Dillon: How does powder failsafe bar work?

[majorsmackdown]

I bolted that failsafe mechanism on the bottom of the powder measure together, and wrapped a spring around the powder measure funnel, and the thingy on the powder bar. Works awesome. I never show a .1 grain difference. If I do see a difference at all, I clean the expander funnel, and swab it with a bit of bounce then it's perfect again for a few more thousand loads. I'm sure it's me, but I found the clunky failsafe system to be super annoying. The spring works awesome. I backup my method with a hornady powder cop die.

 

[Tilos]

I bolted that failsafe mechanism on the bottom of the powder measure together, and wrapped a spring around the powder measure funnel, and the thingy on the powder bar. Works awesome. I never show a .1 grain difference. If I do see a difference at all, I clean the expander funnel, and swab it with a bit of bounce then it's perfect again for a few more thousand loads. I'm sure it's me, but I found the clunky failsafe system to be super annoying. The spring works awesome. I backup my method with a hornady powder cop die.

Yep, I always thought all the "safety" mechanisms on powder drops were designed to appease corporate lawyers, and most always prove to be problematic.
I'm with you on the use of a spring rather than a rod (or chain), because with a spring the drop tube/expander follows the case back down and the measure is completely closed with the expander still in contact with case.

With a rod/chain closure, the measure is open until the case/shell plate gets to the bottom of the stroke, allowing any residual powder to fall out onto the shell plate....a mess that could hamper the press operation.
jmo

 

[Crohnos01]

I was just talking to a guy the other night about his Dillon 650 and he had nothing good to say about the failsafe. He was seeing a lot of powder on the machine during reloads and finally tracked the issue down to the plunger that drops into the case knocking powder out and onto the shell plate.... he tore his off and said that solved the problem... that would kind of piss me off to spend 50 or 60 bucks on a piece of equipment that caused more problems than it was worth

 

[majorsmackdown]

I like to say its an amazing mess 4.4 grains of powder will make.

 

[Member 5605]

Look at diagrams/cutaways of a Lee powder through expander die.

Case goes up, pushes a funnel, that goes up and activates lever that moves bar/disc.



Expander plug and rider plug are free floating. Case pushes up on these.

 

[Tilos]

Look at diagrams/cutaways of a Lee powder through expander die.
Case goes up, pushes a funnel, that goes up and activates lever that moves bar/disc.
View attachment 338699
Expander plug and rider plug are free floating. Case pushes up on these.

Well for me, using the component names from you nice pic:
Case goes up, pushes Expander Plug, that pushes up the Extension Tube, that Extension tube pushes the powder drop cycling it/flaring the case, upward travel of the Expander Plug stops when it hits the bottom of the outer Riser tube, (no Funnel Adaptor used, Riser Kit outer tube screws directly into the Expander Die)
Whew my head hurts,

 

[CHLChris]

Before getting into the guts, the way Dillon was describing the motion was that the press detects whether or not there is a case present, and only then is the powder bar activated. I wondered how the shell plate detected a case and then how it communicated that upward. Clearly there is no detection, per se. Instead, the case itself behaves as a PART of the movement. Very clever!

 

[MrElectric03]

Not sure if it has been answered yet but the purpose of the failsafe is to avoid a double charge. Watch the powder bar inside of an empty powder measure. The lock will engage before the opening in the powder bar passes in and gets another charge. Only when the shellplate is all the way down where it would index does the lock disengauge and charge for the next case.

Without the failsafe it charges pretty soon after the shellplate starts moving down.

 

[v0lcom13sn0w]

No deal. I watched that vid and all he does is show how it installs. That part was easy for me. In fact, one only needs to take off the cotter pin and feed that end through the bracket hole at the bottom all the way up...no need to remove the entire threaded assembly with delrin plug and spring like he did.

But he never got to my actually query. Most people don't care, they just want to know that it IS working. I love knowing HOW it works.

One thing I've figured out is that I was thinking the failsafe bar pushed up on the powder bar somehow. After thinking about it a bit more, I believe the brass shell, itself, is pushing up on the powder funnel, which is, in turn, doing something to the powder bar, which is PULLING up on the failsafe bar. I'm getting closer...

it is commendable that you want to know how stuff works! i used to love working on my own cars and everyone elses so much that i started a career as an automotive technician.when i first started my job i wanted to know WHY this part on this car failed. now, as a flat rate tech, i dont give a sh!t and just fix it to get paid. moral of the story: dont let your profession ruin your hobbies... aka dont become an ammunition manufacturer. keep doing it for personal use and dont burn yourself out!!