Beam scale users - A new App

[1066]

I know I'm not the only one who likes their beam scales, and I know a good many of you are using the webcam or smart phone trick to eliminate parallax error.

http://bulletin.accurateshooter.com/2012/07/monitor-balance-beam-with-magnified-image-on-smartphone/

I've now found an even better/easier way to get the same results. With a new free app you can now plug a $5 webcam straight into your tablet or smartphone which makes it very practical and cheap.

The app I use is "camerafi" for android but it's available for a few pennies for Apple users.

You can see it in action on my scales here:
https://www.youtube.com/watch?v=A2PF2xv_OPs

 

[mdi]

Thanks for that info. I've thought of doing something like that, but I don't own a cell phone, smart or stupid...

Mebbe work with a laptop?

 

[Ex]

Nice work 1066!!! Not only on the vid but the ideas also!

Cheers!~!

 

[gamestalker]

Not a bad idea really, especially if eye level isn't convenient, or possible.

But I've checked my loads when reading the pointer knowing it was out of parallax, and the variance was .025 grs.. That's obviously only an estimate determined by using the .1 gr. wheel on my RCBS 5-10. But considering how very little it effected the weight, I don't get to worked up about it.

But I do however try to set the scale at close to eye level to minimize it as much parallax shift as possible.

GS

 

[Lost Sheep]

You can also just set a small mirror or prism instead of a camera. No electricity, no app, no phone required.

Lost Sheep

 

[gamestalker]

As a matter of fact Lostsheep, I've done that with mirrors before, just as effective.

GS

 

[catgunguy]

"1066" would you explain how you put the extended pointer on the beam of the scale? I really think that it would make my scale a lot easer to read. Thank you.

 

[1066]

"1066" would you explain how you put the extended pointer on the beam of the scale? I really think that it would make my scale a lot easer to read. Thank you.

The extended pointer works well if you're using a camera system, remember if you add any weight to the pointer end of the beam you will need to add about 10 times as much to the weight box under the pan to balance the scale.

I drill a small hole in the beam and fit a printed circuit board connector to hold the pointer, the connector has a little spigot that would normally pass through the circuit board.
Here's a picture that might help:

 

[gamestalker]

No thanks, I wouldn't want to go drilling and altering a scale that is known to be spot on accurate. Been using mine as is for better than 30 years.

GS

 

[lbs]

i think i would try a sewing needle and some crazy glue.

 

[Lost Sheep]

We can do it with mirrors

If one mounted a mirror near the fulcrum point (so that it would not cause the scale to change zero outside its normal adjustment range) such that a beam of light reflected from the mirror shone across the room, and that beam of light was narrow (laser would be perfect), the reflected light spot would swing VERY wide indeed, making it easy to see zero.

Would not have to be a laser, but just a very small source from across the room and reflected back towards the source. Essentially, the spot of light would be a weightless extension of the beam pointer.

Lots of work for what? An imaginary increase in precision? Easier to see the pointer swinging around zero?

Lost Sheep

 

[1066]

If one mounted a mirror near the fulcrum point (so that it would not cause the scale to change zero outside its normal adjustment range) such that a beam of light reflected from the mirror shone across the room, and that beam of light was narrow (laser would be perfect), the reflected light spot would swing VERY wide indeed, making it easy to see zero.

Would not have to be a laser, but just a very small source from across the room and reflected back towards the source. Essentially, the spot of light would be a weightless extension of the beam pointer.

Lots of work for what? An imaginary increase in precision? Easier to see the pointer swinging around zero?

Lost Sheep

Yes, I've tried that, reflecting a laser onto a wall eight feet away, a 10th grain translates into about 1/2" of movement, anyone who has used a sextant would see how it works. I've also tried it with just a bright light and used the shadow of the beam, no modification of the beam necessary but too much faffing about for very little gain.
With a simple cheap camera you can get about 100x magnification and with a sensitive scale, single kernels of powder are easily recognisable.

This is one of my scales showing weighing to single kernels of Varget, there are about 5 kernels of Varget to 10th grain.

https://www.youtube.com/watch?v=dnVOoGd1bDU

And here's an experimental beam I just made for the new RCBS M500 scale, this one's range is from 0-70 grains.