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Evan
04-29-2007, 10:55 AM
I was in at the local job shop recently and Justin, one of the machinists there, was line boring hardened bushings on a loader bucket. I took a few pics to show how this is done using a portable boring machine.

http://vts.bc.ca/pics2/linebore1.jpg

http://vts.bc.ca/pics2/linebore2.jpg

Note that in the below pic the pillow block to support the boring shaft has been mounted on a temporary bracket welded to the bucket. It will be removed when the job is done.

http://vts.bc.ca/pics2/linebore3.jpg

http://vts.bc.ca/pics2/linebore4.jpg

lazlo
04-29-2007, 11:04 AM
Nice job -- that rig is shop-built: a couple of large pillow blocks bored for guide rods and tapped for the leadscrew, a large hammer drill,
and a Bridgeport power-feed driving the creep feed.

Pretty clever!

Evan
04-29-2007, 11:16 AM
Yep. Manual machining isn't dead yet.

Al Flipo
04-29-2007, 11:19 AM
That Tim Horton Coffee (pre roll up the rim) is the clincher. The worn out bore is welded up and then machined to fit the new hardened bushings.

tattoomike68
04-29-2007, 02:10 PM
While thats a nice way to do the job..... I would have made the whole pin bosses on the lathe, torched the old pin bosses out of there and welded in the new ones in using the new pin to line it up.

John Stevenson
04-29-2007, 03:24 PM
Somewhere in an old engineering book I have a sketch of a similar machine.
This one differs in that the boring bar is clamped to the drive motor one end and supported in a tempory bearing the other end [ as in Evan's ] but the bar doesn't move, only rotate.
The feed screw goes down the centre of the bar and the boring carriage is on this and slide via a slot in the boring bar.

Feed is applied automatically by differential gearing on the motor end.

This type of boring head can do blind bores and also bore large valve seats.
It's not a new idea I think Wilkinson invented it in 1775

http://www.making-the-modern-world.com/stories/manufacture_by_machine/03.ST.01/img/IM.0429_zl.jpg

motorworks
04-29-2007, 04:29 PM
Evan
That is a York bar See movie:
http://www.yorkmachine.com/yorkClip.html

JCHannum
04-29-2007, 06:45 PM
This is a steam powered portable boring bar being used to bore the cylinder of a steam engine. This is in the Ford Museum. I want the little vertical engine.

http://members.aol.com/jchannum/fordbore

Carld
04-29-2007, 08:57 PM
I found and bought a portable boring bar for steam locomotives for the railroad museum here. They were very pleased to get it as they thought they would have to bore out their steam locomotive. Turned out the cylinders were acceptable.

I would have repaired the bucket like tattomike said. The boring bar in that case would be overkill to me.

Edit: When welding in new pin rings they will shrink some so after they are well tacked in it is best to remove the alignment bar or you may not get it out. The holes can be honed out to fit. I can't justify the boring bar for the few times I would use it.

Bguns
04-29-2007, 09:09 PM
Have seen that cutting out and welding in new bores, often distorts bore enough to need boring anyway......

Evan
04-29-2007, 09:21 PM
There must be a reason Justin is doing it that way. This is an ordinary event for these guys, they fix heavy equipment on a very regular basis. With two major mines and seven major sawmills there is a LOT of heavy equipment here.

wierdscience
04-29-2007, 10:50 PM
Last one I did was a 6 yard bucket off a JD loader.Same basic setup,but mine was shop built and caught all four bores in one setting.I just used a 1" Milwaukee drill motor for power.

Buckets are easy,articulated steering joints on loaders are the PITA.Dirt,grease and hydraulic hoses everywhere,nasty job.

Wonder what they charge for a job like that?That 6 yarder cost the company $950 and took the better part of a day.