Macap M4 Doser Mod

I spent a few minutes searching the web for some instructions on disassembling the doser on a Macap grinder but came up empty. I decided to go for it on my own and documented the steps along the way. It isn't really very hard, and it's probably very similar to the Mazzer doser which has been documented a number of times.

My goals were to improve the sweeping action of the doser with the electrical tape mod and to quiet down some loud buzzing sounds coming from the plastic housing and the metal dosing sector.

Tools needed: small Phillips screwdriver, 5mm Allen key, 7mm socket or small wrench, pliers, hobby knife, and black electrical tape.

The first step is to remove the two 7mm machine screws that hold the plastic housing onto the grinder body. They come out without much resistance and the housing pops right off.






The doser with the plastic housing removed.








This nut is covered with a slotted plastic cap that you can pull right off with your hand. The pin near the top must be removed - I used a small nail and a pair of pliers to get this done. Once the pin is out, remove the nut.





After the nut is removed, the top of the dosing star will slip right off. There are three screws on the bottom of the star can be removed if you want to clean everything.






The flat metal piece is the dosing sector. This was the source of alot of vibration in my grinder. I decided that for my usage, this thing serves no purpose so it was left out during the reassembly.






To get the doser body off of the grinder, turn it on it's side and remove the three small screws on the bottom plate. Next, use a 5mm Allen key to remove the single bolt that holds the doser in place.

The doser is now removed

There is a plastic cover on the bottom of the doser held on by two small screws. Remove the cover and use a small nail to push out the set pin that holds everything together. Once the pin is out, you can slide the lower doser star out.





The lower dosing star showing the built up coffee gunk.








Close-up of the tape mod. I put the tape on the trailing edge of 3 of the vanes. I folded up the bottom edge of the tape so that there would not be any adhesive exposed inside the doser.






Since I grind per shot, the metal dosing sector serves no use to me. I decided to leave it out... less places for coffee to get stuck and much less noise.






There was alot of buzzing coming from the plastic to metal contact on the doser housing. I used a single layer of electrical tape to help create a snug fit. The tape cannot be seen once the cylinder is in place.





One other change I made was to use a piece of padded double-sided tape as a bumper for the dosing lever. This change makes a big difference in sound since I thwack the dosing lever aggressively while grinding.





Doser sweep - before & after
Here's a shot of pre-tape mod doser sweep. The Macap sweeps fairly clean right out of the box. There is always a bit of coffee packed into the edges though.






With the tape mod, the doser sweeps out absolutely spotless! This picture was taken after a couple of shots and just a few thwacks of the lever.