Re: [papercreters] Re: Spacesman's version of McCain Scissor mixer & Foam Grinder

Trying to make a wooden pulley when there are readily available and relatively cheap alternatives such as heavy duty cast iron ones is OK if one is into experimenting and not necessarily concerned with getting some PC mixed. I think by Spaceman's posts on the subject he wants to get some PC mixed and made into dome pieces before the weather gets too cold. Trying to reinvent the wheel doesn't accomplish that. As far as building a 50 gallon pc mixer whith a dc hobby motor, cardboard pulley and rubber band drive belt I'd have to say that's a pretty incredulous concept that I personally don't think would even have a remote chance of working. The wooden gears and pulleys of the old water wheel powered grist mills and saw mills you speak of were many times bigger than any PC mixer any of is going to build. They were huge. While we're on the subject, wooden wagon wheels carried our pioneer forefathers across many miles of plains and deserts and the early automobiles used wooden spoke wheels. I doubt if anyone would want to use them for a trailer towed at highway speeds or a modern car. Just because they could be made to work doesn't mean that they would be the best option. Spacemans McCain scissor mixer project in my humble estimation only lacks the power and the ridgidity of the structure to work. The number of chopping blades and the length and spacing of same will probably need some tweaking but with enough power and torque it will work. The only issue I have with this design, and why I have not made one, is that getting the mix out will be difficult. I make a stiff mix out of cardboard but perhaps a mix made of paper with more water would not be a problem. Also, most of the electric motor mixers I have read about have had problems with lack of power and reliability and after looking at pictures of people tearing newspaper into strips so the mixer can handle the mixing task does not seem like a good way to go. I am 68 years old and I don't want to spend any more time experimenting with mixers and mixer concepts when the vast majority of the people on this forum and others online who have actually built anything of substance have used a version of the McCain tow mixer. I need to make 2000 more 16X16X6 inch blocks and a mixer that will do the job faster and with fewer problems is what I prefer to work with. I don't want to spend any time reinventing the wheel. --- On Wed, 10/31/12, JayH <slurryguy@yahoo.com> wrote: From: JayH <slurryguy@yahoo.com> Subject: [papercreters] Re: Spacesman's version of McCain Scissor mixer & Foam Grinder To: papercreters@yahoogroups.com Date: Wednesday, October 31, 2012, 3:32 AM   Do you have any idea how much torque and brute power is required to chop even 50 gallons of paper pulp? Yup. A wooden pulley would be no match for Spaceman's creation. Not necessarily. There are a variety of factors that need to be considered, but if they are all taken into appropriate account wooden pulleys can designed and built for most any situation.  Designed and constructed correctly, the weak link in a pulley system will be the belt. I could chop 50 gallons of paper pulp using a DC Hobby Motor and a cardboard pulley driving a rubber band belt.  It might take over a month to chop all 50 gallons, but I could easily design such a tiny little toy blender that could eventually get the job done.   Don't take my humorously extreme example as something someone should expect to be practical.  It's not, obviously.  My point is that there are multiple ways to accomplish a task.  Large torque and power become necessary if the desire is to churn up massive quantities of mix in a rapid time frame, especially if the mix is a thick and viscous one. Build a wooden pulley out of a very dense hardwood, especially if it is laminated for strength and you'd be amazed at how strong and durable it can be.  Old waterwheel powered grist mills and saw mills had wooden gears and pulleys that transmitted a lot more power than Spaceman is going to get out of that motor.  Some of those are still operating after over a 100 years of service. I think Spaceman is onto an interesting design, and it is fun to watch him develop it. For example, Spaceman could drastically reduce the torque and power requirements for this scissor mixer if he altered his blade design.  If the spinning blades were more streamline, like knife blades, they would not not be nearly the load that he is currently encountering.  It would chop trough the paper much easier requiring far less torque and power.  The sacrifice would be that it wouldn't stir the mix as vigorously. As this mixer is currently configured it looks a lot more like a mortar mixer than a chopper.  Those big angle iron blades look more designed for throwing stuff around than for chopping it up.  Of course, that may be exactly what Spaceman is looking to achieve, if so, he's definitely on the right track. That's something that is rather unique in a papercrete mixer compared concrete or mortar mixers.  It's a combination of a chopping device and a mixing device.  There are trade-offs between the two functions.  These angle iron blades with sufficient power driving them should "mix" like a "sumb**ch."  Its chopping ability is going to be mostly limited to brute force tearing and smashing almost hammermill style.   In any case.  I look forward to seeing the wanton destruction those blades might produce.  I almost wonder if this is a combination papercrete mixer and papercrete SPRAYER.  Assuming no lid gets placed on the barrel, and depending upon the tilt angle of the barrel, I bet it would fling papercrete against the upper part of a wall or the inside ceiling of a dome at a prodigious rate.   A YouTube video of that alone should be more than worth the time and effort Spaceman has invested in this mixer.  heh heh heh --- In papercreters@yahoogroups.com, Donald Miller <donald1miller@...> wrote: > > Do you have any idea how much torque and brute power is required to chop even 50 gallons of paper pulp? A wooden pulley would be no match for Spaceman's creation. I'm thinking the reason Mike McCain moved on from this design to big batch truck mounted mixers is because of the amount of effort and engineering required to make this design work. I notice that no one has posted any pictures and or descriptions of a working model. The reason tow mixers or stationary mixers using a car differential work so well is that the differential is very sturdy and can hold up to the stress of the mixing. > > --- On Mon, 10/29/12, JayH slurryguy@... wrote: > > > From: JayH slurryguy@... > Subject: [papercreters] Re: Spacesman's version of McCain Scissor mixer & Foam Grinder > To: papercreters@yahoogroups.com > Date: Monday, October 29, 2012, 4:35 AM > > > >   > > > > It is a rather simple task to make your own V-Belt pulley out of wood. > > Yes, Wood. > > You have a table saw right? > > Check out this website. One of the best websites out there. > http://woodgears.ca/cider/motorizing.html > > Matthias Wandel is what we called as I was growing up, "A Dude..... A righteous smaaaaart DUUUUUUDE!!!" > > If you paint your wooden pulley with a waterproof sealer, it should be able to withstand the wet environment. > > If you ever attempt to use that thing to grind up styrofoam, better put a lid on it. Those little bits of foam will pick up static electricity, stick to everything, and you'll soon be walking around looking like the abominable snowman. > > On second thought... go ahead and grind styrofoam without a lid, but make absolutely sure you post photos. heh heh heh > > Spaceman wrote:------------------------ > > Yesterday I did a second test with water and paper, and found that the pulley on the dryer motor just won't get enough grip on the V belt to make it spin with a load. I had other things to do and again today, so maybe tomorrow I'll dig around and find a suitable pulley. I didn't really want to go larger because I like the speed and torque ratio, but I'm pretty sure I don't have a V belt pulley that small. I definitely don't have a larger pulley for the blade shaft and calling around to stores didn't turn one up. It is the wrong season for cooler parts. >

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