It is possible to so mount the threading tool whereby the cut can be made FROM the shoulder TOWARD the Tailstock, eliminating the possibility of a crash. Al --- Patrick Coppens <develop@xxxxxxxxx> wrote: > Ron Head wrote: > > Hi Patrick > > > > The retractable toolholder is a nifty device, but > the only benefit seems to > > be that you don't have to remember the tool > setting at each pass. You still > > have to be quick to disengage the leadscrew at the > end of the cut. > > > > When I'm screwcutting, I like to make an undercut > at the end of the thread, > > for the tool to run into. I also run the lathe at > a fairly slow speed, to > > give me sufficient reaction time! > > > > Which brings me onto one of my big grumbles with > the Myford lathe. The > > leadscrew engagement lever is on the left of the > saddle, which means that > > when you are holding the lever and getting ready > to disengage, you have to > > put up with hot swarf bouncing off the back of > your hand! Why they couldn't > > put it on the right, I'll never know. > > > > Regards > > Ron > > > > ----- Original Message ----- > > From: "Patrick Coppens" <develop@xxxxxxxxx> > > To: <modeleng@xxxxxxxxxxxxx> > > Sent: Saturday, November 24, 2007 9:19 AM > > Subject: [modeleng] Re: Screwcutting > > > > > > > >> I find, that one of those retractable tool > setups, an invaluable aid. > >> I saw the principle on the "Hemingway Kits" > website. > >> > http://www.hemingwaykits.com/acatalog/Retracting_Tool_Holder.html > >> The principle is almost silly in its conception! > >> I have "improvised" one to try it out, and now, > it is on my to do list > >> to make > >> a proper one, by next spring. It is especially > helpful on the more > >> economical lathes, where > >> a dead stop system is difficult or impossible to > use. > >> > >> It is a project, that can be adapted for all > lathes, and will help anybody > >> to overcome the fear, of not being fast enough, > in retracting the > >> cutting tool, and thus creating > >> bedlam, if the cutting tip, digs itself in the > chuck! > >> > >> Patrick > >> Flanders > >> > > MODEL ENGINEERING DISCUSSION LIST. > > > > To UNSUBSCRIBE from this list, send a blank email > to, > > modeleng-request@xxxxxxxxxxxxx with the word > "unsubscribe" in the subject line. > > > > > > > Ron, > > It is indeed true, that the prime feature of the > device would be the > "nancy-ing" about with the dials, that can be > omitted. > But I find, that even the improvised version of the > tool, gives me just > that much extra time to stop the lathe. > Indeed this will not wash for all shapes and sizes > of pieces to be > threaded, but in a sufficient amount of cases, I > find that > this type of set up,gives me some extra reassurance. > As far as making an undercut goes ; yes it is a > handy practice, but then > again in some cases that wouldn't be possible or > desirable. > > All is well, as long as you work with a lathe, that > actually has two > half nuts! (contrary to the complete nut that is > trying to work it!) and > an indicator! > My big lathe, has that feature, but my small 7*12 > doesn't. > I do most of my screw cutting in the small one > however, as it has the > handy feature, of an electronic reverse. > And with this tool, you only have to advance the > cutter by how ever many > x/10 th you want your next pass to be, and providing > you > are not cutting strait up to a shoulder,and remember > to retract the > lever when you are at the end of the cut. > > I am however thinking about an electronic stop, that > somehow slides on a > guide , covering, say the first half of the bed. > The problem there is, that even when the lathe is > spinning at low revs, > it does at least 1/2 if not 3/4 of a revolution, > before it is completely > still. > If I disengage the feed, then I loose my > positioning, and that is why I > use the setup discussed, to give me that extra bit > of time. > > > Regards > Patrick > > > > > > > > > > > > > > > > > > > > > MODEL ENGINEERING DISCUSSION LIST. > > To UNSUBSCRIBE from this list, send a blank email > to, > modeleng-request@xxxxxxxxxxxxx with the word > "unsubscribe" in the subject line. > ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.