I have the older model of the small cocoatown melanger and have been through one belt change over a year or so with one batch a week in the last nine months. Recently I've noticed that the roller weels have stopped turning, first one and now both. At first I could put some pressure on the end of the tension arm that goes accross the rotating bowl and the rollers started turning again, but now they just stay put and there's nothing doing.
This only starts after at least 24 hours running. Initial refining goes fine.
Is there some way to increase the tension on the stones?
Has anyone had similar problems and found ways to correct?
I look forward to your comments.
The bushings wear out. Either get new stones or have the old ones refitted with new, Teflon bushings.
You are disassembling and cleaning the stones after each use right?
by 'bushings" you mean the nylon fittings inside the roller stones? I was looking at everything with an engineer friend of mine yesterday and we did notice that they were pretty much toast, we ordered new nylon to replace.
Yes the stones are being disassembled and cleaned after each use. Isn't teflon toxic, especially when heated? I can order new bushings at cocoatown?
No, food grade Teflon is not toxic. How else would there be millions of Teflon-coated nonstick pans out in the market?
Cocoatown will sell you the stones with the original crappy plastic bushings. Up to you to have new bushings made. Be warned, solid Teflon is pricey, and add to that the machining costs, you may be just better off buying the new stones every year or so.
If the bushings are just plastic, it seems to me that making new ones can't be that difficult. I would hazard a guess that the hole in the granite is pretty standard, and there is a hole saw (drill bit attachment) with the same size.
The hole saw will cut a "plug" in a thick sheet of plastic with a pre-drilled hole in it already. Cut out the plastic from the granite, push the "plug" in the hole, and then redrill the hole in the center of the plug to whatever size you need.
Super easy and done for less that $20, PLUS you can create a whole bunch of "bushings" at the same time, and replace them as needed, never having to buy a granite wheel and pay scads for taxes and shipping.
Just an FYI - I use the older Cocoatown as well & last I checked you could no longer get the rollers for it. Apparently the newer model has a narrower drum & the newer rollers won't fit - though I haven't confirmed this physically. Maybe someone else has.
I have a similar problem with my bushings & am intrigued by Brad's idea. I just need to ingratiate myself with a machinist.
Thank you for the feedback folks.
I made some rudimentary bushings following the recommendations of my engineering friend again (basically thin plastic angled washers with a small protruding plug). Fitting them was a bit hard because they had to be nice and thin in order to avoid having them pinched by the nut at the end of the axle which would prevent rolling. I got that done and did the install but the machine is basically doing the same thing. Is it possible that there is some sort of wear that has caused the rollers to experience less contact with the drum bottom? My next step was to check whether there were replacement bushings available. Any ideas how to adjust the shear on this machine?
What happens is that the insides of the bushings get worn away as the rollers rotate around the metal shaft that holds the rollers. With extra play in the assembly it no longer applies consistent (or any...) downward pressure along the point where the roller contacts the drum bottom below. With the machine off you can test this by running little strips of paper between the roller & drum at various points along the roller. In my case I found the outer 2/3 or so of each roller doesn't really come into much contact with the drum bottom. Without the benefit of much friction there isn't much to make the roller want to keep turning if something bigger & better decides to push it the other way. Interestingly, it doesn't seem to affect the final liquor smoothness - at least in a way I can detect - or overall refining time.
Thanks Eric. I will do this test. I talked to Cocoatown and they can sell me new rollers for $200. I'm thinking of trying to redo the roller tubing and bushings instead. Also, if there is some other way for me to increase downward pressure, the extra shear might make up for the wear in the tubing. In my case refining time is very affected because as soon as the mix starts to get nice and liquified (maybe after 6 hours) the rollers stop moving. I think my next steps will be 1 - trying to hack an increase in pressure from the tension bar using spacers on the top of the central axle. 2- Removing the roller tubing and trying to make new tubes.
I will post the results.
Yes I have had similar issues. The first 24 hours of refining the liquor or nibs goes fine. When I add sugar and little butter, one side and a once, both stones stopped turning. I also made a few batches of milk chocolate and the milk powder did the same thing. I found that increasing the amount of butter helped.