Lathe Question

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joewhite
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Lathe Question

Post by joewhite »

I now have access to a lathe but have a question. What's tyhe best way to chuck PVC piping? I notice quite a few scratch-builders turn PVC however the owner of the lathe nor myself could figure out a good way to chuck hollow piping. He recommended stuffing the ends with an appropriate sized and rounded piece of wood or dowel and inserting screws to hold it in place then chucking.

Here's what I mean..... http://joesmodels.50webs.com/pictures.html

It'd be nice if someone made large solid plastic cylinders. Anyway....any help would be awesome! Thanks in advance!

Joe
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Kylwell
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Post by Kylwell »

Ah, wood lathe I'm guessing.

Most metal lathes come with a 3 jaw chuck, or a 4 jaw chuck. This makes mounting anything really easy.

What you describe looks like the best bet with the equipment given. The tough part will be centering the piece.

As for solid rod....
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Andrew Gorman
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Post by Andrew Gorman »

Another possibility is to put a PVC pipe cap at each end. Friction alone could hold them in place, or use setscrews or glue. The cap could be cut back if you need to work right up to the end.
Andrew
Darth Humorous
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Post by Darth Humorous »

If it be a wood turning lathe, I would first turn a long wood plug with two stepped shoulders, one on either end against the lathe centers. The stepped shoulders could have the exterior diameter of th pipe, and obviously the remaining turning in between would have the interior diameter of the pipe, snug to tight fitting. Make sure the shoulders are at the very ends of the turning blank.

When done turning the plug, cut it in half. Insert a half plug into each end of the pipe. Hopefully, you will need to coerce them a little to get them in. Now put the entire piece in the lathe and turn away.

The advantage of this method is, (1) the imprints of the lathe centers are already centered on the plug halves so the plug/pipe assembly can be chucked in the lathe accurately, (2) the tail stock can apply the appropriate pressure without pushing the plugs further into the tube, and (3) possibly, no additional cross pinning is necessary, depending on how snug/long the plug halves are.

Of course, removing the plugs might be difficult if they are too tight. Once the pipe turning is done, attaching eye screws to both plug ends will allow you to put tension on them using a variety of methods. Most likely, one will come completely out before the other. Then, a largish loose dowel can be placed inside the pipe, resting against the remaining plug bottom and protruding out of the pipe. This protruding dowel can be hit sharply with a mallet while holding on to the pipe. Repeated blows may be necessary, but eventually the plug should come out. This removal process really is no biggie.

Still, if there is a concern, don't make the plugs so tight and cross pin them as you show.

Mark
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Mr. Badwrench
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Post by Mr. Badwrench »

...Or if the plugs are pressed in to tightly to pull out easily, just drill one of them out.
I speak of the pompatous of plastic.
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Post by Kekker »

I've seen this done on wood on a show on DIY network about wood turning. They've done a couple of things (small round boxes, etc.) that need to have an end lathed smooth.

They use the slightly tapered plug method, with a bit on the other side of the plug for the chuck to hold. Should work about the same for the pipe.

If you can find the show (Woodturning Basics on th DIY Network), it has a lot of really good tips for the entry lather.

Kev
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joewhite
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Post by joewhite »

Thanks for all the advice! I'll try some of these methods next time I go down to the base wood shop.

I wonder if I could bother you guys again with another lathe question. Harbor Freight. They've got a $134 wood lathe minus chuck and stand. I've never dealt with this company. Any opinions? I'm a "you pay for what you get" kind of guy but the price is attractive and again, I'm a lathe noob so I don't really know what a good price is for a good lathe is. Thanks in advance once again!

Joe
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Kylwell
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Post by Kylwell »

Harbor Freight's a decent enough company but you do get what you pay for.

I'd save you money up for a small metal lathe. Even the one HF carries would probably suit you, or you could try for the MICROLUX 7 x 14, Sherline or others. Mini-lathe has varous reviews.
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big-dog
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Post by big-dog »

kylwell wrote:Harbor Freight's a decent enough company but you do get what you pay for.

Mini-lathe has varous reviews.


Dude, the lathe Frank owns is made by Sieg, his is from Grizzly IIRC, but it's the exact same machine sold by Harbor Freight. It's a Sieg C-2, though Frank recently upgraded to a larger Sieg.
Stand back, I don't know how big this thing gets.
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Kylwell
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Post by Kylwell »

And they're both manufactured in China.

Which means they can be great peices of equipment, of youcould get the parts one. The one where you end up replacing most the parts to make it accurate.
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Umi_Ryuzuki
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Post by Umi_Ryuzuki »

I haven't bought a lathe, as I am pretty confident that once I buy a lathe, I will be short a few hundred dollars in tooling. :|

However my friend is planning on upsizing to a larger lathe, and he offered me his, 7x12 Grizzly, when he finds "the one" he want to buy. It will be all "dialed in" and setup for tight tolerances. He spent some time doing all that.
I don't think it will be cheaper, as it will probably come with some extra tooling and parts he has aquired for it over the years. I will have a real job convincing him that he won't need all the boxes of bits or that,
"Those bits are for the small lathe, they won't work on the big one,...Give them to ME!"
'
"I have to go now,... because my life is stupid and leprachans are dorks."
Nyow!
/
=^o^=
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Kylwell
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Post by Kylwell »

Oh gads, I'd spaced tooling. Bits, lotsa tiny bits. And tool posts, and clamps, and indexing wheels, and centers, and...

*sigh*

So many tools, so little time.
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