Home made LNL powder check alarm

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Jan 13, 2008
Central, Mn.
When I designed this project it had to meet four criteria.

It had to cost lees rthe $20:
It had to be simple to build:
It had to be accurate:
It had to be easy to adjust:

My main concern was not an under charge, I can watch the plunger on the powder check for that, and now when I see powder it the case I know it is not an over charge or a double charge. It is very difficult to detect a OC or DC in a 45 ACP case when using 231, tightgroup or Bullseye.
I can adjust the check down to detect 2/10 gr. overcharge.

All elec. components are from Radio Shack.
Other components are from the hardware store.


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I guess if I have to ask what it is and what it does I wont understand the answer anyway :) but it looks neat as heck!
I figured it out, all on my own.

The case is placed on the spring, butt down. The spring serves a dual purpose, holding the case in position and acts as a grounding jumper. Power is applied through a contact in the point of the white rod.

When the electrical charge is applied, the force of the blast is measured in the sensor with two wires connected. If the proper charge is in the case, the case continues to the next position. :D


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MCM, thanks for the compliment, much appreciated.
And Buck & Jesse, someone has to be the trailblazer,
Jesse, that was funny!:D
Am doing some mods to the alarm, will have updates soon.

Meanwhile I will be doing extensive explosion testing on the design.:)
Later, Boom Boom a.k.a. Floydster

I take NO responseability for anyone wanting to build this unit.
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I was trying to see if you used the LNL powder cop?
Can you check low and over charges?
How many grains +/- ?

I worked up plan using a led beam break circuit mated to a powder cop die.
Added the RCBS bullet feeder and filled all five LNL stages instead ;)

Thanks for sharing
WV, I am using the powder check die from RCBS.
It will detect an over chsrge of 2/10 gr., I watch the plunger rod for an under charge.

MM, ya I think us Minnesotans are a cut above.:D
charge weight

how can a hornady ap over charge a case? if the case advances with every pull of the handle. only so much powder will fit in the powder drop

Powder has been known to bridge and hangup in the drop tube, resulting in an undercharge followed by an overcharge.

Floydster, What's the yellowish tube taped to the press used for?
Hey Floyd,

I have no clue how your device works, but it sure looks impressive. I know you have the EZ-Ject on your press, but it does not look like you use a case feeder. Looking at your pictures, I can see your primer feeder is somewhat different than mine also, and your powder dispenser has a different volume adjustment than mine. My powder dispenser has but one big rotor, but it came with two different sized rotor inserts for large and small volumes of powder. The inserts also have micrometer like scales on the adjustment parts. Your powder adjustment insert looks different to me.

It looks like your powder is droppeed in Station 3, your moniter is in Station 4, and you seat and crimp in Station 5. Is that correct? I am still in the dark ages where I only use the first four stations since I use no powder cop, and I seat and crimp in Station 4.

I have found when the shellplate rotates a charged straight walled case over to Station 4, I can easily see the powder level. However, when reloading bottleneck cases, I am unable to see the powder level as I can with straightwall cases. Because of this, I use only ball and flake powders in my loads. Oveer the years, I have found ball and flake powders to make very consistent drops in my powder dispenser.

Congratulations and

Best wishes,
Dave Wile
I de-prime, resize sta#1, bell case ( Lee belling die sta#2, powder drop sta#3,
powder check ( alarm) sta #4, seat bullet sta #5.

I made mods to the check alarm, omitted the 5/16" nuts and made threaded thru knobs for elevation adjustments, also put a cap on the spring so it doesn't bit into the switch button.

After running 2,000 rounds it runs great, now I don't have to worry about powders like Red Dot hanging up the the measure and giving an erratic charge.


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ofb, hey if I ever get to Kansas , u old buck, I'm going to look U up!!!

Hope all is going well with u.

Keep your powder dry!!!

Car Knocker,
The yellowish tube is a LED book lite, works great for lighting up the inside of the case. They last a loooonnnngggg time and work great.:)
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