Knurling on a Mashmaster Mini Mill

[Liam_snorkel]

I've brewed 3 times with the new rollers now - efficiency is the same as before, I BIAB so no comment RE sparge - the only noticeable difference has been NO dough balls when mashing in.

 

[Wimmig]

Hmmm I've got one of these units with knurling, makes me edgy :/

 

[Zorco]

Weekend before last: English Barleywine - Pre Boil 1.100 First Runnings, 1.060 Second Runnings for another Overall grain yield 82%.
Last Weekend : American Barleywine - Pre Boil 1.090 First Runnings, 1.044 Second Runnings for overall grain yield 81%

Super fast crush, not a single chance of a stuck sparge or slow recirc. I'm going to tighten the crush from 0.88mm to 0.80mm and try again.

I need a grant as well; suspect I'll get a better sugar transfer if I'm not sucking the wort with my pump.

+1 no doughballs
total, 50kg of grain in a fortnight.....in a matter of minutes.

Sounding stoked in my post above was entirely and libation inducedly deliberate.

 

[Rocker1986]

Echoing Liam's comment re the dough balls. I also BIAB, but my efficiency has gone up; this coincided with moving to a coarser crush and keeping the mash agitated through stirring it periodically, which I actually started doing before getting the new fluted roller. Coarser crush was mainly to try to get the grains to go through the thing. Now of course, no issue with that. So I guess the efficiency has remained pretty much the same on my system as well.

 

[waggastew]

I had some issues with crush in the last few brews and this thread made me paranoid. My main issue was grain jumping over the rollers and a slow feed.

Had a play yesterday with gap size and drill speed. Ended up widening the gap and speeding the drill up. I had previously made the gap thinner after reading about 1mm gaps. I had also slowed the drill down as again I thought slow results in less husk damage.

Long story short the crush now seems back to normal (i.e. how it performed when I first bought it), hardly any uncrushed grain and a nice fast feed.

Just posting to ensure people consider other parameters before assuming it's the knurling. no affil etc

 

[BrissyBrew]

I should have my new rollers by Friday so I will attempt to do a side-by-side with 2 different gaps measuring the time taken and with a photo of the crush.

I'll do something like this, all with 1kg of the same base malt:

Old rollers, 1.25mm
Old rollers, 0.9mm
New rollers, 1.25mm
New rollers, 0.9mm

My current rollers are possibly a bit more problematic than other people here - they are not perfectly cylindrical (i.e., the ends are smaller than the middle) so this may or may not be of use.

Just a quick word to advise that you will not get the same crush comparing new rollers and old rollers at the same gap setting, its a little apple and oranges comparing the fluted rollers to the knurled rollers. As for the slightly tapered effect (its super small) it is there to balance out that the rollers do flex under load like all mills and obviously they flex in the centre.

 

[BrissyBrew]

The gears do separate, they are held in place with three small screws. I’ve just tried removing the gear from the non drive roller so my mill now has one driven and one passive roller.

Really surprised to find that grain won’t pass through the rollers at all now. It just rolls and bounces around on top of them. Had to open the gap up till the grain could almost fall through before it worked.

Needless to say the crush wasn’t adequate.

Drive both rollers double the applied friction force in the pinch point of the grain and rollers, hence why still put gears on our mills plus you don't have any problems getting the mill to feed with a full hopper. With the two fluted rollers on the new mills the 26 flutes in each roller are synchronised with the mesh of the two flutes (it's why you mill with a gap setting of zero). The mesh of the two flutes vary as the rollers spin around this actually changes the grist distribution by a couple percent in each pan if you change the gearing ratio. Last mill development I tested no gears 1:1 gears and gears with a ratio of 1:1.25, statistically no difference between 1:1 and 1:1.25 ratios although some of the sieves there was a 2-3% shift in distribution and more flour with the 1:25 gear ratio. Zero gears forget it, grist distribution shifts with the gap setting as the differential speed. The new fluted rollers are also more stable across a larger RPM range tested at about 220RPM and 530RPM measured with a digital tachometer. For those thinking we put gears on as a marketing ploy, we have not, gears ensure the mill feeds grain and you don't get slip, almost doubled the friction force applied at the pinch grip squeezing the last drops out of the smaller diameter rollers. The 1:1 ratio on the gears along with the fluted rollers meshing allows for a constant get setting for each revolution and more constant grist distribution regardless of RPM (no gears obviously you get larger speed differentials).

