Steam & Excursion > Honing AT&SF 2926's big cylinders

Looks like they got most of the rods on now, and they are trying out the home made cylinder hone. Be sure to watch the video in amongst the photos. And this is a nice bunch of photos if you like cats, I counted about nine this time, but didn't see any rodents. http://nmslrhs.org/Photos/2014/10-04/index.html

Don't some of the big marine diesels they use on ship have cylinder bores about the same size as 2926?
That could be a source of a "proper" cylinder hone.

Sunnen Products Co in St. Louis manufactures all manner of honing equipment. The hone they are using looks like one of Sunnen's (we used to call them cages at Sunnen). They make bigger ones that would have maybe worked better in the bore without the stones and shoes extended so far. Looks like you guys rigged a support to minimize chattering.
You should wind up with a nice round hole with a crosshatch pattern in the bore.

According to the web site, they fabricated the hone and supporting/driving mechanism from scratch in their machine shop. I would guess that they either didn't have a reference to where to get a correct size hone, or they decided that they could make one themselves for significantly less than they could buy one, since they would probably have had to build all of the supports and driving bits themselves anyway.

The cage and feed/drive mechanism as well as the stone and shoe holders look Sunnen. Can't tell for sure because I can't get a close look at them.

lwilton Wrote:
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> According to the web site, they fabricated the
> hone and supporting/driving mechanism from scratch
> in their machine shop. I would guess that they
> either didn't have a reference to where to get a
> correct size hone, or they decided that they could
> make one themselves for significantly less than
> they could buy one, since they would probably have
> had to build all of the supports and driving bits
> themselves anyway.

From the 2926 July meeting minutes:

Preparations are being made to begin the process of tramming the crosshead
guide to perfectly line up with the centerline of the pistons. Dave V. has been
working to design the various devices to make this happen. Once they are
trammed it will clear the way for many more projects which have been on
hold pending the return of the crossheads. We will use them to support the
cylinder hone driver motor. When finished we will be able to begin the
Walschaert gear assemblies and install the four remaining side rods.

This crew obviously "knows their onions" (as the old time jazz men used to say). It's a real treat to see the progress week after week. And they get extra credit for taking good care of their furry friends--those look like well-fed kitties.

Actually I think this quote is more appropriate:

10-04-2014 After months of design and fab, the hone works like a champ and the cylinders are done . . . kind of anti-climatic!

(BTW, how do you post messages here with things like italics and underlining?)

lwilton Wrote:
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> (BTW, how do you post messages here with things
> like italics and underlining?)


Don't ask me, I just recently learned how to type a degree symbol °.