DS Flamegun Logan's Run, Functional or not ? I need Help of specialists

alexis

Member
Hi,
I was buyed some few days a replica of Sandman DS Gun. The title of auction say that it's a working replica with calcium carbide. I was go to bring back the gun, and at my home, when I was inspected the gun, I have now a big doubt. Here is somes pictures if someone know this system and can help me, beforehand, thank you very much.



In first, one thing is strange, I don't see a valve in the barrel just a tube smaller inside :


The second thing that is strange, this is the main barrel which is welded on the gun frame : it's not removable. And the gun frame is complete in top, not same the others functionnals flamegun.


In three, I don't understand that the trigger activate : because I don't see a mechanism in the main barrel.


But apparently, the glow plug is good :

Other thing I don't understand : the power switch of glow plug.

You can see here the tube inside with a hole :

The valve of the gas tank is completly removable. I don't know this system :


The glow plug :

The gas tank without the valve :

So I don't know if it's really a working or not flamegun, because I'm very surprise by the system : what the trigger activate ? Why, it don't have a valve in the barrel. and why the main barrel is welded and we can see inside ? And for terminate, I don't how to made the electrical ground with just one wire... If someone can to help me. Thank you very much !
A last information, the guy who sell me the gun tell me that it's a replica made by JJ Lastelick.
 

Apollo

Legendary Member
RPF PREMIUM MEMBER
If it's a JJ I would be real cautious about firing it.

I'm sure Ry will chim in and trust me he has more knowledge on this Prop than the original prop-Makers
 

Rylo

Master Member
RPF PREMIUM MEMBER
It is indeed a JJ replica and it was a working flamegun at one time.

He sealed those things up tight and used the same unreliable lighter valves that were put in the original guns. Sadly, many of his guns just didn't hold up well over time and it's just about impossible to get inside some of them.

It's very difficult to bring one of those back to working condition, but good luck! You could always charge the tank up and pull the trigger to see if you have any control of the gas.

You'll then need to wire the plug up before you can fire it. But, at a glance it looks complete but for the Hawker Cyclone battery.

Never know, it might work for you, but probably not more than once or twice before the rotted o-ring which is most certainly in there blows out. You just can't service the thing once it goes...big design flaw. LIke Tony said, safety first; load small and with caution if you simply must mess with it. Perhaps it's the language barrier, but it doesn't really sound like you understand the basic mechanics of the prop so I suggest a little homework first. Lot's of good info out there on these pieces.

Good luck just the same! Worse case, clean it up; it'll make a neat display piece. JJ was one of the first guys to tackle this prop so it does have an interesting history behind it.

-Rylo
 
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alexis

Member
Thank you very much for your answers. I will be very careful, then I will use this gun. So I will see for to find a Hawker Cyclone battery. Thanks Rylo.
 

alexis

Member
One question again. I saw on the blueprints that it had a felt filter who's missing on the gun :



Must I put one in the filter tank ? And if yes, where I can find this filter, if it's possible. Or can I made a filter myself, with what material ? Beofrehand thank for yours answers.
Don't worry Apollo : I tell you if I'm burning like a chicken or not with this gun ! :lol
 

Apollo

Legendary Member
RPF PREMIUM MEMBER
It is just craft felt cut out a square and roll it up and put it in
 

Delmustator

Sr Member
Those look like surface welds to me. I'd bet money that you can use a Dremmel cutting blade and cut those welds, allowing dis-assembly. Replace the valve or at least the o-ring with a different material that is more resistant to the chemicals.

Also, I would suspect that a couple of 18650 Lith-Ion batteries could be used in place of the Cyclone battery. At least you could put a re-charge port someplace and recharge them without opening the frame grip.

Just some thoughts.
 

alexis

Member
Yes Del, mee too I saw it. I think to try to cut the welds in the futur if the gun don't working in this state.
thanks del for the informations on the battery. With my friends who know very well electricity, I see with them if I can put a coupler cells for can put 2 AA (LR6) 1.5V battery that it's more easy to find in France...

EDIT : This Filter is in all functional flamegun replicas ? Because my second functional flamegun don't have this felt filter and it's working very well, but the system is completly different :





What is exactly the function of the felt filter ? Sorry for all these questions...
 
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alexis

Member
Well,
the first step is good ! I was changed the electrical power, and made a new electrical system for to have the ground. Now, it's working with 2 cells type AA, and the glow plug works !!! :)



But I Think that the power switch is broken, because it's can't stay in on position. I must to push the switch permanently for to stay in on position.
Tomorrow I will test the gun with calcium carbide : I will put a little quantity and protect my hands for to made the test...
 

Rylo

Master Member
RPF PREMIUM MEMBER
The valve is from a 1975 table lighter. It is not owner servicable. Most have rotted over the years. I went down this road over a decade ago and scrapped about a dozen matchomatic lighers trying to repair them.

It has nothing to do with anything being resistant to chemicals. Nothing was 'eaten.' Rubber O-rings simply dry out over time. JJ's guns suffered from the same problem as the original guns. An off the shelf valve was used in a prop that simply generated too much pressure for it's intended purpose. What valves weren't blown have simply rotted. It's very difficult to find a working JJ gun, these days.

