[Gristmillers] Need top for pillow block Mill SN: 3287 - 16" Meadow Mills

[jeb lloyd]

Faber;

With regards to the bearing cap, there are a couple of things you would want to keep in mind. First off, the casting is not the bearing. The casting HOLDS the bearing, which is made of babbit. Babbit is a soft, lead-alloy that melts easily but is great for low-RPM applications. Great for mills and hit-and-miss engines...not so good for car and truck engines. The babbit is what actually contacts the shaft. The bearing cap usually has a couple of holes cast in it to allow the babbit something to "grab ahold of" once it is poured. Babbit can be poured 2 different ways: You can pour it so as to form a solid block and machine the proper diameter for the shaft out of it once the babbit has cooled, or  you can place the bearing cap on the mill and bolt it down against the other half of the bearing (with shaft in place) and let the shaft make the radius in the babbit for you.

The other thing you want to remember is that these bearing caps nearly always had shims between them and the other half of the bearing. As the babbit would wear out, the bearing would get loose. To tighten it back up, you remove a shim from between the two halves and tighten it back up. You would continue to do this until you ran out of shims to remove. At that point, you would re-pour the bearings. If you were to pour the babbit as a solid block and have a machinist mill the shaft bore out of the solid block of babbit, you would have to keep this fact in mind as the shims would effectively force the shaft center to be farther away from the center of the bearing cap. Just some things to keep in mind.

Jeb

From: faber at mssblue.net
To: gristmillers at gristmillers.com
Subject: Re: [Gristmillers] Need top for pillow block Mill SN: 3287 - 16"	Meadow	Mills
Date: Sat, 21 Mar 2009 19:00:23 -0500

Joe:
Thanks for the info.  I may definitely need a piece made.  I think I could fairly easily make the outside profile of one out of wood, but I would have trouble getting theinside part where the shaft goes smooth and a true radius.  I could maybe have it flat and explain to the machinist that it will couple to a 1.3/4" shaft and theycould put the radius in a casting.  If someone on the list has one they could loan us to use as a pattern for a casting that would be 50X easier.
Concerning a rebuild, I would love to have come to your place, but I wasn't sure folks who would come would have as much knowledge as John Baily aseveryone on the forum kept directing me to him.  I learned a lot in the several hours we spent together.He mentioned he'd never been to your place, and we talked about the idea of  once I've done this rebuild we could go up there and have a working seminarand show folks what all we've learned.  I'm going to look for another mill that we could redo and I could perhaps donate it to a cultural museum that we'rewanting to build here in Navasota.  I could bring it to Starr Homeplace and we could do a weekend seminar.  Once I've done it, I will understand what weneed to have to make it happen in a 2-3 day period to give people the satisfaction of seeing one happen completely.
On this part, let's wait a day or so and see if anyone has an extra part to sell me or for me to make a casting from.  Thanks again for your offer to cometo Starr Homeplace.  I look forward to meeting you in the future.
Kindest Regards,Faber


On Mar 21, 2009, at 2:54 PM, cen66133 at centurytel.net wrote:  Faber,
 One other alternative is to borrow the piece and have one cast at a small job foundry - not as expensive as you might think, though it will probably require some machine shop work too.  We had a rocker arm cast for an engine for $30.00.  The freight for shipping the original to and from Oregon was more than the cost of having the casting done.  I have friends who know of a foundry doing that kind of work in Mobile.  We will eventually be able to do it here. You can also carve an original of wood - or make one of pyroclastic clay (fimo) though this shrinks.  Really doesn't take long to carve one of wood using a side grinder , band saw, etc.
 We have a machinist who will probably be here working at our blacksmiths hammer in - but ultimately - you are better off having all the pieces parts and workmen in the same place.
 
 Later,
 Joe Rolfe
 Starr Homeplace
 
 P.S.  
 Sorry I couldn't get up a crew to do your rebuild for you - it would have been a lot of fun.  Everyone is stuck in their own ruts I guess -- including me.  All are still, and will always be, welcome here.  www.StarrHomeplace.org
 
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