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Old Jan 13, 2013, 12:43 PM
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daboz's Avatar
HB cali
Joined Apr 2006
4,025 Posts
Lots of room

I was able to get lots of room...

First I put a 5OZ fishing weight shaped like a stretched out football, (rugby ball for those of you in other English speaking countries) in the nose and it almost fit perfectly in the nose. I just cut the connector of the front and glued it in with some Led shot and epoxy. This allows for a very dense nose weight, pure lead. Second I put the RX in the saddle and put the antennae in the nose behind the battery.

Airtronics RX fits great.


Perfect shaped Led sinker.
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Old Jan 13, 2013, 02:25 PM
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ALEX HEWSON's Avatar
Christchurch, New Zealand
Joined Jul 2005
5,187 Posts
I wonder if submerging the nose in Dry-Ice then pouring in molten lead would work??? Any one tried this before?
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Old Jan 13, 2013, 02:42 PM
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United States, CA, Los Angeles
Joined Oct 2003
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Typically, cool water is enough to prevent damage to the paint. Just make sure it doesn't leak thru into the nose before you pour the lead... that would be BAD! No guarantees on what effect it has if any regarding the strength or toughness of the structure... Tape a cup to the nose once the elevator servo is done so you can see just how much lead you're going to need for balance. I anticipate roughly 11-14oz for the heavy layup. Fitting the necessary nose weight really hasn't been an issue.
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Old Jan 13, 2013, 04:52 PM
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ALEX HEWSON's Avatar
Christchurch, New Zealand
Joined Jul 2005
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All good, I tend to over analyse things. I just want it all to go really well and have no failures. I hate Hate HATE it when a model of mine crashes because something has failed. I would much rather dumb-thumb a model, at least then I know it was me and I could have prevented it.
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Old Jan 13, 2013, 06:19 PM
Can you DS it??
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Australia, NSW, Berowra
Joined Aug 2008
1,420 Posts
I've made wet sand moulds for my models before. Just get a large cup or a small bucket, fill it with sand, wet it enough so it stays together and poke the nose of the plane in it. Slowly pour in some molten lead and voila! A little bit of shaping, and it should fit perfectly.

A good trick is to quickly put a fishing swivel into it as soon as you have poured it, while the lead is still molten. That way you can tie some cord to it and pull it back out while your testing the fit.
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Old Jan 13, 2013, 07:44 PM
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Australia, WA, Perth
Joined Oct 2003
875 Posts
Done similar but with plaster of paris mold. An old tin can with the wet mix in it, slather the nose of the glider with release or even just something like cooking oil. Hang so it doesnt touch the bottom of the tin. When dry pull the fuse out and then I baked the tin in an oven for an hour at 80C or so. Engouh to ensure all moisture is out, then melt lead and pour into mold, allow to cool, job done.
IMHO much safer than pouring lead into something containing water.
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Old Jan 14, 2013, 12:01 AM
gizzo don't tweet
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Adelaide, Australia
Joined Jan 2008
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Leo, thats how I usually do it (wet sand mould), but I like the swivel idea, never thought of that. Sometimes the lead shape needs a bit fettling with a hammer afterwards, to make the diameter less so it fits properly, if it's a thick moulding. My Homebuilts I've been pouring the molten lead in directly, with the nose submerged in cold water with ice chips after AvB described the method. Works great and from my experience, doesn't make the nose exposed to heat any weaker than it would have been otherwise. The thing that catches me out is, I balance the model with a cup taped outside then melt that weight of lead. Pour it in and it ends up a bit nose heavy ('cause the lead gets right up the front) and you can't get it out to drill it.
My 2c, YMMV, IMHO etc
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Old Jan 14, 2013, 12:31 AM
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LVSloper's Avatar
Las Vegas
Joined Mar 2009
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Quote:
Originally Posted by gizzo View Post
Leo, thats how I usually do it (wet sand mould), but I like the swivel idea, never thought of that. Sometimes the lead shape needs a bit fettling with a hammer afterwards, to make the diameter less so it fits properly, if it's a thick moulding. My Homebuilts I've been pouring the molten lead in directly, with the nose submerged in cold water with ice chips after AvB described the method. Works great and from my experience, doesn't make the nose exposed to heat any weaker than it would have been otherwise. The thing that catches me out is, I balance the model with a cup taped outside then melt that weight of lead. Pour it in and it ends up a bit nose heavy ('cause the lead gets right up the front) and you can't get it out to drill it.
My 2c, YMMV, IMHO etc
I always subtract about 2 oz. from the cup and just add stick on weights to balance it out. This way, you don't run the chance of being nose heavy and have to grind out any weight or add tail weight. My2c.
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Old Jan 14, 2013, 02:45 AM
AvB
Wind, hill, ... I'm keen ...
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Australia, QLD, Woody Point
Joined Nov 2006
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Pouring into the nose is a regular thing for me now, very quick and easy. But a word of warning! I've had a couple where I've failed to get the cloth to close over the seam right at the tip of the nose. It may look fine (closed over with epoxy and paint) but when you pour the lead in, the lead melts the tip hole and runs out like water! Don't hold the fuz over your feet!

