the newbie says Hi and a question.

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Diogenes on the hill
Posts: 8
Joined: Tue Mar 27, 2018 3:45 pm

the newbie says Hi and a question.

Post by Diogenes on the hill »

Hi all, been lurking here for awhile now and just now jumped in the water. Not a machinist by trade, more the Jack of all trades guy, and self taught on just about everything, though I am not so proud as to think I know it all: Ha, only fools think such. No, the more I learn, the more I realize I really know very little and its a big bad world out there that has many surprises for the unwary.
Anywhoos, my current lineup is a venerable but beautiful 1921 27B Southbend 11, a cheapy chinese 3-1 that (hopefully) is about to be retired, and, oodles of imagination, drive and a really hot fire for the crucibles. I am slowly building a vertical mill to replace the chinese (hf 5980) and subbing out the castings to a local foundry so things are in iron, not aluminum.

Now, as for my question. I am making tapered mandrels for turning 'tween centers, and do not have a taper attachment. . The mandrels are only .002" difference between ends. One end +.001" the other -. I know I can offset the TS, but has anyone tried the "paper trick" of using a strip off paper on one side of the MT to gain just a touch offcenter. I am going to try it, but was wondering if anyone else has and if so, what kind of success/failure they saw.
Stupid questions remain silent. So speak up.
John Hasler
Posts: 1852
Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: the newbie says Hi and a question.

Post by John Hasler »

Welcome to the group. This is the first I've heard of that technique. Let us know how it goes.
pete
Posts: 2518
Joined: Tue Feb 10, 2009 6:04 am

Re: the newbie says Hi and a question.

Post by pete »

I've not heard of that trick either. It should work after some thinking about it. I use Zig Zag cigarrette rolling papers as an edge finder between the tool and the part sometimes. There almost exactly .001" thick. My guess is the paper is likely to compress a bit so maybe one folded over would get you pretty close to a .001" offset or .002" on diameter.
John Hasler
Posts: 1852
Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: the newbie says Hi and a question.

Post by John Hasler »

I don't think it would be repeatible since the degree of compression will be highly variable. It may also change during operation if the paper compresses more. Worth a try, though.
earlgo
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Joined: Sat Jan 29, 2011 11:38 am
Location: NE Ohio

Re: the newbie says Hi and a question.

Post by earlgo »

I'm surprised that your tailstock is not already offset to give you some taper, just because of its age. If it doesn't, then you must know someone.
Just an FYI, the foil wrapper from a Reese's Miniature PB cup is .001 and it shouldn't compress like paper. Don't ask how I know :lol:
--earlgo
Before you do anything, you must do something else first. - Washington's principle.
John Hasler
Posts: 1852
Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: the newbie says Hi and a question.

Post by John Hasler »

Every time I need to turn something long to an accurately uniform diameter I have to re-center the tailstock. Fortunately I don't do that often.
Diogenes on the hill
Posts: 8
Joined: Tue Mar 27, 2018 3:45 pm

Re: the newbie says Hi and a question.

Post by Diogenes on the hill »

One of the reasons I am going this way is due to my Southbend being off line while I finish building the new shop. The Chinese 3-1 is just convenient and accessible, but not adjustable. :-(
I'm not looking for repeatable here, just quick n dirty turning that will fill the bill for something else. These mandrels are for turning pulleys and gear blanks,,and so long as they are a decent cross section, and I can press the blanks on,,good'nuff.
Reeses foil is .001" huh. Had to make a shim in a pinch didya? Lol. I like using the sides of pop cans for stuff like that (and .ay do that instead of the papaer, hmmm.)
Stupid questions remain silent. So speak up.
Diogenes on the hill
Posts: 8
Joined: Tue Mar 27, 2018 3:45 pm

Re: the newbie says Hi and a question.

Post by Diogenes on the hill »

Ok, little update for the question I posted.
I set everything up today, and,,, no point in pursuing it, at least on this machine.
The tailstock is seriously offcenter, to the tune of .010" rearward of center. I'm not going to waste stock at this stage, and this machine is just not worth the effort to correct the issue. Good parts as salvage for other projects, but as a whole, no. Not sure what happened as this machine had been spot on as of two years ago when last set up in another state. I probably did something in the move, but danged if I recall anything 'rough'.
Oh well, onward and forward. Finish the shop and get the SB in her new home.
Stupid questions remain silent. So speak up.
John Hasler
Posts: 1852
Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: the newbie says Hi and a question.

Post by John Hasler »

Not adjustable?
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Harold_V
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Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: the newbie says Hi and a question.

Post by Harold_V »

If the machine was good and has changed since moving, may I suggest you check the level condition? Level isn't critical, but having the bed straight is, and that's generally determined by leveling the machine.

That said, you can't do that with a carpenter's level. At the very worst, a Starrett 98, or equivalent, should be used. If at your disposal, a 199 would be a better choice, as it resolves a half thou in twelve inches.

I suspect that your tailstock is off due to the bed having a twist, which can normally be eliminated by leveling. Worth taking a look, for sure.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
John Hasler
Posts: 1852
Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: the newbie says Hi and a question.

Post by John Hasler »

You can still adjust out twist without a level, of course. It's just a bit more tedious.
Diogenes on the hill
Posts: 8
Joined: Tue Mar 27, 2018 3:45 pm

Re: the newbie says Hi and a question.

Post by Diogenes on the hill »

To John H: not adjustable. This is an older HF 5980 and the TS is bolted to a cast housing that is fitted to the ways. Very little adjustment possible and only by reaming bolt holes or other non-precise methods.
Harold: I will agree that level, or lack of, is the likely culprit, but not overly concerned with it at this point. The concrete for the new shop will be poured soon and I will be making certain that it starts as near to perfect level as can be, and that should make installing and leveling all of the machines less of a chore. I really truly miss being able to use my Bend on projects. And that list continues to grow while waiting.
Stupid questions remain silent. So speak up.
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