I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.

None of the usual suspects (MSC/Enco/McMaster) even admit to the
process. Several specialty suppliers have setups which seem godawful
overpriced ($1500 or so and up) for what they are - and don't even start
me on bore welders (5K+ and it still needs a MIG welder to run it - but
I can get by with boring and sleeving, I think). One guy offers a book
and plans and DVDs, also godawful overpriced ($1.5K). None to be found
on sleazebay at present.

I'm leaning towards kludging something together in the $500 (less if I
can) and sweat realm, which may not have auto feed (if it's manual feed
and the manual feed is fine enough to work, that should be OK, and
cheaper).

The basic structure of these things is a bar/shaft of whatever length,
and bearing sets that are tack-welded (or tackwelded and screwed) to the
machine. You line the bar up with either the hole (easy with cones) or
the centerline of where the hole is supposed to be if it's badly worn
(they mostly are) and chuck a lathe bit into one of several square holes
in the bar. There's some sort of power to rotate the bar, and some sort
of feed which will at least go a bit further than the spacing of the
holes in the bar. You fire it up and bore as far as you can, or though
one flange if it's something like bucket pivots, then set the bit in a
new hole and bore more, or in the other/next flange. Good for things
where the machine to be worked on is difficult to bring into the machine
shop.

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

On Mar 2, 12:05*pm, Ecnerwal
wrote:
I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.

None of the usual suspects (MSC/Enco/McMaster) even admit to the
process. Several specialty suppliers have setups which seem godawful
overpriced ($1500 or so and up) for what they are - and don't even start
me on bore welders (5K+ and it still needs a MIG welder to run it - but
I can get by with boring and sleeving, I think). One guy offers a book
and plans and DVDs, also godawful overpriced ($1.5K). None to be found
on sleazebay at present.

I'm leaning towards kludging something together in the $500 (less if I
can) and sweat realm, which may not have auto feed (if it's manual feed
and the manual feed is fine enough to work, that should be OK, and
cheaper).

The basic structure of these things is a bar/shaft of whatever length,
and bearing sets that are tack-welded (or tackwelded and screwed) to the
machine. You line the bar up with either the hole (easy with cones) or
the centerline of where the hole is supposed to be if it's badly worn
(they mostly are) and chuck a lathe bit into one of several square holes
in the bar. There's some sort of power to rotate the bar, and some sort
of feed which will at least go a bit further than the spacing of the
holes in the bar. You fire it up and bore as far as you can, or though
one flange if it's something like bucket pivots, then set the bit in a
new hole and bore more, or in the other/next flange. Good for things
where the machine to be worked on is difficult to bring into the machine
shop.

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

Guy Lautard had a description/rough diagram of such a setup in one of
the Machinist's Bedside Readers, the one he described was used for
blower housing reboring. I've also seen similar rigs shown for
reboring steam locomotive cylinders in situ, basically a keyed
rotating bar with two end plates and a drive pulley, the cutter holder
slid on the keyed bar and was advanced using a screw with a star wheel
on one end. The trick was to get the two end plates lined up in the
center of the hole to be bored, then fastened into place so they
didn't shift under cutting load. I've seen similar rigs in Model
Engineer magazine in the past for boring stuff that was too big to
swing in the lathe. So not a new idea. Just something that's not
really a commercial product these days.

Stan

On Mon, 02 Mar 2009 14:05:48 -0500, Ecnerwal
wrote:

I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.

....

I'm leaning towards kludging something together in the $500 (less if I
can) and sweat realm, which may not have auto feed (if it's manual feed
and the manual feed is fine enough to work, that should be OK, and
cheaper).

Can you borrow the head from a Bridgeport? Then all you need to do is
scab together a mount for the head, a boring bar, and a guide bushing.

--
Ned Simmons

I know of a place in Roberts Wisconsin that has (or at least had) a
pallet load or two of J heads. When they rebuild a Bridgeport, they
always take the J head off and upgrade at least one notch.

Pete Stanaitis
-----------------

Ned Simmons wrote:
On Mon, 02 Mar 2009 14:05:48 -0500, Ecnerwal
wrote:


I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.


...

I'm leaning towards kludging something together in the $500 (less if I
can) and sweat realm, which may not have auto feed (if it's manual feed
and the manual feed is fine enough to work, that should be OK, and
cheaper).


