Freewing 80mm A-10 Modifications

[Mike_Then]

I picked up some aluminum tubing from my LHS yesterday. The idea is to use that to have the powder exit the front of the airplane. I figured the A-10 is roomy but not roomy enough for a bottle the size of an isoproply alcohol bottle. So I'm going to head to Target today to pick up a few of those travel-sized shampoo bottles that are like 4-5 oz. They have a screw-on lid which is what I want, and they are stiff plastic which is also what I want. I'm going to butcher up another inner tube to get the Presta valve... think it will be perfect to use that for both ends of the bottle, simply because they are threaded. That will keep them on the bottle hopefully.

I'm hoping to mock up the inflator and bottle in the next few days, as I can at least work on the logistics of that while I wait for the servo.

[RCjetdude]

Yep, totally agree. I went ahead and ordered the servo because apparently I had a store credit of almost $6 that either forgot about or wasn't aware of. LOL It's on the way.

Forgot to mention that I cut up an old inner tube to use the valve. It's a Presta-style valve so the CO2 infaltor screws onto the valve nice and tight. Perfect. And Presta valves are threaded all the way down and come with a threaded locking ring. So my idea currently is to drill a hole in the lid of an old bottle of isopropyl alcohol. I'd use an old fuel tank if I still flew slimers but those days are long gone. ;) I'll use those threaded locking rings to secure the Presta valve to the lid of the bottle. Fill the bottle with talcum powder and have a tube exit the bottle at the bottom and that's where the powder will supposedly come out of. I'll post pics once I get it mocked up.

Mike, keep up the good work. Eventually we might be able to figure out how to make a system that is reliable, looks right in the air, is light weight, easy to install and service and is consistent. Clearly it is not an easy challenge. Speaking from experience you will find the talcum powder has the tendency to cake a bit leading to inconsistent shots and a fair amount of it remaining in the bottle. I am looking forward to seeing how yours turns out.

[crxmanpat]

For those who have painted their struts white, what type of paint did you use? I'm thinking Testors enamel with some king of protective coating.

[RCjetdude]

For those who have painted their struts white, what type of paint did you use? I'm thinking Testors enamel with some king of protective coating.

I used plain old Krylon metal primer which was white to begin with and then Krylon semi-gloss white enamel. Give 'em a good wipe down with alcohol first. Worked great.

[Nucastle]

Hey a thought for the guys making the powder guns......Years ago when I was a kid, I built a Guillows stick and tissue model of a crop duster. The way they made the "dusting" action was to run the rubber band thru a paper "hopper" that you would fill with Talcum powder. So just thinking out loud....if you had a very simple "hopper" for the powder, a simple way to agitate it......then pick a location that faces forward for an air inlet scoop (the refueling dock???) and as long as it is bigger than the outlet of the "gun" you would push air thru the hopper and out the gun. A servo to block the air flow. Real cheap, and just a thought.....

[Nucastle]

and thinking it thru more, have the outlet facing down....so you dont have the airflow trying to work against you on the outlet.....

I hate being stuck in traffic......

[crxmanpat]

I used plain old Krylon metal primer which was white to begin with and then Krylon semi-gloss white enamel. Give 'em a good wipe down with alcohol first. Worked great.

Cool, thanks. I'll have to do that soon.

[Mike_Then]

Mike, keep up the good work. Eventually we might be able to figure out how to make a system that is reliable, looks right in the air, is light weight, easy to install and service and is consistent. Clearly it is not an easy challenge. Speaking from experience you will find the talcum powder has the tendency to cake a bit leading to inconsistent shots and a fair amount of it remaining in the bottle. I am looking forward to seeing how yours turns out.

Thanks for the insight and encouragement. I was wondering about how that blast of air was going to react inside the bottle and get most of the powder out. I was hoping for perhaps 2-3 "shots" before needing a refill but I guess that also depends on how long I hold the trigger, so to speak. My first thought was to put the intake (the inflator side) right in the middle of the cap of the bottle and the output (where the powder will exit the bottle) on the very bottom of the bottle. That will, in theory, help get all the powder out of the bottle rather than having some powder dance around at the bottom of the bottle. Will require testing of course and the reason why I'm buying multiple bottles.

