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View Full Version : Any reason not to cut two more key slots in R8 collets?



noah katz
12-24-2008, 04:40 PM
As others who have made power drawbar attachments have said, the most time consuming part of changing collets now is aligning the slot in the collet.

Any reason not to cut two more slots in them?

http://i273.photobucket.com/albums/jj224/nlkatz/bp1.jpg

http://i273.photobucket.com/albums/jj224/nlkatz/bp2.jpg

Teenage_Machinist
12-24-2008, 04:57 PM
HOLY>>>> What kind of power drawbar is THAT?


I dont' know but you should check the clearance amount and the strenght.

davidh
12-24-2008, 05:17 PM
those little impacts are about 50 fto lbs. about the same as a 3/8" air ratchet. don't get excited. . . . . , oh,
and merry christmas. . . . .

Teenage_Machinist
12-24-2008, 05:19 PM
Oh, um just remembered. May not be an issue of why as much as how. They're hardened.

Forrest Addy
12-24-2008, 05:31 PM
Why use the collet key at all? It's easy to hold the collet/tool holder in place when the drawbar is actuated. When the drawbar is spinning up the thread there's no holding counter-torque requred to speak of. Once the drawbar takes its first tention there collet is against the taper.

Unscrew the quill bearing retainer, remove the dog point setscrew, and live your milling life free of further trouble.

Sure as hell you will be using a shell mill or a small carbide face mill, spin the adaptor, and bugger up the setscrew/key anyway.

BTW, good home made power drawbar hook-up but I'm puzzled by the big honkin handle.

noah katz
12-24-2008, 05:46 PM
I made it using a crossed roller slide (the black part) that I got on ebay.

The handle is just to put it within easy reach.

"Sure as hell you will be using a shell mill or a small carbide face mill, spin the adaptor, and bugger up the setscrew/key anyway."

I've never spun an end mill, but I am concerned about that happening with a face mill and messing up the spindle bore.

I'm not clear if you're recommending leaving or removing the set screw.

If my collets are hard, they're not very hard. They score easily with a file, so it should be easy w/a carbide end mill.

lane
12-24-2008, 06:03 PM
Remove the screw. If every one would do that. The milling world would be a happy place. IT serves no good purpose.

Teenage_Machinist
12-24-2008, 06:38 PM
I guess r8 is still a driving taper. Not like CAT-40 or something

noah katz
12-24-2008, 06:43 PM
"Remove the screw. If every one would do that. The milling world would be a happy place. IT serves no good purpose."

It would sure be a lot easier, and achieve the purpose better; even w/3 slots I still have to align to one.

So the consensus is that if there's enough force to spin the collet, it's likely enough to damage the set screw?

lane
12-24-2008, 07:36 PM
"Remove the screw. If every one would do that. The milling world would be a happy place. IT serves no good purpose."

It would sure be a lot easier, and achieve the purpose better; even w/3 slots I still have to align to one.

So the consensus is that if there's enough force to spin the collet, it's likely enough to damage the set screw?

If you spin a collet are a cutter . you are already doing something bad wrong.
I take the screw out of every mill I have ran,and throw it as far as i can. nothing but a pain in the a$$.

Frank Ford
12-24-2008, 07:42 PM
I'm impressed by the homebrew power drawbar setup. So simple - you just grab the handle to lower the driver onto the nut!

JCHannum
12-24-2008, 08:08 PM
The only purpose of the key in the R8 spindle is to generate posts on these sites as to it's value and how to remove a collet or endmill holder that has become jammed in the spindle when it spun.

Rockwell mills and probably others do not have the key from the start.

ckelloug
12-24-2008, 08:28 PM
I'm probably about to get flamed. . .

I followed everybody's advice and took the screw out for a while but I had to put put it back in to save my sanity. The threads on a few of my collets are sticky and the lack of the screw quadruples the time required to get the collet tightened down on the tool since several more hands are then required to keep the collet in place while trying to tighten the draw bar.

--Cameron

noah katz
12-24-2008, 08:34 PM
So how do you get the screw/pin/key or whatever it is out?

