I was reviewing these messages this afternoon and came across this thread. Larry is correct in that the issue can be strictly about ratios, the absolute numbers are not important in relation to weight as long as the system balances and the "tare weights" are not out of whack. I think his description in the original response addresses this OK. My concern is when he talks about using pennies for weights. I built a similar coin based scale for my kids to use in a science project in school and ran into trouble using pennies, so I know. It seems that there are two species of US pennies in circulation that differ dramatically in weight. The copper clad zinc coins made after 1978 weigh 2.5 grams while the older solid copper coins that were made before 1978 weigh 3.33 grams. Mix them and your balance beam scale will give you some funny results. It is fun, however, to bet your kids that you can prove that two pennies (new style) equal one nickel (five grams). Or that three pennies (old style) equals two nickels. ----- Original Message ----- From: "Larry Taylor" <[EMAIL PROTECTED]> To: "Harley Michaelis" <[EMAIL PROTECTED]> Cc: <[email protected]> Sent: Sunday, January 23, 2005 1:00 AM Subject: Re: [RCSE] Mold Help?
> NO! You would take your 4 coins on one side and put something close to > what you want it can be any amount. Than Balance it on a point that both > sides are are now balanced. The stick may only have 3inches where the > resin is and 10inchs where the coins are. You just find where it balances. > Than you add the one more coin and add the hardner till it balances again > at that same balance point. You will have the 4 parts Resin and 1 part > Hardner in the cup. > Just try putting 4 quarters on one side and 4 pennys on the other side > balance it than add the quarter to the quarter and penny to the penny side > and it will balance. > ----- Original Message ----- > From: "Harley Michaelis" <[EMAIL PROTECTED]> > To: "Larry Taylor" <[EMAIL PROTECTED]> > Sent: Saturday, January 22, 2005 8:41 PM > Subject: Re: [RCSE] Mold Help? > > >> Hi Larry. . .I think you have something here, but it needs some >> clarification, starting with "Let's say you want to mix up 7 ounces of >> resin and hardener and at a ratio of 4 parts resin and 1 part hardener by >> weight. Here is what you do". >> >> Having made the beam and the cup setup, >> I gather that you'd first determine what 5 of some coin, nut, bolt ,etc. >> of equal denomination or size would weigh 7 oz. You'd then pour (pore?) >> out enough resin to equal 4 of them in weight, add one more coin, etc >> and add hardener to equal the 5. >> >> Is that the gist of the thing? >> >> >> ----- Original Message ----- >> From: "Larry Taylor" <[EMAIL PROTECTED]> >> To: <[EMAIL PROTECTED]> >> Cc: <[email protected]> >> Sent: Saturday, January 22, 2005 3:38 PM >> Subject: Re: [RCSE] Mold Help? >> >> >>> Here is a trick that I learned from a world champ. you take a long >>> stick (8 to 18 inches) and get some items that weigh the same ( Dimes, >>> Quarter,Dollars coins) Take 10 coins and put it in a little plastic >>> cup. The cup has to be suspended by a wire loop going around and bent up >>> to the long stick where you drill a hole and the hole thing pivots in.. >>> The other end you do the same thing with a cup to hold the epoxy in. . >>> With nothing in the cups it should balance. If not make it balance >>> exactly in the middle of the stick. Now take the 10 coins put them on >>> one side and put as much epoxy as you need in the other side and than >>> find the balance point of the coins and epoxy. Add the 11th coin and >>> pore in the catalyst in the Epoxy you will now have your 10 to 1 ratio. >>> This is the same with 5 to 1 mix with 5 coins. This is fast and >>> accurate. I had forgot how to do this my self till I was shown. I use to >>> put one washer on a balance beam and dump washer on the other side till >>> it balanced and I would have 100 with out counting and it works!! I >>> counted it once just to make sure for myself >>> ----- Original Message ----- >>> From: <[EMAIL PROTECTED]> >>> To: <[email protected]> >>> Sent: Saturday, January 22, 2005 12:48 PM >>> Subject: [RCSE] Mold Help? >>> >>> >>>> Hi All, >>>> >>>> I know this is off topic but I need help with a mixture ratio for ACP's >>>> tooling resin and thought someone here might know. My digital scale >>>> died and I can't find one locally. The mixture ratio on the can is >>>> 10:1 >>>> by weight but no mention of mixing by volume. Anyone else use their >>>> tooling resin and have any idea what the mix by volume would be? >>>> Snowing like crazy here and I'd like to lay up a mold while the weather >>>> is bad. >>>> >>>> Happy flying, >>>> >>>> Jim >>>> www.jtmodels.com >>>> >>>> >>>> RCSE-List facilities provided by Model Airplane News. Send "subscribe" >>>> and "unsubscribe" requests to [EMAIL PROTECTED] Please note >>>> that subscribe and unsubscribe messages must be sent in text only >>>> format with MIME turned off. Email sent from web based email such as >>>> Hotmail and AOL are generally NOT in text format >>> RCSE-List facilities provided by Model Airplane News. Send "subscribe" >>> and "unsubscribe" requests to [EMAIL PROTECTED] Please note >>> that subscribe and unsubscribe messages must be sent in text only format >>> with MIME turned off. Email sent from web based email such as Hotmail >>> and AOL are generally NOT in text format >>> >>> >> >> > RCSE-List facilities provided by Model Airplane News. Send "subscribe" > and "unsubscribe" requests to [EMAIL PROTECTED] Please note > that subscribe and unsubscribe messages must be sent in text only format > with MIME turned off. Email sent from web based email such as Hotmail and > AOL are generally NOT in text format RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
