I've been using a popcorn popper to roast but it was too small key 4oz a time. and I didn't want to invest in a 400$ home roaster. is I set out to build something similar. roasting outside times will vary based on ambient temperature not the best for winter but hey suck it up.
Behmor roasting basket 30-$40
Step 1: Find a Roasting Basket
for this I searched high and low to find a cylinder to use, then thought of making my own with my welder friend. then I stumbled upon he Behrmor basket that's used for their home roasters . was perfect size for a pound of more had a lid and slats to let the beans turn right.
Step 2: Rotisserie Assembly
I have a four burner gas grill. I used an off he shelf rotisserie kit. due to the construction of the basket he rotisserie has to go through the basket off center or you could remove the center supports I left them as it still spins normal.
next you have to attach the skewers this helps the basket spin properly. I used a rubber mallet to pop he skewers through the basket on the bottom. the other side has the latching lid so you only need to cinch the other skewed rightly so you can load the beans.
Step 3: Testing and More Testing
temperature is everything so based on the hotspots on your grill adjust the dials accordingly. I used low-medium on the ones right under and a little hotter on the outside burners. As you can see In this test run if you're too hot it will catch fire ! you want around 600 degrees so try not to open the lid too much. there is tons of info on roasting so I'll leave that to you.
happy roasting !