 

[BrissyBrew]

If anybody is having issues with their old knurled rollers please email me [email protected] (unfortunately my [email protected] gets about 3000 to 9000 pieces of spam a month, and I am yet to find a spam filter that is as good as the one gmail uses.

A big thank you to all my customers for their time, patience and understanding to resolve the knurled roller problems.

 

[Parks]

BB you are a legend. You have come through in spades. Thanks!

 

[user 35653]

Drive both rollers double the applied friction force in the pinch point of the grain and rollers, hence why still put gears on our mills plus you don't have any problems getting the mill to feed with a full hopper. With the two fluted rollers on the new mills the 26 flutes in each roller are synchronised with the mesh of the two flutes (it's why you mill with a gap setting of zero). The mesh of the two flutes vary as the rollers spin around this actually changes the grist distribution by a couple percent in each pan if you change the gearing ratio. Last mill development I tested no gears 1:1 gears and gears with a ratio of 1:1.25, statistically no difference between 1:1 and 1:1.25 ratios although some of the sieves there was a 2-3% shift in distribution and more flour with the 1:25 gear ratio. Zero gears forget it, grist distribution shifts with the gap setting as the differential speed. The new fluted rollers are also more stable across a larger RPM range tested at about 220RPM and 530RPM measured with a digital tachometer. For those thinking we put gears on as a marketing ploy, we have not, gears ensure the mill feeds grain and you don't get slip, almost doubled the friction force applied at the pinch grip squeezing the last drops out of the smaller diameter rollers. The 1:1 ratio on the gears along with the fluted rollers meshing allows for a constant get setting for each revolution and more constant grist distribution regardless of RPM (no gears obviously you get larger speed differentials).

Out of interest what's the difference in performance between a Fluted pair and a Fluted/Knurled Mix pair from your test results?

 

[dicko]

Hi Brissy Brew,

What would be your recommendations on the gap setting for a nominal crush on the two fluted roller model. ?

 

[mckenry]

Frank is going to post me a new roller, which means I'll have one fluted, one knurled roller. Ive seen a few on here have that too and am happy to read they are happy with its performance in this configuration. For those that have replaced a roller, how hard was it? Cant get a visual right now. When do you realise that it needs to be sanded? The email I have says "if its a tight fit" I dont want to bother him with more and more questions so I'm asking here. What / which part is a tight fit, if at all? Can you tell before you have 30 parts of a mill on your bench?

 

[Crusty]

Frank is going to post me a new roller, which means I'll have one fluted, one knurled roller. Ive seen a few on here have that too and am happy to read they are happy with its performance in this configuration. For those that have replaced a roller, how hard was it? Cant get a visual right now. When do you realise that it needs to be sanded? The email I have says "if its a tight fit" I dont want to bother him with more and more questions so I'm asking here. What / which part is a tight fit, if at all? Can you tell before you have 30 parts of a mill on your bench?

It couldn't be simpler buddy.
I just unscrewed the two adjustment locking pins, 2 bolts on either side to allow the end to pop out. Slide off the gap adjustment knobs. The rollers just slipped out from the other end. The shaft on my new roller wouldn't allow the adjustment knob to seat fully so you just sandpaper the little round copper olive inside your adjustment knob until it seats all the way home. It takes a while so grab a beer. It took me about an hour but by God, the mill is a grain eating machine now.

 

[mckenry]

It couldn't be simpler buddy.
I just unscrewed the two adjustment locking pins, 2 bolts on either side to allow the end to pop out. Slide off the gap adjustment knobs. The rollers just slipped out from the other end. The shaft on my new roller wouldn't allow the adjustment knob to seat fully so you just sandpaper the little round copper olive inside your adjustment knob until it seats all the way home. It takes a while so grab a beer. It took me about an hour but by God, the mill is a grain eating machine now.

Perfect reply.

 

[Mr B]

Or sand the roller ends - this is what I did, not sure how you did the bush but it must have worked.

 

[Rocker1986]

Yeah I sanded the roller ends too, stuck it in a wood lathe and spun it around in that to do it quicker though. Took about 5 minutes to get them to fit nicely.

 

[Liam_snorkel]

I used grinding paste, worked a treat.

 

[Bridges]

Hi Brissy Brew,

What would be your recommendations on the gap setting for a nominal crush on the two fluted roller model. ?

Yeah this too. I've just finished dodging up my new mill, I think I have some choc malt that's a bit old I'll throw through for it's maiden run, currently set to the width of a metric standard myki card spose its as good as anywhere to start.

