Alright, time to update this (once every few years ).



It has been difficult and I had a huuuge lot of help from Stefan (Bug Stomper), but I was finally able to have all the steel parts bent, welded and blued. The NG steel kit (M1A1) seems to be parkerized instead of blued, but I‘ve grown a bit fond of it, so it‘ll stay that way. I was reluctant to let the SPAS cage out of my hands, so I painted it myself with matte black paint for ovens (high-temp paint) and put the whole thing in my baking oven at 280 degrees Celsius for an hour to „bake“ the paint. The paint is very tough, but we‘ll see what racking the pump a few thousand times will do to it.

I had to redo the front block as the mag tube of the Dominator airsoft 870 seems to sit a few millimeters higher than on the real thing. I should get the replacement by the end of January.

Next step: modifying the HCG aluminum shrouds. They don‘t really fit yet at all, seems the SPAS cage on the HCG sat a bit higher, and I‘ll need to make room for the stock and the plate holding it to the Thompson. Also, I had to enlarge the opening for the barrel/barrel vent in the front. Will update again at some point in the future.

Cheers!
Roman

Stunning!

Whoa slow down cowboy, that’s two updates in as many months!

Looks great buddy! Excited to see you tackle the shroud fitment issues

_________________
AKA: Simon

Yeah, I wish... the first post is from November '21 though, and the new one from December '22.
But here's a new update, and this time it really is a month (and a half ) later:



New front block and barrel installed.
I had to have this re-machined, since the mag tube sits about 2mm higher on the airsoft Dominator DM870 than on a live-fire 870 and I couldn't get my old block to fit.
I wouldn't have believed it, but Stefan (Bugstomper) insisted that the four grub screws of the front block will not only lock the front block to the mag tube, but also the barrel to the 870 (since the barrel isn't fixed to the gun in any other way). And what do you know, it hasn't moved a bit yet, even with two shells loaded and racking the launcher.

The only thing dampening my joy is that although the shotgun works and ejects the shells, if I rack it all the way back, it's then stuck open and I have to use force (as in: every time I believe that this is gonna be the one where I won't get it unstuck again). I just used CLP on all the parts I could get to from the outside (i.e. without complete disassembly) and was able to grease the arms and most of the trigger group. This made the racking action smoother, but didn't solve the problem.
Does anyone have any idea on how to fix this?

Cheers!
Roman

Hi Roman,
I do like what I see!
As for the mechanism getting stuck:
If you disconnect the pump handle from the racking mechanism, is it moving freely?
Installing the Dominator into the SPAS cage might bend it slightly outward in the area of the receiver and thus the handle might get "stuck" in the rear.
Does the Dominator rack freely, if it's out of the SPAS cage?
Are the screws or screw holes used to mount the launcher to the Thompson blocking the bolt in any way (like is there an edge or something the bolt might catch)?

Cheers,
Stefan

Thanks for the good ideas Stefan!

Last time I racked it back fully, it really became so stuck that I couldn't rack it back forward. So I began to take the whole thing apart.
The second I removed the front block and the barrel, I was able to move the mechanism again.
It might be that either the follower or - more likely - the barrel may prevent the shell loader from moving upwards and thus blocks the action, or in some other way interfere with the mechanism. Possibly because the barrel might be ever so slightly pushed upwards or to one side because of the front block. The bolt doesn't seem to be the problem, as it doesn't even touch the barrel in its rearward position. Maybe the racking arms somehow touch the barrel when it is slightly out of alignment?

I'll look into it further tomorrow and post my findings. But thank you very much for your input!

Cheers!
Roman

So I finally found the problem:
The ring of the action bars was sometimes getting stuck between the barrel and the mag tube of the 870 when the gun was racked hard/far back. It seems the slightly different angle (because of the front block) managed to trap the ring. A few minutes with the dremel has now permanently solved the problem, took way less time than locating the problem.
Preparing the shrouds is coming along, will post updates soon.

