BCG800XL Grinder Jamming due to Worn Impeller - The

BCG800XL Grinder Jamming due to Worn Impeller
BCG800XL Grinder Jamming due to Worn
This guide will walk through replacing the impeller to fix the most common cause of jamming with
the Breville BCG800XL and BCG800 Smart Grinder.
Written By: Ben Gottemoller SteadyMouseLLC
© iFixit — CC BY-NC-SA
Page 1 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Many users of the BCG800XL SmartGrinder experience jamming or clogging and a horrible gearstripping, clacking sort of sound during use at some point. This is usually due to either a worn out
impeller or stripped drive gear. This guide will show you how to replace the impeller on the grinder.
Please review the Breville Troubleshooting page first to be sure your grinder does indeed need an
impeller replacement.
Breville, unfortunately, doesn't sell replacement parts, so this tutorial has been made possible only
recently by 3D printer technology. I've designed an improved impeller for the BCG800XL and made
it available here: Shapeways Impeller Source
Here's a quick two-minute overview of this replacement part.
If you have a BCG600SIL or BCG400SIL then go here instead.
Long shaft Phillips #2 Screwdriver (8 inches
or more) (1)
Socket Wrench (1)
BCG800XL Impeller (1)
Coffee Impeller
This is a 3D printed part.
150 Grit Sandpaper (1)
© iFixit — CC BY-NC-SA
Page 2 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 1 — Inspect your grinder impeller
 Unplug your grinder before completing this repair to avoid electric shock.
Remove the hopper and take the upper burrs out. Empty out any coffee grounds (An air gun or
vacuum helps) and then inspect the impeller blades.
If the impeller can fit through the hole (ie: be removed just by taking out the lower burr) then it
definitely needs replacement.
A good impeller should not be removable without dis-assembly and the tips of the impeller blades
should not be visible.
 If your impeller is made of stainless steel rather than plastic you likely have a newer model with
significant design changes (eg: BCG820). Stainless steel should not wear out and so your problem
is elsewhere.
© iFixit — CC BY-NC-SA
Page 3 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 2 — Obtaining a new impeller
I modeled and 3D printed this replacement part it several times at the local library. I've made the
final design available for printing at (See link below). Of course, you can
also model your own design if you wish to spend the time.
Shapeways BCG800XL Impeller Shop
Here's a video with some background on the Shapeways part.
 Impeller v1.0 in the 3rd picture looks a little rough because I printed it on a lower end 3D printer
my local library makes available. With the route you can expect the item to be
of nicer quality. Even the coarse plastic one worked though so don't be too concerned with the
aesthetic appeal.
© iFixit — CC BY-NC-SA
Page 4 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 3 — Tools you'll need
You'll need either a 10mm socket
with ratchet or a 10mm wrench.
A #2 Phillips screwdriver with 8
inches of shaft or longer, and
preferably with magnetic tip.
 You can rub a magnet against the
tip to temporarily magnetize it.
© iFixit — CC BY-NC-SA
The sandpaper and file are only
necessary if the 3D printed impeller
isn't a perfect fit.
Page 5 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 4 — Remove hopper, upper burrs, and lower burrs
Remove the hopper and upper burrs.
Use a 10mm socket to remove the nut for the lower burrs.
 The nut for the lower burrs is reverse threaded. Rotate
clockwise to loosen.
Turn the grind-adjustment knob to the finest setting.
Remember what order in which the washers were removed for proper reassembly.
© iFixit — CC BY-NC-SA
Page 6 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 5 — Remove the base
Unwrap the power cord and remove the 4 screws from the base.
Remove the four rubber pads
Slide the power cord through the hole in the base while lifting the base away from the grinder.
© iFixit — CC BY-NC-SA
Page 7 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 6 — Remove 4 screws holding the top on
Use the long Phillips #2 driver to remove the 4 screws holding the top in place.
Flip the grinder over and slowly lift away the top.
 The top is still attached to a wire so the lid will hang off to the side.
Step 7 — Remove the front display
Remove the two screws from the top of the display.
Lift the display up and out of the frame.
© iFixit — CC BY-NC-SA
Page 8 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 8 — Gear / Burr holder Assembly Removal
Be sure the grind knob is turned to the finest setting.
 It's critical that the alignment be preserved when removing the gear assembly. The small gear in
the picture is an encoder. Its purpose is to track the position of the grind adjustment level so it
can be displayed on the digital readout. If it gets out of alignment the display will end up reading
Use a permanent marker to make alignment marks on the three parts of the gear assembly. The
marks should line up during reassembly.
There are 4 plastic tabs radially holding the big white gear assembly in place. I used both hands,
placing my finger tips under each side of the big gear and pulled straight up to remove it.
If pulling straight up isn't working, try curling your fingers under just one side of the white gear, and
prying upwards until that side pops free a little. Then do the other side.
© iFixit — CC BY-NC-SA
Page 9 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 9 — Worn impeller removal
Lift out the old impeller making sure the steel washer underneath the impeller doesn't fall out.
