RCBS Chargemaster Combo Parameters & Modifications.

[littlebang556]

Found on the net...

You can make a tremendous difference in your reloading experience with the RCBS Chargemaster scale.
The scale is fully adjustable and there are many settings that you can change.
To enter the program mode pres EDIT MEM and ENTER at the same time.
After making an adjustment press ENTER to go to the next option.
After the last setting the scale will reset and countdown. If you passed a setting you have to start from the beginning, there is no back button.

This is the list of settings that you can make to your scale, for some of the functions I do not have detailed instructions as to what they do, and would recommend that you do not change them:
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.
HSB_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) ?


Only make changes to your scale if you are confident to do so, and remember that there is NOT a “Return To Default” setting in the scale. If all else fails return your scale to the default settings listed above in brackets.

I am now able to throw 25.4 grains of AR2208 in less than 11 seconds (average of 15 charges), and with no overthrows. This did take quite some time to adjust and make sure you safely store these instructions for future reference.

Another problem I experienced with the scale was that there were continued overthrows. The RCBS employee advised me to take a McDonalds's straw (because it is thicker than a normal straw), cut off about a half inch piece and put it into the tube where the powder exits. This caused the last part of an extruded powder to clutter less, and reduced the amount of overthrows dramatically
I have spoken with Don Legg at RCBS (who is the main technical contact person at RCBS for the Chargemaster product) and he was not aware of the function of the "HSP" parameters. This product is actually made by Excell Precision in China for RCBS, and Don has not been able to get a full definition of the programmable parameters from Excell.

He informed me, though, that the "W_" parameters control the initial speed of the trickler. They are properly interpreted as having an implied decimal point. That is, the "200" means 20.0 grains and the "100" means 10.0 grains. Above 20.0 grains the charge will start at the highest speed, between 10.0 and 20.0 grains the charge will start at the medium speed.

I tried changing the "MSP_" and "SSP_" parameters, but did not obtain results that I could interpret. I'm not sure why the unit would ever want to downshift if it was 196.00 grains below the target weight but I would love to be loading for a 50 Cal to find out.

Legg said that the "S_" parameters control the dwell time for measurements at the different speeds and that a setting of "64" corresponds to 2 seconds (each unit being 1/32 second). When I increased these parameters I did notice a longer lag time in detecting the scale reading and adjusting the trickler speed. I assume that this will allow the scale measurement a longer time to settle when running at the slower speeds.

A large setting for "S_F" causes serious over-charging, as the unit doesn't seem to be able to properly detect the downshift point. I assume the time delay also involves some type of time averaging, so the unit has to run past the desired shift point quite a ways before the average reaches the required value.

I also noticed that the "HSP_", "MSP_" and "SSP_" parameters are scaled versions of each other and appear as parallel linear lines if plotted on a log-linear scale. I'm not sure what this means, but I doubt that it is a coincidence.

25.4gn for .223
HSP_A1 = 5.50
HSP_B1 = 2.25
HSP_C1 = 0.40
I suggest a similar setting may save you some time also.
Further to these instructions make sure you check the output voltage of your power supply as mine (& many others) have been found to be delivering 170% of the rated power requirement of the Chargemaster. A simple talk to your supplier should sort things out whilst under warranty if required otherwise a trip to Dick Smiths’.
Also be sure to keep your unit clean by covering when not in use. Try not to use it in a dusty environment...Your reloading station should always be spotlessly clean anyway and periodically wipe down Combo unit with a little anti-static spray (eg: electrolube) on a cotton cloth.
I hope you have more joy a with your scale now.
If you have any other suggestions or work out some of the other codes please let me know.

Newest mod is to take a tapered reamer to the output dispenser tube to dull the effect the threads have in clumping the powder(much the same result as the straw...but is sure looks more professional).

There is also a guy on 6mmbr.com advertising neat covers at a good price. For those in Australia just contact me and I can forward details of someone that might be able to help...thus reducing postage costs.

Note: In stating the above I do in no way take any responsibility for any problems you may encounter when altering any of the factory set parameters. Not sure if waranty would be void either so do so at own risk...I though think the risks is small and maybe even negligable.

Regards
Rob Alman

[littlebang556]

So has anyone had a fiddle?

Regards

Rob Alman