Cheers!
Roman

I think mine may be the slowest build, it's still in parts and have not started it yet. I do have a spas cage though. I appreciate the tips shown above.

So today was airbrush day!

I recently got an airbrush with compressor and finally got around to painting an aluminum sheet in the most readily available Brown Bess alternatives. I always wanted to paint my shrouds (and other Aliens props) in a paint that was readily available, since Humbrol Brown Bess seems to be pretty much impossible to find anyways in a useful quantity (and also doesn't have a reputation to be easy to work with).

Apparently, they didn't use Humbrol Brown Bess for the movie props but a "Braungrau" color from Germany. That seems sensible seeing that it most likely wouldn't have been feasible to get Humbrol Brown Bess in the desired quantity. However, Brown Bess does seem to be the best match for the unknown original paint. So that's why I got the current best possible alternatives to compare them and spent the day airbrushing the following paints:
- SMS Blaster Brown
- ArchiveX Brown Bess
- Mig Jimenez Ammo AMIG0111 SCC 2 (British 1941-42 Service Drab)
- RAL 7013 ("Braungrau")
- RAL 6013 ("Gelboliv")

I was sure that I had a tin of Humbrol Brown Bess lying around, but it must have gotten lost when I moved a few years back... So I used the closest thing I had for comparison, my HCG aluminum shrouds ("Brown Bess" variant, which I have no idea how close they are to the real Brown Bess). If anyone has a tin of original Humbrol Brown Bess for sale for me to use in my comparison, I'll happily buy it! Also, I put the Snow Wolf (the "brown" version) next to it just for the heck of it.

Without further ado, here's the pics (Snow Wolf at the top, HCG aluminum shrouds at the bottom):
Natural lighting indoors:


Sunlight outdoors:


I'll try to snap a few pics next to the blue hue lamp tonight to see how the paints behave in "screen accurate" lighting.

As for now (at least for my naked eye, since the pics do not convey the tones perfectly), it seems that the ArchiveX Brown Bess is the closest match to the HCG shrouds, followed very closely by SMS Blaster Brown. SMS Blaster Brown is a dream to use in the airbrush. ArchiveX is much more of a chore, and before the paint finally dried completely, I actually thought that it was going to be a total mess because the texture wasn't anywhere as nice as SMS Blaster Brown.

Even now, I'm unsure if I'd not much rather go with the SMS Blaster Brown, since it does have a much more noticable brown/green effect and is really very nice to work with. To my eye, it seems to be almost as close as the ArchiveX in terms of color, maybe just a slight tint more green. I might try to sneak a drop of ArchiveX Brown Bess into it and see where that leads.

Cheers!
Roman

BTW, I should say something about the other colors as well:
British SCC2 is much too light, so I consider this to be the least suitable paint.
RAL 7013 is close to the Snow Wolf in most conditions, but to the naked eye, it seems a bit too light and too green compared to the HCG shrouds.
RAL 6014 in fact seems to be a nicer color, even it is definitely much too green when viewed by the naked eye.
So SMS Blaster Brown and ArchiveX Brown Bess are - at least in my opinion - the only real contenders with regard to the HCG shrouds.
Would be nice to compare them to real Brown Bess though...

Cheers!
Roman

I have to revise my opinion somewhat:
The longer I look at it, the more SMS Blaster Brown actually seems to be closer under most lighting conditions.

Here's a shot with pure LED lighting, i.e. warm LED lights on inside the house while it's dark outside:


And here are all the colors only lit by blue LED light (the small shroud plate all the way to the right is the one from the HGC, for color reference):


Granted, in the last pic, all of them seem to have an OD color, and the light isn't even overtly blue, but just a light/cyan blue.
But anyways, I'm tending to SMS Blaster Brown being closer to the HCG shade at least.

Give me a few days and looking at it in all lighting conditions again, and I'll give you my definite verdict.

Cheers!
Roman

Thanks for the comparisons. I’ll hopefully be spraying some shrouds soon so this is very useful info.

