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adatesman
12-30-2010, 11:50 AM
Hey All,

Having a devil of a time trying to track down a taper reamer with a 16 deg included angle (8deg per side). All of the usual suspects (McMaster, Travers, Enco, MSC) have 7deg per side, but then skip to 10deg. Any thoughts where to find one? It's for cleaning up the ER16 socket I just made, so I'm kinda stuck with using that angle.

Thanks!

-aric.

IdahoJim
12-30-2010, 12:29 PM
Hey All,

Having a devil of a time trying to track down a taper reamer with a 16 deg included angle (8deg per side). All of the usual suspects (McMaster, Travers, Enco, MSC) have 7deg per side, but then skip to 10deg. Any thoughts where to find one? It's for cleaning up the ER16 socket I just made, so I'm kinda stuck with using that angle.

Thanks!

-aric.

You could have one made. Dave at Pacific Tool & Gauge could do that for you.
http://www.pacifictoolandgauge.com/

miker
12-30-2010, 04:14 PM
aric have a look here.

http://www.big-daishowa.com/pdf/cleaner_series_mm.pdf

Rgds

Forrest Addy
12-30-2010, 05:25 PM
Are you sure of the angle? I don't know what the standard says but often 7/24 (3 1/2" per ft) total taper is the default figure for machine steep (self-releasing) tapers. This is 8 degrees 17 min 50 sec on the half angle or 16 fegrees 35 min 40 sec total included.

Parenthetically the R8 taper is fairly close but different from MMT 30 taper. They will not seat properly nor can they be used to gage each other.

Incidentally the Wiki entry quoted below from this link is incorrect (observe the taper angle citation marked **)

The taper is variously referred to as NMTB, NMT or NT. Essentially this defines a taper of 3.500 inches per foot or **16.7112 degrees.** All NMTB Tooling has this taper but the tooling comes in different sizes. NMTB-25, 30, 35, 40, 45, 50 and 60. With the 40 taper being the most common by far."

adatesman
12-30-2010, 06:09 PM
Yup Forrest, the ER series uses 8 deg per side / 16 degree included angle. I've seen it referenced a couple places, but here's a link to the Rego-Fix specs (http://www.rego-fix.ch/eng/katalog/ti/1301.asp).

Sorry for the confusion, Miker... By "clean up" I meant smoothing out the tool marks from boring it rather than wiping away chips and oil.

And thanks for the link IdahoJim.



I'd be just as happy with a tapered endmill, but those seemingly also only go up to 7 deg and skip to 10 deg. I wonder why this is?

Anyway, I guess I may have to try my hand at making the reamer myself. Shouldn't be too hard to do; turn a male taper and then throw it on the mill to cut flutes. Hmm....

Thanks guys!

Forrest Addy
12-30-2010, 09:22 PM
OK, that's cool. So long as the two angles agree right on the button it doesn't matter what the actual angle is.

I don't agree about the reamer for a one time use. For one thing it's expeensive and for another it may remove the tool marks but it leaves a finish of its own. With a little care you can bore the taper and fine tune the bored finish with a scraper or a stone. Use blue and check the fit frequently so you don't get center bearing with rolled off edges.

dp
12-30-2010, 10:08 PM
That's in the range of tie rod ends. Check the Snap-On catalog.

Hear ya go:

http://extremecustomparts.com/i-361563-tie-rod-reamer-dana-44-dana-60-jeep-8-degree-u-s-a.html

Oh daym - that's 8 included, I think.

Don Young
12-30-2010, 10:13 PM
You might just make a lap and use it with an abrasive. Would be easier than making a reamer, I think.

TGTool
12-30-2010, 10:19 PM
Adatesman,

I make ER collet cavities frequently and you should be able to avoid the reamer purchase. Turning with a boring bar with a small corner radius will help smooth out the surface followed by stoning as Forrest suggests.

If you're having trouble zeroing in on the angle, use a dial indicator to set the compound. If you have small angle blocks you can use them against the compound sides if they're ground parallel to the dovetail, or check against the dovetail itself. Lacking angle blocks, make a shaft with carefully centered holes that you can thread an existing collet onto and use that between centers as the reference. My compound is only a casting so I finally broke down and machined and scraped a parallel surface on one side for stuff like this.

Mcgyver
12-30-2010, 10:21 PM
laps with a cone are trouble....you need that in and out motion with a cylindrical lap for it to work otherwise there's no way to stop and low points developing.

You can't bore it? I've not seen reamers like that, but that's not to say there isn't such a thing