Machining pipe conundrum

[Old Hat]

Can you elaborate on how you locate the pipe when you flip it? I can certainly get two bores of the right size that way but have some uncertainty whether the centerline of each will be coincident and/or parallel.

Apropos of the boring mill setup, I have used a between centers boring bar on the lathe with the workpiece clamped to the crosslide. It introduces some other problems (centering on the workpiece and making sure it's parallel to the ways) but it does guarantee that both end bores will be exactly in line and with a little twitching they can be exactly the same size.

Sorry, I've sort of scaled down my thinking automaticly without realising it.
Often when doing large work on floor-bars, it's just assumed that quallification cuts (indicatable areas)
need to be cut on a part. At times even requiring a set-up that acheives nothing else
but the formation of a patch in line with another patch, or perhaps a full length or full width witness cut.

The pipe would have needed something along these lines, indicatable, or rested on the witness in a V-block etc. etc.
===========

If cuts are not allowed but are needed, temporary pads are tacked on for these cuts
and removed when done.

[loose nut]

Just heard back from the guy I machined the pipe for (machined as stated in first post) and he said it worked fine. Thanks.

[mike4]

If its just for an axle ,why not grip it in the chuck use a steady ,just for safety, and machine one end to finished dimensions , assuming the chuck is a four jaw flip the pipe/axle over and machine the other end to finished size.
Easy and quick , I and others here have made our own tyre carriers for workshop use to allow one person to change truck tyres etc .

Material used was common garden variety gal or black pipe.

Michael

[Rosco-P]

It is for an axle, not a precision spindle.

I think everyone reading and commenting on this thread figured that out. Yes, for a simple axle. Carry on, tilting at windmills Don Quixote.

[darryl]

It is for an axle, not a precision spindle. Chances are it will be more than adequate for the job, and chances are it will be 'typically German over-machined' at that, even if it's detectable that the bores aren't precisely in line with each other. Ball bearings have more than enough tolerance for any 'off axis' misalignment that this proposed method would give.

[Rosco-P]

What about saying: No. No, I can't make it from this piece of water pipe you have. I can make it from DOM tubing, if you are willing to pay for the material. Even schedule 80 pipe would be a better starting point. Sometimes you can't make a silk purse from a sows ear, not matter how much of your time your willing to waste.

[loose nut]

Not a knee mill or a horizontal, I have a small home shop, not a big fab shop, so line boring or other ideas requiring equipment I don't have are out, hence the use of the lathe. As far as making it out of a tree stump, no I wouldn't but as far as pipe, well I'm not going to buy a piece of DOM tube (even if it is available locally, which it might not be. Country area not near a big city) for him so it is what I would use.

[MrSleepy]

A knee-mill has four mysterious bolts that when loosened

Does Loose Nut have a milling machine .. ?..

[TGTool]

A knee-mill has four mysterious bolts that when loosened, allow the head to be swung to the left
till your pipe can extend below the table surface. Bore, flip, bore, done.

Can you elaborate on how you locate the pipe when you flip it? I can certainly get two bores of the right size that way but have some uncertainty whether the centerline of each will be coincident and/or parallel.

Apropos of the boring mill setup, I have used a between centers boring bar on the lathe with the workpiece clamped to the crosslide. It introduces some other problems (centering on the workpiece and making sure it's parallel to the ways) but it does guarantee that both end bores will be exactly in line and with a little twitching they can be exactly the same size.

[Lu47Dan]

I have used pipe in the past and had it machine alright, but the vast majority of it did not like to be turned. I have tried various speeds and feeds on the bad pipe without success. Older American made pipe seems to turn better than the new stuff. I did use some recently that surprised me in how well it turned.
But if I could get or would have had DOM in stock I would have used it instead. Less problems and less time invested in it.
This is just my machining experience with BIP.
Dan.

[Old Hat]

Well! If he had given you a tree stump would you try to use that? :-) In some cases the "offered"
or "supplied" material just isn't suitable. :-)
...lew...

+1

If I wasn't busy and if the piece was short enough, I would line-bore it on the horizonal mill.

Get yourself some t-shirts made: "I'm a Machinist, not a Magician."

+1

A knee-mill has four mysterious bolts that when loosened, allow the head to be swung to the left
till your pipe can extend below the table surface. Bore, flip, bore, done.

My T-shirt Idea is:

He can do it Faster?
.........Great!.......
Then take it to him,
and I'll warm up the
... ... Dynasty ... ....

[gzig5]

The way I have done this in the past...
Cut work piece over final length, mount in 3jaw chuck, face end, bore bearing seat, bore minor ID if desired.
Remove work piece from chuck and either create an expanding arbor or turn a sacrificial arbor to press the work piece onto, registering on the bearing seat you have created.
Mount part onto the arbor you have created (use tailstock to press on if needed), face end to correct length, bore bearing seat, true OD if desired. Light cuts may be required depending on the mounting method.
Remove part from arbor and go enjoy the beverage of choice. The seats on the end should be square to each other and in line because your arbor was turned in place without removing it.

[Rosco-P]

Well! If he had given you a tree stump would you try to use that? :-) In some cases the "offered"
or "supplied" material just isn't suitable. :-)
...lew...

If I wasn't busy and if the piece was short enough, I would line-bore it on the horizonal mill.

Get yourself some t-shirts made: "I'm a Machinist, not a Magician."

[ironmonger]

How about reversing your thought process,,, build a v block to clamp the od of the pipe and bolt it to the compound in place of the toolholder, mount a boring bar in the chuck and bore the pipe.
If you are close to the correct ID my blacksmith side votes for machining a tapered swage a few thou undersized, heat the end of the pipe and drive the swage in, and the shrink fit the bearings in place. I either event, I would use a shaft to align the bearings as they were pressed into place.

As far as 'gummy' pipe is concerned, the only pipe that fits that description is wrought iron or 'Byers' pipe. It can be identified by a spiral red stripe... or if that is worn off by the crappy threading characteristics. Never had a problem threading pipe with the exception of an occasional inclusion. Using ark cutting oil, sulphated if available will yield excellent results.

see:

http://www.oatey.com/brands/hercules/products/oils-lubricants-and-hand-cleaners/cutting-oil/dark-cutting-oil

delicious!

paul

[Lew Hartswick]

DOM tube is out, it is a project for a friend and he gave me pipe.

Well! If he had given you a tree stump would you try to use that? :-) In some cases the "offered"
or "supplied" material just isn't suitable. :-)
...lew...