I looked up the spindle w/a light and mirror, and there's just a nub sticking out, though it seems to have been machined part way across the diameter, making a step.

Thanks, Frank. It really is great, couldn't be simpler or more intuitive, i.e move the lever the way you want the drawbar to turn.

Cameron, if it were me I'd get a new drawbar and/or set of collets; that kind of annoyance just isn't worth it.

oldtiffie
12-24-2008, 08:38 PM
Er-r-r-r Cameron,
why not just "clean up" those threads?

As its Christmas, instead of getting "flamed", get "flambé"-ed instead.

http://en.wikipedia.org/wiki/Flambe

BadDog
12-24-2008, 08:39 PM
1) Lower the quill about 2" and LOCK it.
2) Look on the back, there is a 1/4(?) set screw. Back it out about 2 turns (might be safer to remove).
3) Look at the ring on the end of the quill. There are two holes, one on each side. Find/Make a spanner to fit those holes and turn it off like a common right hand nut.
4) Look on the front, opposite the other set screw, just up above the area exposed by removing the nut. Remove the set screw you find there. You should find 2, one a locker, the other with a dog point the forms the key.
5) Put the "nut" back on and line up the spot (mark) with the rear set screw.
6) Tighten rear set screw "snug". DO NOT FORGET TO TIGHTEN THIS BEFORE RAISING THE QUILL!!!

Teenage_Machinist
12-24-2008, 08:42 PM
Possibly by removing the spindle

EDIT< I got ninjaposted, I was thinking that it might be a really big job for other types of mills.

noah katz
12-24-2008, 09:39 PM
I like BadDog's way (thanks!) better :)

I guess you were composing at the same time.

Forrest Addy
12-24-2008, 09:55 PM
Excellent post BadDog. Step by steo instruction that are lucid as mountain air.

noah katz
12-24-2008, 10:50 PM
Yes, thanks again, BadDog; the Chinese should outsource their users manuals to you :)

Teenage_Machinist
12-25-2008, 05:40 PM
sorry i thought you meant fro a different mill

juergenwt
12-27-2008, 02:29 AM
Forrest - ever use a left hand end mill?

fasto
12-28-2008, 01:34 AM
Let's say the R8 taper has zero driving force, the worst case condition. All the driving force is applied through the collet alignment screw.

Let's say you're running a cutter @ 150 RPM, pulling 2HP (this happens to be the HP of my knee mill).
This requires 70 ft/lb of torque, as t = (HP * 5252) / RPM

Let's assume the collet alignment screw is touching the outer surface of the collet.
An R8 collet is 0.950 Diameter or 0.0792 feet diameter. That's 0.0396 feet radius.
70 ft/lb applied at a radius of 0.0396 feet gives 1767 pounds of force.

I believe the collet alignment screw is 3/16" (0.187) diameter.
The area of a circle is pi * r^2, so the area of the screw is 0.0276 in^2.

If we assume the screw is loaded in direct shear (the collet and spindle are touching, there is no gap between them), the shear force ('t') is just t = F/A.
So, the force applied to the collet alignment screw is 64021 PSI. Yes, 64 thousand PSI.

If we assume that there is a gap between the collet and the spindle, the situation is far worse, as the collet alignment screw then becomes a circular beam loaded in shear.
In this case, the shear force is t = (4 * force) / (3 * area), which comes out to 85362 PSI. That's 85 Thousand PSI.

Notes:
(1) Increasing RPM makes the force decrease, as is obvious from the RPM to torque calculation.
(2) Most people probably aren't pulling 2HP. This calculation is for a worst case, but realistic, scenario.
(3) The decision to keep or remove the collet alignment screw is left as an exercise for the reader.

Teenage_Machinist
12-28-2008, 03:14 AM
Hooray for PHYSICS!!!. WOOT! :D

Good lord, that pin doesn't have a chance! How can a single, innocent pin defend itself against the dread forces of TORQUE?

If your power drawbar is spinning the collets, I suggest a bit of rubber, or something where the pin was to hold them against the side of the taper until they engage. You even might use an o-ring. Also lube the drawbar threads and clean up the collet.

