The best way to avoid banging your portafilter in the dustbin or sink is to make a knock box at home. It is much cheaper and you won’t have to worry about disposing of the puck. A utensil container or a big PVC pipe would suffice. You have to make sure that the container has a wall thickness of 0.5’’ to 0.75’’ to make a good knock box.
What You’ll Need
- A container or PVC pipe
- Copper pipe with the length of 0.5 inch
- Two copper pipe caps of 0.5’’
- Rubber grommets of 0.5 inch each
- Reinforced clear tubing
- An index card for the purpose of transferring cut lines
You can buy all the supplies from any local hardware store and also you can search your store room for few.
- A drill
- 1’’ bit, you can use a spade or paddle bit. It depends on the outside diameter of the inner ring of grommets
- A clamp. You can use a pipe clamp
- You’ll need a hacksaw, or you can also use a Dremel
- Coping saw
- You will be needing a crosscut saw, or you can use a chop saw if you have it
- Glasses for covering your eyes
- A mouth guard
- Fine sand paper
- Rounded file
Now that you have all that is needed, it is time to start working on the knock box:
Knock Box DIY | How To Make
- TAKE PRECISE MEASUREMENT AND CUT
You can cut the container according to your requirements. If you want to just use it to store spent espresso grounds then you can cut the container according to whatever size suits you. If you want it to fit into your espresso machine, then you have to take the size and length into consideration. You can make a cut after measuring size and length (1 3/8 inch down), and just make sure that it can easily fit into it. It is recommended to cut the tunnel in a manner that it fits into the machine so that you won’t have to worry about counter space or catching drips.
- DRILL HOLES ON BOTH SIDES OF THE CONTAINER
It is better if you practice drilling holes in a scrap or something. Take full measurements on both sides of the container and drill holes. You must be wearing mouth guard and glasses because during drilling some parts can fly off the container. You should drill slowly to avoid any chipping out of the back.
- CUT THE “MOUTH” OF THE CONTAINER
In order to cut the “mouth”, you’ll have to draw an arc. The arc needs to be 4.25 inches across, and 1.75 inches down. Cut the arc by coping or using a jigsaw. The look after coping will be rough, but sandpaper and files are best at giving rough things a smooth look.
- USE FILE AND SANDPAPER
To expand the drilled holes a bit, you have to use a rounder file. You need to make it certain that the size remains the same on both sides. After using the rounded file, you have to use sandpaper to give a smooth touch to the mouth.
- START INSERTING GROMMETS
Put the rubber grommets in both drilled holes. They’ll easily fit if you took right measurements in the start.
- SLIDE THE PIPE THROUGH THE HOLES
Take the copper pipe and slide it through the holes in the container. You have to make sure that the pipe fits perfectly in the container. Cut the pipe that is coming out of both ends and put caps on them.
- GIVE FINAL TOUCHES
You need to tighten the caps around the copper pipes and use sandpaper to give the last touches. You have a perfectly made knock box prepared.