How would you machine this part without a lathe?

R

rodjava

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I have this job about twice a year to machine the end of the bolt as in the picture. Approximately 100 at a time. It was simple enough to do on my lathe. But now the lathe has been sold.

How would you machine this bolt with only a manual or cnc milling machine? I do have a 4th axis and a 5c cam collet fixture.

If at all possible the setup and run has to be simple and easy. The tolerances are very loose. 3-5 thou.

Any ideas would be appreciated.

Thanks to the membership in advance.

I don't know how to add pictures to my post. I only have this link.

https://www.amazon.com/photos/share/QSTpKzOTfLQdX6kuSuVAK7ghp5sFbacNnMNOIXkoR71

Rod in San Francisco
 
Hi Rod,
the first thing that came to mind was to put a nut on the bolt and create the correct stick out for use in a Hex collet in the spindle of the mill and use it a a vertical lathe.
then use blocking under a ground HSS or carbide bit, in the milling vise, to the correct depth- without interference of the table.
set the correct center of the bolt with the table axes and then,
simply use the spindle or knee feed to whittle away at the the bolt until you come to the correct depth of cut
with some experimentation you could create a system, i'm sure.

i'd like to hear other folk's take too, you got me to thinking here.....:cool:
 
You didn't say the bolt size but you could make a threaded bushing to fit an R8 collet and thread the bolt into it mounted so the head is up. Use the mill as a vertical lathe with single point cutter tool held in the vise or other appropriate method. Use the mill's z axis for the equivalent of the carriage movement and the x or y axis for the facing movement.

edit: Mike, you beat me to it!
 
another thought occured....
if you had a spindexer and a tailstock, you could horizontally chuck up the bolt/nut arrangement in a hex collet, like mentioned above,
and use an endmill in the vertical spindle to take light cuts in a manual spindexer using rotary motion to create the desired effect too, i suppose
 
Might put 5/10 holes in a plate, or between the edges of two plates to hold 5/10 bolts with the threaded ends up then circle mill the dia. onto the bolts change cutter and cut the chamfer.

Jim
 
I'd make a set of soft jaws for the mill (threaded end of the bolt pointing up, pocketed at the bottom for the hex head) and cut the turned dimension with a boring head. I did a similar job about a year ago and remember even some of the retirement-age guys being blown away at having never thought of doing OD work like that with a boring head. A good friend and mentor showed me that trick years ago and I've used it to good advantage several times since.
 
It might be useful to bore the end of a shorter bolt, and press/glue a pin into
it. You can get lengths of drill rod in better alloys than most bolts
are made of. A threaded block that you can position for drilling is
an easy jig to make.

I'm fold of soft solder for this kind of thing.
 
I'd use the spindexer with a collet in the mill vise , use a stop to set length of cut and use the feed stop for diameter. Mount in collet down feed the endmill spin the indexer by hand to turn the diameter. Can be done lots of ways. I try to use the simplest and quickest.
 
Here's a pic of the project in question.

screw.jpg
 
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