Can you borrow the head from a Bridgeport? Then all you need to do is
scab together a mount for the head, a boring bar, and a guide bushing.

I know this isn't exactly what you are looking for, but why not have it
done for you, since you are probably only going to have it done once?
Friends of mine in Rochester, MN run a fab shop/repair welding company
where they do exactly what you are talking about on a regular basis.
There must be others.

I bet my backhoe is older than your backhoe, and even if it isn't, I bet
mine is uglier,
Pete Stanaitis
---------------------

Ecnerwal wrote:

I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.

None of the usual suspects (MSC/Enco/McMaster) even admit to the
process. Several specialty suppliers have setups which seem godawful
overpriced ($1500 or so and up) for what they are - and don't even start
me on bore welders (5K+ and it still needs a MIG welder to run it - but
I can get by with boring and sleeving, I think). One guy offers a book
and plans and DVDs, also godawful overpriced ($1.5K). None to be found
on sleazebay at present.

I'm leaning towards kludging something together in the $500 (less if I
can) and sweat realm, which may not have auto feed (if it's manual feed
and the manual feed is fine enough to work, that should be OK, and
cheaper).

The basic structure of these things is a bar/shaft of whatever length,
and bearing sets that are tack-welded (or tackwelded and screwed) to the
machine. You line the bar up with either the hole (easy with cones) or
the centerline of where the hole is supposed to be if it's badly worn
(they mostly are) and chuck a lathe bit into one of several square holes
in the bar. There's some sort of power to rotate the bar, and some sort
of feed which will at least go a bit further than the spacing of the
holes in the bar. You fire it up and bore as far as you can, or though
one flange if it's something like bucket pivots, then set the bit in a
new hole and bore more, or in the other/next flange. Good for things
where the machine to be worked on is difficult to bring into the machine
shop.

In article ,
spaco wrote:

I know this isn't exactly what you are looking for, but why not have it
done for you, since you are probably only going to have it done once?
Friends of mine in Rochester, MN run a fab shop/repair welding company
where they do exactly what you are talking about on a regular basis.
There must be others.

Not much in Backside of Nowhere, Vermont. I went though a round of
trying to get this done a few years back - I was able to get one part
done at a local machine shop (the "shoulder" casting from the backhoe,
or main pivot, which I could get into the truck and bring to them), but
I couldn't find anyone for love nor money to do the matching part on the
hoe, so it's clap-trapped together with a new bushing, and key stock +
"plastic titanium" (whoop de do, a lousy 18KSI, but it's better than
"plastic steel" at 9KSI) to hold the bushing in the oval hole.

I looked at renting a portable line boring rig, and about gagged on that
price, too - pretty much the cost of buying one new. I might be able to
haul the thing a few hours to have someone work on it, but hauling it
costs money, and having it worked on by someone else costs more money.

You can hire folks that will drive in from wherever and do this sort of
work for you, but they are big bucks - nice to have on call if your
factory is down due to a spun bearing, not so much for your personal
backhoe...

Exceeding its actual value in repair costs is quite feasible down that
road, and that's not an amount of money I'd like to put towards this
project.

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

On Mar 2, 2:05*pm, Ecnerwal
wrote:
I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.


How big, how long, how smooth/accurate?

I've cobbled up a few hole-aligning rigs from reamers and drill rod.
AFAIK a single-bit boring bar needs controlled feed but you might be
able to drive a shell mill with a hand drill.

How about modifying a ridge reamer to be able to go fell depth? Maybe on a
threaded feed rod of some kind. Would it even work or would it just go back
and forth in the hole?




"Ecnerwal" wrote in message
...
I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.

None of the usual suspects (MSC/Enco/McMaster) even admit to the
process. Several specialty suppliers have setups which seem godawful
overpriced ($1500 or so and up) for what they are - and don't even start
me on bore welders (5K+ and it still needs a MIG welder to run it - but
I can get by with boring and sleeving, I think). One guy offers a book
and plans and DVDs, also godawful overpriced ($1.5K). None to be found
on sleazebay at present.

I'm leaning towards kludging something together in the $500 (less if I
can) and sweat realm, which may not have auto feed (if it's manual feed
and the manual feed is fine enough to work, that should be OK, and
cheaper).

