A while ago the friend of mine phoned me regarding his RCBS Chargemaster combo scale. Up to then I have not taken much notice of my own scale, but he informed me that his scale was charging extremely slow. I timed mine and found that mine was running a lot faster then his. This set me on a journey to find out why there was a difference. The outcome however was that his scale was defective, but it gave us insightfull information about the working of these scales.

After doing some research on the internet I was able to determine that these little green scales are fully re-programmable. I sent an e-mail to RCBS on which I received no reply, and eventually telephoned them. They were very helpful and gave me their instructions on how to change the programming on this scale.

This has made a tremendous difference in my reloading experience with this scale. The scale is fully adjustable and there are many settings and that you can change. To enter the program mode pres EDIT MEM and ENTER at the same time. After making an adjustment pres 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
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) ?


I have to advise you to 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 56 grains of S365 in less than 18 seconds (average of 15 charges), and with very few overthrows.

Another problem I experienced with the scale was that there were continued overthrows. The RCBS employee advised me to take a McDonnell'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 hope you have more joy a with your scale now.
If you have any other suggestions or recommendations on how to improve the functionality of this scale please reply on this topic

Post edited by: Jaco Brink, at: 2007/11/07 15:27

Jaco,
Weet jy dalk of 'n mens dieselfde kan doen met die Lyman 1200DPS skaal?
Hy is stadiger as die RCBS.

THOMAST wrote:
Jaco,
Weet jy dalk of 'n mens dieselfde kan doen met die Lyman 1200DPS skaal?
Hy is stadiger as die RCBS.

Ek het so ‘n paar jaar gelede my Lyman verkoop (toe ek die RCBS aangekoop het). Van wat ek kan onthou was die skaal redelik vinnig. Die stadig waarvan ons praat wat Martel ervaar het met sy RCBS was ongeveer 3 keer die tyd wat dit neem om ‘n lading met my skaal te gooi. Ek vergeet nou die presiese tyd, hy kan my dalk reghelp maar dit was in die omgewing van 45 sekondes vir ‘n 52 grein lading.

Hy (Martel) het toe ‘n nuwe Lyman gekoop. Die nuwe skaal is blykbaar blitsvinnig maar nadat hy dit twee keer omgeruil het, het hy sy geld teruggevra en wag nou weer vir ‘n RCBS. Ek wil nie kommentaar lewer oor wat sy probleme met die skaal was nie want ek ken nie die presiese detail nie.

As jou skaal regtig so stadig is moet daar ‘n fout wees en moet dit met Lyman opgeneem word. Van wat ek verstaan is hulle diens baie goed. Ek glo die skaal sal ook geprogrammeer kan word (dit moet geprogrammeer word om te werk so dit moet verander kan word).

Neem ook in aanmerking dat die Lyman stadiger is as ‘n RCBS en dat jy nie die tye wat jy kry moet vergelyk met wat ons met die RCBS kry nie. Ek het‘n vergelyking tussen die skale, hierby aan. Kyk of jy min of meer dieselfde tye as in die toetsverslag kry. As jy tyd drasties verskil moet daar foute gesoek word.

Post edited by: Jaco Brink, at: 2007/11/13 11:36

Thomast as die 1200 Lyman skaal testadig gooi, moet jy kyk of die dryfas nie vas is in die buste of daar is kruit tussen die dryfas en die plastiek kruihouer. As dit die geval is sny die hoeke weg van die plastiek kruithouer. Dit sal n groter gaaping maak tussen die dryfas en die plastiek kruithouer. My skaal n Lyman 1200 gooi S365 56gr @20sek.

Dankie Hermann,
Waar presies sny jy die plastiek weg?

Ek gebruik ook 'n Lyman 1200 en ja hy gooi poeier stadig. My plan wat ek bebruik om die gooiproses te bespoedig, is om 'n "powder dipper" van Lee of enige ander maathouer van so ±35 grein te gebruik om 'n redelike hoeveelheid poeier eers in die pannetjie te gooi. Die res word dan deur die skaal gelewer. Ek gooi 46.2 grein S365 in onder 8 sekondes op die manier.

Vir die 375H&H gooi ek 2 van die ±35 grein mates in die pannetjie en die res van die 74 grein word deur die skaal gelewer in ook ongeveer 6 - 7 sekondes.

Ek het gevind dat die akkuraatheid van die ladings op die manier nog steeds baie goed is, baie dikwels presies en soms so ±0.1 grein wat 2 of 3 korretjies 365 is en wat maklik bygevoeg kan word as 'n mens wil hare kloof oor 0.1 grein op 74 grein poeier.

Ek gebruik n Lee powdemeasure om spoed te bevorder. Dit het n stukkie rubber wat die kruit vee dus, die growe kruit soos S335, S355, S365 en tot S385 word nie gesny nie. Die Lee is seepglat. Ander powdermeasure sny die kruit.

Jaco,

I found your post very helpful. Thank you! I was able to re-program the "HSP_" parameters on my unit and greatly reduce the time it takes to dispense a charge, without reducing the accuracy.

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!

Don 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.

Robert

Paola, KS, USA

Post edited by: Burdge, at: 2008/03/18 21:57

Robert

Wonderful stuff. Thank you. Now I will have to spend some time behind the scale to test some of these new settings.

Regards

Jaco

I just noticed this discussion, what settings do you use now?

I'd like to try them out to see what the effects are.

I am trying to slow down the trickle speed (i.e. not the fast, slow, medium speeds but the last portion where it trickles to get to the final weight).