I've spent some time evaluating low cost electronic scales suitable for accurate weighing while powder trickling, and ended up with something interesting instead.
I have a RCBS Chargemaster 1500 scale. It works well enough. Drift is not bad, but it does drift, sometimes a significant part of one grain.
I am not prepared to spend what I consider a huge amount of money on a FX120i or equivalent, so I bought and tried a few different scales in the same price range as the one I have, and none of them are better.
They all drift.
I have an old 10-10, which weighs accurately, but does not have a fine enough resolution to easily indicate a single granule of powder being added to the pan.
I then recalled that years ago, when I first began reloading, my first scale was a Lee Precision. I also recalled that it was extremely sensitive, but a perpetual motion machine, making powder weighing an exercise towards sainthood. I also remember giving it away and buying something orange, can't remember exactly what it was.
I now bought another Lee, and tried to figure out why it could never stop moving. The reason is that brass or aluminium when moving through a magnetic field, experience a force to retard the motion. The magnets in the Lee scale are not strong enough to distract a compass needle, so I removed them and replaced them with rectangular neodymium magnets. Perpetual motion problem solved.
I have an old laptop - look up HP 6730b to see how old - that's too slow for anything useful, and an almost equally old USB HD webcam. I used them to give me a big picture of the scale reading. I used two strips aluminium tape superimposed on the scale to give a finer demarcation line.
I've checked what the Chargemaster 1500 says against the 10-10, and they concur.
So I'm trying a new thing :
1. use the 10-10 to weigh the initial charge, being accurate to 0.1 grain
2. zero the Lee using that charge
3. drop powder from the powder measure slightly below what's required
4. trickle up on the Lee while viewing on the laptop screen
So far so good. The video is showing 40.2 grains of N555. The resolution of the scale is such that it shows a change with just one granule of N555.
I've now got consistent charge weights to the granule, and I don't have to constantly re-check if the scale has drifted.
Use this link to get the video clip -
Lee Safety Scale Revisited
I have a RCBS Chargemaster 1500 scale. It works well enough. Drift is not bad, but it does drift, sometimes a significant part of one grain.
I am not prepared to spend what I consider a huge amount of money on a FX120i or equivalent, so I bought and tried a few different scales in the same price range as the one I have, and none of them are better.
They all drift.
I have an old 10-10, which weighs accurately, but does not have a fine enough resolution to easily indicate a single granule of powder being added to the pan.
I then recalled that years ago, when I first began reloading, my first scale was a Lee Precision. I also recalled that it was extremely sensitive, but a perpetual motion machine, making powder weighing an exercise towards sainthood. I also remember giving it away and buying something orange, can't remember exactly what it was.
I now bought another Lee, and tried to figure out why it could never stop moving. The reason is that brass or aluminium when moving through a magnetic field, experience a force to retard the motion. The magnets in the Lee scale are not strong enough to distract a compass needle, so I removed them and replaced them with rectangular neodymium magnets. Perpetual motion problem solved.
I have an old laptop - look up HP 6730b to see how old - that's too slow for anything useful, and an almost equally old USB HD webcam. I used them to give me a big picture of the scale reading. I used two strips aluminium tape superimposed on the scale to give a finer demarcation line.
I've checked what the Chargemaster 1500 says against the 10-10, and they concur.
So I'm trying a new thing :
1. use the 10-10 to weigh the initial charge, being accurate to 0.1 grain
2. zero the Lee using that charge
3. drop powder from the powder measure slightly below what's required
4. trickle up on the Lee while viewing on the laptop screen
So far so good. The video is showing 40.2 grains of N555. The resolution of the scale is such that it shows a change with just one granule of N555.
I've now got consistent charge weights to the granule, and I don't have to constantly re-check if the scale has drifted.
Use this link to get the video clip -
Lee Safety Scale Revisited
