interrupt the operation of the handle itself. I cut the screws down and then dremeled the inside end of the screw to make it truly smooth.

Thanks those pictures are a great help. Anymore tips for a novice?

I am thinking of taking this route, but need to buy all the parts first.

Thanks again

LDR

Great stuff Glenn, thanks!

Russ

_________________
"A writer needs a pen, a painter a brush, and a filmmaker an army." - Orson Wells.

http://www.rookscastle.com
http://www.alchemyarms.com

I will go one by one.

1) So I'm thinking about cutting a channel, but I'm afraid that I'll cut too much away. How did you go about this, and how much did you trim away

Just start cutting the channel until it slides into the spas cage firmly. There is tons of material there that does not interfere with the mechanics inside. Especially on the Metal body. So Dremel it, test fit, dremel it, test fit, and then when it goes in nice and firm (it should not cause the spas to deform), stop.

2) Is it easy to move the shottie inside the cage now? How did you affix it then so that it doesn't move when you pump?

That is exactly why I build the cover for the shell tube using hardwood. I then have the screw that goes through the front block into the secured cover screwed tightly. That secures everything firmly (remember the shotty fits in tightly). So when you pump, the shotty fits tight, and the screw in the front block secures it in place. Works great.

3) Do I need to cut the two "bumps" on top or couldn't I just go with flathead screws and attaching the cage before sliding the shottie inside?

I made the two bumps because I am using Tommin's Airsoft Adapter (amazing piece of kit) and the screws that came with it are heavy duty but unfortunatly bumped. If you are not using that system then flathead screws will work. Just make sure they are flat and secure the spas hardcore. Because nothing sucks more than pumping the shotgun only to have the spas-12 section bend and break because the screws give out.

Hope that answers your questions! Let me know if you have anymore.

Say Glenn, what length is your 870 barrel cut to?

Did you have to enlarge the grenade block hole to fit the barrel through?

And did you use a Phil S. grenade block, or resin/custom build one?

Russ

_________________
"A writer needs a pen, a painter a brush, and a filmmaker an army." - Orson Wells.

http://www.rookscastle.com
http://www.alchemyarms.com

During the build of the GL I had a good deal of help from my friend and the guys he works with in the engineering trade. One of them came up with a top idea for attaching the cocking mechanism (pump action) on the 870 to the SPAS 12 pump grip without welding a plate to the mechanism to attach the pump grip altogether. I used the idea on mine and its never fouled, failed or jammed ever. It pumps full and sweet everytime. I will try to explain the idea and will get some pictures done as soon as possible.

Sitting comfortably, then I'll begin.

Once your 870 is installed into the SPAS cage in the correct position make sure the end is secured so it wont move, view the PR from the left. The pumping mechanism should be visible through the vents in the SPAS cage. The pumping mechanism seen is basically a ring that fits over the lower 870 barrel attached to a small vertical section of metal that bends 90 degrees right as you look at it and then runs into the main stem of the gun. Through the vents that vertical piece is clearly visible. What we did was to machine a piece of aluminium (about the size and shape of a large cold capsule but flat) with a slot cut in the back and tapped at each end. The slot fits over the small vertical section of the pump mechanism into the SPAS vent and then screws directly to the pump grip where you tap the holes. Don't forget to remove the small bits of metal in the relevent vents in the Spas cage to allow the mechansm to pump fully. This method removes any need for welding plates onto the pump mechanism altogether.

UKG

Any chance we could get some pics of yours (Minus the Spas grip of course)?

Russ

_________________
"A writer needs a pen, a painter a brush, and a filmmaker an army." - Orson Wells.

http://www.rookscastle.com
http://www.alchemyarms.com

I respectfully disagree with this statement. The Tanaka 870 receiver
fits just fine in the real steel Spas cage without requiring the side
of the receiver to be channeled at all. I inserted and removed mine
several times last night (with the trigger assembly removed) and it
works just fine.

I'll need to drill and mount a couple small bolts at the tail end so
the shotgun won't slide when the pump grip is moved, but other
than that it fits just fine as can be.

It took a fair amount of work though cutting down the mag tube
and pump sleeve so that it would fit to the grenade front block
correctly.

The truth is there though, Cut some, test fit, cut some more, test
fit, etc. You can always remove more material easier than you can
add it back in.

Also, here's today's WTH moment.

The receiver is metal. The barrel is metal. The mag tube is metal,
the trigger is metal. The WHOLE BLOODY THING IS METAL... except
the bolt. That's ABS plastic.

No, I don't know why. It doesn't make sense. But for future
reference, you CANNOT dremmel off the "black paint coating" to
reveal silver metal underneath... because there IS no metal
underneath.

*SIGH* Bondo... sand... bondo... sand...

Russ

_________________
"A writer needs a pen, a painter a brush, and a filmmaker an army." - Orson Wells.

http://www.rookscastle.com
http://www.alchemyarms.com

I agree with Russ, the Tanaka will fit into the Spas cage fine, like Russ says test fitting is the key. Once you have removed the lips at either end of the SPAS cage so the ends are flat the Tanaka 870 slides in and out fine. The only thing I did use was a small amount of grease on the 870 when fitting. If you are using a Phil S front block the 3 grub screws in the block should keep the Tanaka in place. The back end of the Tanaka is kept in place by the attachment sleeve made by tommin which I purchased which attaches the GL to the Thompson. Im just waiting for my replicant FX soundboard and counter to turn up then I will post some pics to show my build better for anyone who's interested.

Interesting that you should say that about the Tommin adapter because my bolts don't hang down far enough to impact the 870 receiver at all (or only a very marginal amount).

Like I said, I'm going to be drilling into the rear of the 870 receiver (and through the rear sides of the Spas cage) to completely secure my 870.

Russ

_________________
"A writer needs a pen, a painter a brush, and a filmmaker an army." - Orson Wells.

http://www.rookscastle.com
http://www.alchemyarms.com