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Nose weights?


ralph4hand

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How do you determine the placement, and minimum amount, of counter-weight/s for your tricycle landing gear aircraft models :smiley25:

 

What is your preferred choice for weights and glue/whatever to secure weights :smiley25: .

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Ralph,

I just err on the side of caution and always put in a bunch more weight than necessary. I've heard that if you use superglue and lead weights that over time there is a chemical reaction that can destroy the model.

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I usually cheat by mounting the bird on a base with a small metal rod anchoring the front wheel to the base. Otherwise, BB shot suspended in a glob of 5-minute epoxy.

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- Typically, I'll use whole or cut pieces of motorcycle tire balancing weights. They are usually smaller (typically 7 grams) than car tire weights. In special cases, (ie, 1/48 P-39/400's) where there is limited space in the nose where you might see the weight thru a gear well opening, I use shot like Bob L.

 

- In almost every case, I have been using CA, sometimes with an accelerator too, to secure the weights. But after reading David's note about potential chemical/element reactions, I am now wondering about that. :smiley24: I have used 5 minute epoxy in the past and it looks like I'll be leaning towards using that more often now.

 

- When to know enough is enough? Usually, I just guess. But that has led to some embarrassing and frustrating :smiley7: out comes. The Accurate (Eduards) P-400 is the prime example. Thought I had enough shot in the nose. I repeatedly assembled enough components together dry and set the model on the workbench. It looked funny to see this airframe proped up on its landing gear, teetering on the bench with as many parts set on the nose and the tail and where ever else I could fit them to see if it balanced out. Ultimately, I decided to leave the top of the nose gun port panel off as long as I could during assembly, painting, and decaling so that at the last minute, I could do another balancing check. That paid off, because after all of the finishing, it still dropped tail and I had to add more shot through the top nose section. In the end, three point (correct) tricycle contact. :smiley4:

Edited by Weedeater
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Ralph,

 

I tape together all the main components, including the internals, and set the model on an Xacto knife handle, strategically located at the estimated location where the main wheels contact the ground. (Beware aircraft with forward-raked main gear!) I then get a small resealable baggie and start filing it with lead bird shot. The baggie is placed on the nose of the model where the weight will eventually go, and I keep adding shot until the model tips over on its nose. Then I add a little more for insurance. The bird shot is small, so it can conform to irregular cavites with ease. To be extra cautious, look the model over for other potential spaces for weight, like engine cowls and even drop tanks. Keep the parts separate from the model until final assembly, then perform a final balance check. Add more ballast to the standby location until you have a balanced model. I really feel for the guys who end up adding ballast into the nose gear well.

 

I have noticed that mixing bird shot with CA glue causes slight expansion when the glue sets, which leads to fit problems afterwards, not to mention the risk of frosting painted parts. I use either Miliput epoxy putty or "Mori-Mori" polyester putty (Bondo is essentially the same stuff) in lieu of CA, and the results are very satisfactory. If the ballast needs to be formed, but removed during construction for any reason, line the fuselage cavity with Bare Metal Foil or even plastic cling wrap before stuffing it with ballast.

 

If all else fails, forget the ballast and secure the model to a base. I did a balance check on a Classic Airframes Gannet, and it will require a frightening amount of lead to keep it from tipping over. I may pin the main gear to a base, and run a wire loop over the nose wheel axle to keep the nose down.

 

Hope that helps.

 

Neal

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Neal's method is the common technique to get enough nose weight without over doing it. I'd also like o suggest Terry Dean's nose weights. You can contact him for as listing at: NightieMission@aol.com . He has weights pre-shaped to fit a lot of the Monogram 1/48 bombers (as cockpit floors, etc), many of which are notoriously hard to find enough space for enough weight to make them sit on their gear! Best of luck!

 

GIL :smiley16:

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I checked with a local chemist today. CA doesn't react with lead, but his thought was to try tungsten beads. Tungsten is denser and less toxic that lead. Fly-fishing stores often have them in the fly-tying materials section, and sporting goods stores may sell them in the reloading supplies. More expensive, but in the amount we use, maybe tungsten is a good choice.

Edited by rgbenson
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LHS's that carry the Pinewood derby car kits should have small weights that are used on those cars. I use fishing weights,been useing lead but if you heed the caution that has been aired you can find tungston weights that are smaller in size for the equivalent lead weight size. I just go by what I feel will hold the nose down,better to much than to little.

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One thing I won't use again is plumbers putty to secure those weights. I tried using this stuff to set some wieght in a S-3 kit a number of years ago, and was amazed how the nosed started to drip an oily residue from the putty. I now only use white glue or epoxy to secure the weight, and won't be trying anthing exotic again in the near fuure!! :smiley32:

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I'd like to second Gil Hodges endorsement of Terry Deans nose weights. I've used his nose weights on a variety of models, on the big kits (B-1, B-29) and smaller kits (F-100). I just scuffed up the surface with medium grade sandpaper, & used thick CA glue. Works great.

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