The basic structure of these things is a bar/shaft of whatever length,
and bearing sets that are tack-welded (or tackwelded and screwed) to the
machine. You line the bar up with either the hole (easy with cones) or
the centerline of where the hole is supposed to be if it's badly worn
(they mostly are) and chuck a lathe bit into one of several square holes
in the bar. There's some sort of power to rotate the bar, and some sort
of feed which will at least go a bit further than the spacing of the
holes in the bar. You fire it up and bore as far as you can, or though
one flange if it's something like bucket pivots, then set the bit in a
new hole and bore more, or in the other/next flange. Good for things
where the machine to be worked on is difficult to bring into the machine
shop.

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

Ecnerwal wrote:

I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.


Self aligning pillow block bearings like:
http://www.mcmaster.com/param/images...gs/5967K31.gif

Shafting that fits bore of bearing.

Cross drill it for a piece of a square HSS lathe bit. Use a square file to square only
the corners of the hole so the HSS won't rotate and tap it for a set screw to press the
bit out each pass.

Now you have something you can pass though your boss from one side to another. The
bearing nearest the boss will support the cutting forces.

If you buy yourself a third similar bearing, you can lock that one to the shaft and use
two pieces of threaded rod to pull the bar though. Welding a couple nuts to your work
piece to hold the rods and using nuts on the bearing flange will let you create a forced
feed of sorts.

Wes


--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

"Ecnerwal" wrote in message
...
I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.

None of the usual suspects (MSC/Enco/McMaster) even admit to the
process. Several specialty suppliers have setups which seem godawful
overpriced ($1500 or so and up) for what they are - and don't even start
me on bore welders (5K+ and it still needs a MIG welder to run it - but
I can get by with boring and sleeving, I think). One guy offers a book
and plans and DVDs, also godawful overpriced ($1.5K). None to be found
on sleazebay at present.

I'm leaning towards kludging something together in the $500 (less if I
can) and sweat realm, which may not have auto feed (if it's manual feed
and the manual feed is fine enough to work, that should be OK, and
cheaper).

The basic structure of these things is a bar/shaft of whatever length,
and bearing sets that are tack-welded (or tackwelded and screwed) to the
machine. You line the bar up with either the hole (easy with cones) or
the centerline of where the hole is supposed to be if it's badly worn
(they mostly are) and chuck a lathe bit into one of several square holes
in the bar. There's some sort of power to rotate the bar, and some sort
of feed which will at least go a bit further than the spacing of the
holes in the bar. You fire it up and bore as far as you can, or though
one flange if it's something like bucket pivots, then set the bit in a
new hole and bore more, or in the other/next flange. Good for things
where the machine to be worked on is difficult to bring into the machine
shop.

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

My dad use to sleeve Hopto's. He attached a engine cylinder boring bar
machine to the side of the boom. Can not remember exactly how, been 40
years. then bored to size.

....
I bet my backhoe is older than your backhoe, and even if it isn't, I bet
mine is uglier,
Pete Stanaitis

....
Looks like the gauntlet has been thrown down. My Sherman is 55-60 years old
and looks it. It sits on a Ford NAA golden Jubilee (1953) I think it came
with the hoe but can't be sure.

Are you boring out pivots that have wore out? I repaired mine by
bolting/welding/clamping a plate orthogonal to the hole. Then using a mag
drill to enlarge the hole. You'll need a sacrificial piece to start the
drill and then act as a drill bushing. When you're close use an expanding
reamer to ream perfectly perpendicular.

An alternate to enlarging is to weld in the pivot point then die grind kinda
close before doing the above.

Its not that bad a job to do it this way once you've done one to get the
hang of it. I've rebuilt loader, scraper and backhoe pivots this way.

HOWEVER, I did buy a monster radial drill press to make this job easy. Of
course, I waited to buy the drill until after I had all my equipment
rebuilt.

Karl

On Mon, 2 Mar 2009 12:55:51 -0800 (PST), Jim Wilkins
wrote:

On Mar 2, 2:05*pm, Ecnerwal
wrote:
I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.


How big, how long, how smooth/accurate?

I've cobbled up a few hole-aligning rigs from reamers and drill rod.
AFAIK a single-bit boring bar needs controlled feed but you might be
able to drive a shell mill with a hand drill.
----------
Some of the old old time machinist's books [reprints] that
Lindsay books sells covers the technique of boring a cylinder in
place including line drawings of the set-up. This apparently was
for steam engines with the cast iron of the day, so I don't know
about the accuracy.
http://lindsaybks.com/prod/index.html

if you have a high speed internet connection and adobe reader
installed [free] download
http://books.google.com/books?id=eeE...WdJ4RR4lQBPCCs
and take a look at pages 224-230 [247 on reader]

Looks like a perfect RCM project. Lots of moving parts and
dangerous as hell.
Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).