Discard the fibrous felt washer below the metal washer. This is no longer needed as the new
impeller design hugs the bushing pedestal more closely and does a good enough job keeping
grounds away from the bushing anyway.
Optional Modding Tip: Replace the metal washer with a washer that's about 0.1 to 0.2 mm
thicker if you'd like your grinder to grind even finer than it did before.
© iFixit — CC BY-NC-SA
Page 10 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 10 — Clean the exit chute and new impeller
While it's accessible, use compressed air or toothpick to clean out the exit chute so it's free of any
compacted coffee.
Give your new replacement impeller a quick rinse and pat down with a towel to prevent static
charge during first grinding.
© iFixit — CC BY-NC-SA
Page 11 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 11 — Installing the 3D Printed Impeller Replacement
It is important for the 3D printed part to fit properly. Tolerances of the design error on the tight side.
Check that the burr drive pegs fit the holes of the conical burrs. If it’s too tight, apply a small
amount of sanding to the impeller and you’ll be in good shape.
Do not sand the flat part of the center hole. Only sand the curved part slightly if needed. The flat
part takes the most stress from the drive shaft.
The gap here should be small with the new part. If it's too tight, you can sand the edges slightly.
Here's a video of the fit-up with the Shapeways printed part.
© iFixit — CC BY-NC-SA
Page 12 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 12
© iFixit — CC BY-NC-SA
Before reassembly, check that the
conical lower burr and impeller fit
well onto the driveshaft with the
steel washer underneath. The lip on
the drive shaft should be within
about 0.5mm of the top surface of
the conical burr. When the nut is
tightened it will squish to about flush.
The lip on the drive shaft should be
within about 0.5mm of the top
surface of the conical burr. When
the nut is tightened it will squish to
about flush.
If the burr is too high above the lip
on the shaft (higher than in the pic),
try putting the nut+washer on,
tightening hard, and then taking it
back off.
If the lower burr is still sitting too
high on the shaft, take a quick
detour to Step 20 and then come
Page 13 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 13 — Reinstall the Gear / Burr holder assembly
With the following pieces aligned carefully set the gear assembly into place:
Avoid rotating these pieces to maintain alignment.
As you set the assembly into place, make sure the two stop-screws are on the left side of the
black plastic stop.
Align the large peg with the wide slot.
Align and the small peg with the small slot.
Press down on the gear assembly to snap it into place.
Once in place, rotate the coarseness knob through the full range to make sure it's all working.
 Watch the reinstallation video here for clarification.
© iFixit — CC BY-NC-SA
Page 14 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 14 — Optional Modification for Better Grind Adjustment Range
© iFixit — CC BY-NC-SA
Advanced Modding Tip: If you want
greater grind-control range, you can
back out the two screws in the big
gear in the photo. You will then be
able to adjust the grind much
beyond the normal range. Caveats:
Go too fine and the grounds become
like paste and it will certainly jam.
Also, you must not adjust too fine or
the burrs will hit!
Note: The encoder driven by the
little gear also has a hard stop built
into it. You will still run into this stop
if you keep turning the adjustment
DISCLAIMER: This step is
completely optional. It is up to you
and ultimately your responsibility if
you choose to do it. Understand the
risks of jamming and burrs hitting.
Also be aware of the possibility that
others may use your grinder and
need to be informed of the
modification. You do this
unnecessary and optional step at
your own risk.
Page 15 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 15 — Reinstall the Display and the Conical Lower Burr
Place the display back into the
frame and screw in the two screws
that hold it in place.
Put the conical burr in place making
sure it sets on the pegs of the
impeller properly.
Place the washers on while
maintaining their original order.
Tighten the reverse threaded
10mm nut.
 Tighten the nut as hard as you
can. The impeller, being plastic,
has a small amount of springiness
to it and must be squashed hard
so that the height of the lower
burr does not vary. If you find that
the burrs are too close after
you're all done, then this is the
reason. Tighten until the motor
begins to move, and then give it
an extra wack.
© iFixit — CC BY-NC-SA
Check the grind knob to be sure it
has full range of motion.
Page 16 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 16 — Put the top back on and screw it back in
Put the plastic top back on.
Flip the grinder over and use the long Phillips #2 screwdriver to reinstall the 4 screws that hold the
top in place.
 If the screwdriver is not already magnetized, it'll be worth rubbing a magnet on it to do so prior to
this step.
© iFixit — CC BY-NC-SA
Page 17 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 17 — Reinstall the bottom
© iFixit — CC BY-NC-SA
Put the four rubber feet back in
Screw back in the four base screws.
Re-wrap the cord.
Page 18 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 18 — Reinstall upper burrs and hopper
Put the upper burr back on and reinstall the hopper (without coffee beans yet).
Run the (empty) grinder briefly to make sure it all sounds OK. Try both coarse and fine grind
If all sounds well, add some coffee to the hopper. Dial in the grind and try it out! If something
seems off, see the troubleshooting steps below or refer to the troubleshooting page here.
Congrats on using 3D printing to repair something! Enjoy your coffee! Godspeed! Deus tecum.
