Matching up Two Cheap Spin Indexers

I've got a project that needs to be indexed to drill a bunch of holes. Its 3D part of course so part of the initial machining is to leave it
"mountable." I have an idea worked out, but it has to be supported at both ends. I was thinking two cheap spindexers face to face would work. The work piece is machined with a radius slot in each end that can be clamped to a pin mounted in each spindexer. Yes, I know. You all have a better way, but this is the way I am going to do it.
Now once you learn a trick you are sure to want to do it again.
I can clamp the two spindexers to the table with a lathe truing bar between them, and get them dialed in straight to the machine I am pretty sure. It will just be tedious and time consuming, but after I figure out how to deal with any flex in the setup it shouldn't be much worse than truing up a vise. Should be able to get within a half thousandths over its length.
That's fine for one job, but I'm making a single prototype piece. I'll want to get the indexers off the table and out of the way when its done. Of course if the customer likes the prototype I'll be making a bunch of them over time. So I'll need to throw them on the table and take them off regularly. I have enough clearance on my knee mill I could mount them in my vises.
No comes the problem. They will need to be re-indexed to the machine every time they are used. The front and the bottom are the only reference surfaces. The sides of the base appear to be as cast. I looked at the slight step up to Phase II indexers, but they don't look to be any better. In fact to find an indexer with more good reference surfaces the price jump is substantial. Well the quality of the indexers is much better too, but to much for the prototype part they will be used to produce. I'd like to mill off the sides of the base so they are square and perpendicular... not to hard... but also equidistant from the center line of the indexing body in a mirror relationship to its counterpart... I have no clue... , so I could just drop them in the stepped jaws of the mill vises when I need them.
Actually I just had an idea. Cut the minimum to square up the base. Flip and mount. Mount a work piece in each. Measure the offset. Remove the offset from opposite sides of each base. This thought JUST came to me, so I am sure there has to be something wrong with the idea. Hit me.
Flame suit on.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I have two spin indexers facing each other on the table. It would be easy enough to clamp them on opposite ends of a stiff 1" rod, spaced far enough apart to hold the center of the rod in the vise with the indexers base-up, but then I don't have enough support for the bases to risk milling them. Threaded rod screwed into and protruding above 1-2-3 blocks might work(?). I'd be happier with angle plates bracing the side the end mill pushes toward.
If they could be supported well enough a shallow lengthwise slot for a key that fits a table tee slot should repeatably locate them in line. The slot wouldn't have to be accurately centered, it's enough that the rod in the vise ensures that both bases were slotted at the same offset. -jsw
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Monday, November 13, 2017 at 11:44:21 AM UTC-8, Bob La Londe wrote:

Ideally, you'd want those spindexers to have a bottom-mounted rib that engages the mill table tee slot. If you add a reference surface (a button would do), you can align 'em on the slot, and measure the button-to-button distance to space 'em.
I wouldn't involve the vise. You'll fiddle with its jaws some day.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 13/11/17 19:44, Bob La Londe wrote:









milling the sides parallel to the spindle axis, I believe the Suburban Tools indexer the cheap ones are a knock of have this as standard. I was taught that the T slot are accurately machined and can be used for alignment so I slot a piece of 5/8" wide cold rolled into the slot on the BP and use that to align the indexer, quick and simple.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Bob La Londe" wrote in message
I've got a project that needs to be indexed to drill a bunch of holes. Its 3D part of course so part of the initial machining is to leave it "mountable." I have an idea worked out, but it has to be supported at both ends. I was thinking two cheap spindexers face to face would work. The work piece is machined with a radius slot in each end that can be clamped to a pin mounted in each spindexer. Yes, I know. You all have a better way, but this is the way I am going to do it.
Now once you learn a trick you are sure to want to do it again.
I can clamp the two spindexers to the table with a lathe truing bar between them, and get them dialed in straight to the machine I am pretty sure. It will just be tedious and time consuming, but after I figure out how to deal with any flex in the setup it shouldn't be much worse than truing up a vise. Should be able to get within a half thousandths over its length.
That's fine for one job, but I'm making a single prototype piece. I'll want to get the indexers off the table and out of the way when its done. Of course if the customer likes the prototype I'll be making a bunch of them over time. So I'll need to throw them on the table and take them off regularly. I have enough clearance on my knee mill I could mount them in my vises.
No comes the problem. They will need to be re-indexed to the machine every time they are used. The front and the bottom are the only reference surfaces. The sides of the base appear to be as cast. I looked at the slight step up to Phase II indexers, but they don't look to be any better. In fact to find an indexer with more good reference surfaces the price jump is substantial. Well the quality of the indexers is much better too, but to much for the prototype part they will be used to produce. I'd like to mill off the sides of the base so they are square and perpendicular... not to hard... but also equidistant from the center line of the indexing body in a mirror relationship to its counterpart... I have no clue... , so I could just drop them in the stepped jaws of the mill vises when I need them.
Actually I just had an idea. Cut the minimum to square up the base. Flip and mount. Mount a work piece in each. Measure the offset. Remove the offset from opposite sides of each base. This thought JUST came to me, so I am sure there has to be something wrong with the idea. Hit me.
Flame suit on.
********
Of course I am doing it wrong. LOL. Actually, I keep two vises in the mill I plan to use for this. They are indicated in, and then the soft jaws have steps milled in place. If something wonky has happened I take a skim cut of all step surface and I am good to go again. They will most likely get used in the vises as a pair.
********
Toolguy on home shop machinist had the best answer to the actual question I asked. Its dead simple to do his way.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.