On 2010-08-11, Gunner Asch wrote:
On Wed, 11 Aug 2010 08:14:24 -0400, "Rick" wrote:

[ ... ]

Curious myself..what is the thickness of the spacer? Material?

Tubular, out of steel (first batch was marked 12L14..but it was not!
That **** was hard hard hard!! and the first set of spacers Cracked when
pressed on the shafts. And they were .002 under. Hard enough to burn
out a decent carbide insert at 500 rmp in about 10 seconds. I tossed the
entire bar into the scrap bin. All 75 lbs of it.

Hmm ... 500 RPM at your (corrected below) diameter of 2.166" is
283 SFM. 12L14 with uncoated carbides should be between 615 and 935
SFM, so no problem if it were really 12L14.

4140 anywhere between 330 and 705 SFM depending on hardness for
"hard" carbides. For "tough" carbides, it is between 125 amd 175 SFM
for Brinell 375-425 -- so it might have been some of that.

wall thickness was about (from memory) about .235

OD was about 2.166, best as I can recall at 6:38 in the morning

O.K. *That* sounds a lot better than the 2.667" from an earlier
post. This calculates out as 55.0164 mm -- so it is almost certainly a
55 mm bore in the bearing.

Out of curiosity -- how large was the stock you started from?
That could determine just how hot you got the workpiece while turning.

They were spacers that were pressed on to the ends of a double
herringbone drive gear, with a 13" x 3" herringbone gear near one end.
Then a 8" bearing was put on each end to support the drive gear(s),
which then drove a second larger herringbone drive gear, which actually
turned the drive shaft that spun the counterweights and lifted the
pumping unit "arm".

Sounds like an impressive piece of equipment.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---