Prometheus Powder Thrower

[ds1]

I got the Prometheus from "Taffy" on here - excellent bloke.

 

 

In short the Prometheus is a 10-10 scale with a powder thrower and electric trickler combined. What it does is to throw an exact charge every 10 seconds. All you do it pull the handle and it delivers a perfect charge 99.9% of the time. The bloke who designed it must have had "mouse trap" as a kid. The principle is simple - when the beam rises it cuts an infra-red beam and stops the tricker. It is quick as the majority of powder is dumped by the thrower, it is also quick as the upward movement of the thrower handle releases the last charge from the bucket into a case or scale pan and the downward movement puts another charge into the bucket.

 

Accuracy comes from the way the trickler puts powder into the bucket - through a small window on the side of the bucket - as the bucket lowers more powder progressively misses the window - and falls into the second capture funnel - it is a bit messy. The rate is variable as you can set the window position and amount of powder dumped by the measure - about 8 seconds of tickling seems accurate and fast enough for me. As the beam is about 1/3 longer than a 10-10 scale you can get a litlle more accuray from watching the pointer on the Prometheus than the pointer on the 10-10 scale.

 

I have had a good play with it now - some nice little features such as the agate bearings sit on ball-bearings and the ends of the knives that ride in the bearings sit against polished steel inserts - no pointer change due to friction.

 

Dislikes and changes, I have not attached the pointer magnifying glass. Also there is a tilt bar on the bucket I have un-attached as it would only stop bridging of powder within the bucket but the hole is so big it has not happened. However the supplied drop funnel goes down to 17 cal, - AA2015 powder bridged, solved by using a 30 cal funnel. What had me pulling my hair out was a small hair spring that controls the rear of the pointer and stops the beam smacking into the infra-red unit when powder is dumped from the bucket - as it rest on the pointer on the side of the beam it causes slight lateral movement of the beam and destoys repeatability - using a stronger piece of wire bent at 90 degrees that provides a stop for the beam (not the pointer arm) before it contacts the infra-red unit gives repeatable beam movement and does away with the need for the hair-spring. I threw over 200 test charges, weighing them on the 10-10 scale, I`m satisfied it is now totally repeatable and more accurate than the 10-10 scale.

 

Between the 10-10 scale and Prometheus there is a couple of tenths of a grain difference when setting a charge weight of 42 grains. This is not important to me as I only want the Prometheus to throw charges for my 308 - 42 grains of AA2015, not sure which scale is off, or not zeroed correctly - I suspect thePrometheus.

 

For any volume reloading the Prometheus is the mutts-nuts, you can set it up and throw charges one night, go back to it a day or two later and the first charge will be spot on. Compared to my experience with an RCBS Chargemaster the Prometheus is 1000 times better - faster, much more repeatable, more accurate and you can varify the charge at the same time with the pointer. For only a few reloads I will still use the 10-10 scale. What I want the Prometheus for is batch re-loading 300-400 308`s at a time

 

Small stuff - I like the idea of the Frankford trickler - if it goes tits-up, easy and cheapish to replace - I think this part gets the most work. Also I'm not sure how but the RCBS powder thrower has been modified so it does not stick when throwing stick powders - not pulled it apart yet but I will get round to it as I want my other RCBS measures to work like it. Power supply is by 9v battery and 2x 1.5v AA batteries in the trickler.

 

 

David.

[Barrelsniffer]

Good wright up dave....never seen one of them before.

Did you manage to get that NV scope ?

 

Mick

[ds1]

Hi Mick,

 

My mate did not get the PVS 14 in the end as the bank rang up to confirm the cash was ready - his Mrs answered it - short story, wife stopped play.

 

David.

[foxing2night]

David that looks very interesting,,,

Good write up and pic,s

I some times think that the simple ideas are the best.

 

Could i ask you what kind of price they are???

 

All the best Darrel

[brown dog]

 

From the same school of design?

[ds1]

Hi Darrel,

 

I paid 750 quid for it, used but in VGC. They were about 1200 dollars when new (not made now), a newer model - with more electronics is abailable now for about 2k dollars, but it comes with a long waiting list. I wanted the mouse-trap version. Brand Cole is the designer / maker.

 

David