Talk:Machine taper

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Contents 1 How many Morse tapers??? 2 Another thing to add 3 Strange angle measurments 4 Finding the angle for 3.5 per 12: wrong and right 4.1 Wrong 4.2 Right 5 Advantages/disadvantages of tapers?

[edit] How many Morse tapers???

This article is internally inconsistant in a number of ways. In one place, it says, comes in 8 varieties, from "Morse 0" [...] to "Morse 8" (which would be 9 sizes). In another place, it says, Morse tapers come in seven sizes identified by number -- #0 through #7 (which would be 8 sizes). The table lists seven sizes, #0 through #6. Could somebody who is really familiar with machine tools please fix this? --RoySmith 17:02, 16 August 2005 (UTC)

[edit] Another thing to add

There should be a discussion of "self-holding" and "self-releasing" tapers. SASGW 18:23, 23 January 2007 (UTC)

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Do you have any information on this matter? I have try everything at my university and only found 4 page about the subject in the hanbook of mechanical engineering calculations by Tyler G. Hicks —Preceding unsigned comment added by 70.50.252.192 (talk) 21:48, 21 February 2008 (UTC)

Self-holding tapers hold themselves in place both axially and with respect to torque. Once they have been lightly pushed or tapped into place, friction holds them stationary. (Chips or burrs can prevent them from holding properly.) Self-releasing tapers have a larger degree of taper and rely on things holding them stationary, such as a drawbar or a retention knob to pull the tool into the spindle, and tangs or driving lugs to resist the torque. They are the taper of choice for automatic toolchanging with indexable toolholders. When the machine is ready to change the tool it stops pulling on the retention knob, allowing the taper to be released. A blast of air keeps any chips off of the taper surfaces during the toolchange. — ¾-10 02:12, 22 February 2008 (UTC)

[edit] Strange angle measurments

"16 degrees 15 minutes 37 seconds" (refrencing the NMTB taper angle)? I've never seen minutes used in measuring angles, outside of 19th century navigation...

Replaced the NMTB taper information with the (correct) decimal equivalent.

[edit] Finding the angle for 3.5 per 12: wrong and right

[edit] Wrong

To the anon who has twice recently changed the degree measurement of the NMTB tapers (3.500 inches per foot) from 16.2602047... degrees (correct) to 16.59428994... degrees (incorrect): Please note that tan 16.2602047° = 0.2916666 = 3.5/12. You can check this for yourself using Google.com (Google Calculator). Please note that when you type tan(n) into Google, it assumes by default that n is in radians. 16.2602047 degrees = 0.283794109 radians. tan(0.283794109) [radians] = 0.291666666 = 3.5 ÷ 12. Thanks. — ¾-10 02:18, 13 November 2007 (UTC)

[edit] Right

Please note that the correct way to calculate the angle is:

The taper is the change in the size of the diameter as you travel down the axis of the taper. So, take 1/2 the change size (1.75") and divide that by 12", arctan of the result is 1/2 the included angle. So 16.5942899... is correct. —Preceding unsigned comment added by SamELLI (talk • contribs) 17:45, 29 April 2008 (UTC)

D'oh! I can't believe I made that obvious mistake. 1,000 apologies. Thank you for explaining the correct calculation. — ¾-10 03:12, 30 April 2008 (UTC)

[edit] Advantages/disadvantages of tapers?

Could someone please clarify the advantages or disadvantages of tapers when compared to say, chucks or collets? Perhaps I just didn't get it, but to me it seems like the article states that tapers are outdated, and are being replaced by chucks and collets... —Preceding unsigned comment added by 24.45.0.133 (talk) 17:51, 15 January 2008 (UTC)

Not true at all (i.e., that tapers are outdated, and are being replaced by chucks and collets). Tapers are not going anywhere, because of their ability to provide both (1) repeatably high concentricity with successive tool changes and (2) easy CNC toolchanging with repeatable tool length offset. In fact many CNC toolholders have both a taper (to interface with the spindle) and a collet (to interface with the tool). Neither of those components is going to replace the other. It is hard to explain this if the audience is not familiar with how CNC mills do automatic tool changes. I lack the time to tackle it now, but hopefully will make time to try it in future. This may be something that is very hard to teach via Wikipedia alone. But I can imagine some diagrams that could help. — ¾-10 03:13, 16 January 2008 (UTC)

I should qualify my comments. It is true that, specifically regarding new manual machine tools, such as the average new manual benchtop drill press or new manual vertical mill, you are not going to be doing your tool changes by drifting out one Brown-&-Sharpe-taper-shanked drill bit or milling cutter and tapping in another. There is going to be either a drill chuck or an R8 collet setup mounted semi-permanently in the spindle. (The drill chuck itself will usually be held in the spindle by a self-holding taper). Tool changes will not involve unseating that taper; they'll be done with the chuck or collet. So in that limited respect, people are right when they say that a milling cutter with a taper shank is old-fashioned. However, that drill chuck is still held by a taper, even if you go years without unseating it; and when you change contexts and talk about CNC mills with automatic toolchanging, tapers are still being seated and unseated on a daily basis. (In this case, self-releasing tapers, 3.5/12.) The fundamental reason is that tapers provide indexability—i.e., you can separate a matched pair of tapers and put them back together again, and the geometry of the two parts is back to the same place it was last time. (And in more than one axis—both concentricity and tool length offset). As I said earlier, this is easier to understand than it is to explain. I will try to improve Wikipedia's coverage of these concepts when I get a chance. — ¾-10 15:37, 16 January 2008 (UTC)