Simon’s guide to building a Bio-Diesel Mixer.

Parts list: 45 gallon drum 4x 4ft 11/2x11/2 angle 2x 2ft 1/12x11/2 angle approx. Shaft approx. 1” 4ft long (maybe from lawn mower or a go-kart??) 2x Bearings to suit shaft with grub screws. (I used 1 pillow block and 1 flange type. Would have been 2 pillow blocks but I cracked the housing getting it off the shaft it was on.) Pulleys to give 2:1 reduction Motor running at 1500rpm Copper pipe Various plumbing fittings Drain tap(s) For the blade I used a fan blade from an Austin A35.

The first test with water proved this to be to big – the water flew all over the place. I cut it down to about 5”. It’s welded to an old gear that fits the shaft. Start with a 45 gallon drum. Cut half the top out using a hammer and chisel. Cut the 2 2ft pieces so as they fit inside the drum. Make them the sam length and the bearings will line up. Markout and drill the angle to take the bearings. Weld 1 piece of angle under the top and onto the sided. Weld the other about 8” from the bottom.

Here is the mixer blade before it was cut down. A piece of steel approx. 5x1” could be welded into a slot cut in the end of the shaft.

Heating element made from cooper pipe. This is heated from a tank of hot water in the workshop. It could be connected to the central heating. I’ve no idea if this will be adequate but as I normally make biodiesel at room temperature it should work.

Motor and pulley fitted.

Pulley combination gives approx. 800rpm

The motor is fixed to a plate which hinges off one of the rear legs.

The cut down mixing blade. Approx 5"

Circulation pump scavenged from a central heating system.