Another Challenging Job On The Craftsman 109 (parting)

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ericc

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Hi. I had some success parting with my little 109 lathe. This is 1.25" hrs with a blade salvaged from a junk ryobi table saw that a contractor left in the street. This works much better than an import HSS blade in a BXA tool holder. The HSS blade, even in a supposedly more capable Jet 1440 lathe was prone to going bang at $10 pop.20160905_215336.jpg
 
Hi Ericc,
I have always hated parting off. :)
Little old lathes have so much play in them. I usually use a hack saw when I'm doing 1 off's
If it is too much to saw I make a grove 1.5 x the width of the blade and step my way down.

How did you make a circular saw blade into a parting tool?
And how are you holding it?
Looks like you are getting a nice cut with no chatter.
Have you tried it with deeper cuts yet? like 3 , 4 or 5 times the width of the blade?

More information please. :)

David.
 
Hi David. I think that I got this idea from Hobby Machinist. The concept is very simple. An angle grinder with a zip wheel is used to cut off a tooth with enough of a tang on it to slip into a tool holder with a slot in it. The slot was made on a mill in a cooperative shop, but it could be made with simpler tools. The only important thing is that the slot must fit well. The slotted holder is mounted temporarily on my boring bar holder. You can see a C clamp holding it on. Note that the C clamp only keeps it from sliding in the slot. I am not planning to part this piece all the way off. It will be finished with a hacksaw. There will be chatter if you run dry on cutting oil. I use rendered lard and daub it on.

This tool works much better than the standard wedge shaped HSS blade:
http://www.use-enco.com/CGI/INLMKD?SIITEM001=397-7028&SIQTY001=1&SICOUNT=1
 
This is one way to do it
image.jpeg
May have to hone it sharp again
 
I think I get it.
I'll have to keep an eye out for some old saw blades. (I may even have some in the bottom of the bottom draw)
 
One of the sure ways to bend the spindle on a 109 is to try parting on it. the spindle just isn't heavy enough. When i was using my 109 i always used a hand held hacksaw to part with. Now that i have my Craftsman Commercial 12 x 36 with the 1/2 ways I still part with the saw. I'm looking at making a new crossfeed with the rear tool post for parting as the force and chips come away from the center line of the part when the parting tool starts to catch instead of being forced into the part and stalling the machine or breaking something. the parting tool needs to have sufficient side rake in order to keep it from jamming into the part as it heats up or gets further into the part. The parting tools that my sons CNC machines use have carbide inserts with the insert wider then the holder and they also have a chip breaker designed in.

Making the tool out of a saw blade using the carbide saw blade cutter gives the same kind of side clearance and does work well. it does tend to walk length ways as the saw carbide is ground at an angle.

Art b
 
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Hi master53yoda. Yes, I am aware of this. The lathe is really quite marginal. I loosened the belt tension so that it would slip instead of break. There's still enough torque to cut a pretty good chip. I always part with a center and finish with a hacksaw. Too gun shy.
 
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