Re: [RCSE] Digital Scales - a positive vendor message
Andrew E. Mileski wrote: I just got a digital scale from Digital Scales Direct, and I'm quite satisified with it, and I'm impressed with the fast shipping and superb packing job. It looks like it came straight from the factory to me. They have a web site front for their EBay auctions: http://www.digitalscalesdirect.com/ Seems this address doesn't have scales :( I'm sure it is the same people though. Weird. Digital Scales Direct's EBay Store: http://www.stores.ebay.com/id=4352192ssPageName=L2 This works though, and is where I got mine. -- Andrew E. Mileski Ottawa, Canada http://isoar.ca/ 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.
[RCSE] digital scales
I purchased a Sunbeam digital scale at Office Max and have had good luck with it. one other club member has done the same. they cost $29.99. I have not tested it with some sophisicated accuracy device, but sure beats anything I had previously. kevin kavaney KEVIN KAVANEY [EMAIL PROTECTED] Why Wait? Move to EarthLink.
[RCSE] Digital Scales
I also purchased one of these inexpensive digital scales ($40), another manufacturer, 2 gramincrements.For monitoring building weight it didn't work out very well, as the rough resolution prevented us from seeing what each component was contributing to the build. To do a better job on the Drela designs we are building, many on the Allegro-Lite group recommended a scale with 1/10th gram increments. Our inexpensive and accurate solution was to buy a usedOhaus beam balance on eBay--cost with shipping under $50. Weighs up to 610 grams in 1/10th gram increments. A set of weights at $32 plus shipping extends the range to 2510 grams, or 5lbs 2 oz. Not as easy to carry into a store, but accurate, inexpensive, and a high capacity when you want it. Aradhana Singh Khalsa New Mexico
Re: [RCSE] Digital Scales
I have used many scales while working in test laboratories. My all around preference is the old standard Ohaus 2610 g Triple Balance Beam Scale. They're extremely accurate, and with a inexpensive set of calibration weight set, you can easily maintain your scale accuracy with no problems. I am able to mix as little resin as 10 grams of material, and yet stay within the tolerances ofmy epoxy mixing ratios.Generally speaking, your inexpensive digital scales can easily be off by several percentages. That may not be a major concern when mixing resins that require 20 % by weight on an ounce or more of material, but mixing smaller amounts of material, especially materials that require a hardenat 7 % by weight, that's when you begin torun intodifficulties. The majority of the modelers seldom calibrate their scales, and for the most partyou may not experience any noticeable problems if you don't calibrate your scale. However,if you are really concerned about having the exact mixing ratios, and want to insure you have the optimum strength, you may want to consider investing in a scale that will give you the proper accuracies! You can buy a good used triple beam scale for as little as $ 15.00, or near new for about $ 35.00. I have a habit of checking my scale calibration nearly once before using it. I've made three standard weights.My weights range form 10, 30. and 50 grams. If you're really serious about your calibration, you can buy an inexpensive calibration weight sets for about $12.00 I use my three normal standard weights regularly, because that's my normal mixing range.All triple beam scale arequick andeasy to make tare any adjustments. Every time you place any mixing cup on yourscale, you automatically see the tare weight zero out. I also suggest spraying a very light mist of WD-40 on yourplate, thishelps prevent from epoxy build-ups, but be careful, not to over spray with the WD-40. Heavy spraying of WD-40 could affect your scale calibration.It's also best to periodically wipe yourscale down with good old reliable isopropyl rubbing alcohol, or even Windex window cleaner. I suggest Checkingout E-bay. They always have triple beam scales for scale. When you buying anyscale iy's best to clean it, light lube it as required, and always double calibrate the first usage ofany scale, whether it's new or a usedscale before ever using it! I hope all that read this, found some useful information. Keith
Re: [RCSE] Digital Scales
Guys: My $0.02 Today in lab,I used balances that ranged in price from $6000+ to $89 The $89 balances were centigram balances with accuracy to 0.1 g, capacity of 250 grams. I will not belabor the differences between accuracy and precision - I do it all the time with students that should know better. However, if a balance has a possible error of 1% for values between 1 gram and 100 grams - than it doesn't matter if you measure out large amounts or small amounts. 1% of 100g is one gram - will not matter for the mix and if you need 10 grams, 1% of 10 grams is 0.1g - well within the tolerance for hardner, etc. or even 2%! Triple beam balances are not as good as a digital balance. The TB balance must be able to swing freely and stop on the zero or the same place each time. If you've used the balance once it is not as good as it was. (I go back to using a chain-o-matic analytical balance, same priciple as a TB and those weighing may have taken 30 - 40 minutes, and the standards I had to use, cost me over $100 in 1963) The use (and repeated use) of the TB balance rounds off the once sharp fulcrum - and then it will not stop swinging at the same place with the same amount of epoxy, etc or the calibrated set, both accuracy and precision are poor. This fact of life will make them less accurate/precise than the cheapest digital. Forget any rough handling, abuse in shipping, or on the flea market table I've had students check (a lab designed to show students the differences between accuracy and precision with multiple measuring instruments)triple beams against cheap digital - and the cheap digital always wins. Taring on a triple beam is not easy nor quick. Weighing on a TB is not quick either. ALL digital balances will tare with a push of the tare button, so you can use used cups, different sized cups, etc. Unless you buy a good set of calibrated masses and DO NOT touch them with anything except clean forceps, they are useless as a calibration standard. Just the oil on your hands (never mind dust and corrosion) will make them worst than the cheapest digital balances. BTW: sometimes you can get really good digital balances at the police station for nothing or a small donation to their fund - they confiscate them in drug busts! Jim Ealy Jim Ealy Education by Demonstration 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.