I'll try for an omnibus reply.

A few commercial sources for those that think this is just old-tyme
stuff.

http://www.yorkmachine.com/
http://www.americanmachinetools.com/Line_Boring.htm
http://www.boremaster.us/
http://www.dlricci.com/drill2.htm

Yes, I'm (hopefully) redoing some worn out pivots - or eventually I am -
I may need to keep abusing them for another summer to get work done, but
if I can do a bit at a time and get the worst ones done, it would help.

Wes has the basic idea down, and one can buy exactly that from several
places, but I see no reason (thus far) I can't put it together myself
for about $1000 less.

Hole size ranges from an inch or so (too small for most commercial
versions) up to 3 inches. It may actually be that the pin in the hole is
an inch, which means that the bore for the bushings (MIA, or I'd just
drive out and replace with new) is bigger - the smallest ones are for
the steering linkage, and lord knows what some idiot did, but there's no
trace of the bushings on those parts. Of course the loose pins have beat
the heck out of the holes. The big ones are either a 2 or 2.5 inch pin
with a bushing for another half inch diameter. Those 1/4" thick hardened
steel bushings were worn right through and wear continued quite some
distance in to the base steel.

George's book link is good, and he's got the right spirit - complicated
and dangerous, that's us. The main difference with the newer systems is
that the moving cutterhead is generally replaced by moving the whole
boring bar through bearings, and setting the bit in a hole in the bar
itself. This would seem to allow a thicker bar relative to the size of
the hole, and that keeps deflection down. I don't think any of the
modern ones try to run a pair of bits, either - getting them matched
precisely must have been fun.

The mag drill by itself places a lot of dependence on getting its
mounting perfect. At least one of the commercial bars does use a mag
drill as its drive (and feed, perhaps...)

Bridgeport head as drive and feed is not a bad idea at all, though I'm
willing to trend cruder. It limits to driving from one end, but that is
not an issue for backhoe parts as far as I can tell. Some of the
commercial bars tout flexible drive options for getting into more
difficult situations, but the hoe (and loader bucket) are comparatively
accessible, on that basis.

Radial drill press - I've had one on my list since I first learned about
them, but haven't gotten one yet. I'll up my shopping effort.

Age and ugliness - Hoe is a ford 4500 industrial TLB, only 40-41 years
old. Many joints and pivots are severely ugly (in the more important
mechanical sense) through some decades of no grease, at a guess. I might
have continued shopping had I known better at the time, but this was
also less than half the price of the next contender when I was shopping,
and a considerably better machine in the sense that it's a hoe built on
a hoe platform (27gpm pump!), not a tiny hoe stuck on an ag tractor.
I've certainly made it pay for itself - I've also wished it was bigger
(it's a 13 foot hoe) which would have surprised the heck out of me when
I was shopping and thought it was a bit intimidating size-wize - that
was before I started stumping hardwoods in bony gravel. The paint is a
crude job, and is has scars and bad welds (many not mine, some mine -
mine are at least not the worst on it), plus some big plates that the
previous owner was fond of tossing over cracks. My old welding
instructor would have looked at those and yelled stress riser, and I
agree, but have not had time to go over them and "fix them right". I do
at least try to make my repairs somewhat better designed. The buckets
both need work - I have a strip of old road grader edge my brother
donated to fix up the severely worn front bucket - the hoe bucket needs
teeth - well it needs shanks, too, as the "teeth" it has are actually
terribly worn shanks that were dug a long time without teeth on them.
Actual hard, sharp teeth would make root breaking about 9 times easier,
and that's the key to stumping - but at this point I have most of the
stumps out - the road is built, etc. Several cylinders are scarred, and
most could stand to be repacked, but time is finite and work to be done
is infinite...

What I really need is some sort of tractor restoration nut in dire need
of a project, but that sort of thing doesn't happen, or they get
terribly upset when you take the newly refurbished, tight hoe out and
scratch the paint on it, or get it dirty.

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

"Ecnerwal" wrote in message
...
I'll try for an omnibus reply.