Cheers

Another task completed!
I was wondering for a long time how to make the "bent" shroud plate in front of the mag well. Luckily, even when making a full metal Pulse Rifle, 3D printing makes everything easier!
Introducing: the "Front Shroud Plate Former" (patent pending... not).





The rear shroud plate is done already (not much to do there), next step is to re-do the bracket in the rear of the shrouds, and then at some point re-drilling all the holes in the shroud.

Cheers!
Roman

Alright, it's story time:
I wanted my ammo counter to have dual functionality: count down continuously when the trigger is pulled („display function“), but also count down with each shot when I use the GBBR („airsoft function“). The solution: I programmed my counter to show the display function when the bolt is closed and the trigger is pulled, and the airsoft function when I pull the bolt back first and then pull the trigger.

More on that and my counter later.
Here‘s the problem: there‘s very little space inside the rifle, and I needed a way to electronically check if the bolt was closed or pulled back (this switch is also needed to count down with each actual shot when in airsoft mode, i.e. every time the bolt slams forward). But where?
Behind the bolt? Possible, but you’d need to run cables next to the bolt all the way back. Also, I don‘t know if the bolt really goes back all the way to hit the switch there, especially when the gas in the magazine is low.
In front of the bolt? Not if I want it to function properly.
But wait, there‘s a steel part just where the bolt sits in its closed position. This is a separate part held in place by screws on my full steel kit, not sure if it‘s molded into the upper receiver on the original WE part:


Now here’s what I want to show off: I recreated the part in Fusion 360, added a recess and a „cable channel“, and had it machined in steel:


Then I designed a „mini PCB“ with the smallest switch I could find and ordered it with pre-installed switch online. I then glued it into the recess after soldering the cables onto the PCB. I used my magnifying lamp and had a couple of beers to „steady“ my hands. Even the glueing was a pain.


You can‘t appreciate how crazy small all this is until you hold the mini switch in your hand… err, I mean… fingernail?


This is the final product:


Installed in the Pulse Rifle:


I'll have to adjust the "bounce" settings in the code, since the impact of the bolt sometimes causes the switch to count down twice, but that should hopefully solve that.

More updates coming soon! Next the shrouds will be painted, and then all the electronics will be put in place.

Cheers!
Roman

Just catching up on this build. This is incredible Roman.

More please!

Alright, it‘s official: I work too much!
First day of Christmas break, and look what I finally found time for:



Sadly, the weather changed and I‘ll have to finish up the other parts another day. But I‘m getting there, I want to finally finish this thing this year! I might get around to a clear coat test tomorrow (on a test piece first). Now off to a hot bath, spending all morning outside airbrushing in winter got a bit chilly.

Cheers!
Roman

After 20 years, I think I'm calling this one done.
And on my birthday too!





And in my display case, complete with custom steel vent and LED illumination:


The trigger switch unfortunately seems to have shifted and doesn't work, I'll have to rewire things at some point in the future, but right now, I can't bring myself to disassemble it again.
Now it's time for natural "weathering" by handling it until the paint chips off in places.

Cheers!
Roman

Hats Off to you !

What a beauty!


Question: have you incorporated a Stock Locking System?
and where have you installed the counter Battery (also which battery type)?

Thanks!
No, the stock doesn't lock. I thought about it, but it works really well without (I used some sort of fabric tape so that moving the stock requires a bit of force), and I did not want to sacrifice accuracy or function for a mechanism.

As for the counter, here's a pic of my setup. I'll post more info about everything on my page soon!


Cheers!
Roman

Your PR looks amazing! Can you share a pic of the other side, too?

I'm with you on not sacrificing accuracy for the locking stock. In fact, on my own build, I might even run the counter wire and toggle switch through the back of the stock.

Hi there!
Sure, here's a pic of the other side of the rifle.


Cheers!
Roman

Cool, thanks! Ha, so many little details you've captured to obsess over.

absolutely awesome!

_________________
still alive