It’s a great trick and I’ve done it a lot. It does load the carriage and compound differently than what they were designed for and you don’t want to take big cuts with this setup. They’ll buck.
![smile smile](/ubbthreads/images/graemlins/default/smile.gif)
Anyone taking big cuts for threading is screwed, blued and tattooed before they start the machine up.
800 rpm’s, eh? I’ll have to try kicking the speed up. I was threading today at 155 RPM, which is the actual, not nominal, lowest speed I can turn on the Feeler.
Big cuts….. I used to have a job that involved threading large stainless shafts in quantity… in a production scenario you most certainly do take big cuts when threading. Big being relative of course. Bigger than you otherwise would, how about. That’s how I know you can make the carriage buck when it’s loaded up wrong when threading away from the shoulder.
![smile smile](/ubbthreads/images/graemlins/default/smile.gif)
Find the limits, then back down a bit and then make some $$$.
The parts I’m making now start out as 2-1/4” solid round T303 bar and end up almost like thin-wall pipe. Long story. A LOT of material gets first drilled out to 3/4” then bored the rest of the way. I use a solid carbide boring bar- which if a guy hasn’t used those, do, they are a game changer- and was taking ~ .350” off ID diameter at a pass. The machine hardly knew it. The biggest issue is minimizing the number of burns from the hot chips.
Maritool is a good place for solids carbide bars. He does a good job weeding out the wheat from the chaff. Won’t sell you junk, Chinese or not.