On Sat, 31 Dec 2005 15:28:25 -0800, "Harold and Susan Vordos"
wrote:
"Gunner Asch" wrote in message
.. .
On Sat, 31 Dec 2005 16:10:52 +0100, "Steve Lusardi"
wrote:
Gee, all that work for a $8.60 part!
Steve
This is a machining hobby group..right? Im learning to be a
machinist. I think of this as a practical application/lab in the
course. This is not like making a steam engine, or a V8 or something
hard. I was just asking about the best way to do something simple.
I agree. It's not always about the cost----what you went through is a good
learning experience.
snip--
The mystery metal I used for the Body of the thingy..its
magnetic..and it rusts..but ****me it was hard turning..you can see by
the blue chips, and drilling it was interesting..chips came out as
flakes rather than curls. Shrug..I have a 6 foot bar of it..
That could be chrome moly, by the machining description. If it's 4140,
4143 or 4340, it won't like being welded.
I'm afraid I'll have to disagree at least a little in this
statement. I actually believe that 4140 was developed to be a high
strength material that could be welded reliably. Yes care should be
taken but it's definitely weldable by any of the low hydrogen
processes without complicated heating schedules like many of the
higher carbon steels. Now I don't recommend machining it near the weld
after it's been welded without proper preheat and post heat. While not
impossible it does make it hard to enough to make it tough to maintain
tolerance compared to the softer material near it (in other words the
cutter does like to ride on top of the hard metal :-).
A example that comes to mind is a pto shaft I repaired a while back.
The splined shaft had sheared off just at the transition from the
bearing land to the large portion that went into the tube. I repaired
it by welding a large chunk of shaft I sawed from a old pump jack tail
bearing shaft onto the remains of the splined shaft. I then turned it
to fit the tube and the bearing. Unknown to me till I went to machine
it but that particular pump jack bearing had been repaired with one of
the above alloys being used for the shaft (some what unusual, most are
mild steel). I found out once I started returning the area where the
ball bearing was to sit. Nice little hard ring right around the shaft
up to the weld deposit. I managed to turn it but it required a light
cut and sharp tool to keep that area from being larger than the softer
material around it. That shaft later failed but it didn't fail at my
weld. It failed further down the shaft near the actual splines the
second time around.
Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm