I would suggest we make it from grey cast iron. No hardening (and risk of warpage, required. While still providing the needed level of wear resistance.
http://www.speedymetals.com/pc-4296-8389-1-12-sq-gray-cast-iron-class-40.aspx
If we can get the threaded post out we just machine the tee.
It’s not welded, looks like a press fit. Once we get to the point we are ready to change over to new lathe, I say we try it get that one out.
Glad I posted. I didn’t think about cast Walter.
The existing T nuts are not quite wide enough for my likings. Will it work, probably. I’m kinda finicky about taking the existing T nut that looks like it’s out of place, then welding the stud to it.
Rather then welding I would suggest a spring pin in a cross position to hold it. That way it can more easily be maintained when our idiot members break it…
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This is the existing tool post on the existing working lathe. It’s the 250 222. http://www.phase2plus.com/details.asp?pr=QUICK_CHANGE_TOOL_POST&
The “new” lathe lower t nut portion is about 1.910" wide by .410" tall. The center is about 1.405" wide & about .440" tall. The depth to be about the same at the tool post of 3".
So rough size for machining is about 2" wide 1" tall & 3" in depth.
I will make a quick cad drawing in a few hours when I get home.
Worse case is, this is something near and dear to your heart: take the existing undersize post, weld some metal on to bring it up to size and machine it down.
Here is a quick cad that I came up with. I saved it in the machine shop drive, it was done in Inventor
The dimensions can be seen in Inventor.
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Gentlemen,
After we get the tool post on there is some alignment checks recommended in the manual which are not difficult to do:
A headstock check: Take a light cut over a 6" steel round, 2" dia., held in the chuck but not supported by the tailstock. Micrometer reads both ends; they should be very nearly identical. Note: no tolerance given; we need to divine our own tolerance here. There is a brass bar in the cabinet that is about 6"x2"dia that may suffice for this test. If the alignment proves that the axis of spindle rotation is not parallel to the ways, there is a procedure given to correct this misalignment that might be a bit tricky in practice.
A tailstock check: Using a 12" ground steel bar held between centers, check the alignment by fitting a dial indicator to the top side and traversing the saddle back and forth; The reading should hold stead if the bar is parallel to the travel of the saddle. Treatment of this misalignment is rather easy. Do we have such a bar?
Is the lathe structure stiff enough that this testing can be done while it is still up on rollers? Pump and motor bases, for example require alignment checking and final adjustment after grouting in place, if memory serves correctly. The manual assumes an installed machine.
On another subject I am changing up some slides of the lathe training to cover the differences pertaining to the new lathe. About 90% of the course material remains the same. The main differences are the starting/stopping, speed and feed levers, and that there is a coolant flush available. Friday’s class is already loaded; If the new lathe is wired and the spindle is working we will visit it to get familiarized with start/stop, speed setting, power feed setups. But then we will do some practice turning and facing on the old lathe. The catch up course for persons familiar with the old lathe to learn about the new one will probably only need be 15 minutes or so.
I would like to participate in the alignment work. Anyone thinking Thursday evening perhaps?
Not likely. We likely need to get the tool post holder done first.
I agree we may need to set it on the floor. The lathe weighs by the book about 2000lbs. It will be interesting to see if we get any movement in alignment. I’ve taken some alignment on some of my machines, the cast D flange is enough to ensure no movement. I’ll like to see if there is enough cast to keep it from moving.
I do want to get the plug & the rest of the stuff done though.
Does anyone know where to get gray iron 40 that Walter linked locally? I do have some mild steel thick enough to make a temporary T nut. Or we could cobble the two holders.
Why not weld up up and machine to size. I’m serious.
We have a run-out test indicator setup made to fit in a tool post. Get with me and I’ll show you how to set it up.
I may go ahead and weld up tomorrow then.
Totally forgot about the tool post! Happy to help with that or other items.
Generally, no. Even on the ground, leveling will affect the alignment. Any metal lathe should generally be leveled with a precision level before working these alignment checks.
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I plan to be out with y’all tomorrow night for a bit, and then I’m Bob’s Monday lathe class. Looking forward to it!
We could set up an indicator on the base vs headstock then set it on the ground to see if it moves. Not sure how we could do the full distance though.