Hey guys, i’m building Hasegawa’s P-38J. The instructions say this ol’ girl needs 35g of ballast to keep her from dragging her cute little tush. Now, I’ve used some superglue and COPPER BBs as ballast. What I need to know is approximately how many COPPER BBs it’ll take to achieve 35g. Thank you so much!!!
Oh, thats 35,000 milligrams. Sorry, couldn’t resist. What dia BB’s are you using?
For steel BB’s it would be 89. I assume we are dealing with .177.
4.5 mm is what the box says, gentlemen
About 83 if I did my math right.
(assumed density of copper ~ 8.92 g/cm^3 and you had 0.177 caliber = 4.5 mm diameter)
You might want to consider lead split-shot sinkers instead.
That depends on the weight of the BBs, Crossman Copperhead BBs are 2500 to a 2 lb. container so thats a bit over 900 grams or .36g per bb, so 35g would be 97 BB. Can you pack that many BB’s in? Have you considered using lead fish weights? I bought a 5 lb. “roll” of pencil thick lead that you can hammer to shape to fit into nose pieces. CA glue works well to hold it in place.
edit 4.5mm is .177 /edit
I’ve not fished in OH even though I live here. Some states do not allow lead fishing weights. If this is so in OH, get some lead for muzzle loaders.
http://www.onlineconversion.com/ here you go makes life really easy. You can convert the grams to ounces and use fishing weights. I buy several differnt weights ranging from 1/8th to 1 ounce and add them accordingly.
LOL…geez, you guys make life hard for yourselves!
Mate, just tape the fuselage, booms and wings together (the major weight of the model), tape a pencil (spanwise) to the booms RIGHT where the rear gear would be located (to act as a fulcrum), then pile on the weight in the nose until the nose stays down even when you push the down tail to the deck.
Make sure you account for any extra bits like the weight of a resin cockpit, spinners and props - maybe tape them in place as well.
I’ve used this method for years - especially on airliners - and have NEVER had a tail dragger.
This method allows you to put just enough weight in to keep the nose down without adding more than is needed. Best of all, it’s dead easy and there’s no maths involved.
Remember, the further forward you have the weight, the less you’ll need, as torque (or turning moment) equals force times distance.
In short, I’ve never actually weighed the ballast in the nose of a model using this method - there’s no need.
About 7 nickel’s worth… $.35. Each nickel weighs about 5 grams each. 5 X 7 = 35.
You’re welcome!
With best regards,
Steve Mack
People, people, people… yer making it all to complicated.
Let me answer this from the “Larry the Cable Guy’s Guide to Metrics”:
“When instructions call for 35g of weight in the nose, what that means is you fill that son-of-a-[censored] up till she’s 'bout to bust and call it a day. Get 'r done!”
Lord, I apologize…
[;)]
As always, yer milage may vary.
about 1 1/2 ounces my method is to drip candle wax onto bb’s or fishing weights, or even mix up plaster type material with weights & spoon into fuselage & engine halfs. or build wheels up & dangle from ceiling! Jon UK
I 've used some thin aluminum sheet and made “forms” for molding melted lead to fit between instrument panels and bulkheads (P-61 & B-25) along side the nose wheelwell of the B-29, inside the instrument panels of the B-29, even inside the nose wheels. I am motorizing these so the extra weight of the electric motors behind the dummy engines help a lot. I use lead shot and fishing weights.
Hi! this is the conversion:
1gr = 0.035274 oz
1 gr = 0.0022046 pound
now you do the math
bye
Jeremias
Hey Mel, that is a fantastic idea!!! Thanks to everyone for your input! I think for this one I’m going to slap some lead fishing weights in the plane and see how that goes! Thanks again!
Wow…and to think, I just use modelling clay or plasticene.
get a scale, your life will become infinately easier.
Thanks or you can also try this unit converter site.
I almost got sucked in to answering a 15 year old post,
But I kinda just go by feel.
wow, rsneha! Are you a doctor, or a miracle worker, perhaps? You really brought this one back from the dead! Lol
You have to cut him a break, he’s a new guy[:D]
Thanks for trying to help, rsneha, and welcome.