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Old Jun 06, 2011, 12:38 AM
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Bozeman, Montana, United States
Joined Aug 2003
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Jofro - nice painting, do you have a website with more?

All the rc squareriggers here sail on the water, there would be no point in rc-ing them otherwise :-) Photos and videos proliferate in the threads, if you want to see them in action. DanL's and Paratrooper's ships even fire their guns with black powder, very cool.
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Old Jun 06, 2011, 03:44 AM
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Quote:
Originally Posted by Brooks View Post
Jofro - nice painting, do you have a website with more?

All the rc squareriggers here sail on the water, there would be no point in rc-ing them otherwise :-) Photos and videos proliferate in the threads, if you want to see them in action. DanL's and Paratrooper's ships even fire their guns with black powder, very cool.
Thanks, fascinating models I have to look more into it just for an interest, never thought you would put these art works on water! Little stagnett for my hipper activities flying EDF and jet turbines but I very much appreciate the fine work in it. No website, my works sell through leading Australian galleries, Cheers Joseph Frost.
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Old Aug 03, 2011, 11:00 PM
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Gun update for Hal

My latest vthinking on firing guns:
I tried to make the firing guns as scale as possible - cast resin barrels around the brass barrel, hidden power plugs, etc. They work and look good, but are a pain in the arse.
The better approach is to have two sets of guns - one set scale/non-firing for display if wanted, and a second set not at all scale in appearance but rigged for easy load, easy maintainance and high reliability firing.
The firing set is simply the brass barrels - made from brass pipe nipples - soldered to about 1/4" dia. copper wire as a ground bus/positioning bracket and with a positive lead to the nichrome firing element. The closest to "ideal" I've built so far is Ray Parateoopers system. See the previous post notes on that and you have what I think is the best to-date system. The loading system is also working very well. Again, all previously posted.
The only two key weaknesses now are that once fired, the guns barrels are exposed to water and a complete drying is necessary before a second successful load/firing can take place. The second weakness is reliability. The balance between 1) getting the filament hot enough for a long enough time to ignite the charge, and 2)not burning out the filament and also getting a fast rate of fire causes some misfires. I'm playing with voltage and use of a ballast resistor to improve the firing reliability. The real key though is to be sure the flash paper and powder are really dry....
I'll try to pull pics and info together in a PDF doc, but that is likely a month out. The info is already posted, but likely hard to find and sort.
More later...
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Old Aug 24, 2011, 12:35 PM
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Amelia Island, Flrida.
Joined Sep 2007
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Hi Danl,
Thanks for the update on your firing guns. I am still using glow plugs for my small amount of test firing. I'll see if I have too much loss with these before moving over to your ignition system.
My guns are all scale and are completely the same as the resin guns Philip supplies. They are all only on the top deck so I shouldn't have any trouble with them getting wet. I can fire the two sides in succession simply by changing the "common" from one side to the other using a push on/push on switch activated by a servo. This same servo also activates the sound of my voice issuing commands. Have you changed the powder you use? Do you mix it with flour or sawdust to get more smoke?
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Old Sep 02, 2011, 08:58 AM
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Just saw the questions you asked....
I think black powder, FFFG, gives the most smoke and fires more reliably than the powder subs tried (Triple 7 , etc) It is the most corrosive, but the gns need to be cleaned and lubed often anyway.
I really haven't given sawdust or flour mix in the powder a good try, but doing that does seem to reduce the reliability of firing.

The only real rmaining problem with the system is getting every gun to fire every time. The least bit of dampness, a dirty gun, a weak battery, etc can all prevent a gun from firing. To fire, say, 9 guns in a 10 second rolloing broadside gives only 1 second to make a contact in the switch mechanism, heat up the igniter and set off the charge. Even tho BP is explosive, the element just does not heat enough every time to set off the BP. That's why the flash paper is used. Seems like an unnecessary complication to loading, but the flash paper goes off quicker than the BP, so the rate of misfires is reduced dramatically by using the FP to ignite the BP.

Evem tho your guns are on upper deck, they will get damp/wet enough to cause misfires. Also, you ned something to hold the charge in place. On the small guns, mounted on the model, its hard to get enough tamping pressure to solidify the BP plug inside the barrel. So far, the best and most convenient waterproof material I've found is foam backer rod.

Safety note: accidents can/will happen. I plan to always wear safety glasses from now on when working with the BP guns. Eyes are pretty valuable parts of the anatomy....
And, always stay to the side of a gun that you are loading.
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Old Sep 08, 2011, 06:26 PM
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Amelia Island, Flrida.
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S006 update

Hi Dan,
I have made some good progress with my Surprise. One step in the progress is in adding speakers. I plan to turn them on just before firing the guns to get everyones attention. See photos. I made a CD on my computer which I sent to RAM. They put this on a chip so it is easy to activate.
I have also completed the wiring under the two upper decks. See photos. I fired all the guns, all 14, as a test. 12 fired. I know why the two did not fire and have fixed the problem. I got a good "bang" and smoke from the cannons. The carronades just went "pfft" and ejected most of the BP. The problem as you know is the short length of the barrel. It is only 1 1/8 inches from the glow plug to the muzzle. I tried cotton wool, which is what a friend of mine uses for his guns but this was ejected the same as the backer rod. I need more back pressure, which I get on the cannons. So I took some 40 thousandths thick rubber and punched out 7/32 inch diameter discs This is the bore of my carronades. I inserted these on top of the BP before adding a wad of backer rod. SUCCESS. I got a good "bang" and most of the powder was burnt. The discs are a little bit larger than the bore so provide back pressure. I tried this several times with no damage to the guns.
The look of the scale firing cannons and carronades is very close to what the resin guns look. If you look very closely you will be able to see two wires under the carronades and under the cannons. See photos.
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Old Sep 08, 2011, 06:52 PM
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S006 progress

Ooops, no photos.
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Old Sep 09, 2011, 01:01 AM
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Very good looking guns and super looking rotary switch design.