I made guns with the exact same set up years ago. I got so tired of replacing the valves, we ended up going with a custom valve of our own design engineered to handle the load. Never had another problem. All of that said, an old friend of mine kept one of the early builds that had a matchomatic valve in it and he never had a single problem. It's def. more miss than hit with those old valves, but you can get a good one.

The larger problem here seems to be a new prop owner who does not understand the mechanics of this prop. This particular model shoots fire generated by a chemical reaction that's held back by a poorly constructed delivery mechanism.

Again, I suggest a great deal of homework before going further with testing this piece. As any owner of a working DS gun will tell you, there's a quite a difference between these and a toy (lightbulb) replica.

As for cutting the frame. Air flow is important to these pieces and finding the correct placement for the venturi hole can be difficult. JJ probably sealed his guns to stop them from leaking in the first place. Either way, cracking it open would effect the way air moves inside of the gun.

Anyway, a couple more tips for the owner:

Never know. This gun may still work. The fact that no battery was in it can be a good sign. If those batteries (Hawker Cyclone or Gates) aren't maintained they die. The owner probably had no idea where to find another one and it just set on a shelf. The fact that no felt was in the tank can be good and/or bad. It means someone either shot it without the felt which would wreck the valve. Or, if you're lucky, it may have never been prepped to be fired at all. Then again if you got CC w/ the purchase, I'd say it's been shot without the felt which of course wrecks the valve.

Should you manage to get an air tight charge on your tank, I suggest loading small. A couple pebbles of CC and about 1.5CC of water. This will help avoid blowing the valve out. Once you pop that o-ring it's over if it hasn't already died. So, if you must test it, I'd put a little charge on it (with the batteries removed) and see if you can control the gas with the trigger.

Good luck and be safe!

-Rylo

NOTE: Your second gun is one of the Aussie replicas. Yes, you should always use felt in the filter tank. It's a custom valve on that replica but CC residue will clog the valve.

Regarding the switch on your first gun. It's a momentary switch. It's not intended to stay on. The web of your hand will push the switch on, activating the glowplug as you grip the gun.

Those look like surface welds to me. I'd bet money that you can use a Dremmel cutting blade and cut those welds, allowing dis-assembly. Replace the valve or at least the o-ring with a different material that is more resistant to the chemicals.

Also, I would suspect that a couple of 18650 Lith-Ion batteries could be used in place of the Cyclone battery. At least you could put a re-charge port someplace and recharge them without opening the frame grip.

Just some thoughts.
 
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Funky

Master Member
RPF PREMIUM MEMBER
Man, that thing just makes me nervous! No wa I would try to fire that thing and I'm pretty ballsy.
 

Rylo

Master Member
RPF PREMIUM MEMBER
No worries. I use 2 AAA's in my replicas.

Thank you very much for your answers. I will be very careful, then I will use this gun. So I will see for to find a Hawker Cyclone battery. Thanks Rylo.
 

alexis

Member
Thanks Rylo for all informations and Tips.
I don't understand very well your words "Again, I suggest a great deal of homework before going further with testing this piece".
In fact, I know the gerenality of mechanism of flamegun, and I was removed completly severals times my first functional DS Gun for to resolves somes problems of shoots (and change the valve). But I don't know every replicas was made and this replica of JJ Lastelick is the first time that I saw it. Specialy the barrel welded on the gun frame. I will listen to you and to try today the gun with CC without to put on the glow plug for see if I control the gas with the trigger.
I will be very careful for to use this gun, I know that it's not a toy ! Thanks for all answers.

EDIT : Rylo do you know approx, the date when JJ Lastelick was builded his replicas ?
 
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Apollo

Legendary Member
RPF PREMIUM MEMBER
JJ started to build roughly in 1992 it was awhile maybe a year before the guns started coming out as he had to raise his price a few times.

If you need an exact date I will have to dig as I saved all my correspondance with him
 

alexis

Member
I made it ! And it's working perfectly !
I was tryed without glow plug with Calcium carbide. I was saw that the trigger control the gaz pressure. So, I'm not hesitated, just after I was loaded with a little quantity of Calcium Carbide and with protection I was shoot ! Great work ! :thumbsup
If I can, I put somes pictures or video soon... Thanks for all for yours tips and answers ! :)

If you need an exact date I will have to dig as I saved all my correspondance with him
If it's not a big work for you, I say Yes ! Beforehand, Thank you very much !
 

Nicksdad

Sr Member
RPF PREMIUM MEMBER
Actually, JJ told me back in the day that he had found a way to make a valve last. I think the reason he spot welded the guns was to keep the secret as it were.
I traded mine to a friend and it shot with no problems other than a small leak in the back cap due to an old 0-ring.
 

alexis

Member
A little picture, I'm waiting that the video where I take this picture will be load on vimeo. I'm not very cool here, because after to read all the answers here, I'm a little nervous for trying the gun ! :lol

 
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