BadDog
12-28-2008, 03:18 AM
Just hold it up in the bore with your finger tips. Even that is enough to keep it from spinning as long as the draw bar threads are in decent shape. I swapped 3 collets and a drill chuck tonight without giving it a moments thought...

Fasttrack
12-28-2008, 03:26 AM
I'm probably about to get flamed. . .

I followed everybody's advice and took the screw out for a while but I had to put put it back in to save my sanity. The threads on a few of my collets are sticky and the lack of the screw quadruples the time required to get the collet tightened down on the tool since several more hands are then required to keep the collet in place while trying to tighten the draw bar.

--Cameron


One of the bridgeys at work has a worn out brake lever so you can't "cam" it to the locked posistion. Whats worse is that one of the collets has slightly sticky threads, as you say. The key was destroyed or removed many eons ago and getting that darn collet to tighten is a real PITA. Ordinarily, I just cam the brake on, and push the collet up snug in the spindle. A firm push is ordinarily enough to overcome sticky threads. On this machine, I find a piece of scrap or the vise or whatever is handy and raise the knee slightly to push the collet up in the spindle and then tighten the drawbar. Its a silly routine considering I just need to run a tap through the collet to fix it, but anyways :rolleyes:

TM - not sure how rubber or an o-ring would work... sorta defeats the purpose of removing the key. An o ring on a collet will just get sheared off.

BadDog
12-28-2008, 03:44 AM
Yeah, fix the collet and/or draw bar... :D

As for caming the locking lever, I never do that. I just push the collet up by moderate finger tip pressure and run the draw bar down snug by hand. Then use my left hand to lock the brake while pulling one good time with the wrench on the draw bar to seat the collet and give a little "bind" on the draw bar threads (reason is obvious in next point). Now, release the brake and push the wrench back to the starting position. It will rotate the spindle rather than unscrew the draw bar. Now lock the brake and pull forward again on the wrench. Release the brake and repeat until you feel the sudden ramp in torque required to turn and you are done in just seconds. Kinda like working a ratchet, except the pawl is your brake lever/hand. Just make sure it's not in back gear. This technique is fast and easy enough that I don't really desire a power draw bar...

oldtiffie
12-28-2008, 04:59 AM
I have both ER-32 and C5 collets and not an R8 collet either in sight or in the shop. I only use the C5's in the grinders. I use ER-32 collets for everything that I can as they have none of these problems that I see so often here with R8 collets.

R8 collets seems to be mainly used in the US so far as I can see. ER collets seems to be generally preferred and then C5 to a lesser degree most other places than the US for general use except for grinders.

I am intrigued to see, and if possible to know, why C5 collets which also have a single key-screw as well as a draw-bar have so many less of these problems than do R8 collets.

Why are R8 collets so popular and if the US won't use more ER collets why does it not use more C5 collets?

noah katz
12-28-2008, 05:03 AM
"Let's say the R8 taper has zero driving force, the worst case condition."

A most flawed assumption; one would have to go to great lengths to create a situation where this were true, if it's even possible.

"If we assume that there is a gap between the collet and the spindle, the situation is far worse, as the collet alignment screw then becomes a circular beam loaded in shear.
In this case, the shear force is t = (4 * force) / (3 * area), which comes out to 85362 PSI. That's 85 Thousand PSI."

What formula is that based on?

In any case, a circular beam loaded in shear is a bit of a contradiction; the definition of a beam is that its length is much longer than the other two dimensions, such that bending stress dominates.

davidh
12-28-2008, 08:25 AM
i love it when engineers talk / type. it all seems way too easy for them :D


i do however wish i would have gone to real learning school instead of the one of "hard knocks" :(

lane
12-28-2008, 01:45 PM
About every 3 months just for cause. I run a 7/16 -20 tap whrough my collets just to clean any thing out of the threads ,also run a die over the threads on the draw bar just so every thing will work like it is suppose to . At work I keep a tap and die real handy in my tool box just to do than on the many different mills when a collet does not fit right. only takes a minute are two and all is good.