A few commercial sources for those that think this is just old-tyme
stuff.

http://www.yorkmachine.com/
http://www.americanmachinetools.com/Line_Boring.htm
http://www.boremaster.us/
http://www.dlricci.com/drill2.htm

Yes, I'm (hopefully) redoing some worn out pivots - or eventually I am -
I may need to keep abusing them for another summer to get work done, but
if I can do a bit at a time and get the worst ones done, it would help.

You're probably aware that you only have to bore that line very rough.
Portable align-honing equipment to finish the job will take out a lot of
metal these days, although you won't be able to take out the tens of
thousandths they get with fixed diamond honing machines.

--
Ed Huntress

Info on one version he
http://www.cpmt.com/tool_over_bm.php

Click on the pdf specs on the right side--has some good drawings.

I've also seen one that used a power head kind of like a handheld electric
pipe
threader. We had a guy come out and line bore the front axle pivots on a
large
4x4 John Deere tractor. Took him a couple of hours, cost around $150.

....
http://www.americanmachinetools.com/Line_Boring.htm

They're using the mag drill the way I did it. I was lucky my biggest holes
were two inch. My bucket was similar to the one in the picture. I set up the
drill four times - each side of each support. I see this line bore would do
it in one shot.

For mounting the mag drill you got to think outside the box sometimes. The
vertical pins that swings the whole backhoe were totally shot. There's
nothing left to mount to after removing the hoe. So, I mounted the drill to
the loader bucket of another tractor, got a pile of blocks and pressed the
bucket down on it. This worked really neat cause adjusting the angle was
just bucket tilt.


You're probably aware that you only have to bore that line very rough.
Portable align-honing equipment to finish the job will take out a lot of
metal these days, although you won't be able to take out the tens of
thousandths they get with fixed diamond honing machines.


My efforts were REALLY rough. A carbide burr on a die grinder will move a
hole over quickly.

Good luck in your project.

Karl

In article ,
"Ed Huntress" wrote:

You're probably aware that you only have to bore that line very rough.
Portable align-honing equipment to finish the job will take out a lot of
metal these days, although you won't be able to take out the tens of
thousandths they get with fixed diamond honing machines.

No, I was not aware of that, though most of the web-links that come up
on align honing are about engine building and concerned with working to
tenths. I do find a few things more in the line of the work I'm doing.

Mind, for most of the stuff I'm doing, if I can press in a bushing
without deforming its inside surface too much, I don't have to get too
fussy about the bore finish.

And I freely admit (and would welcome enlightenment) that I don't have a
great understanding of honing - I've got one of those "three swivelling
stones on a spring spider" cylinder hones which I've used to reduce some
burrs in a hydraulic cylinder, but those seem to be dependent on having
a good round, straight hole to start with.

Something like this:

http://greatnecksaw.com/images/produ...arge/25041.jpg

These look somewhat different, though there's not enough detail to see
how the head works in terms of stone movement. I gather it might be
somewhat more controlled than the above type.

http://www.precitech.no/Finbearbeidi...20prtabelt.pdf

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

"Ecnerwal" wrote in message
...
In article ,
"Ed Huntress" wrote:

You're probably aware that you only have to bore that line very rough.
Portable align-honing equipment to finish the job will take out a lot of
metal these days, although you won't be able to take out the tens of
thousandths they get with fixed diamond honing machines.

No, I was not aware of that, though most of the web-links that come up
on align honing are about engine building and concerned with working to
tenths. I do find a few things more in the line of the work I'm doing.

Mind, for most of the stuff I'm doing, if I can press in a bushing
without deforming its inside surface too much, I don't have to get too
fussy about the bore finish.

And I freely admit (and would welcome enlightenment) that I don't have a
great understanding of honing - I've got one of those "three swivelling
stones on a spring spider" cylinder hones which I've used to reduce some
burrs in a hydraulic cylinder, but those seem to be dependent on having
a good round, straight hole to start with.

Something like this:

http://greatnecksaw.com/images/produ...arge/25041.jpg

These look somewhat different, though there's not enough detail to see
how the head works in terms of stone movement. I gather it might be
somewhat more controlled than the above type.

http://www.precitech.no/Finbearbeidi...20prtabelt.pdf

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

Honing has changed a lot in the last ten years. It used to be strictly a
finishing operation. Now, thanks to the diamond abrasive and non-compliant
production-honing techniques developed by Sunnen and others, it can be used
to remove remarkable amounts of metal and it can correct out-of-round and
out-of-line conditions that were impossible years ago. It's replaced boring
in some production applications, combining what used to be two steps into
one.