 

[dicko]

Yeah this too. I've just finished dodging up my new mill, I think I have some choc malt that's a bit old I'll throw through for it's maiden run, currently set to the width of a metric standard myki card spose its as good as anywhere to start.

20160228_165333.jpg

yes, if I am reading between the lines of a previous post there is no correlation between the gap on knurled compare to fluted rollers.

BrissyBrew where are you....????

 

[Bridges]

I run a 20Litre BM and have the dual fluted rollers on my new mill. Is anyone else running similar, so I can work out a starting point for the gap? Cheers!

 

[dicko]

I run a 20Litre BM and have the dual fluted rollers on my new mill. Is anyone else running similar, so I can work out a starting point for the gap? Cheers!

I have closed mine down to 1mm and my mate is getting 77% to 78% MASH EFFICIENCY in his BM 20
I did a brew at around 1.1mm and got 77% on my BM.
I am interested to see if we get an increase with the fluted rollers.
When I finally brew again I will report back.
I would appreciate BrissyBrews thoughts on this..

 

[Chridech]

I have closed mine down to 1mm and my mate is getting 77% to 78% MASH EFFICIENCY in his BM 20
I did a brew at around 1.1mm and got 77% on my BM.
I am interested to see if we get an increase with the fluted rollers.
When I finally brew again I will report back.
I would appreciate BrissyBrews thoughts on this..

I have milled once with my new mill with the (double) fluted rollers. I received some advice from Frank (see post #220 in this thread) regarding crush size and he recommended a 0.6mm gap (as a start) which seemed a tad fine for my set-up (Grandfather - prone to stuck fly sparges with fine grist) so I started at 1.3mm. It came out a little coarse with a noticeable number of intact barley grains, so i put it through again at 1mm. It looked pretty good (freed up the husks, grains cracked) so I went with it. There was a little more flour than I have noted with previous shop milled grists, but i didn't have too much trouble with the sparge. My fly sparges have been almost instant with previous shop grain crushes, but at 1mm gap the sparge took about 15 minutes which is not too bad. 5.6kg of grain giving pre-boil gravity of 1054 for 28L. Brewsmith calculated mash efficiency of 86%. It was a cool mash (63C) after a protein rest as I'm aiming for a dry finish for my Saison. However if i've got it right (i'm a newb) the temperature of the mash will affect fermentability but have little impact on mash efficiency. My mash pH was a tad low (4.9) and I'm not sure what impact that will have.

So I'm pretty happy with a mill gap of 1mm for the Grainfather, and will use this again next time. Don't know a lot about the BM but I suspect 1mm is going to be in the ballpark. Also don't know what a second pass through the mill does for grain that is already partially cracked?

 

[dicko]

I have milled once with my new mill with the (double) fluted rollers. I received some advice from Frank (see post #220 in this thread) regarding crush size and he recommended a 0.6mm gap (as a start) which seemed a tad fine for my set-up (Grandfather - prone to stuck fly sparges with fine grist) so I started at 1.3mm. It came out a little coarse with a noticeable number of intact barley grains, so i put it through again at 1mm. It looked pretty good (freed up the husks, grains cracked) so I went with it. There was a little more flour than I have noted with previous shop milled grists, but i didn't have too much trouble with the sparge. My fly sparges have been almost instant with previous shop grain crushes, but at 1mm gap the sparge took about 15 minutes which is not too bad. 5.6kg of grain giving pre-boil gravity of 1054 for 28L. Brewsmith calculated mash efficiency of 86%. It was a cool mash (63C) after a protein rest as I'm aiming for a dry finish for my Saison. However if i've got it right (i'm a newb) the temperature of the mash will affect fermentability but have little impact on mash efficiency. My mash pH was a tad low (4.9) and I'm not sure what impact that will have.

So I'm pretty happy with a mill gap of 1mm for the Grainfather, and will use this again next time. Don't know a lot about the BM but I suspect 1mm is going to be in the ballpark. Also don't know what a second pass through the mill does for grain that is already partially cracked?

Thank you for your input and comments.

I crush grain for other brewers as well as myself and at the moment I have only done it for myself with a BM and one other with a BM.

With a setting of close to 1mm we are achieving approximately the same Mash Efficiency that we were getting with the 1.2mm on the knurled set up.

When I am personally ready to do another brew for myself I will close it down to 0.9mm and give it a try.
I would not do this for others in case it causes wort fountains or drops efficiency.

