Purchased a MES 40 from SAMS, Set it up. Seasoned it, took 52 minutes to get it to 275 degrees. meat probe was reading 300? Put in 1/2 cup of chips and they caught on fire, I think they were too small of a cut, they were chips for a little chief smoker and very thin cut more like a shred. After the flames went out I tried Cowboy wood chips, they did not catch on fire. I extended the time and tried some more of the cowboy chips and they worked again with no fire. The chips did not give smoke for a long time, How long should 1/2 cup of chips give smoke? How often do I need to add another 1/2 cup of chips?