Project, 1903 Autocar. The engine specifically. My buddy is hip-deep
in the rebuild. He's manufacturing new connecting rods out of 4140.
This is for sure 4140, he purchased it from a steel supplier.

1). Any tips for milling this stuff? I think I turned some once and
it's challenging, but the results can be spectacular. Anyway, he's
using a boring head to cut a radius near the "large" end of the rod
and experiencing chatter. Switching to a new (sharper) boring bit,
definitely helped. This is an interrupted cut, making it more of a
challenge. Coolant? He's using cutting oil & a brush.

2). Any known (reliable) end-mill sharpening services in the Twin
Cities metro area. He wants to resharpen his destroyed carbide end
mill.

2a). I was wondering if one of those carbide insert mills might work,
like from plastools?

3). J-Head bridgeport "newer than the round ram". Power quill feed
won't engage. What are the proper steps, start-to-finish to engage the
power feed for the quill? Link to owners guide, anything?

4). Back to the connecting rod. After shaping, what is appropriate
heat-treating for this use? Stress relief? Nothing? Any other
treatments prior to final fitting?

2a). I was wondering if one of those carbide insert mills might work

Carbide insert mills work very well indeed. Even the cheap ones.

3). J-Head bridgeport "newer than the round ram". Power quill feed
won't engage. What are the proper steps, start-to-finish to engage the
power feed for the quill?

First thing to do with the mill turned off, is to pull the lever with
the black ball handle to the left. If it doesn't click and stay over
there, then you simply need to start taking apart the powerfeed until
you find the problem.

Strongly suggest you contact whoever is sourcing BP parts and get a
manual and reliable source for BP parts before you begin.

GWE

--
Posted via a free Usenet account from http://www.teranews.com

2). Any known (reliable) end-mill sharpening services in the Twin
Cities metro area. He wants to resharpen his destroyed carbide end
mill.

Chuck Keske, Cokato, MN is great. Evening job for him. its best to send him
a bunch at once. I live 7 miles from there, but I'm sure he does US mail.

karl

On Fri, 28 Dec 2007 07:30:02 -0800 (PST), JHP
wrote:



3). J-Head bridgeport "newer than the round ram". Power quill feed
won't engage. What are the proper steps, start-to-finish to engage the
power feed for the quill? Link to owners guide, anything?

I think Ig has a B'Port manual available online. Failing that, I
have one but not online.

You were very right Grant. I got a call this afternoon and after a day
of work he was able to have success. Something about a split-ball with
separating disk, and some gunk. There is joy in the shop once again.
Thanks very much.

I did have some luck, not having a bridgeport (sigh, sniff) I'm not
sure of the model but these two seemed to have promise:

http://www.bbssystem.com/manuals/jhead_huge.pdf
http://www.bbssystem.com/manuals/M105H_Series1.pdf

In article
,
JHP wrote:

Anyway, he's
using a boring head to cut a radius near the "large" end of the rod
and experiencing chatter. Switching to a new (sharper) boring bit,
definitely helped. This is an interrupted cut, making it more of a
challenge.

Correct me if I'm wrong, but could you perhaps machine 2 at once, bolted
together, and not have an interrupted cut? as best I fuzzily recall,
most rod ends appear to be a half-circle, with the cap being another
half-circle (perhaps not quite to permit for some shimming to size - but
you could bolt two together with a shim, then?)

--
Cats, coffee, chocolate...vices to live by

JHP wrote:

I did have some luck, not having a bridgeport (sigh, sniff) I'm not
sure of the model but these two seemed to have promise:

http://www.bbssystem.com/manuals/jhead_huge.pdf
http://www.bbssystem.com/manuals/M105H_Series1.pdf

The latter appears to be a Bridgeport manual no. M105H which is the
latest (and probably last) one i.e. the correct one.

Glad it worked out.

Grant Erwin
Kirkland, Washington

--
Posted via a free Usenet account from http://www.teranews.com

snip ---he's
using a boring head to cut a radius near the "large" end of the rod
and experiencing chatter. Switching to a new (sharper) boring bit,
definitely helped. This is an interrupted cut, making it more of a
challenge. Coolant? He's using cutting oil & a brush.

It took me a long time to realize that most carbide cutters have poor
front relief in order to have enough strength, so the heel rubs before
the tip can cut. This causes all sorts of problems. Try simple HSS
cutter with more of an acute front rake. If the radius of the cut is
around a half inch or 3/4, then it's a definite possibility.
Also, the boring bar may not be rotated properly in the boring head
so the heel of the carbide cutter is dragging.

Lastly, how long is the shank of the tool? Keep the boring bar as short
as possible.

As you know, carbide doesn't usually like interupted cuts.

western Wisconsin,
Pete Stanaitis
---------------------------------

spaco wrote:


snip ---he's

using a boring head to cut a radius near the "large" end of the rod
and experiencing chatter. Switching to a new (sharper) boring bit,
definitely helped. This is an interrupted cut, making it more of a
challenge. Coolant? He's using cutting oil & a brush.


It took me a long time to realize that most carbide cutters have poor
front relief in order to have enough strength, so the heel rubs before
the tip can cut. This causes all sorts of problems. Try simple HSS
cutter with more of an acute front rake. If the radius of the cut is
around a half inch or 3/4, then it's a definite possibility.
Also, the boring bar may not be rotated properly in the boring head
so the heel of the carbide cutter is dragging.

Lastly, how long is the shank of the tool? Keep the boring bar as short
as possible.

As you know, carbide doesn't usually like interupted cuts.

western Wisconsin,
Pete Stanaitis
---------------------------------

Pete,

You know that the brazed carbide cutters are usually just a starting
point for a tool, right?

They generally need to be ground to make them useful, as the sharp
corners are fragile, and, like you said, the heel rubs. You really need
a decent carbide grinder, with a green wheel on one side, and a diamond
wheel on the other, to see how nice they can work. :-)

Inserts. Different story. Lots of good insert grades out there.

The interrupted cuts thing is OLD tech. Pick the right grade of
carbide and you can do brutal things to it. Pick the wrong one, and you
will have a miserable day.

Consider also that every carbide endmill made, has at least one
cutting edge swinging around in circles, and it is a continuous
interupted cut, and they hold up just fine.

HSS is a good pick for this job, all said. Sharp edge, a bit of a
radius on the tip, and a fairly fine feed to finish.

It seems a waste of effort though, as like as not, the rods should get
put on a hone and be brought to size and roundness.

Jigging pairs of the rods back to back, and boring the hole out seems
a reasonable way to bring the hole up to near size.

Cheers
Trevor Jones

Here's a picture

http://hofstad-parkhill.com/pics/rod_004.jpg

Any clues on heat treatment? Is peening sufficient?

disclaimer
Not my project.
/disclaimer

It's been a very long time since I've visited this group. It's awesome
to see familiar names out there.

JHP wrote:

Here's a picture

http://hofstad-parkhill.com/pics/rod_004.jpg

Any clues on heat treatment? Is peening sufficient?

disclaimer
Not my project.
/disclaimer

It's been a very long time since I've visited this group. It's awesome
to see familiar names out there.

Carillo lookalikes in an 11 bhp engine? Nothing like the originals.
Heat treatment? LOL
Is this going to be a hotrod? :-)

Tom