Versalab M3 vs. Others - Page 6

March 18th, 2016, 1:58 pm

I am so very impressed with this amazing work and collaboration! Superb job gentlemen!

March 18th, 2016, 3:56 pm

+1!!

#53: Post by **Rush** » March 21st, 2016, 10:30 am

AssafL wrote:I am learning quite a bit about grinders via this ad-hoc project. Via PM I am working with ericc on his Versalab and getting different results - which ends up sending one down rabbit holes one wouldn't fret over otherwise.

I am finding that as well. I have had an M3 for 4 years now, and I have been mostly happy with the grinder except for the alignment. Now I am excited to install the nicer OEM controller and get some more intelligent controls in place. Thanks for sharing your work!

AssafL wrote:After all these discussions I decided it is time to realign the grinder - but this time I had the nerve to tear the top apart. 2 hours later, with a head-visor lens and feeler gauges my grinder is now "perfectly" concentric and parallel ("perfectly" as to my ability to gauge - not with a run-out gauge etc.).

Would you mind sharing how you went about aligning the grinder? I imagine it is intuitive once it's apart, but I don't want to get stuck and have no espresso grinder in the off chance I don't understand what I am doing! Thanks for any help or links, etc.

#54: Post by **AssafL** » March 21st, 2016, 1:19 pm

Rush wrote:Would you mind sharing how you went about aligning the grinder? I imagine it is intuitive once it's apart, but I don't want to get stuck and have no espresso grinder in the off chance I don't understand what I am doing! Thanks for any help or links, etc.

Sure.

The thing to understand (which I owe to nickw and terranova for explaining on another thread) is that the alignment is actually the relation between the top plate (which holds the bearing) and the middle plate (which holds the stationary top burr).

Both plates are held by the two big and long hex screws on the top plate (which are also imperial for the convenience of us Europeans). Once these screws are loosened - the top plate can be moved.

Do make sure to clean the grinder well prior to disassembly as I encountered situations in which coffee residual grinds made alignment impossible (to the extent of wiper rubbing!).

I know that in extreme cases shims may be necessary but if you get there do try first to clean the parts again and well.

As for alignment - I try to make the burrs touch when the plates are loose and examine them with a visor magnifier. To ensure they are perfect. I then tighten the bolts a bit and loosen the burr - repeat the process until the bolts are tight and the burrs are aligned. It may take quite a few attempts (it took me 2 hours last time!!!) as it tends to fall out of alignment as the bolts are tightened.

Also do the process with the top burr locked as there is a difference between burr adjustment collar loose and tight.

I like to end the process (or restart it...) by using a feeler gauge snug in the gap. I then rotate the bottom burr and either feel elated as it rotates smoothly - or the horror of the feeler gauge getting stuck which means more sessions....

On a last note - sometimes rotating a burr a 1/3 turn makes alignment easier. Not sure why.

HTH.

March 24th, 2016, 5:09 pm

Wow, great explanation. Thanks for the help! I will post back after I spend a few hours working on it and let you know how it goes.

#56: Post by **AssafL** » May 3rd, 2016, 1:29 am

A short status report.

1. The ETA (or other) circuit breaker is highly recommended. It trips if the belt stalls or slips, saving the belt and the motor.

2. The controller can extend the life of the belt and all but prevents it from slipping/stalling. It still happens with some beans. So better than before but not as good as a belt with teeth.

In short - a worthwhile update but it doesn't eliminate all the problems of the design.

I had a thought of adding a sort of tension wheel to the top plate (like the tension wheel used on Audio tapes and cassettes). Sort of using the small wheel as a capstan and a tension wheel to force the belt on the capstan. May try it if I figure out how to do it easily.

On a side note: alignment is a pain in the neck (as it is one of these annoying situations when the device tends to lose alignment when torquing the screws) - but it is well worthwhile to do so.
1. The coffee is sublime.
2. The timing is dead on.
3. If previously a small change was the difference between a gusher and a drip - now I have 1-2 numbers to play with.

#57: Post by **AssafL** » May 29th, 2016, 4:17 pm

Notes: See edits below.

Ok - So while the controller improves performance considerably - As stated in the previous update - I did have some slippage with light roasts and slow grind speed (in the 300 or so RPM range). Since I already had the Dr. Bean mod in storage I decided to install it. It works well.

However, the original finger guard no longer fits. The belt is toothed, reinforced, and isn't elastic. Worse - the cog has a lip - that while not sharp, seem pretty ominous to inquisitive fingers. As I also have an inquisitive 3 year old with an impressive ability to get anywhere - I needed a solution.

Openscad and a 3d printer made this replacement. It uses the original screw and the original screw-hole (note that the first picture is prior to removal of rafts and supports):

Sources for the print can be found at: http://www.thingiverse.com/thing:1596236

Openscad code for the replacement guard:

// Versalab digit protector for the Dr. Bean timing belt mod
$fn=100;
//
translate([-47.5,-59,0])difference () {
    cube ([95,100,22]);
    // Creating the wedge shape
    translate([-1.5,0,-1]) rotate([0,0,68])cube(120,40,24.5); 
    translate([97.5,0,-1])rotate([0,0,22]) cube(120,40,24.5);
    // Large cog - Three large cylindrical cutouts - one for the belt area and 2 for the cog "lip"
    translate ([10,28,-1]) rotate([0,0,45]) cube([10,10,23]);
    translate ([75,32,-1]) rotate([0,0,-45]) cube([10,10,23]);
    translate([47.5,0,-1])cylinder(25,50,50);
    translate([47.5,0,-1])cylinder(9,54,54);
    translate([47.5,0,19])cylinder(9,54,54);
    // Smaller cog - Three large cylindrical cutouts  - one for the belt area and 2 for the cog "lip"
    translate ([0,98,-1]) cube([95,95,23]);
    
    translate([47.5,106.8,-1])cylinder(25,12,12);
    translate([47.5,106.8,-1])cylinder(6,15,15); 
    translate([47.5,106.8,16])cylinder(9,15,15);
    // Two coincidental cylinders for the recessed screw opening
    translate([47.5,55.2,-1])cylinder(25,3.3,3.3);
    translate([47.5,55.2,10])cylinder(25,4.6,4.6); 
    }
//eliminating belt slap by rounding the corners
translate ([-33.12,-21,8]) cylinder(11,0.5,0.5);
translate ([33.45,-20.6,8]) cylinder(11,0.95,0.95);
translate ([-8.7,38.4,5]) cylinder(11,0.90,0.90);
translate ([9.3,38.6,5]) cylinder(11,1.15,1.15);

Edit1: Code edited for clarity, as well as added rounded edges and modified sizing to limit belt slap.

The left side (the pulling side) caused some belt slap so a mm was removed - some slap is still audible and I'll probably trim 0.5-1mm more from the left side of the guard. Also, printed with better texturing for the top layer (using a Hilbert pattern).

Edit 2: Still some belt slap. Ended up redoing the guard. Widened the gap to the belt to about 5mm. Ensured it is safe by recessing the gap and leaving overhangs above and below the belt at the cog width - to both allow belt "play" while ensuring fingers can't "poke" between the belt and the guard. Currently no belt slap at all. SCAD code and SCAD rendering below. No image since it looks just as previous versions before it...

New STL file ready for printing is available on Thingiverse link above as v2 file.

// Versalab digit protector v2 for the Dr. Bean timing belt mod
$fn=100;
//
translate([-47.5,-59,0])difference () {
    cube ([95,100,23]);
    // Creating the wedge shape
    translate([-2.5,0,-1]) rotate([0,0,68])cube(120,40,24.5); 
    translate([97.5,0,-1])rotate([0,0,22]) cube(120,40,24.5);
    //eliminate belt slap by cutouts for belt 
    translate([1,0,6]) rotate([0,0,68])cube([120,40,15]); 
    translate([94,0,6])rotate([0,0,22]) cube([35,120,15]);
    // Large cog - Three large cylindrical cutouts - one for the belt area and 2 for the cog "lip"
    translate ([0,0,-1]) cube([95,41.5,25]);
    translate([47.5,0,-1])cylinder(25,50,50);
    translate([47.5,0,-1])cylinder(8.5,54,54);
    translate([47.5,0,19])cylinder(9,54,54);
    // Smaller cog - Three large cylindrical cutouts  - one for the belt area and 2 for the cog "lip"
    translate ([0,96.5,-1]) cube([95,95,25]);
    translate([47.5,106.8,-1])cylinder(25,12,12);
    translate([47.5,106.8,-1])cylinder(8.5,15,15); 
    translate([47.5,106.8,19])cylinder(9,15,15);
    // Two coincidental cylinders for the recessed screw opening
    translate([47.5,55.2,-1])cylinder(25,3.3,3.3);
    translate([47.5,55.2,10])cylinder(25,4.6,4.6); 
    }

#58: Post by **Rush** » August 15th, 2016, 7:39 pm

I just wanted to follow up because I said that I would. It took many tries over many sessions to get it close to aligned, but I finally got it as good as I feel it can be with all the other tolerances involved. It required having to use force to shift the plates laterally to get them to align when they are torqued down by the bolts. It was a painstaking process.

Does anyone have a good way to replace the belt without having to give Versalab any more money? I would be okay with a toothed belt, but I am not finding one for sale anywhere right now.

Rush wrote:Wow, great explanation. Thanks for the help! I will post back after I spend a few hours working on it and let you know how it goes.

#59: Post by **AssafL** » August 15th, 2016, 9:20 pm

The toothed belt is from Elvis Hsiao aka Dr Bean in Taiwan.

I was able to communicate with him by phone and via Facebook.

#60: Post by **Rush** » February 1st, 2017, 12:08 pm

Another quick update to this thread: I tried my hardest to get the grinder aligned but I could never achieve even the runout when new. I bought 10

toothed setups from Elvis, and now I have to sell them here to try to get my money back out. But I wasn't about to give Versalab any more of my money, particularly on those belts! I have just resorted to sending the grinder to Terranova for his care and expertise. I hope I won't be posting in threads like this any longer!

Thanks all for the help and this great thread. I have referenced back to many of it's posts and a friend of mine with a VL M3 has referenced it quite a bit as well.