There's a lot to like about the RCBS Combo. The design is first class and its easy to use and to clean and calibrate. The quality of assembly and build is poor and thats being kind to RCBS.
I waited ages to get mine and have only been using it for the last week but I have some tips and what helped me over come the poor assembly and quality control.
The first one I got home and used would not trickle and had a punctured clear cover over the digital display. That was interesting because whoever assembled it, placed a thin film plastic strip over it to protect it after the damage was done.
The first unit only ran at 2 speeds and would halt with an incomplete load, miles from the target weight. Tried Manual trickle and the feed screw would not drive at all. The plastic platen,powder pan sits on this) fits into a hole in the scale. This hole was so far off center that the platen shaft rubbed against the scale body. The shaft transfers the weight to the load cell and any rubbing would give incorrect and inconsistent weight readings. I went back and exchanged it for another one. RCBS have a great replacement policy and for the Combo it would appear we need it.
Straight away even with the poor charge dispensing part of the unit I was impressed by the scales. These scales are rock steady and accurate when checked against my RCBS 10/10. This unit worked for the first 2 charges and target weight was achieved. Then the unit stopped operating in the final trickle mode. I could hear the electronics switching but the motor would not turn.
Take it back and try for number 3? I would have but there was none left in the store I bought it from. I am an electronics tech and considered pulling it apart except that it would void the warranty. It appeared to me the feed screw was mechanically binding and that the friction was too much for the final part-turn trickle operation. So I pulled, pushed, flexed and part turned the feed screw gently to see if I could fix a probable assembly misalignment. It worked and I could now achieve target weight or close to it, every time.
Next problems encountered were how slow the target weight was achieved and an occasional over target weight caused by inconsistent powder drop at the final trickle. I looked here to find out how to reprogram the combo to work faster. http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=775552 This fixed the fill rate with 15s fills for 42gr of H4350 being achieved.
The inconsistent powder drop at final trickle was fixed simply by using a tapered reamer to chamfer the course threads in the end of the feed screw a little. This flattened the threads out meaning less powder would build up in them and drop out as a clump of granules. The taper on the reamer meant that the threads nearer the end were flattened the most which is exactly what is required.
The final problem encountered was cleaning, how to get the powder out of the feed screw. I simply marked a black dot on the end of the feed screw, so that when it was at the top and easily seen, the cup of the screw in the powder cylinder was facing down. This meant when I was finished loading I just drove the feed screw using the Trickle button till the black dot was at the top. Tilt the unit back towards the cylinder and the powder in the feed screw empties back into it.
I now have a Combo unit that works fantastically well and drops accurate loads consistently, which is what I bought it to do! It should have worked like this out of the box.
RCBS have designed a brilliant unit but poor assembly and quality control have let them down badly. If you buy one of these units please check it for platen shaft misalignment and rubbing, as this will ruin the accuracy of the charge being weighed. I hope RCBS improve their quality control on this Chinese made product because the design and function is just so good. Assemble it in USA and increase the price a little if needed but I would think that a greatly reduced return rate would offset labour costs.
I waited ages to get mine and have only been using it for the last week but I have some tips and what helped me over come the poor assembly and quality control.
The first one I got home and used would not trickle and had a punctured clear cover over the digital display. That was interesting because whoever assembled it, placed a thin film plastic strip over it to protect it after the damage was done.
The first unit only ran at 2 speeds and would halt with an incomplete load, miles from the target weight. Tried Manual trickle and the feed screw would not drive at all. The plastic platen,powder pan sits on this) fits into a hole in the scale. This hole was so far off center that the platen shaft rubbed against the scale body. The shaft transfers the weight to the load cell and any rubbing would give incorrect and inconsistent weight readings. I went back and exchanged it for another one. RCBS have a great replacement policy and for the Combo it would appear we need it.
Straight away even with the poor charge dispensing part of the unit I was impressed by the scales. These scales are rock steady and accurate when checked against my RCBS 10/10. This unit worked for the first 2 charges and target weight was achieved. Then the unit stopped operating in the final trickle mode. I could hear the electronics switching but the motor would not turn.
Take it back and try for number 3? I would have but there was none left in the store I bought it from. I am an electronics tech and considered pulling it apart except that it would void the warranty. It appeared to me the feed screw was mechanically binding and that the friction was too much for the final part-turn trickle operation. So I pulled, pushed, flexed and part turned the feed screw gently to see if I could fix a probable assembly misalignment. It worked and I could now achieve target weight or close to it, every time.
Next problems encountered were how slow the target weight was achieved and an occasional over target weight caused by inconsistent powder drop at the final trickle. I looked here to find out how to reprogram the combo to work faster. http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=775552 This fixed the fill rate with 15s fills for 42gr of H4350 being achieved.
The inconsistent powder drop at final trickle was fixed simply by using a tapered reamer to chamfer the course threads in the end of the feed screw a little. This flattened the threads out meaning less powder would build up in them and drop out as a clump of granules. The taper on the reamer meant that the threads nearer the end were flattened the most which is exactly what is required.
The final problem encountered was cleaning, how to get the powder out of the feed screw. I simply marked a black dot on the end of the feed screw, so that when it was at the top and easily seen, the cup of the screw in the powder cylinder was facing down. This meant when I was finished loading I just drove the feed screw using the Trickle button till the black dot was at the top. Tilt the unit back towards the cylinder and the powder in the feed screw empties back into it.
I now have a Combo unit that works fantastically well and drops accurate loads consistently, which is what I bought it to do! It should have worked like this out of the box.
RCBS have designed a brilliant unit but poor assembly and quality control have let them down badly. If you buy one of these units please check it for platen shaft misalignment and rubbing, as this will ruin the accuracy of the charge being weighed. I hope RCBS improve their quality control on this Chinese made product because the design and function is just so good. Assemble it in USA and increase the price a little if needed but I would think that a greatly reduced return rate would offset labour costs.
