I have just acquired my first lathe with the intent of making whistles and flutes out of PVC. If someone could point me to a source of info on how one turns PVC I would appreciate it.
Thank you.
RVC
metal or wood lathe?
take it slow or the plastic will get hot, get soft and produce nasty fumes - cooling even with just air helps, water mist works better but creates a mess if you are set up well for it.
don’t know of any particular online resources, I have seen some references on drills and tools to use for plastic - do a search I do not have any of them handy, standard metal working tools have worked for me
It’s a metal lathe. Thanks for the info and insights.
RVC
What do you need lathe for, actually??? 
Eventually to make a conical-shaped whistles, but then you’ll need solid plastic rod, not PVC pipe.
Anyhow, i had been working with plastic on industrial machines (programming industrial CNC lathes and graters) but it wasn’t PVC.
I worked on PVC with modeling tool and it turns out that it heats very easily and acts as it’s kinda layered (or laminar); meaning that it doesn’t heat evenly, but the layer that has contact with the drill actually melt. 
If you’re working on a lathe, do it on low speed.
And stay out of the dust, it’s not good. 
Also, use cutting tools with sharp edges instead of the standard hard metal inserts that have edges that are way too blunt. With the inserts you will shear the material instead of cutting it…
Cheers,
Anders
If you turn PVC, you won’t really get dust-- you’ll get ribbons of plastic. With acetal, I snatch that ribbon off the lathe tool and gather it up in my hands as it comes off. It’s a pain in the butt and requires constant attention, but if you don’t do that, the ribbon wraps around the turning plastic, bunches up and interferes with the turning.
If you sand PVC, you will get dust . Sand it with wet/dry sandpaper, used wet.
Just as the others have said… Any tutorials or books on machining will give you a decent start. They should all talk about plastics along the line too. Use sharp tools. Mind your spindle speed, depth of cut and feed rates and you’ll do fine. You will discover what works best for your set-up as you go. Let us know what turns up. 
Feadoggie
I want to try to make a whistle with a mouthpiece along the lines of the Water Weasel. From looking at the various pictures I’ve managed to find of this whistle it appears the outer piece of the mouthpiece is machined on the inside to about half the original wall thickness. The inner piece appears to be machined to fit snuggly in the outer piece. I couldn’t figure any way to accomplish this except on a lathe.
To all others, thank you for the input. This will be an interesting learning curve.
RVC
That’s the gist of it. The thickness of the outer mouthpiece collar determines the widway height. That can be varied depending on how you like the whistle to sound and behave. A lathe is the right tool to make that piece. That was what prompted me to buy my first lathe. There are a couple of ways to approach it. But basically you chuck up a piece of tubing and bore out the inner wall to achieve your desired diameter. The thinner the wall becomes the more interesting it can be to control your cuts. After a hundred or so whistles you’ll get the hang of it. 
Of course you can make a PVC whistle without using a lathe but since you have purchased one you might as well hop on the cafeteria tray and just start sliding down the slippery slope of whistle making.
Feadoggie
I want to try to make a whistle with a mouthpiece along the lines of the Water Weasel. From looking at the various pictures I’ve managed to find of this whistle it appears the outer piece of the mouthpiece is machined on the inside to about half the original wall thickness. The inner piece appears to be machined to fit snuggly in the outer piece. I couldn’t figure any way to accomplish this except on a lathe.
Jesus Christ, just 2 minutes before reading this (again) i have been thinking of taking my Al tubing to a locksmith’s workshop down the street, for the same treatment… 
Yeah, thinning of the inner wall of the mouthpiece cover and thinning the outer wall of the mouthpiece part of the whistle body is the right stuff. 
Turning the inside as you describe is known as boring. You’ll need a lathe tool called, no surprise, a boring bar.
RVC, here’s a visual example of a boring operation. I apologize to Misha Somerville for shamelessly borrowing this picture from the MK Whistles website.
You can see the tube stock held inside the lathe spindle and being worked on close to the chuck, probably a collet chuck. The boring bar is held in the toolpost and runs inside the tube stock shaving off material from the inside of the tube. Hope that helps.
Feadoggie
There are some annoying fumes released when machining pvc. I do not know if they are poisonous but they make my nose stuffy, and irritate my eyes. I tried working under a celling fan to dissipate the fumes but it seemed to just recirculate them. There are some flute makers that have made a vacuum system with a collector hood just above the work. I did not want to go the expense of a good vacuum. I made a four sided box around my lathe covering some of the top and the two sides and bottom. Left the front open enough to use the machine. Put a small window fan in the back to draw air over the work collecting the fumes and disapating them outside. Also had to put a cheap AC filter on in between the fan and box to prevent curly Q’s of PVC getting into the fan.
