Goofs & Blunders You Should Avoid.

[jim18655]

Never weld a rim with the tire still inflated. My uncle was killed putting a weld on a large wheel from a slag hauler in a steel mill. Those are huge tires on those machines, it exploded and hit him.
Be safe
Martin W
Sent from my iPad using Tapatalk

Youtube has videos from testing labs and tire companies showing how dangerous this is. It doesn't always happen while welding but the heat from the weld builds up or starts the tire on fire internally and you soon get the explosion.

 

[Cheeseking]

As a HS kid working summers in a tool and die shop did my fair share of newbie blunders.
.....forget to turn on the magnet when grinding a group of tall skinny perforator punches in a punch block. I can still feel the sting and taste of the vitrified bits that ricocheted somehow under my face shield. That was the summer of black boogers grinding all day long.

... Borrowed a nice test indicator from a guy to dial in a part on lathe. Some reason I thought you could run the lathe at speed with indicator still in contact. Oops. Payroll deduction

 

[francist]

Giving in to that "hey, this is going pretty good..." feeling when turning plexiglass on a woodworking lathe. Bonus points if you think it's going so good you can take a deeper cut.

It's been hanging on a nail behind my lathe for twenty years, just to jog my memory every now and again.

-frank

 

[AlbertNakaji]

see some guys on youtube doing this and don't understand the reason. can't read if it's moving so fast.

Borrowed a nice test indicator from a guy to dial in a part on lathe. Some reason I thought you could run the lathe at speed with indicator still in contact.

 

[Cheeseking]

Agreed Albert. Of course if one is careful and knows what they are doing and the potential risks (very low rpms/ a smooth surface that is not way out, etc) its can be done without incident. I think tubalcain has a video out there where he's got the needle on an indicator a whumpin pretty good. I ribbed him a little in comments but again theres a perfect example of a guy who knows his stuff and uses his professional judgement and takes a risk. I think all of us have done things where we say to ourselves "well this may or may not go well but I need to get this or that done. Heck with it lets roll!"

 

[AlbertNakaji]

Another mistake that's related to not realizing there is such a thing as "tool spring", is not realizing there is something called, "backlash". My lathe enough of it when I got it (first lathe I owned) and after making a cut and backing out the cross slide, I wanted to take a little more so I used the compound to feed in a few thou. Couldn't figure out why it wouldn't cut. Of course, I kept feeding in and trying, not knowing how much backlash there was, so I inevitably cut too much. Typical newbie error....but I learned.

 

[Wreck™Wreck]

Yep, and during that 200IPM move, the E-Stop shrinks to the size of the head on a pin, and moves to a completely new location.

You want a bit of High Drama program an internal left hand thread. When you push the start button the tool rapids through the bore and threads from left to right. Normally I run the program one line at a time with no tool or part.

 

[Wreck™Wreck]

Another mistake that's related to not realizing there is such a thing as "tool spring", is not realizing there is something called, "backlash". My lathe enough of it when I got it (first lathe I owned) and after making a cut and backing out the cross slide, I wanted to take a little more so I used the compound to feed in a few thou. Couldn't figure out why it wouldn't cut. Of course, I kept feeding in and trying, not knowing how much backlash there was, so I inevitably cut too much. Typical newbie error....but I learned.

I fail to understand why backlash has an effect on the work being done, you are using the same side of the lead screw for the actual work and have returned it to the same position, please explain this.

 

[Tony Wells]

You want a bit of High Drama program an internal left hand thread. When you push the start button the tool rapids through the bore and threads from left to right. Normally I run the program one line at a time with no tool or part.

Not really the best approach. Shouldn't cut with forces pulling the part away from the chuck or bottom of soft jaws unless you have to. Use M04 instead of M03, and left hand tooling. And unless you have a sufficient width thread relief to start at the bottom, there can be sync errors with the spindle encoder trying to get everything up to speed. But, ya gotta get by with what you got sometimes.

I've pulled parts out of chucks on manual machines cutting -Z- plus. I try to avoid it.

But you're right, when it rapids to the bottom of the bore, there is a bit of white knuckle time. I appreciate single stepping through a new programming on those types. I've worked with programmers who made virtually every program a white-knuckler. Couldn't even trust him with an old program. He was always tweaking it, and never said a word. New tape, new wreck.

 

[AlbertNakaji]

I initially used the cross slide to make the cut, backed it out, and moved the cross slide back to the original reading before making the next cut. To make the next cut, I used the compound by turning the dial in a few thou, but only from where the dial was positioned, without taking up any backlash. The compound had been previously backed out, so when the dial was cranked in, it was still taking up the backlash.

I fail to understand why backlash has an effect on the work being done, you are using the same side of the lead screw for the actual work and have returned it to the same position, please explain this.