RCBS Chargemaster

[ranger3]

My new chargemaster seems to be throwing a lot of light charges that read as the charge weight, most are off by .1 or at most by .2 when I check them on my OHAUS 1010 scale. I have inserted A MCD straw. That has helped. The scale slightly drifts on throws sometimes, but weighs my weights accurately. I have not reprogrammed it yet. This is my second chargemaster, the scale went out on the first one, so I'm nervous and skeptical anyway. Any thoughts on a fix or is that as good as it gets?

 

[basshusker]

For power cable.
https://www.solar-electric.com/feemisucofor1.html

Stay away from fluorescent lighting

 

[Twoboxer]

Before getting one of Adam's Autotricklers, I used a Chargemaster to throw probably a thousand charges which were weighed and trickled up on my FX120i. One of the things I noticed was a significant number of under-throws, as well as several throws the Chargemaster called "Overthrow" that actually proved to be underthrows when weighed on the FX.

Seemed to me the issue was this: the Chargemaster would make it's final throw, the powder would fall to the pan with some velocity causing it to momentarily appear heavier than it actually was, the scale would say the charge was now at or above target, and the process would stop.

I reprogrammed the dispenser to wait as long as possible for the scale to stabilize before timing out (parameter S_S, factory set to 128, adjusted to 255). It helped some . . . the number of low throws clearly diminished but did not disappear. The number of high throws increased slightly which might well be expected after reprogramming this way.

Pure speculation: What remains are probably due to the strain gauge and its programming to appear more stable, ie, not flutter.

 

[ranger3]

I had the same thought about slowing down the final. I left the machine on all afternoon and threw some more charges, they were spot on or much closer. I'm also going to switch my lighting to led from the current florescent. Maybe those things will help. Thanks to all of you for your help.

 

[Twoboxer]

I had the same thought about slowing down the final.. . .

To clarify, if you mean slowing down the final trickle it's probably parameter W_S (Factory set 036, lower numbers would be slower).

The parameter I changed was S_S, the "scale sensitivity timeout time in ms, slow speed".

 

[ranger3]

I'm learning something here, I was unaware that you could adjust scale sensitivity. I thought the only adjustment was basically the time of each phase of dispensing powder. Where do you adjust the sensitivity.

 

[Twoboxer]

I'm learning something here, I was unaware that you could adjust scale sensitivity. I thought the only adjustment was basically the time of each phase of dispensing powder. Where do you adjust the sensitivity.

The "S_S" parameter does not adjust scale sensitivity. It adjusts the TIMEOUT time, ie, the length of time the dispenser will wait for the scale to stop fluttering and give a stable reading. Factory setting is 128ms, max you can change it to is 255ms.

To the best of my knowledge, below is a list of what parameters are available and their meaning/use. These have been published on the web in a variety of places; frankly, some do not make sense nor seem to really be used as described. The number in parenthesis is the factory setting:

HSB_A1 (15.68) Grains under target weight to go from full to high speed for low weight
HSB_B1 (3.42) Grains under target weight to go from high to slow speed low weight
BSP_C1 (1.08) Grains under target weight to go from slow to final trickle speed low weight

MSP_A2 (39.20) Grains under target weight to go from full to high speed for medium weight
MSP_B2 (8.55) Grains under target weight to go from high to slow speed medium weight
MSP_C2 (2.25) Grains under target weight to go from slow to final trickle speed medium weight

SSP_A3 (196.00) Grains under target weight to go from full to high speed for heavy weight

SSP_B3 (42.75) Grains under target weight to go from high to slow speed heavy weight
SSP_C3 (11.32) Grains under target weight to go from slow to final trickle speed heavy weight

SEL (065) ???
F_A (050) Grains for a Heavy Charge
M_A (035) Grains for a Medium charge
S_A (006) Grains for a slow charge
W_F (200) Rotation for Full speed
W_M (100) Rotation for Medium speed
W_S (036) Rotation for slowest speed

S_F (012) Scale sensitivity timeout time in m/s fast speed
S_M (024) Scale sensitivity timeout time in m/s medium speed
S_S (128) Scale sensitivity timeout time in m/s slow speed.

FR1 (040) ?
FS1 (016) ?
FR2 (080) ?
SR1 (032) ?
SS1 (008) ?
SR2 (040) ?
DEC (000) ?
AT (000) ?

 

[ranger3]

Thanks everybody for their input. I have made some adjustments and run a new set of charges. Of the ten charges thrown only two were not an exact 31 grains. Of those two one was at 31.1 and another at 30.9. The adjustments I made were not on the chargemaster they were on the body. I wiped down body with static wipes and put in a new MCD straw. I also moved the machine slightly. I'm more than satisfied with that ratio of Throws and the results thereof. My OHAUS indicated that the throws were exactly 31 grains. I did also use auxiliary lighting. So off to price LED lights.
Thanks again everyone.