Hunting for a new grinder to replace the Champion flour mill I've been putting to double duty. Ascaso iMini looks nice, not too large for the kitchen. Reviews I read on CoffeeGeek seemed reasonable. Nobody seemed to stock them locally, so bought online. Couldn't find a specific detailed photo review prior to buying, so thought I'd post this.


The hopper is well moulded in what seems to me to be polycarbonate. (I think there is a way to tell exactly what type of plastic that involves shaving a bit off and melting/burning it, but I'm not up for that.) Hopper is an interference fit in the top burr carrier.


A single screw at the rear holds the lid on. There is no mechanical attachment at all at the front of the top cover, save for the hopper holding it on. The original screw is a standard cheap zinc plated steel self tapping pan head. I changed mine to stainless steel 8 gauge which seemed to have the same thread pitch. Stainless is a better color match for the polished aluminum.


The top burr housing has 72 teeth. The 32 holes just inside the teeth are used by other manufacturers as click stop settings. One full turn of the grind adjustment knob turns the housing 5 degrees (one tooth).


With the lid off, the pile of grounds which doesn't come out is easily visible sitting on the plastic ramp. The ramp is in two parts. The inside part is part of the grinding chamber housing. The outside part is a separate piece clamped on by the housing. The foam surround seals with the top housing and stops grounds getting inside the casing where the motor lives. (PS the foam should probably be bigger, because you can see some grounds on the right side of the photo that are inside and you can see the gap where there is no foam seal at the lower half of the grind chamber port.)


The worm screw mounting frame has to be removed to undo the top burr. (Well I suppose it could be removed with a lot of turns of the worm adjustment knob - approx 600 turns.) Two fine threaded machine screws attach it to metal nuts in the grinding chamber base plate. The worm screw frame can't be fully removed without loosening the entire grinding chamber base plate (4 self tappers into the aluminum case), but you don't have to remove it completely to undo the top burr housing. The self tappers are not impressive, because repetitive use tends to strip out the holes. (Always be very careful to turn self tappers backwards when reinserting them to get them to drop into the original grooves. Even then sometimes they try to make their own new groove if they are even a little crooked - if they bind up, start over. After a few bad attempts of screwing self tappers into aluminum, they could easily strip out.) Note the gap between the plastic housing and the brass worm screw - it translates to about a quarter turn of slack when using the grind adjustment knob.



Burrs look beautifully machined. Double portafilter basket fills in about 15 seconds.


The grinding chamber being flat tends to hold a lot of grinds. (I'm tempted to experiment with building new grind sweeping vanes and reducing the space under the conical burr to reduce grind retention, but it might result in coffee flying out rather quickly.) I'm curious that flat burr grinders seem to have a depression in the middle of the bottom fixed burr which might also tend to accumulate some stale grinds.



Coffee grinds compact on the left side of the chute. They can be easily dislodged with a stick or brush. Bamboo skewers are good.


I was tempted to try to get rid of the free play in the grind adjustment knob with a washer, but not sure I could safely get the shaft out of the brass worm screw without destroying the frame. So for now, I have a few winds of teflon tape to pack the gap and I tied a knot between the ends so it wouldn't unravel. Still have maybe 5-10 degrees of slack in the knob, but that's better than the quarter turn it used to be. Because the top burr housing plastic threads are a little rough, the thread tends to bind a little and there is flex in the plastic worm screw housing when adjusting. I expect this will settle over time as the threads wear in and loosen up. Not worth trying any food grade lubricant (eg medicinal paraffin or castor oil), as it would just make the coffee grinds clag up in the threads more.

Under the grinding chamber baseplate is the motor and reduction gear inside cast aluminum housing. The bottom conical burr is immovable on its shaft by hand and seems to have no detectable gearbox backlash or shaft play. There is a slight electrical motor smell during/after grinding.


The manual page refers to i-2mini. But the machine says i-3 underneath, and 140W (manual says 170).

I would like to see some modifications to the i-Mini to improve functionality and build quality:
* sloped internal floor on grind chamber and redesigned vanes and chute to minimise grind retention/buildup
* machine thread inserts on the aluminum housing in preference to self-tappers
* graduations around the inside of the hole in the top housing for reference as to burr position (the stiffeners in the hopper make good pointers already and because the hopper is an interference fit, you can point the stiffeners in a convenient position)
* lugs on main housing and top housing to hold down the front of the top housing
* metal rather than chrome plated plastic motor button (which others have reported wears through over time - I'm using my thumb on it for now)
[added] * a little crank wheel instead of a knob would make large adjustments more feasible.

Some of these modifications could be made at home by those with an engineering bent.

The only other major competition at a similar price point seems to me to be the KitchenAid burr grinder. I much prefer the minimalist modern styling of the i-Mini. Beyond the i-Mini are the seriously large semi-pro grinders that cost nearly twice as much. Overall, I'm still a happy i-Mini owner.

[added] other competition - Le'Lit PL53, Nemox Lux. The burr set and worm drive appear identical to the Ascaso I-2 conical as seen in review http://coffeegeek.com/proreviews/detailed/innovagrinder

Here's a totally superficial (and probably pointless ) follow-up your extremely detailed and helpful post...
It seems there are at least two different castings for the iMini "cover top lid/spout"... Your "cover top lid/spout" has both a set of "course" to "fine" markings cast into it near the ajustment knob, and also has "Ascaso" cast into it near its front.

