Machining a leaf spring flat on a lathe. Any advice?

[jster1963]

Hi Guys,

I restored my father's Atlas 618 lathe and have been doing TONS of research on how to use a lathe. I was AMAZED when I saw videos on the use of a 4 jaw chuck. I decided to try to make a flat square piece of steel from an old rusty leaf spring. I cut off about 2 1/2" square off of the end and gave it a go. Here it is.

Lessons learned. That steel is HARD!!! I went through a few carbide bits trying to get that flat and square. The HSS bit I tried to sharpen did not work well. It was a combo of me not knowing what I was doing, and me not knowing what I was doing;-) That steel dulled the HSS bit in short order. I know I didn’t have the correct angle to the work, etc.

Using a carbide cutter with a higher speed and an interrupted cut creates sparks. Sparks + metal shavings + cutting oil = FIRE. Ask me how I know!

I got close..........

My next try will be to do the same thing with my milling attachment, and end mills on the same lathe. Wish me luck. I WELCOME all advice!

 

[Bill Gruby]

Milling that spring will give you the same results. Hard is Hard. The spring needs to be annealed to machine it. My 2 cents worth.

"Billy G" )

 

[jster1963]

Milling that spring will give you the same results. Hard is Hard. The spring needs to be annealed to machine it. My 2 cents worth.

"Billy G" )

And HARD it is! Thank you. I had no idea that hardened steel should not be machined. I better find some better material to practice on! Thanks again....

 

[DMS]

Hardened steel CAN be machined (and sometimes should), its just er... harder to do.

Since that piece is square, you also have what is called an "interrupted cut", which means the cutter is constently engaging, and then disengaging the work. It tends to be hard on cutters, especially carbide, which is likely the reason you dulled all your carbide.

I would recommend grabbing some aluminum round stock to get accustomed to, it's cheap and fairly forgiving.

 

[jster1963]

Hardened steel CAN be machined (and sometimes should), its just er... harder to do.

Since that piece is square, you also have what is called an "interrupted cut", which means the cutter is constently engaging, and then disengaging the work. It tends to be hard on cutters, especially carbide, which is likely the reason you dulled all your carbide.

I would recommend grabbing some aluminum round stock to get accustomed to, it's cheap and fairly forgiving.

Thank you very much! I'll look for some......

 

[OrangeAlpine]

Yay, I've found interrupted cuts to be death on carbide. Interupted cuts seem to be way of life for me, so I've given up (well, almost) on carbide. Way to expensive to last only a few seconds. Hard to beat HSS. No carbide, no QCTP. I feel like a leper.

Bill

 

[Bill Gruby]

Get to know the local machine shops. Most of the time they will be happy to have you take their left-over stock from a job. You would be surprised at what they scrap.

"Billy G" )

 

[DMS]

Avoid the stuff at the hardware store, it doesn't machine well, and it's over-priced. There are a number of online places like www.speedymetals.com and onlinemetals.com. Places like Enco use-enco.com also have a limited selection of stock, and it is usually pretty cheap. I would also recommend looking around your area for a local place, preferebly a scrap yard, or a place that sells material by the foot, they usually have a "remnants" section where they sell stuff cheap. There is also metalsupermarkets http://www.metalsupermarkets.com, they are a chain, and have local stores in lots of places. The one by me has a remnants section you can poke through. I find their prices decent on structural steel, but pretty outrageous for aluminum. YMMV.

 

[jster1963]

OrangeAlpine: You're not a leper, lol. You just like the "tried and true" methods;-) Ps. The carbide worked the best with this material, but I had to go REAL slow. Thank you.

Billy G: Once again, great advice. I'm going to try to find a local machine shop next week. Thank you.

DMS: Thank you so much! Excellent advice. I'm going to look at all of those places. Thanks again for the info.

 

[Chrispy]

If you want something cheap and easy to practice on try PVC pipe. It's on the other end of the spectrum from that spring steel you tried to machine. PVC is really handy to practice threading on. If you want to try some very easy to machine steel try 12L14. It's a "leaded" steel. Machines easily with a great finish.