The other thing I was just thinking of was tying it into a sound system. The Holy Grail would be to have a 1 - 1.5 second powder burst with a 1 - 2 second delay, then hear the sound. That may be a problem because since the inflator is on-off via a lever that will be operated with a switch on the radio. If I flip the switch to operate the inflator and then flip the switch off to close the valve, that will shut off the sound system. So I'm going to have to perform some really fancy mixing in the radio to do this or simply put the sound system on another switch. That's unfortunately going to be more work on me, the pilot, and I'll have to make sure to pay attention and not pile the A-10 into the ground while counting off seconds in my head and flipping multiple switches. :Scared:

That comes much later of course; I gotta get the cannon working first. Just thinking ahead.

[Mike_Then]

Hmmm I just got to thinking about this while proofreading my post... I have several three-way switches on my radio that I can set things to actuate in one position (Up OR Center OR Down), or two positions (Up/Center OR Center/Down). I could tie both functions into the same switch... have Up position be off for all, the Center position be powder cannon, and Down be the sound system. When flipping the switch to down, it would shut off the CO2 inflator but activate the sound. That way I'd just have to flip the switch to the middle, leave it there for about a second, and then flip it all the way down to activate the sound. The sound would be programmed to play for about a second or two and then stop. I could then simply leave the switch in that position for the rest of the flight so I wouldn't have to think about it anymore and just concentrate on flying the plane.

*scratches chin* That's an idea for sure. Will require more thought.

[RCjetdude]

I have mine tied to one two position switch. When I flip the switch it does two things. 1) It activates a solenoid and my powder hopper agitator so I get immediate powder out of the gun. 2) It activates my cannon sound file on the card. The sound file has a 0.5 second of silence at the beginning of it. I started out with a longer delay but with the scale of the model, the speed with which it is moving and the typical distance away from the pilot it would be the other end of the runway by the time the sound was heard and just did not present well. The sound file plays until completed and stops. The switch needs to be turned off after only a short second and what I found happening to me at least was that I would position the plane and set it into a gentle dive, come completely off the power, flip the switch and forget to turn if off which would inevitably expel all my powder on the first shot. Believe it or not but there is a lot going on in that moment as you are trying to keep from getting too distracted. Just like anything, with practice I will get better at it. The reason I say all this is plan to set set yours up to keep it as simple as possible. Toggling 3-position switches or additional switches adds complexity. My desire would be to also have the canon fire for only a limited time and stop automatically so I don't have to think about turning the switch back off after a certain time.

[RCjetdude]

Another thing to be aware of is placement of the powder hopper and CO2 cartridge. The powder does have weight, even more than one might think. Placing the hopper clear up in the nose just behind the canon could have a significant enough impact on the CG as it is expelled to be an issue. I have mine as far back and as close to the CG as I could reasonably get it.

[Patrnflyr]

Can someone steer me in the right direction for the best deal on a working Nerf football whistle source. I know several have tried and failed and cheaper versions like the saucer and generic footballs. Just don't want to waste money. Thanks
John

[dkalwishky]

This is where I bought mine, I bought two of them. I didn't see it anywhere else (in stock) for less money when I bought mine.

https://www.amazon.com/Nerf-Sports-Howler-Football-Orange/dp/B00QZ2PUVQ/ref=sr_1_2?ie=UTF8&qid=1498072117&sr=8-2&keywords=nerf+vortex+football

[Twowingtj]

I got mine directly from the Hasbro toy shop on ebay for $11.99. Best price I found.

[dkalwishky]

I forgot about them. When I checked a month ago there was no stock, looks like they have some now. I might pick up four more from this eBay site just so I have them for future projects.

[crxmanpat]

So I had mentioned before that I was running out of my Walthers Solvaset decal setting solution, and would have to order more. I went on Amazon last week and they were out of stock with no estimated restock date, so instead I ordered Micro Set from Microscale Industries as I've heard good things about it. Got it in a few days and wanted to use the application brush from my Walthers bottle as the Micro Set bottle didn't come with one. I opened the Micro Set bottle to pour it in the other bottle and was hit with a powerful odor. Oddly enough, it smells EXACTLY like distilled white vinegar. Hmm, I wonder...

[Patrnflyr]

Thank you both for the Nerf direction

[Ronniehinesh]

The last bit of exterior detail I had to complete before painting is now done. No ladder yet but the box and door are made as well as the vent covers just ahead of it. Paint goes on tomorrow.

Where did you get the vents you put on the side?

[RCjetdude]

Where did you get the vents you put on the side?

I made them from 0.5mm styrene. :)

[Ronniehinesh]

Thanks