If you thought this guide was thorough, you should see our primary work. SteadyMouse LLC helps
folks with Parkinson's disease use their mouse again. Come check us out anytime at and perhaps help us spread awareness. Cheers!
© iFixit — CC BY-NC-SA
Page 19 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 19 — Troubleshooting #1 - Overspray
© iFixit — CC BY-NC-SA
If you encounter ground coffee
escaping the chute and getting on
the counter, it may mean your coffee
is too dry, humidity is too low (static
charge), or even that the grinder
chute is too clean.
To fix this, try placing a tiny dab of
cooking oil on your finger and
rubbing it high up inside of the
coffee chute. This will allow a fine
layer of grounds to coat the walls of
the chute.
The added friction of the grounds on
the wall of the chute should slow the
velocity of the grounds down enough
that the overspray stops.
FYI: This whole step happens
naturally with oily coffee beans, but
takes a little longer than with the
vegetable oil trick.
Page 20 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 20 — Troubleshooting #2 - Burr Clearance
TOO CLOSE (ie: grinding too fine): If the burrs are too close, or even touching (but centered), the
nut on the lower burr may not be tight enough. With the ratchet and 10mm socket, give it a quick
counter-clockwise jerk. If that fails, recheck your fit-up against the second photo to make sure the
lower conical burr is the proper height.
If it's clear that the lower burr is sitting too high on the impeller, see the 3rd picture and sand the
area highlighted in RED. While doing this, periodically install and re-check the lower burr height
until it matches photo #2. Careful not to sand off too much as it's easy to remove thickness but
hard to add it back.
TOO FAR: If the burrs are too far apart such that the grind isn't fine enough, it could be that the
steel washer underneath the impeller got left out. See step #9. Additionally, you can try removing
*one* of the two washers above the lower burr and not tightening the nut as much. There's also a
shim kit offered by Breville if you contact them.
Lastly, both of the above issues can happen if the alignment in "Step 12" got shifted. If so, you may
need to pop-off and adjust the rotation of the upper-burr holder assembly. This is tricky, but doable.
I suggest marking the existing alignment with permanent marker before experimenting.
© iFixit — CC BY-NC-SA
Page 21 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 21 — Troubleshooting #3: Horrible clacking sound when running (Even without
© iFixit — CC BY-NC-SA
If it sounds horrible when running
(even without coffee beans) like this:
v=PcQcbHIP... then it's probably
either a damaged torque limiter or a
stripped drive gear. FYI: The
situation in the video was the
aftermath of a rock getting jammed
in the burrs.
I don't cover tear down all the way to
the gear box. Step #9 is as close as
I go. In the photo though there are 4
washer screws and 2 screws on the
encoder. If you remove those you'll
be well on your way to investigating
the gear box.
The options to fix either of these are
not as well explored, so if there is
damage here and you fix it
successfully, post a comment below.
FYI: Breville has a repair service for
about $90 and that may still be the
best option in this situation.
The torque limiter may be "fixable"
by stretching each of the radiallydistributed springs about 2mm each.
This should increase the torque at
which it slips.
Page 22 of 24
BCG800XL Grinder Jamming due to Worn Impeller
The drive gear on the right has a
potential source found by a user
below (Thanks Dave Gordon!):
ville-... This is not yet verified to
work, but the price is reasonable, so
if you try it out and it works, post
below so we can know!
Step 22 — Troubleshooting #4: Static Electrical Charge on Coffee Grounds
© iFixit — CC BY-NC-SA
Occasionally a user reports statically
charged coffee grounds coming out
that seems to defy the laws of
gravity. They float up into the air and
cling to things, making a mess!
Often it will stop on its own after the
impeller gets a few days of use. It's
a bit of a mystery however, I believe
the issue arises mainly in dry
climates, with certain beans in
combination with the plastic
To fix the issue, simply give your
impeller a scrub and rinse in the sink
and then pat it down with a towel
until dry.
This slight bit of moisture seems to
take care of static issues
permanently. I suspect it gets us by
until the impeller builds up a natural
coat of coffee, which also serves to
prevent static charge.
Page 23 of 24
BCG800XL Grinder Jamming due to Worn Impeller
Step 23 — Troubleshooting #5: Clumpy Grounds or Little to Nothing Coming Out
Some beans, especially the "roasted
so dark it's nearly charcoal" variety
can be way too oily. The
characteristic is that rather than
grind to a powder it turns to "paste"
in the lower chamber. This is
obviously bad, because it then
comes out in clumps or not at all.
Clumpy grounds, for some reason
tend to overshoot the portafilter and
make a mess. I suspect this is
because the large clump size has
more mass, and comes out of the
chute with too much momentum.
If you pull the upper burr, and see
what looks like a nice smooth black
surface where the impeller would
normally be, then that's your sign.
The Fix: Clean the lower chamber,
or at least break up the cake of
grounds, and switch to a less oily
The steps should have taken you all the way through re-assembly. Provided that impeller wear was your
issue, everything will work again. If you have other issues see the troubleshooting steps or post below
for further help.
This document was last generated on 2017-10-21 08:15:02 AM.
© iFixit — CC BY-NC-SA
Page 24 of 24