At 1.0mm there is very little flour and all husks are still in tact, indicating that we must be pretty close.
My first brew was at 1.2 with the new rollers and I still got very close to my original mash efficiency.

I consider that one only result is not an accurate assessment as I used to vary around 1 to 2 percent with the knurled rollers depending on the type of grain...eg wheat, oats etc etc.

As long as all the brewers with two flutes and the others with a combination continue to report then it gives us all a good chance of getting the gap very close for our individual requirements.

 

[Jack of all biers]

Anyone consider posting a You-tube video of the fluted mill in action? Or better still a comparison of grains crush with fluted rollers v knurled rollers. Those of us considering the new mill would be interested in seeing it first hand and I haven't found a good video of the knurled mill in action let alone the fluted.

 

[nosco]

I just put my new roller in very quickly. The fluted roller went in really easily, snug as and no sanding required. It did get a bit of oily metal out of it and a bit of actual metal filling came out too which is a bit of a worry as its not even 12 months old. The adjustment knobs come out really easily now but it should be fine. It will make it easier to get a bit of lube in there. Cant wait to try it out on Friday! If I get a chance ill post a vid. I might have a vid of the old rollers and some pics of the old results.

 

[nosco]

Yeah this too. I've just finished dodging up my new mill, I think I have some choc malt that's a bit old I'll throw through for it's maiden run, currently set to the width of a metric standard myki card spose its as good as anywhere to start.

20160228_165333.jpg

Nice hopper Bridges! Howd ya make it? Some kind of down pipe/rainwater filter bits?

 

[Smokomark]

Thank you for your input and comments.
I crush grain for other brewers as well as myself and at the moment I have only done it for myself with a BM and one other with a BM.
With a setting of close to 1mm we are achieving approximately the same Mash Efficiency that we were getting with the 1.2mm on the knurled set up.
When I am personally ready to do another brew for myself I will close it down to 0.9mm and give it a try.
I would not do this for others in case it causes wort fountains or drops efficiency.
At 1.0mm there is very little flour and all husks are still in tact, indicating that we must be pretty close.
My first brew was at 1.2 with the new rollers and I still got very close to my original mash efficiency.
I consider that one only result is not an accurate assessment as I used to vary around 1 to 2 percent with the knurled rollers depending on the type of grain...eg wheat, oats etc etc.
As long as all the brewers with two flutes and the others with a combination continue to report then it gives us all a good chance of getting the gap very close for our individual requirements.

I've settled on 0.9mm gap with 2 fluted rollers. I find I get the best crush with the mill just ticking over. It's a bit slower but less flour produced. Even going slow it still mills in a quarter of the time compared to the knurled rollers.
This is fine in my brau clone, my grainfather and my 3v system. Very happy with the efficiency on all three systems.

Smoko

 

[dicko]

Thanks Smoko

That gives me a bit of confidence.
I will report back on results with the BM as I hope to brew on Sunday time permitting.

 

[Bridges]

Nice hopper Bridges! Howd ya make it? Some kind of down pipe/rainwater filter bits?

Exactly!
Went to the green shed. Didn't get a sausage got these or something similar
Hopper; http://www.bunnings.com.au/rain-harvesting-rain-head-leaf-catcha-dual-fit_p4760081
Adaptor thing; http://www.bunnings.com.au/holman-100-x-50-x-90mm-pvc-stormwater-downpipe-adaptor_p4770382
The bit I fixed to the ply (which I carved out an angled slot in) and attached to the mill; http://www.bunnings.com.au/icon-pvc-square-downpipe-pop-for-metal-gutter_p4775627

Thanks Smoko for your input, I'll dig out the feeler gauges and set to 0.9mm too for a brew sometime in the next week.

 

[Jack of all biers]

Exactly!
Went to the green shed. Didn't get a sausage got these or something similar
Hopper; http://www.bunnings.com.au/rain-harvesting-rain-head-leaf-catcha-dual-fit_p4760081
Adaptor thing; http://www.bunnings.com.au/holman-100-x-50-x-90mm-pvc-stormwater-downpipe-adaptor_p4770382
The bit I fixed to the ply (which I carved out an angled slot in) and attached to the mill; http://www.bunnings.com.au/icon-pvc-square-downpipe-pop-for-metal-gutter_p4775627

Thanks Smoko for your input, I'll dig out the feeler gauges and set to 0.9mm too for a brew sometime in the next week.

Legen........ wait for it...........dary.