Crashed my lathe

[zippyslug31]

Speaking in the abstract. I often see people posting about how they get stressed trying to do things as quickly as possible. Especially when threading. Like I posted above I did massive amounts of practice when I started in this hobby. I practiced until I was comfortable doing things.

I treat my machines with a lot of respect. They can be extremely dangerous if you are not careful. I only wear short sleeve shirts and rarely reach over the top of the lathe when it is running. Another example. I made a spider for the outboard end of the spindle on my lathe. I only put the bolts in the spider when I am using it. To be honest those bolts in the spider scare me. To easy to get something caught in them.

I have only crashed my lathe once. No damage was done to anything My lathe is belt driven and the belts are probably a little loose.

I don't know what speed you run your lathe. I tend to run my lathe at the slowest speed that will get the job done. Especially when threading. For threading I run my lathe at its slowest speed. 28 rpm. For turning I try to run my lathe at the right speed and feed for the type of material. I only use HSS tool bits. You can run at slower speeds when using HSS. If I have any doubt as to the proper speed I error on the slow side.

Fair enough. I was running my lathe about as slow as it would operate, but with the change gear stack that I had in place (plus the higher speed setting in the gearbox), it does indeed feed in quicker than I'm accustomed to. My threading tool is also HSS, so this wasn't a problem. I almost always turn at about the slowest speed the lathe doesn't complain about; will probably up the speed as I gain more confidence/experience.

I understand why, but it's a shame that the lathe has to feed at an increased rate... damn you physics and math!

 

[Tozguy]

The slowest speed on my lathe is 65 rpm. I really have to pay attention even with a relief groove.
If it could go slower I would enjoy it more.

 

[markba633csi]

A lot of modern hobby lathes don't go slow enough, since many have eliminated backgears.
Being able to go lower than 60 rpm with good torque sure makes threading easier

 

[mickri]

Turning is different from threading. Threading is really light cuts. At least for me. ,005 DOC is the most I take when threading. Even turning I rarely go over .020 DOC. Even then I only go to .030 or maybe .040. That's what I am comfortable with.

 

[zippyslug31]

Well, not that anybody is really waiting on bated breath, but here's an update - good news, other than the decorative chunks of missing metal, no mechanical damage. Yeehaw!

In the chuck, I did find some very slight deformation within the journals that the jaws run in, but I pulled the chuck, took it to my bench, and spent some quality time with a hone and got it running nice and smooth once again.

Beyond that, no broken teeth, no odd sounds, and everything still feeds well via the power feed shaft and the lead screw. Crisis averted, it would seem. Thanks for input and ideas for improvement, everybody.

 

[RaisedByWolves]

Using a carriage stop when power feeding or threading has to potential to do some serious damage to the gears, the lead screw, or the half nuts.

One extremely important thing to know is that when the carriage comes in contact with the stop and starts pushing it, the feed lever/half nut lever become very hard to disengage.

I have been doing this a long time and this still catches me off guard some times.

The usual result is crashing through your runout groove, but you can lose your threading tool tip or even find the chuck with the noisy indicator.....BANG BANG BANG BANG!!!