I'm looking for a good way to get uniform dinner rolls cut from a batch of dough (6 lbs dough and 4 oz per roll). I use an old-fashioned scale and I have found that unless I work very slowly, it does not measure 4 oz accurately. The pieces are visibly different in size even though they appear to balance the scale. (The scale works well with larger weights.) When I eye-ball it the pieces are better but still not great. I'm wondering if there are any tricks to get good cuts? Note that the dough is 70% hydration so it's somewhat sticky.
If you want to try to manage with the existing scale, it sounds like all you can do is try to measure larger quantities. For example, you could measure 1-pound or 2-pound pieces, then eyeball cutting them in half repeatedly until you get the 4oz pieces you want. When you eyeball things, it's often a good idea to try to get it into a uniform shape before you cut; we're a lot better at drawing a line down the middle of something symmetric than we are at cutting an irregular blob in half.
But a new scale would probably be pretty cheap and useful for other things, so it's not a bad idea if you aren't happy with the accuracy of what you have.
Well there is a (rather expensive, but if you are a bakery operation, probably worth it as a MAJOR timesaver) tool made for exactly this job - a dough divider. Used would presumably be more affordable if you can find one, and they seem to last well.
Here's a video (yes, unfortunately also for a particular maker's product - a different one, though) which shows a basic manual divider in use. Turn the sound down, it's very loud and is just pointless music. Basically the dough is pressed flat and then cut into equal pieces. Some even more expensive models do additional processing to round the dough mechanically as well.
Simply cut the dough into two pound pieces, then roll it out into a tube shape. Cut until off 4oz of dough by weight, then you know how much to cut off for the rest of the tube... Then roll your buns. And by the way, 4oz is really way too big for a dinner roll. Usually a dinner roll is 1.75 to 2oz. Just sayin'.
There are different methods you could use depending on how accurate you want to be. If you don't mind a little variation then you could simply split the dough once by weight and from then on by eye. 6 lbs is 96 oz which would give you 24 4oz bits of dough. To divide into equal parts you could first cut the dough into 4 equal pieces by weight, then split each of those pieces in half by eye, then each of those halves into 3 pieces. Or you could cut the dough into 6 equal pieces by weight, then each of those into 2 by eye, then each of those into 2 by eye as well. Because you are dividing by weight first you are putting in a reasonable level of accuracy allowing some variation.
If you really want pinpoint accuracy then you need to buy a new scale because your old one isn't accurate enough and it probably takes a long time to read it. Digital ones are inexpensive and there's many to choose from, switching to one of these means that you get an accurate reading very fast. Next you need to switch to using grams instead of ounces to measure your rolls, grams are much smaller and it's easier to be exact with them.
Once you have an accurate scale then you would want an efficient method to get equal size dough balls. You could just cut each one individually, but that would take ages. First you need to know how big you want your dough balls in grams, 4oz is 113.398 grams which is not very friendly, but 110 is very close to that. 24 balls at 110g is 2640g, or 2.64kg, so weigh the entire batch of dough and then remove some of it to make exactly 2.64kg. Then cut your dough into 6 sections at 440g each, then cut each of those into 4 equal pieces by eye. Finally weigh each ball on your scale and add/remove dough so it is exactly 110g - the dough you removed at the beginning is handy for this.
To keep deal with the stickiness you could put a small piece of wax paper/baking parchment on the scale, or a teflon sheet if you have one. You could also put an oiled bowl on top and tare the scale, meaning that it will read zero with the bowl on it.