Using sharp tools has been mentioned. The cutting tool must be at the correct height also.
To high and it will not cut it will just rub. To low and it will gouge, chatter, and the pvc will try to climb up on the cutting tool.
Would nylon be a better option? I used some machined nylon rod as a fipple block on a couple of PVC whistles. I’m not an expert though…
Thanks again for the info, guys, and for the really good picture. It’s all appreciated.
RVC
Turning PVC is not much different then turning wood. If you have metal lathe, that is nice as you can get a better looking surface by keeping the coolant spraying on it - works real will with delrin.
I’ve used Gray PVC from http://www.usplastics.com and it’s nice turning material. When you do cut PVC, you have to go easy on the final cuts because the material is springy. You try to cut it and it bends out of the way. Get a live center for the tailstock of the lathe to hold the material still.
If you’re going to do conical work, you’ll might want to learn about gun drills.
This is going to go against the grain of what I’ve read posted so far, but…
PVC is going to behave differently than CPVC. PVC is more “springy” like acetyl (Delrin), whereas, CPVC is harder but less brittle (than PVC) and machines much more like a hard wood, although I find it is stronger than PVC and has greater elasticity. I prefer to patiently use clean, sharp files or round metal stock wrapped with wet/ dry paper, rather than tool bits. I also prefer to use my wet/dry paper DRY when working with plastic rather than wet, as I find that using it wet makes the material dirty. Again, this takes patience, because your paper must be kept clean lest it will clog and begin to cut and gouge your material. CPVC is very porous as compared to PVC and acetyl.
My biggest issue with heat tends to be expansion. Expansion of the material affects the finished result by a wide margin. I have learned to anticipate the expansion to some extent, which can be helpful for a tight fit of pieces - and this works both ways, when trying to achieve inner OR outer diameters, but this comes with experience - it is beyond my means to explain. For the most part, I deal with heat by periodically dousing the material, rather than continually cooling it. This gives me a better idea of what further working of the material is required. Having the material continuously cooled is not as good as having it at an average temperature comparable to what will develop when the whistle is played - but that is just my opinion.
Also, although they cannot be glued practically, acetyl and CPVC , when fit together well, will act well together, so they are okay to combine. Most whistle heads that I experiment with now use a combination of these materials, pinned together with soft copper. The whistle head I am developing now uses both of these materials, and a metal (brass or silver) wind split.
The nice thing about working with plastic is that it can be very forgiving, and there is very little frustration once you get used to working with it. Also, it’s cheap, so learning on it isn’t costly or damaging to your inspiration
The bad thing about making whistles is that it becomes more addictive than collecting them…
Have fun!
I appreciate this. Actually I had planned to start with CPVC and, not thinking there was much difference between it and PVC, I didn’t think to differentiate between the two.
Your mention of the material expanding with heat is interesting as well. This is something I hadn’t thought about. I had intended to just go slowly with no coolant. Will this work?
Finally, I’m curious why one would use an acetal plug fastened the way you mention instead of a CPVC plug. Solid CPVC rod is readily available and can be turned to size and glued in place with regular CPVC cement. Seems simple enough. Is there a reason this wouldn’t work?
Thanks for your comment and help.
RVC
Yes, it can work. The usual common sense rules apply. Keep the heat down using sharp tools, proper turning speed, feed rate and a conservative depth of cut. I turn CPVC/PVC without coolant myself with good results. Some photos are here:
http://s266.photobucket.com/albums/ii254/feadoggie/Fauxcettes/
You may get a few “mistakes” for the scrap pile before you discover what works.
Nope, no reason. If you search through previous posts, you will find the thinking on pinned delrin plugs.
Feadoggie
What Tommy said above about the fumes being annoying is true but there’s more. When pvc is heated it releases deadly chlorene gas which can give you a nasty headache or even take you out. I read of one account where this guy was making didgeriedoos and heating them to shape them, unfortunately, in an unvented room and he died. And as Brewerpaul has pointed out the sanding dust can cause a lot of respiratory problems. I experimented with making whistles out of pvc but decided otherwise when I got fairly sick. If you use it, I highly recommend using a good exhaust system and be careful.
Ronaldo