Beam scale - a new idea. Prototype. Date 15/01/2012 

Thank you Kassi - Yes indeed, just trying out some ideas - a readily replaceable blade would be a step forward in reloading scale design in my opinion.

@@Targetmaster1066 Absolutuely! I could imagine it would be ultra sensitive too pivoting on a literal razor's edge and ceramic bearings.....Ive kind of wondered if there would be any benefit to milling out the posts under the bearings and installing a steel ball bearing in it's place to reduce friction between the ceramic bearing and base.

Thank you Boyd - This was an idea I kicked around with several years ago. If you investigate really high-end mechanical scales of the 1950-60's you will see that they are capable of incredible resolution, way down in the micro-milligram range, tens of times better that a standard reloading scale and would have no problem differentiating sizes of individual powder kernels. stanton-instruments.co.uk/page19.html So- how do these super-scales achieve their sensitivity? Just a sharp edge on a hard surface, no more, every other pivot just adds friction. The biggest problem with common reloading scales is the short moment length, this makes it very difficult to see the very small movement of a sensitive scale. The good laboratory mechanical scales usually have a long moment length, typically 2-3 times as long as a basic reloading scale and then an optical projector/screen or some sort microscope to read a graduated scale. Fitting a camera to a common scale goes a long way to remedy this problem - The agate bearing used on most scales is quite hard and suitable for our purpose but the knife edge used is quite poor, obviously cheap to produce and manufacture and robust enough to withstand hard use. Using a replaceable hardened steel razor edge, in the form of a craft knife blade makes sense, cheap, readily available, easily replaceable and will give a performance approaching a laboratory micro balance. The pan holder stirrup on the common scale is also a weakness causing unnecessary friction even if perfectly set-up, a single point suspension if far superior. In hind sight it would have been better to have a fixed pin on the beam and a receiving cup on the pan carrier rather than as shown in the video. The adjustable sensitivity works well. By altering the centre of gravity over the knife edge you can adjust the sensitivity to suit your needs. The low mass carbon fibre beam means it is very temperature stable and quick to respond to small variations. The 0-70gn range covers almost all powder measuring requirements, most being in the mid range section, using a common scale most powder charges only use the first one tenth of the range making it even more difficult to see any movement. This "add on" beam, if a suitable manufacturer could be found, could be produced for fairly minimal cost and would give better than "tuned" performance "out of the box". This idea, being a weight comparator rather than a "scale" would have no problems concerning certified weight calibrations etc. The required weight of powder is set using third party checkweights or a second scale.

On the reloading side, it is not so much that we need to hit a load to such a small increment, but that we need to make a set of loads that are identical so that we can minimize velocity variations. Given that reality, a regular tuned scale could be used to arrive at a load, and your comparitor scale could be used to produce a set of loads, using a weight manufactured by the loader, using his tuned scale for a reference. If you comparitor was fitted with a mirror and laser like in the video I sent, it would be interesting to compare the results with one of the popular magnetic force restoration scales that are used to trickle up to loads by long range shooters. @@Targetmaster1066

Couldn't find any video you sent Boyd but I have tried using a laser reflected off a mirror mounted on the beam and onto the wall a couple of yards away. A set-up like that certainly shows minute deflections of the beam but just too inconvenient for practical use. The comparator easily detects a single kernel of Varget and the Targetmaster auto trickler can be set up to deliver a very fine feed. I too look for repeatable weights for my long distance loads but for me a single kernel +/- is good enough. No matter how many decimal places a scale resolves to I really won't be cutting kernels. Increasing the beam length is the easy way to get better resolution. A Lee scale fitted with a 10" beam has remarkably fine resolution.

Thanks for the interest Tobias - I'm back working on this project, although an entirely new approach. Unfortunately I can't take on any scale tuning at the moment but I can supply you with a Targetmaster trickler.

thetargetmaster thanks! I will get one as soon as you have the new version ready and if I can get my scale tuned, too. I would like to get the whole deal 😉

Thanks for the interest Chase - Unfortunately this is a project that's on the back burner until I have more time available.