That's all done with fairly hefty stationary machine tools, but the portable
honing equipment used by small-time engine rebuilders and so on has
benefitted from some of this technology. I knew the subject fairly well six
or seven years ago, when I was researching and writing about it, but it's
slipped away from me. I don't know where we are today except that it's
somewhere better than we were with the compliant-hone tools you're talking
about.

Maybe someone involved in engine work or commercial machining applications
can fill you in. If not and if you want to know, get back to me and I'll see
if there's still anyone at Sunnen I can call.

--
Ed Huntress

--I'm having a little trouble visualizing the problem so take my
suggestiong with a grain of salt but could you not blacken the shaft with
lampblack and pour a babbit bearing in place?

--
"Steamboat Ed" Haas : Politics is a sinkhole for
Hacking the Trailing Edge! : people without hobbies...
www.nmpproducts.com
---Decks a-wash in a sea of words---

On Mar 3, 11:11*am, Ecnerwal
wrote:
...
Mind, for most of the stuff I'm doing, if I can press in a bushing
without deforming its inside surface too much, I don't have to get too
fussy about the bore finish.

If you do compress the bore too much, you could try this:
http://www.geocities.com/Paris/5701/...ipes/tools.htm

The head needs to be hardened steel, like a large socket, but the
shank could be water pipe turned smooth and guided by drilled plates,
with enough end clearance to start the cutter. You might be able to
anneal the socket, bore it to fit over the pipe, tap some holes to
attach it to the center of the pipe, mill teeth, and harden it. Before
I bought the surface grinder I sharpened home-made annular cutters on
the lathe with a Dremel on the toolpost.

Check the pipe's roundness before you buy it. Some that I've bought
recently cleaned up round with a 0.005" cut, other pieces were pushed
in along the weld line. You don't have to clean it up all the way
around but a dip can throw it off in the 3-jaw and tailstock center.

Weld a socket onto the end and drive it with a flex extension so you
don't put a bending force on the shaft.

Keyed shafting is less expensive than drill rod and quite useful for
homebrew lashups. I've had good luck with Enco's import keyway
broaches and home-made shims and guide bushings.

Jim Wilkins

"steamer" wrote in message
...
--I'm having a little trouble visualizing the problem so take my
suggestiong with a grain of salt but could you not blacken the shaft
with
lampblack and pour a babbit bearing in place?

--
"Steamboat Ed" Haas : Politics is a sinkhole for
Hacking the Trailing Edge! : people without hobbies...
www.nmpproducts.com
---Decks a-wash in a sea of words---

Ed - remember the conditions these plain bush bearings work under.
Vast load and in a mixture of concrete dust / earth etc. The welded in
bushes a usually pretty hard. The daily greasing does push the gunge
out but it'll be back as soon as the bucket goes in the muck!

AWEM

Wes wrote:

I'm seeking thoughts, insight, tips or tricks relating to portable line
boring. I have a backhoe, and when it was built, LBJ was president.

I didn't verbalize really good so here is a picture of a home made boring bar.

http://www.garage-machinist.com/usen...Boring_bar.jpg

The drawing is using a 1" shaft, 1/4" HSS lathe bit, and tapped for a 5/16 set screw to
push the tool out.

You don't need fancy bearings. Plates with close fitting holes tacked to each side to
center bar, use lots of lube.

Look at Bill Marrs link, specifically,
http://www.cpmt.com/docs/bm/BB5000%2...%20Machine.pdf

You don't have a big pin hole so the cutter head shown isn't going to work but I think
what I drew would work for you.

Wes

In article ,
steamer wrote:

--I'm having a little trouble visualizing the problem so take my
suggestiong with a grain of salt but could you not blacken the shaft with
lampblack and pour a babbit bearing in place?

'Fraid not. This is joints in hydrualic construction machinery - steel
pins running in hardened steel bushings is typical construction. If the
bore for the bush is not hosed, maintenance is pretty simple, for
moderate values of simple - yank pins (swear), remove bushings (swear
more), new bushings (and pins, if needed) (swear a little, but most of
the swearing is for removal). Keep it greased...