If in doubt, or if there is a hole, it's easy fixed ... just wrap a couple of layers of aluminium foil around the tip and tape it on with masking tape, then pour lead. Works perfectly.

You need to use a butane bottle and burner to get enough heat. Forget about using kitchen gas stoves. Get a small container of water and ice cubes and get the water level so you can stick the nose in and rest it on the bottom without water entering the cavity. I hold the fuz in one hand, take the pannikin with molten lead in the other and pour in fast, then put the nose in the cold water quickly. Watch the lead and soon as it's gone solid, I run outside, making sure that I bang the fin against the door frame when exiting the shed, and hold the lead tip under a running tap for a minute or so. Finished.

I agree with the guys above ... it's better to put about 10% too little into the nose and then add a couple of shaped plates of lead on top, which can be easily removed to get the CG right. I've had to take a big drill up to the slope sometimes, to remove lead when trimming, which is a pain. And you can twist the nose right off your model with a powerful drill if you're not careful.
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Old Jan 14, 2013, 03:24 AM
Dave Pope Manawatu NZ
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Palmerston North NZ
Joined Dec 2006
1,207 Posts
We do the same as avb all the time, works great, I used to cast it in sand but too much shaping to get it in and it never goes right to the front. The last hot lead pour I did the other day did have a tiny hole in the nose, saw it when we had a pin line of lead in the bucket of water, all fine though. I normally splash a little water in the nose just after pouring whlie the nose is in the bucket, once cool I stuff paper towels in on top of the lead and tip the fuse upside down for the towels to soak up the water.
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Old Jan 14, 2013, 05:57 AM
gizzo don't tweet
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Adelaide, Australia
Joined Jan 2008
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Quote:
Originally Posted by LVSloper View Post
I always subtract about 2 oz. from the cup and just add stick on weights to balance it out. This way, you don't run the chance of being nose heavy and have to grind out any weight or add tail weight. My2c.
I will learn some day.....
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Old Jan 14, 2013, 06:05 AM
DS state of origin NSW Vs QLD
Forrest12's Avatar
Joined Jul 2009
1,371 Posts
These should fit nicely will have mine tomorrow and will double check on a heavy lay-up, Just add a Vreg/bec and everyones happy, Just dont crash and start a fire!

http://www.hobbyking.com/hobbyking/s...dProduct=17283
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Old Jan 14, 2013, 06:09 AM
making my own planes...
decones's Avatar
Curitiba - Brazil
Joined Oct 2007
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Quote:
Originally Posted by Forrest12 View Post
, Just dont crash and start a fire!
Why don't you use LiPoFe ?
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Old Jan 14, 2013, 06:10 AM
DS state of origin NSW Vs QLD
Forrest12's Avatar
Joined Jul 2009
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Originally Posted by decones View Post
Why don't you use LiPoFe ?
Can you get it in those dimensions?
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Old Jan 14, 2013, 07:19 AM
making my own planes...
decones's Avatar
Curitiba - Brazil
Joined Oct 2007
1,088 Posts
I do think yes
http://www.hobbyking.com/hobbyking/s...iver_Pack.html
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