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View Full Version : Making a Lathe Drive Cener



Frank Ford
09-14-2007, 02:26 PM
A number of folks have asked me about the "drive center" I used to turn the bearings for the MLA filing machine kit, so I posted an article about it on my Web site, along with another about the sine fixture I use to establish accurate taper angles on my lathe.

Making the Drive Center: (http://www.frets.com/FRETSPages/Machining/Projects/DriveCenter/drivecenter.html)

http://www.frets.com/FRETSPages/Machining/Projects/DriveCenter/drivecenter23s.jpg


Making the Sine Fixture: (http://www.frets.com/FRETSPages/Machining/Tooling/LatheSineFixture/sinefixture.html)

http://www.frets.com/FRETSPages/Machining/Projects/DriveCenter/drivecenter01s.jpg

Cheers,

Frank Ford
FRETS.COM (http://www.frets.com)
Gryphon Stringed Instruments (http://www.gryphonstrings.com)
My Home Shop Pages (http://www.frets.com/FRETSPages/Machining/index.html)

Lew Hartswick
09-14-2007, 03:55 PM
Frank, Couldn't you have put a "fairly strong" spring in behind each
of the drive pins to accomodate any irregularities on the end of the
part????? In effect make then float just as the center does.
...lew...

BadDog
09-14-2007, 04:01 PM
You make me feel SO inept, but I love reading your articles. Does that mean I'm masochistic? ;) Seriously though, very fine work on both. You guys that post these very nice projects inspire me to do better work. Thank you!

I really like the drive center, and the sine bar fixture too. Unfortunately, my compound, being "old iron aesthetic" with "as cast" rounded top and non-reference flat side is not suitable for such. :( I suppose I might be able to make it work by scraping in the side and changing the design, but the DTI and exemplar will have to suffice for the near future.

Alistair Hosie
09-14-2007, 04:08 PM
something like this would be xcellent for woodturning as a drive dog well done nice workmanship.Alistair

wschoenbeck
09-14-2007, 04:41 PM
Frank,
In one of the Bedside Readers, Guy Lautard has an article on using a sine fixture for setting the compound angle (or tail stock offset) but somehow it never made sense to me. He mounted a plate with a spigot on it in the chuck but the explanation never made sense to me. Your method is very clear and concise.

Like BadDog My SB9 with it's "old iron curved aesthetic" will need a bit of adapting to make this work. Perhaps a couple of well place alignment pin holes or a side trued up will do. Or better yet a rectangular boss on the bottom of and "L" shaped piece (you made a "Z" shape piece) sized to be a close fit in the slot inthe compound.

Edit: A square boss would be better so you could get 90 degree steps in rotation if needed

The DTI with sample was going to be my method as well. Another method is always nice to know.

Bill

pcarpenter
09-14-2007, 04:54 PM
For those of you with compound slides that are a rounded in design, I would think that perhaps cleaning the paint and filler off a spot (or even spot facing one place maybe 3/8" diameter) and then using a set screw to fine adjust the L-shaped piece for square to the lower slide half would do the job. In effect, you would be adding a jack screw and then using the L-shaped piece as a bit of a sine bar. Once adjusted to the proper height, drip a bit of cyanoacrylate on the screw threads and let it wick down in....or use a piece of monofilament line down in before threading the set screw in as has been recommended here by others. Its a cheap way of making a set screw into a locking set screw.

Paul

lazlo
09-14-2007, 06:23 PM
Fantastic job Frank!

How is the 12L14 holding up on the drive center? Does it look like it will last in a home shop environment?

quasi
09-14-2007, 11:40 PM
You know, you have the makings of a lot of good articles on your website. You should sell some to H.S.M. magazine. It could pay for a lot of new tooling for you.

Frank Ford
09-15-2007, 12:47 AM
Actually, I had one published a while back, and the next issue of Machinist's Workshop will be running a short article on making a simple form tool from an old file.

I have written a lot for magazines over the years (mostly guitar related) and yes, it does help pay the bills.

Next issue of MAKE Magazine (http://www.makezine.com)will have one of mine, too.

I suppose the 12L14 will hold up OK for me, because none of my tools get all that much mileage - only so much "spare time" you know.

Offhand, I don't think it would be a good idea to have both the center and the drive pins spring loaded. I'd be afraid of not being able to get enough "bite" unless the springs were bottomed out. And, the force along the axis of the work would move the part being turned with the carriage going to the left.

Cheers,

Frank Ford
FRETS.COM (http://www.frets.com)
Gryphon Stringed Instruments (http://www.gryphonstrings.com)
My Home Shop Pages (http://www.frets.com/FRETSPages/Machining/index.html)

lazlo
09-15-2007, 12:52 AM
I have written a lot for magazines over the years (mostly guitar related) and yes, it does help pay the bills.

I thought HSM just pays a pittance (~$50?) for an article?


Next issue of MAKE Magazine (http://www.makezine.com)will have one of mine, too.

That's a really neat site Frank! I'm surprised I never ran across it before...