Main gun flash unit.

Dennis Jones · Post by **Dennis Jones** » Tue Jan 04, 2011 4:26 pm

Prototype flash unit built. Not a very good video I'm afraid. Some mods to do yet with sourcing a different shape xenon flash tube and a larger capacitor to give brighter flash.

Dennis

Click on this to see video.

Dennis Jones · Post by **Dennis Jones** » Sun Jan 09, 2011 4:44 pm

Flash unit now linked to sound board. You will need sound up for this one.

Dennis.

John Clarke · Post by **John Clarke** » Fri Feb 11, 2011 10:45 pm

Hi Dennis

Have adatped and disposale camera flash unit for Joe's Comet, using two 1.5 cells giving a cycle charge time of about 7 seconds. The flash unit can be fitted into a small plastic tube in the muzzle break. The wiring is passed down the tube to the stand alone cct in the turret. Joe's turret also incorperates recoil
The camera's can be picked up for less than Â£2 from evil bay and all you need to do is link the exposure switch to micro switch operated from a servo. D cells in atwo pack holder should give a few hundred flashes.
Just remember to keep the three core wiring insulated and correct on the flash tube and try not to handle it too much especially if it's charged

Jon

phil fitzpatrick · Post by **phil fitzpatrick** » Sat Feb 12, 2011 9:47 pm

Hi John
Did you take any pictures or a vidio of the adapted camera
flash and the recoil you did for Joe's Comet,it would be great to see them.
What is the correct recoil distance for the Comet,I cant find that
in the Comet 1 handbook or using Google?
Cheers
Phil

John Clarke · Post by **John Clarke** » Sun Feb 13, 2011 5:13 pm

Hi Phil

The flash unit is waiting to be fitted into Joe's turret when it is completed. At the moment the cct is in a box with power on switch and flick switch to operate the flash.(micro switch when fitted). The actual flash tube reflector was trimmed to fit with the flash tube into the clear plastic tube. It does not work without it (reflector)

From old film reels the 17 pounder does not have a long recoil, so with minimum modification to the barrel and turret internals have got a recoil of about 30mm. It's simply a high power servo fitted to the counter weight, attached to the barrel, When the servo is operated from the momentry switch on the transmitter, it pushes the barrel from the mantle at the same time operating a micro switch triggering the flash. When the servo returns the barrel returns to rest.

I've been just scanning though some of the Comet topic's seeing that other flash units have sync'd sound to flash and wondered how it was done. With Joe's comet we were just going to sync manually using (two) sound and flash switches together on the transmitter. Another question, Joe's is also adding the independant switch to swop bow and coax machine gun at will, looking at some complex cct drawings could'nt understand why a simple servo and micro switch with common, n/o and n/c contacts were used?

Jon

phil fitzpatrick · Post by **phil fitzpatrick** » Sun Feb 13, 2011 7:25 pm

Thanks for the info on Comet recoil distance and how you have
done yours.
RE Flash and sound sinc.
Using the 3 pins at F on the Amplifier module to drive a relay.
Dennis is doing the Quasar Xenon which I think he has nearly
finished the Xenon is very quick I think so no problem with the
quick pulse.
I have been doing mine wirh Halogen Capsules and after experimenting
with upto 24vdc 100 Watt I have chosen 24vdc 50 Watt.
I needed a true delay off timer though because the pulse was too
quick for the Halogen.
I only had to delay it for 1.375 to 1.625 seconds and I liked the
flash it gave from yellowto white and as it decayed back to yelow and a bit of red.
I am putting some simple drawings on to Mick's Comet posting tomorrow for him
RE Splitting the MG's I just used a 24vdc DPDT relay operated by
the 3rd switched channel available on the Auxiliary module
because I had the spare lead already that was not going to be used on the gun firer,I asigned Switch G on the Futaba 7C to
operate this.
My MG travers mechanism is operated with the VR knob which
traverses the servo to either side at any speed you want.
I think I have put pictures and details on my Comet postings of these.
There are 4 or 5 vidios showing the Halogen Gun flash from
20 Watt to 50 Watt aswell.
You have to click on the photo to go to the vidio on photobucket.
Cheers
Phil

John Clarke · Post by **John Clarke** » Mon Feb 14, 2011 12:26 am

Thanks for the info Phil, will pass on to Joe and look forward to seeing the drawings. At the begining of the venture Joe and I pitched for the 10C with 14ch RX which gives an a plentyful choice of control and as such allows for simple control of the auxillaries as long you can remember what does what. I find a cheat sheet comes in handy.
Going back to the recoil system needs a good lumpy counter weight to stop the barrel binding though the mantle hole which is also thoughly greased to reduce drag. Will not know how reliable it is until the turret is finished, but it's simple so thats in it's favour.
Jon

phil fitzpatrick · Post by **phil fitzpatrick** » Mon Feb 14, 2011 8:51 am

Thats a nice choice of radio John,I,ve got Y leads comming out of my
Y leads.
Thanks for the info on your recoil.
You might be interested in a site I think its called Technobot,I am at
work at the moment I think it might be www.technobot.co.uk/rc
They do some little relays and switches that fit direct into your receiver
via a servo lead,one is a 10 amp relay.
I will check the sight details out for you if I have got it wrong.
Cheers
Phil

Post by **Armortek** » Mon Feb 14, 2011 9:06 am

Hi John.

Just a word of caution. The Futaba 14channel reciever has a non standard output on channels 3-14. The new Armortek control gear is digital and is not compatable with these channels.

Mark

phil fitzpatrick · Post by **phil fitzpatrick** » Mon Feb 14, 2011 9:13 am

Hi John
That site address is wrong for the servo relays I will update it later.
I mist that bit in your posting that you were using a 14 channel receiver
on the 10C.
Cheers
Phil

phil fitzpatrick · Post by **phil fitzpatrick** » Mon Feb 14, 2011 10:51 am

Hi John and guys
Here is the replacement site address for some good little switches that
plug straight into your receiver.
www.active-robots.com/rc
Cheers
Phil

Dennis Jones · Post by **Dennis Jones** » Mon Feb 14, 2011 11:27 am

John,

If you need details for driving the gun flash from the main gun sound (which only involes a relay and a careful bit of soldering) then email me and I will send details.

Dennis

Dennis Jones · Post by **Dennis Jones** » Tue Feb 15, 2011 5:15 pm

Unit now boxed up and have tried it the tank but my video camera is not very good resolution so I am working on a suitable video.
Unit below with larger capacitor installed.

Dennis.

phil fitzpatrick · Post by **phil fitzpatrick** » Tue Feb 15, 2011 9:10 pm

Hi Dennis
That certainly is a bigger capacitor than the one they fit,is that
the one you said you needed to buy a minimum of 100 or did
you find an alternative supplier?.
Look forward to your vidio

Cheers
Phil

Dennis Jones · Post by **Dennis Jones** » Wed Feb 16, 2011 11:34 am

Hi Phil,

Radio Spares 3847880P about Â£7-50. 5 mfd 700 volts working polyester. It's the 700 vdc that makes it so expensive but it does make a difference to the brightness and I also connected it in parallel with the original 2.2 thus giving about a total of 7 mfd.
The reason for a lot of wires coming in to the box is 2 for the flash activate, 24 volts into a 6 volt regulator chip and 2 for the turret m/c gun. I have also fed the 24 volt supply from the channel 5 switch which I am using to swap m/c guns to the flash unit so when I am on the lower m/c gun then the flash unit is switched off saves it bashing away all day.

Dennis.

Main gun flash unit.

Main gun flash unit.

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Main gun flash and recoil

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Relay site

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Quasar Flash