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terry_g
01-01-2010, 08:14 PM
Why does no one sell a R8 spin index? I have a set of R8 collets why should I have to buy a set of 5C collets when the R8 collets would work for most of what I would use an index for. I decided to build my own. I took great pains with the setup and cutting the R8 taper. I almost peed myself when I dialed a piece of 1/2" stock in it and could not detect any runout.
It's not complete yet I still need to make a washer and draw bar for it and figure out how to attach the indexing plates and pin that I still need to make. I would like to make a 90:1 worm gear to mount on it and the necessary indexing plates.

Terry

http://farm3.static.flickr.com/2780/4235589986_a9d48555e7_o.jpg

http://farm3.static.flickr.com/2704/4243290760_413e0f226c_o.jpg

Carld
01-01-2010, 08:27 PM
Because the R8 collets only go up to 7/8" diameter work and the work will not pass all the way through the collet. 5C collets are drawn in with a hollow drawbar allowing the work to extend past the end of the collet.

Machinist-Guide
01-01-2010, 08:35 PM
Another advantage to the 5-C is you can work with a longer work piece. The R-8 has a draw bar that prevents you from spinning a longer work piece. The 5-C uses a lock collar that allows your work piece to go threw the collet.

Ken_Shea
01-01-2010, 09:06 PM
Still, a dang nice effort in making something that can still be very useful.

loose nut
01-01-2010, 10:15 PM
R8's also have a very limited size range.

rockrat
01-01-2010, 10:18 PM
Nice work. While R8's might be limited, most of us have them. What you have there can be indispensable when it comes to full use of existing tooling.

Cheers!
rock~

Machinist-Guide
01-01-2010, 10:22 PM
Still, a dang nice effort in making something that can still be very useful.

Yes looks like you done a nice job. I can think of a lot of things it could do.
Make a small face plate for it.
Make the face plate to hold a small 3" or 4" lathe chuck

Ken_Shea
01-01-2010, 10:24 PM
R8's also have a very limited size range.

While that is true, I have seen a number of full 5C collet sets that peopled have, guess how many never get used ;)
, guess again on the ones that do ;)

With the exception to the 1" it was pretty much the R8 Range.

Carld
01-01-2010, 10:40 PM
R8 collets only go to 7/8".

I have a full set of R8 collets and I only use about 8 of the sizes most the time. I also have an almost complete set of 5C collets, I think I am missing 6 of them. I seldom use the 5C's.

I think the tool Terry made is a good idea and most the time when your using a spin index you seldom have a long piece in it. It could be handy to have.

Ken_Shea
01-01-2010, 10:46 PM
"With the exception to the 1" it was pretty much the R8 Range."

That is what that was referring to Carl.

Carld
01-01-2010, 11:12 PM
:o oh 'scuse me.

Ken_Shea
01-01-2010, 11:20 PM
:o oh 'scuse me.
Well OK, but just this once :D

Black_Moons
01-01-2010, 11:21 PM
Actualy can't you get 1" R8 collets? they are just so thin its not even funny.

Doozer
01-02-2010, 12:02 AM
You can get thin wall 7/8" R-8 collets. The 1" R-8 collet is a joke that made it into production in China.

R-8 is a tool holding collet.
5C is a work holding collet.

--Doozer

dockrat
01-02-2010, 12:24 AM
my collet set came with a 1" collet. No way in hell could I cut with a 1" EM in it tho. The cutter just kept falling out. The 7/8" wasn't much better

davidwdyer
01-02-2010, 07:37 AM
That's really great work!! And close tolerances too.

But what is that other project that can be seen in the upper right of the picture? It looks like something which fits on a tool post.

terry_g
01-02-2010, 10:22 AM
That's the slotter I built for my lathe I posted about it earlier.
Here is the link.
Terry
http://bbs.homeshopmachinist.net/showthread.php?t=37713

davidwdyer
01-02-2010, 11:14 AM
That is quite nice.

I'm planning to make something similar soon (or at least try).

John Stevenson
01-03-2010, 06:59 AM
If you insist on using large endmills in a wimpy R8 you need one of these.

http://www.stevenson-engineers.co.uk/files/R8_1.125.jpg

For those who insist that endmill holders are the best thing since sliced bread you must be lacking the 1 1/4" fitting one because I have probably the only one in captivity.:D

Guaranteed two tenths run out [ not saying tenths of what ], hardened to a hairs breath of Evan's concrete floor, two locking screws instead of one.

No self respecting butcher should be without one of these.

.

Carld
01-03-2010, 09:37 AM
I have two of those type holders John. A 3/4" and 1" and they are available up to 1 1/2". I would be a little careful about using an endmill with an 1 1/2" dia. shank in a BridgePort. I can just imagine the load a large endmill would have.

Doozer
01-03-2010, 10:06 AM
Obviously an easy way to bend a spindle if things got hot and heavy.

--Doozer

John Stevenson
01-03-2010, 11:02 AM
Doozer,
This has been on the back of the bench since I got it and I have no intention of using it, not even sure if I have any 1 1/4" shanked cutters anyway.

If I want to bend the spindle on the Bridgy all I need do is leave the door open on a windy day :rolleyes:

BobWarfield
01-03-2010, 01:33 PM
If I want to bend the spindle on the Bridgy all I need do is leave the door open on a windy day :rolleyes:

Now that is funny!

Cheers,

BW

Scishopguy
01-03-2010, 03:04 PM
Obviously an easy way to bend a spindle if things got hot and heavy.

--Doozer

Aren't you supposed to use that one for holding marshmellows??? :D :D :D

terry_g
01-03-2010, 09:33 PM
I made an dividing plate and pin for the index tonight. 8,10, 12 holes in the plate,gives me 2,3,4,5,6,8,10,12 divisions.
I downloaded a degree wheel and used it to lay out the holes in the plate. I think they are plus or minus a degree maybe two,
good enough to make some speciality cutters for the mill.

Terry

http://farm3.static.flickr.com/2704/4243290760_413e0f226c_o.jpg

http://farm5.static.flickr.com/4009/4243290782_25d97ff783_o.jpg