Like etw said metal!
I have built many and sold many. i only have three of my own and honestly i have really had better results with food plots.
but i would suggest you buy a motor. i personally like game countrys cause i have had good luck with them. find you a 30 or 55 gallon drum and make sure you burn them out. i use charcoal lighter fluid and light them up . then wash them good .
my first was a hanger. i took a 6" 1/2 bolt and drilled a hole in the barrel on two sides of course and two bolts of course. i used some 1'square tubing to space the chain i used to hang with so i could take the top off while it was hanging. i just mounted my motor on the bottom and let her rip.

now i really like to weld legs to them with 1" square tubing . you could bolt them but getting a bend in them you would need a welder. i decide how long i want the legs and then make a cut 6"down from the top . i only cut three sides and not the whole thing . i make a gap big enough to bend the metal to the right angle for all three legs and weld the gap.

but if you don't weld or have a friend that does you maight see if a welding shop would do it for a reasonable cost. for me to build a feeder i would say it only costs me about 50 bucks.(metal costs are high now so i just have to guess)

And clogging?? i havent found a way to keep them from doing this . clean corn helps but even claimed clean corn sometimes has cobs in it. just check them as often as you can.
i would highly recommend a funnel . i make them out of sheet metal .