Indexing Plate

Not a bad idea at all!

Dominic Greco in Richboro PA

>Dan,

I was running an almost identical idea around in my head for a while. I had access to a couple (I only grabbed 2 from the dumpster) 15 3/4" diameter x 3/8" thick aluminum plates and I wanted to trap them between the chuck and spindle shoulder as you're speaking of.

I had a machinist friend of mine bore an exactly centered hole for my 1 1/4"-8 TPI spindle. From there it should be an easy matter to use my drawing as a pattern to drill the holes.

BUT, have I had a chance to take it any further? Nope! Not enough hours in the day. If you find you can make them economically enough, I say, go for it. Many of the lathes I've seen make a half hearted attempt at indexing. IMHO, an accurately machined metal indexing wheel would be a perfect add-on accessory. (BTW, Sorby sells one that looks pretty flimsy)

Make a limited run and see if they sell. You can probably just sell them to your turning club members at first. I betcha' you'll sell out.

I wish you luck in your endeavor.

See ya around,

Dominic

Re: Indexing Plate

Fred in NC

>I have been looking at indexing plates myself. For woodwork single row 24 hole plates seem to be the most useful.

Now that I invested in a rotary table I am planning to make one for my Jet Mini as soon as the weather allows me to work in the garage again.

Re: Not a bad idea at all!

Fred in NC

>Of course, an arm with a pin is needed to hold the plate in position.

Most of the time either a drill or small router will be used to cut the wood. A table or jig to hold it is also necessary.

Mag article on indexing

John K Jordan

>The spring 2005 issue of Woodturning Design (http://www.woodturningdesign.com/) has an article by Bob Heltman, "Make an Inexpensive Indexing System for your Lathe"

While I see room for improvement in the construction techniques, this article may provide some useful information.

JKJ in East TN

Definitely!

Dominic Greco in Richboro PA

>Fred,

You wrote:

"Of course, an arm with a pin is needed to hold the plate in position.

Most of the time either a drill or small router will be used to cut the wood. A table or jig to hold it is also necessary."

That's the part that is holding me up. I keep trying to come up with something simple, yet secure that will allow me to secure it. I have an idea for a spring loaded pin. But lack the mechanism for holding it in place.

See ya around,

Dominic

Re: Definitely!

Fred in NC

>Dominic, I have a design in mind that will be simple to put together. No way for me to make a drawing at this time....

A bar of aluminum or hardwood holds the bottom end of the bar that carries the pin. Something like 3/4 x 1-1/2", the idea is the same as a banjo. A horizontal hole is drilled through it for a 1/4" bolt near one end. Another hole is vertically drilled for a bolt just like you hold a banjo to the bed of a lathe.

Essentially, the pin is permanently affixed to one end of the bar. There is a hole near the other end for the bolt.

Now the good part: Take the bolt and put a compression spring about 5/16" on it. Then put the bar on the bolt. The put the bolt through the hole, and a locking nut at the other end. You can pull the bar away from the banjo to change holes.

This is easier than a retracting pin.

Re: Definitely!

John K Jordan

>>I have an idea for a spring loaded pin. But lack

>the mechanism for holding it in place.

The article I mentioned used a simple sliding bar mounted on the top of the headstock. The bar fit through two holes drilled on either end of a piece of flat steel, each end bent up 90 deg "to form a shallow U shape approx 8 inches long". The indexing plate was designed such that the holes lined up with the bar, the radius of the holes defined by the postion of the bar on the lathe headstock.

The bar itself had a handle made from a 90 deg bend at the far end which was sized to double as a safety device - when not indexing the handle was rotated downwards on the left end of the headstock to prevent the bar from accidentally engaging the holes in the indexing plate. The author built the sliding indexing pin first, bonded it to the top of the headstock, then used it to define the exact radius for drilling the indexing holes.

I would not like this exact method myself since I use the top of the headstock for other things. However, the sliding bar could be mounted elsewhere on the headstock.

Depending on the headstock, it might even be possible to find clearance to drill support holes for the long pin through the headstock body itself. A quick look at my Jet 1642 indicates there is plenty of space for a long through-rod just in front of the belt. It could easily be made removable.

JKJ in East TN

Re: Isn't there room left of the indexing plate

Al Crandall --NE of Indy--

>Isn't there room left of the indexing plate to put a verticle support for the pin which bolts to the lathe bed? Couldn't it be snugged up tight to the headstock casting and when it was high enough to clear the top, then the pin could be mounted in any manner of ways?

Re: Isn't there room left of the indexing plate

John K Jordan

>>Isn't there room left of the indexing

>plate to put a verticle support for

>the pin which bolts to the lathe bed?

Al,

I think the only issue would be how to easily keep slop out of the pin support. With a long rod supported by two widely spaced holes, the tolerances can be relatively low. A pin mounted as you mentioned would be a much better design but require tighter side tolerances, although I imagine nothing beyond the reach of someone with a good drill press, or better, access to a machine shop.

JKJ in East TN

Re: Indexing Plate

Ruth Niles

>Sounds like something I'd love to have for my Jet Mini. Let me know when you have them available for sale.

Please, do go for it......I just love inventors! : )

Ruth

Re: Isn't there room left of the indexing plate

Dan in the NW

>Thanks for all the encouragement. As this thread has progressed you've hit upon the one item that I am still working out, the indexing pin.

As I've thought about the indexing pin I've come up with some working assumptions. It needs to be adjustable horizontally and vertically to fit multiple lathes. The mounting system should not require drilling holes. It should be spring loaded but should have a retaining arm that keeps it in the retracted position.

I've got a design in mind I just need to find the parts and pieces. It's basically a rare earth magnetic mount with an adjustable L bracket. The pin is a rod that is spring loaded with a tight U bend on the left side of the retaining device. The retaining device has a J hook. With a 1/4 turn the U bend would latch on the J hook.

It's hard to describe something that is still in the mental process without a mock-up or drawing to reference but hopefully you get the idea.

Dan

Re: You don't have to be "locked in" to a pin.

Al Crandall --NE of Indy--

>I saw a design which used a metal blade to lock the index wheel. The wheel had slots in the periphery and the blade fell into them like a railroad crossing gate. The blade could also be positioned horizontally and rotate into the slots from the front. This would make it very easy to raise or lower the blade support so the indexer could be used on various sized lathes. If I ever need a spacing which the built-in lathe indexing won't give me, this is the design I'll adopt.