Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: how much can this roast at a time?
Document: Even when this roaster was working at its best, it would deliver uneven roasts without a lot of body. The time between first and second crack is just too long to deliver a full bodied roast. I believe this to be because as the beans expand, there is too much heat dispersal in the vertical travel between the heating element and the beans.
In other words you don't have to open anything to check on the coffee beans allowing the smoke to escape. The taste of the coffee is amazing and by far much better than the $30 a pound Kona I used to purchase as a treat. Now I can roast it at home myself for at least half the price. The instructions are very clear cut and amazingly accurate. You simply set the time range they tell you for the roast you like and in 20 to 30 min.
I have had this roaster for over two months. It works great. I used to use an air popcorn popper and I like this so much more. There is no smoke and the smell of freshly roasted coffee is wonderful. I use it 3 to 7 times a week; usually only one time per day. I read the directions and clean it after each use, I don't overfill it, and I let it cool down for hours afterward.
I have been using home coffee roaster for several years. The reason I ordered this one was because de IRoast 2 has been out the market for some time and my was damage after three years of constant use, was really good. This Nesco CR-1010-PRR was not good: very bulky, difficult to clean, too much time to do a very little amound of coffee, not worthy! !I am doing the roasting at present with a popcorn roaster of Cuisinart and it is much better.
But I guess you could say that with any roaster. Depending on the quantity of beans you buy you may actually spend less on coffee when you make it. For me it's not much of a savings since I buy a few pounds at a time and pay postage. But I'll take freshness and break even over store coffee any day.I like Small footprint. I use it in my garage and it sits minimally on my workbench. The machine handles about 1/4lb of green beans.
Between my son and I, we have owned 3 of these machines. They work great for about a year, doing one roast a week. Then they fall apart. Too much heat and poor construction materials are apparently the problem. It's too bad because when it works, it works great!
After the experience we'd gained with the Nesco, I upgraded to the Behmor 1600, which I've now had for about three years. If people are willing to pay a bit more, I'd definitely recommend the Behmor. It's a drum roaster that is seriously built to last (I've run hundreds of batches through it already) and, while still somewhat limited, provides much more control of the roast profile.
My wife bought me one of these for my birthday last year. Before that, I was using hot-air poppers to roast coffee. This one worked well for about 10 months, but then, without warning, the agitator stopped working one day in the middle of a roast, and the beans caught fire. This design is much more dangerous than hot-air type roasters, which use the hot air itself to agitate the beans.
After my Hearthware coffee roaster died from about 8+ years of use, I bought this Zach & Dani's roaster off ebay for about $110. Now it's the Nesco roaster. It takes longer to roast (at least 20 minutes), but it doesn't smoke as much.The glass/plastic container, which holds the beans, broke when it got accidently dropped. A google search showed a replacement part would have cost about $80. Screw it!
I had no intentions of consuming the first roast. So the first roast was darker than dark, didn't smell like much until the next day, which smelled kinda nice but not really. Two days later, it smelled like charcoal. What more did I expect?So my next barrage were at 1/2 cup @ 15 minutes and @ 16 or 17 minutes. These turned out to be light roasts and the beans still smelled a bit beany. That's ok; more experience.
Answer: For a darker roast, it likes about 125 gm. (4.4 oz).. for a medium roast at about 26-27  minutes, it can take 135-140 gm. or about 5 oz...i like a medium roast, where no oil spots show up.. and depending on the bean, i can roast about 5.3 oz.. (150g).. i think i once did a dark roast at about 5 oz.. but you have to crank up the time to like 28 minutes.. but the purists don't like this long roast time.. they will tell you that you are 'baking' the beans instead of roasting them...but i say to them : " throw some maple syrup and pork fat in the mix, and you'll get a damn good meal of baked beans !