Cement Mixer Plans Page 5
Step 5: The test. Lift up the hopper and let go. It should stay up. if not add more water. Take the scrap piece of plywood out of the pail and push the hopper down. It should stay down. If it lifts a little the first time that’s OK. Once you start using it the water and mud will add weight to the hopper. (Fig 34, 35)
Put 2″ of water in the pail. Squeeze the trigger on the drill and lock it on. Adjust the speed screw in the trigger until the blade rotates around 6 rotations per second. You can adjust this to your mix later. Let it run for a while. Make sure everything is fine. Smile you did a good job.
Step 6: The counterbalance. Making a permanent cement counterbalance will insure trouble free operation in comparison. Begin by removing the water jugs from the back of you mixer. Attach an empty pail to the cable. Start adding sand into the pail, one shovel at a time. Be especially sure to count each shovel to insure proper ratio later. When the hopper just begins to rise, stop. Remove the pail of sand and add cement with a ratio of about 4:1. If it took 10 shovels of sand to lift the hopper then add 2.25 shovels of cement.
Reattach the water jugs to the cable. Now in a new empty pail place about 2″ of sand. Place a 4×4 post or a 4″ pipe that is 16″ or longer into the center of the bucket and carefully fill with moist sand. (Fig37) Pack the sand around the post. Now gently move the post slightly forward and back and side to side once. Gently pull the post out without collapsing the hole. This is now your mold. (Fig38)
Put an empty pail under the mixer. Pull the hopper down. Add an inch of water and turn on. Add the dry mixed sand and cement from the earlier balancing act. Adjust the water in the mix so that the cement is on the wet side. The sand from our mold is going to soak up the excess water.
Stop the mixer and remove the cement. Very slowly pour the cement into the sand impression left by the post or pipe. If it doesn’t fill to the top, that’s OK. Do not top it off. Just use the cement from balancing and no more. If you pour to fast it will collapse. I used to make planters this way, with sand impression molds. Wait about 20min. for the cement to start setting. Insert a looped wire into the cement, (like a bent coat hanger).
Wait at least 24 hours then de mold from the sand. (Fig39) Spray off the excess sand from the counterweight. Attach to the cable in back and you are good to go. (Fig40)
Using the mixer: The ratio of cement to aggregate is your choice. Type of material, humidity, temperature and application all play a role. This is not a cement tutorial. The following example is just that, an example.
Place three shovels of sand in a pail. Add one shovel of cement. Plunge the shovel down the side of the pail and pull the sand up on top of the dry cement. Rotate the pail one-quarter turn and repeat 3 more times, total four. Add three more sand and one more cement. Dry mix again. If you have several pails, then make up several of these and set aside.
Place an empty 5-Gallon plastic pail under the mixer and lower the hopper. Spray water into the pail cleaning the hopper and the blade at the same time. After you have an inch or so of water, turn the mixer on. Add the first dry mixed pail. Adjust water. If it is to dry then the pail will spin. (Big mess). Too much water and its soup.
Mix for 2-3 minutes. Turn off mixer. Lift hopper and remove cement. Right away put another pail on the mixer and lower the hopper. Add water from the top again. Turn on the mixer and add dry mix. Now while the second batch is mixing empty your first pail.
Addition: First of all you must use a three wire electric source. This is a wet business and if you don’t have a ground wire your will get a shock one day. Believe me I know this for a fact. The smart thing to do is to hook up a switch so you don’t handle the electric drill with wet hands. One solution is to get a common power strip like those used for computers. Mount it on the back or side of the center post.
I used a variable speed controller used for routers. They are pretty cheep. You can see one at Harbor Freight.
A Drop Light attached to the top of the mixer looking down the hopper is real handy.
That’s all folks: By now you should realize what a great project this is. One thing I would like to make clear. All though no alteration of the drill takes place and whether or not this bends the manufacturers intentions, It should be understood that this paper is for experimental purposes only. I have no control over what materials are used. Also drills very greatly. This is an idea. An idea that worked well for me and I would like to share with you.