A small brooder is very simple to make. What you will need is an enclosed cat litter box. I found mine at a flea market for $5. Mine has ventilation slots in the top, which is perfect. You will also need a square piece of plexiglass large enough to cover the hole in the front (we had all these things here so didn't need to buy anything except the cat box and light), some small pieces of wood, two hinges, two metal eyelets some tape and a metal shop light.
Cut a hole in the top back of the litter box slightly smaller than the metal shop light so that when you set the shop light on top it won’t fall through. Take two small pieces of wood about 1 inch by 5 inches and put one on either side on the bottom part of the littler box below the opening. Screw them together through the litter box. Put another small piece of wood on the underside of the top part of the opening, screw this to the plastic. Now take your piece of plexiglass and cover three of the edges with tape. Drill small holes for the hinges on the bottom of the glass and then put the hinges on screwing them in to your bottom piece of wood. Drill a small hole in the outside top of the plexiglass and put an eyelet screw in there. Put another eyelet screw in the top of the litter box opening screwing it into the piece of wood you put underneath there. Now you may want to add some screws around the litter box to hold the two pieces together (or you could use small bolts.)
To keep the brooder closed just slide an elastic band over both eyelets.
I use a 60 watt bulb in the shop light to start with that keeps the brooder about 99 degrees. After a week or two I lift this light up with a few small blocks of wood on either side. After a few more weeks I may switch to a 40-watt bulb.
This brooder can brood up to 25 quail and maybe 12 chicks for the first 3 or 4 weeks anyway. I have even had ducks in mine but only 3 at a time since they are quite messy and they didn't stay in there more than a couple weeks.