I have two iMinis - both black. One of them has the "cover top lid/spout" piece cast just as yours, with both the set of "course" to "fine" markings cast into it near the ajustment knob, and also has the "Ascaso" cast into it near its front. However, my other iMini has a "cover top lid/spout" piece cast without either the set of "course" to "fine" markings (in fact, there are no such markings on that one, "cast" or otherwise) and also without "Ascaso" cast into it (and, again, there is no such "Ascaso" marking on it, "cast" or otherwise). Both, however, were indeed Ascaso IMinis and came in the identical Ascaso packaging with the identical Ascasl documentation. All other aspects of my two "cover top lid/spout" pieces are exactly the same as yours, though (e.g. they attach with the same single screw at the top, no lugs to attach at the front, etc.)

All just, "FWIW"...

r-gordon-7

I presume the lid with writing and beans cast in is a newer version. I was certainly surprised to see it then I got my i-Mini, as all the photos I had seen to date showed a featureless lid.

This article describes burr set in Lux, Ascaso Conical, La Pavoni PB, Iberital, Isomac, Sunbeam EM0480 & EM0450, etc. as being pretty good and long lived. It also says they are all LOUD, which I suspect is the reduction gear. (One day I'll take out the motor to see what noise it makes on its own.) The plastic in the i-Mini seems to be a glass fibre reinforced engineering plastic (GRP) which is about as stiff/strong as you can get in plastic. Photo shows a machine using the click stop setting:
http://www.coffeeco.com.au/articles/september2002.html

Sunbeam grind chamber in comparison has a slightly better design in terms of pushing out grounds - more angled vanes. It appears similar or worse to i-Mini from other aspects - plastic of the chamber looks cheap as do the "ears" on the top burr carrier. Still has the large flat area around the vanes which will accumulate stale grounds. Article/photos here:
http://www.coffeeco.com.au/articles/sunbeamgrinder.html

[Added]
Trespade burrs from Pavoni on this page ...
versalab-m3-grinder-t408-80.html
... appear to have been redesigned a bit since then (or else burrs have been designed by some other company now as suggested here best-100-to-150-second-grinder-t7527.html). Grind chamber looks the same.

Thanks for posting the internal details on this grinder. I have the Le'lit PL53, the burr set and carrier look identical but the Le'lit spout(SS) sits snug to the burr carrier spout so the grounds don't have that extra ramp length: they make a vertical drop right out of the bottom carrier body. (still retains plenty of grind though.) Also, as you noted the free-play in the worm drive shaft, I just checked on the Le'lit and it appears they have addressed this as there is maybe 10deg at most of play in the knob. (Most adjustments I make are around 1/2 turn increment so this is mostly in the 'noise level' for me. Removing the spout to clean is with one thumb screw, but to get the burrs out for cleaning requires removing 4 screws (and then the worm gear screws). A bit fiddly so it doesn't get done very often... No complaints here on the grind quality.

Reflections on a year's use and some modifications in the meantime.....

1. Noise
I like machinery that is less noisy. After disassembling the grinder, I discovered the motor is pretty quiet. Most of the noise emanates from the speed reduction gearbox - an aluminum casting. I applied some automotive sound deadening (bituminous layer with aluminum backing) to the gearbox and also the grind chamber external surface. The sound quality is a bit lower pitched and less squealy. I am happier with the noise.

2. Wobbly conical burr
The conical burr was a bit wobbly on its shaft. There is a little too much play between it and the shaft so it goes on crooked. This wobbles the top (external) burr, which gradually works the hopper out of its interference fit in the top burr housing. I put a single layer of adhesive tape around the shaft, which substantially removes the wobble in the conical burr. (To remove the conical burr nut, I wrapped the conical burr in several layers of aluminum foil to protect from damage and held it with a 19mm ring spanner. IMPORTANT: The conical burr nut has a left hand thread.)

3. Dialing in
I found it useful to paint a line across one side of the top burr housing at the front when the burrs contact. I have painted one of the grooves on the adjustment knob for reference, to make it easier to count turns back from that point. If one wanted to be able to adjust for widely different grinds, a small crank handle rather than a knob would be great.

4. Spout sealing
As shown on the photo in the first post, the spout sealing foam doesn't go far enough. I am replacing it with some weatherstrip soft rubber seal so I can keep the grinds out of the motor.

5. Top burr crooked
I'm not sure if the top burr was mounted crooked in the top housing or if it has worked itself crooked over time. (Check that there is no gap all the way around between the top of the top burr and the top housing.) Certainly it was very crooked just now and so the burrs were touching on one side and a big gap opposite and the grind was way off. I have hammered it out with a suitable sized round socket fitting, cleaned out the coffee grounds preventing it from seating properly, and hammered it back in again with a soft face hammer (piece of wood and ordinary hammer would do).

Having fixed it, I can get flour-fine grounds again (if needed) and the adjustment knob doesn't bind.

Overall
I am still happy with the performance (grind quality, adjustability, speed), appearance, and maintenance aspects. I do think ascaso could do a better job of build quality. For the money, I'd still buy one despite all the niggly problems, because I like the look and size.

Hi, Bluey!

Do you have pictures of the improvements you made on your Ascaso i-Mini? And did you make any improvement on the grind retention?

Thanks!

Márcio.

Great report, thanks.

It's interesting -- it uses the standard Trespade burr, motor and squealing reduction gear as many other grinders (all very good, but mostly very noisy) -- but the burr carrier looks like it's metal, not the bakelite type plastic one usually sees.

This is the first time I've heard of crooked burrs. The center screw on conical burrs is usually tapped slightly off, so it looks like it wobbles, but an significantly uneven burr would show excessive wear very qyuickly and would be hard to adjust.