If you were to pour up a nice Babbit bearing, then go use the machine,
it would be: hook onto a rock, squeeze the Babbit out like toothpaste.
The joints would have to be made much larger to get the pressures down
where bearing materials like Babbit hold up.

Very low velocity, very high pressure, plus a filthy and abrasive
working environment.

For a vague idea of what's involved, consider that my bucket is rated to
produce 9000 lbs of force at the edge - which is about 2 feet from the
pivot. The cylinder is less than a foot away on the other side, so it
has to be putting 18,000 lbs into the bucket pins, and the pivot itself
gets some large force that's not immediately obvious, but might be as
much as 27,000 lbs...on a pin that's about and inch and half diameter,
with the bearing on the bucket only 1-1/4 inch long on either side of
the dipper-stick.

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

Ed Huntress wrote:
"Ecnerwal" wrote in
message
...
In article ,
"Ed Huntress" wrote:

You're probably aware that you only have to bore that line very
rough. Portable align-honing equipment to finish the job will take
out a lot of metal these days, although you won't be able to take
out the tens of thousandths they get with fixed diamond honing
machines.

No, I was not aware of that, though most of the web-links that come
up on align honing are about engine building and concerned with
working to tenths. I do find a few things more in the line of the
work I'm doing. Mind, for most of the stuff I'm doing, if I can press in
a bushing
without deforming its inside surface too much, I don't have to get
too fussy about the bore finish.

And I freely admit (and would welcome enlightenment) that I don't
have a great understanding of honing - I've got one of those "three
swivelling stones on a spring spider" cylinder hones which I've used
to reduce some burrs in a hydraulic cylinder, but those seem to be
dependent on having a good round, straight hole to start with.

Something like this:

http://greatnecksaw.com/images/produ...arge/25041.jpg

These look somewhat different, though there's not enough detail to
see how the head works in terms of stone movement. I gather it might
be somewhat more controlled than the above type.

http://www.precitech.no/Finbearbeidi...20prtabelt.pdf

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

Honing has changed a lot in the last ten years. It used to be
strictly a finishing operation. Now, thanks to the diamond abrasive
and non-compliant production-honing techniques developed by Sunnen
and others, it can be used to remove remarkable amounts of metal and
it can correct out-of-round and out-of-line conditions that were
impossible years ago. It's replaced boring in some production
applications, combining what used to be two steps into one.

That's all done with fairly hefty stationary machine tools, but the
portable honing equipment used by small-time engine rebuilders and so
on has benefitted from some of this technology. I knew the subject
fairly well six or seven years ago, when I was researching and
writing about it, but it's slipped away from me. I don't know where
we are today except that it's somewhere better than we were with the
compliant-hone tools you're talking about.

Maybe someone involved in engine work or commercial machining
applications can fill you in. If not and if you want to know, get
back to me and I'll see if there's still anyone at Sunnen I can call.

The stones are mounted on rods with a rack cut into them , the center rod
of the hone assembly is a pinion that fits into a square block that has
holes for the rack rods . There is a small planetary gearset built into the
drive/center rod to extend or retract the stones . Two stones and two wipers
constitute a set .
At least that's how my Sunnen cylinder hone is made . And yes , they will
straighten an oval/tapered hole . I've used mine more than once to bore
motorcycle cylinders to the next oversize ... also works very well to
lightly scuff a cylinder and remove the ridge at the top in preparation for
new rings .
--
Snag
every answer
leads to another
question

On Mar 3, 5:52*pm, Ecnerwal
wrote:
...
For a vague idea of what's involved, consider that my bucket is rated to
produce 9000 lbs of force at the edge - which is about 2 feet from the
pivot. The cylinder is less than a foot away on the other side, so it
has to be putting 18,000 lbs into the bucket pins, and the pivot itself
gets some large force that's not immediately obvious, but might be as
much as 27,000 lbs...on a pin that's about and inch and half diameter,
with the bearing on the bucket only 1-1/4 inch long on either side of
the dipper-stick.

18000 / (1.5 * 2.5) = 4800 PSI. When I designed my front end loader I
looked for examples of bearing pressure and found as much as 9000, on
a swinging bridge pivot. I kept mine to 2000 to allow brass pipe
bushings, the max for sintered oilite is lower. It operates at half
the design load which blew the front tires.

Jim Wilkins