Written by Rob Caso As seen in the Summer 2019 issue of Park Pilot
>> The unfortunate reality of being a scale modeler is that you sometimes need nose weight to balance an aircraft. Although non-scale flying models might avoid this by simply having a longer nose, you’re stuck with the scale outline with a scale airplane. Sure, you can build the tail lighter, but there are scale and structural limitations to this.
An ancillary problem is that often, there is little room in the nose to add the needed weight, so I have resorted to making the weight fit the model instead of simply affixing blobs of lead here and there.
The general procedure is to first determine where the weight is to go and then to make a temporary mold of this area using layers of aluminum foil. The lead is then heated either in a steel can or in the mold itself. The resultant custom piece can then be worked with files or sandpaper, but be careful when working with lead—wear gloves and a respirator.
The sequential photos show how to do it.
Rob ground out some of the balsa nose area to accept the weight.
Two layers of aluminum foil are pressed into the cavity.
Lead-shot pellets are heated with a propane torch.
The lead shot has filled the mold. File off the wrinkles on the reverse side when it is cool.
The resulting piece fits nicely in the model and out of the way of equipment—in this case, the flight motor.
Comments
John Vesper (not verified)
Lead Ballast
Fri, 12/13/2019 - 13:40As I have grandchildren and dogs that occasionally venture into my work area, I have foregone lead ballast. Instead I buy steel B-B's, in large quantity.
I place a small disposable cup (about 2-3 ounces) in the approximate location of the intended ballast and start adding B-B's, until balance is obtained. I then add a mixture of Epoxy, microballoons and alcohol to the B-B's and pour into a cavity in the aircraft, at the same distance from the CG. The method is, like in the article, self-forming, but without the need for a torch.
ronald g griswold (not verified)
Bb's
Sat, 12/14/2019 - 09:00I do both. I like using crossman bb's in the nose cavity of jets. No epoxy and i can add and remove weight as needed. The down side to using epoxy is it's hard to remive weight once added
Richard Kovach (not verified)
How is the weight secured?
Fri, 12/13/2019 - 15:02I would hope that the added ingot has enough surface roughness to adhere to an application of epoxy or equivalent, to hold the ingot in place and avoid it coming loose. One alternate option might be to drill a hole through it and the cowl wall (if possible), and pin/glue it secure. On an electric scale model, vibration is virtually non-existent; a combustion engine is another story, and vibration is always a consideration.
doug claypool (not verified)
lead nose weight
Fri, 12/13/2019 - 16:04mix lead shot with epoxy and pour into nose area (or front on cowl). automatically
conforms with the intended/allotted space.
Ed Reints (not verified)
Well now
Fri, 12/13/2019 - 17:59The pictures and techniques you are showing look ghetto. This is not up to the standards of the magazine. Sure this will work, but couldn’t you find a better example of doing this neatly?
Don (not verified)
Lead Balast
Sat, 12/14/2019 - 13:07I go to the tire store and ask for some of the wheel weights that they use on Mag wheels of other large wheels. They have an adhesive backing to hold them in place. They are usually on a strip with small increments marked off. I just lay it on the model where you can put it and add or subtract till you get the right amount and peel and stick.
Jim Martin (not verified)
How much weight is needed !
Sat, 12/14/2019 - 21:56I decide where I can place the weight , get a container ( plastic bottle , milk container etc.) get strong string and hang container filled with water from area where I plan to add weight , pore out water till plane is balanced . I use lead shot , mix with epoxy and match the weight that I need , be sure that you have enough epoxy to cover the lead shot
David Matthes (not verified)
A safer alternative to lead for weighting models.
Sun, 12/15/2019 - 23:28Lipowitz’s metal (158 degree F melting point), an alloy of lead, cadmium and bismuth, can easily and safely be melted in boiling water and poured directly into a cavity hollowed out in styrofoam, wood or plastic - without distorting the cavity in any way. Its density is approximately 90% that of pure lead.
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