full length barrel shrouds

[kiwi]

here's a real dumb question....
What do you use to bore them...?
250mm 10" is the longest I'm able to bore..
I need to bore 15"..i tryed welding a
exstention on to a drill but got to much
wander....and have to clear it every 10mm...
Or are they made in sections..ie tube with
end caps/fittings...

Pete

[SDale]

I usually just turn out an endcap and a tapered tail cap then use a section of tube to join the 2. A .0001" interference fit and some red Locktite hold them together forever.

[Gene_SC]

Sam is right. I make the two solid ends and machine them to press into the tubing. I knurl the end pieces first then clean and locktite and press together. True it up in the lathe and the finishing touches. I also use the mill for milling some projects.

[SDale]

If you're still set on turning shrouds from a single piece, then I'd suggest finding a machine tool supply and getting some long reach drill bits and a set of reamers. Stay away from the adjustable reamers. When they chatter they loosen up and end up giving you a tapered hole.

You could also use a 4 flute end mill (like this guy here: http://www.deltatool.net/resources/4flute/endmill6.jpg )  brased onto a drill rod blank. Use the lathe chuck and a jacobs chuck in the endstock to get em nice & lined up. I believe Silver soldering could also be used instead of brasing.

[kiwi]

SDale - 7/25/2009  4:43 PM

If you're still set on turning shrouds from a single piece, then I'd suggest finding a machine tool supply and getting some long reach drill bits and a set of reamers. Stay away from the adjustable reamers. When they chatter they loosen up and end up giving you a tapered hole.

You could also use a 4 flute end mill (like this guy here: http://www.deltatool.net/resources/4flute/endmill6.jpg )  brased onto a drill rod blank. Use the lathe chuck and a jacobs chuck in the endstock to get em nice & lined up. I believe Silver soldering could also be used instead of brasing.

....Yer have to use a 2 flute to drill with unless yer have a pilot hole........
A 4 flute dosn't remove the centre....Where a 2 flute has the cutter going right across.....

Thanks Guys..Thats what I figgered....tube and end caps...

[wyredvw]

They do make 4 flute center cutting end mills...but I have not seen any in the length that you need.  If you buy a HSS(high speed steel) end mill you can use a carbide turning tool to turn the shaft down then make an extension shaft with a couple of set screws to lock it in place.  There is an industrial supply shop we use called MSC and they have decent prices in there sales flyers. Here's the link... http://www1.mscdirect.com/cgi/nnsrhm