How to make a cut off tool?

jaded13640

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I had to do a little project recently where I needed to make a "bushing" that was about .300 dia by about .300 thick. I had a much longer piece of steel stock, about 3 or 4 inches long, I could have cut a smaller piece on the abrasive cut off saw but, it was kind of a short piece and decided not to. But, of course that meant I had to face away ALL the stock I didn't need AND, had to hold that little tiny piece, that was the finished product, in the chuck.

So, it took forever and was just a stupid little piece to tighten up the shifter rod on a truck where the plastic bushing had worn down to nothing. It was held on with a cotter pin and it broke, I was doing a whole different project on the truck when he mentioned he had to tied it back together with a jump rope. I didn't even notice it till he mentioned it and it had no way of getting the correct bushing that late at night but HAD to get the truck done that night, he had to drive it to work the next day.

What might have done better?

I took the entire machine tool operations sequence in college to get my drafting and design degree years ago. The idea was that by having to actually make stuff we'd become better designers because we'd understand things like tolerances. For example, why you don't put a four place decimal on a drilled clearance hole, you really can't achieve that kind of accuracy with a drill. It all made sense than AND I learned I was actually pretty good at machining in the process. At one point when I got laid off from one design shop I worked as a machinist at a shop. It was great to have gotten that training that I never guessed I'd need. Now I have a small mill and lathe if I need to make something.

So how could I have made that simpler? What should I have done to cut the time? I don't have a good way of cutting stock, the only way I could have really done it better with what I have is to have put the stock in the vice and cut it off with a cut off wheel/die grinder.

Maybe I could have turned the diameter and then used a cut off tool, but I don't know how to make one, I can't remember how we did that in school and never had to do it in the field.

Thanks in advance,

Wayne
 
Wayne, it sounds like you have a definite need for a parting or cut off tool. What kind of lathe and tool holding system are you using? I ask because most of us use a parting blade held in a tool holder, held in a quick change tool post. We buy the tool; we don't make it (although you could if you've a mind to). There are HSS blades and inserted tip blades and brazed carbide blades but all are held in a tool holder. So, what do you have for a tool holder?
 
My tool holding system is just the simple, old screw in the top against the tool holder deal. It's got the rounded "keyway key" and cup deal at the bottom and you have to set it up every time, no quick release.
 
If your parting off small diameter parts (or thin wall) I find a hss tool blank ground to a parting tool works well.

Stuart
 
Are you talking about a lantern tool post? I know they had parting tool holders for those but cannot find a pic of one. If you have such a holder then you'll need to grind a tool for it. Or, you can switch to a more modern quick change tool post and avail yourself of the many choices for parting tools. Hopefully, a member who uses those lantern tool posts will chime in soon and be more helpful.
 
Yep, it looks like a lantern, must be the "lantern style". I do very little with this machine. Every once in a great while I need to make something totally different. I have what I have, I really can't see retooling with a quick release. I know there was a time where there was no such thing, I guess I'll have make one, if anyone can help with that, I'd really appreciate it.

Wayne
 
In a jamb like this one just cut a small "v" where you need to cut and with lathe running slow just use a hack saw.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk
 
If no parting tool, then I would have cut the rod off with a hacksaw to yield a piece about 0.5" long then face it off, turn it around and face it down to 0.3".

David
 
No reason to make one as it is far less time consuming to buy it, you are after all concerned with machining time as you mentioned. Spending 2 hours grinding a tool for one 30 second operation on a handful of parts is not productive.
 
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