What caused the two misfires? Any iinfo shared will help improve everyones design.

Every time I tried to get more back pressure in order to get more sound, the amount of smoke decreased. After realizing that even the loudest gun sound I could get just disapperas outdoors over water, I defaulted to forgetting about sound and going for max smoke. That seems to be everyones favorite effect - lots of smoke...

What happens to your smoke level with tighter wads/larger bang?
Thanks...
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Old Sep 11, 2011, 08:32 AM
1915 Schooner Mariette
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Sydney, NSW, Australia
Joined Feb 2008
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I suspect that the best back-pressure can be provided by way of spherical piece of lead !!

Kind Regards,

Peter D.
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Old Sep 11, 2011, 08:43 AM
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delaney -
Don't we wish!
It's funny that after Ray and I exchange broadsides with the little guns, we sometimes find the foam wads on our decks - direct hits!!!

And there certainly is powder residue spread about.
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Old Sep 11, 2011, 06:37 PM
SCALE Sailor
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United States, MD, Severna Park
Joined Apr 2008
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The Airsoft folks use 6mm pressed paper BBs - and there's actually 6mm paintballs available.
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Old Oct 19, 2011, 10:38 AM
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NYC, NY
Joined Jan 2005
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Hi guys, I'm starting my R&D on repeatable firing guns. Have a quick question as I don't have my Brig yet. What are the dimensions of the cannons and carronades? I'm trying to mock up a brass tube, but need to know which size I should be using... I seem to recall reading something about a 1/4in. dia tube at 1.25" long.. Is that right? what's the other dimension for the other gun? My plan is to insert the brass tube into the resin guns from SC&H as others have done. As I'm doing the Rattlesnake, I might only have 3 guns on each side exposed (needing to look scale). The other guns can be purpose made tubes that just have scale "looking" muzzles out the gun ports.
Thanks!
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Old Oct 20, 2011, 04:56 PM
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Warpd -
Here's an excellent reference link on cannon and carronade ball and bore size.

http://www.arc.id.au/Cannonballs.html

Table 4 shows a 32lb carronade having a bore size of 6.25 inches.

In 1/24 scale, that is a scale bore size of 0.26", just a tiny bit over 1/4 inch. I used 1/8" schedule 40 brass pipe nipples as barrels.

In the weird world of pipe sizes, schedule 40, 1/8 inch pipe just happens to have an ID of 0.269", almost perfect for a 1/24 scale 32-pounder carronade barrel.
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Old Dec 29, 2011, 04:19 PM
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FIRING GUNS for Ship Models

It seems that rimfire cartridges can be fired by an electric current.

"A different form of electrical ignition used in some competition .22 rimfire arms is to pass current through an electrode or heating element which is in direct contact with the rim. The resulting heat sets off the primer material in the rim. The lock time, that is delay between pressing the trigger and ignition of the round, is said to be greatly shortened. Since a gun held by a human competitor is always moving, however slightly, shortened lock times can increase shooting precision. "
Above from: http://rkba.org/guns/principles/functions/firing.html

And,
"Basically the system works on the same principle as a spot welder--low voltage and high amperage amperage strength of an electric current in amperes or milliamperes. . The two 9-volt batteries, in series, provide 18 volts. The voltage is stored in two capacitors until the shooter releases the trigger. When the trigger is pulled a thyristor (a one-way electrical switch) opens ...releases the stored charge against the primer. Because it happens so rapidly the charge is converted into heat in micro-seconds. At the point of contact the heat reaches 3,500 degrees C, and since primers only need 400 degrees C in an instantaneous situation to the primer is fired. In essence all this means is that for all practical purposes there is no locktime. You pull the trigger and the shot is fired--right now! "
From:
http://www.thefreelibrary.com/Kricot...olt.-a03659515

I can get one heck of a metal melt from shorting my current firing system batteries (a 3VDC NiMH, 10A pack). So, using the rimfire case as a ground, a stainless steel electrode just touching the rim should create a local "spot weld" effect that would be more than hot enough to exceed the 400C (750F) supposedly needed to ignite the primer.

Can't wait to get home and build a test setup.
Warpd - anxious to hear the gunsmith info (...probably will think we're crazy)

Concept drawing coming...
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Old Dec 29, 2011, 04:26 PM
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FIRING GUNS for Ship Models - ship damage

Using the current firing BP cannons that Ray and I have in mock battles is pretty neat to see, but as we start to consider .22 BP rimfire blanks, we need to think a bit.
The current cannons have very low density, soft foam wads. We have fired at each other from fairly close range and have found BP residue and foam wads on our decks after battle, but never any damage. I haven't actually seen or fired a BP blank yet, but they seem to have a small paperboard seal. I wonder if that could cause any damage.
If a bolt is run through the muzzle to shred the wad, that might be the ticket for somewhat increased safety and legality.
Ray - this summer should prove interesting....
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