Teenage_Machinist
12-28-2008, 01:52 PM
Rubber: My idea is to have a sticky rubber button sticking out only about half a millimeter from the side of the spindle. You could attach a piece of rubber to the end of the screw that once made the accursed pin. Then, put a little bit of oil on so it is not too sticky. THis will hold the collet from rotating wherever the keyway is;

BadDog
12-28-2008, 02:20 PM
I have both ER-32 and C5 collets and not an R8 collet either in sight or in the shop. I only use the C5's in the grinders. I use ER-32 collets for everything that I can as they have none of these problems that I see so often here with R8 collets.

R8 collets seems to be mainly used in the US so far as I can see. ER collets seems to be generally preferred and then C5 to a lesser degree most other places than the US for general use except for grinders.

I am intrigued to see, and if possible to know, why C5 collets which also have a single key-screw as well as a draw-bar have so many less of these problems than do R8 collets.

Why are R8 collets so popular and if the US won't use more ER collets why does it not use more C5 collets?

My take, for what it's worth (probably not much)...

R8 collets are smaller diameter at both the taper and the key, so all else being somewhat equal, 5C wins that simply due to geometry providing more torque restraint.

5C being work holding (and generally bar stock at that), not tool holding, it rarely holds anything such that work is done at a larger diameter than it holds. On the other hand, R8 often holds tooling such that the work is done at a much larger diameter than it holds. Not only that, but the work is pretty much always interrupted resulting in shock loads. Think fly cutters, face mills, shell mills, boring heads, and even reduced shank EMs or the popular 1" EM holders.

R8 lost before it even got started when compared to 5C, which also is a completely different category (with the exception of Hardinge Horizontals).

And R8 is very popular in the US due to the preponderance of "Bridgeport Class" turret mills that used R8. Other than these mills, R8 was not popular in industry which generally preferred the direct drive tapers (CAT/INT/etc). But R8 was by far the most common tooling for the "ideal" (mythical or not) HSM type machines, and represented the tooling most likely (and most affordable) to be used by the HSM. This also influenced it's adoption by the Chinese clone army which is generally R8 for machines above the smallest. Of course Bridgeports and the other similar turret mills also were available with other spindles like QS, INT-30, BS, some proprietary, and a long list of others; but R8 dominated by considerable margin during the time period from which most HSM machines and tooling come. ER is decidedly unpopular because of extra overhang beyond the spindle bearings, shear market pressure which keeps the price higher due to lack of volume (and so becomes somewhat self limiting), and of course there is the volume of tooling that has a fixed R8 mount which would not be available if using a dedicated ER spindle of some sort (rather than adapter with the hang out issues). Whether the hang out is an issue is up to individual and use, and many (like Robert/Lazlo) love their ER adapters, but all that figures into (more or less) the answer to your question.

Fasttrack
12-28-2008, 02:31 PM
Yeah, fix the collet and/or draw bar... :D

As for caming the locking lever, I never do that. I just push the collet up by moderate finger tip pressure and run the draw bar down snug by hand. Then use my left hand to lock the brake while pulling one good time with the wrench on the draw bar to seat the collet and give a little "bind" on the draw bar threads (reason is obvious in next point). Now, release the brake and push the wrench back to the starting position. It will rotate the spindle rather than unscrew the draw bar. Now lock the brake and pull forward again on the wrench. Release the brake and repeat until you feel the sudden ramp in torque required to turn and you are done in just seconds. Kinda like working a ratchet, except the pawl is your brake lever/hand. Just make sure it's not in back gear. This technique is fast and easy enough that I don't really desire a power draw bar...


:D Yeah see that only works when the collet and draw bar are properly taken care of. I need a wrench to turn the draw bar and the lock to keep the spindle from turning and a third hand to push the collet in the spindle! I actually spent about 30 minutes the other day looking for a 7/16 tap to clean up the threads. Never did find one. Well actually I found a broken one but it only had about three threads remaining - not enough to clean up on a grinder and make work. <sigh> Some day I'll bring in my own tap.

ckelloug
12-28-2008, 03:19 PM
So that nasty thread is 7/16-20. Ah ha. I bet they've got those lying on the shelf in the surplus bin at Ameritool. I never got around to figuring that out. I just bought a couple of lyndex collets to replace the common sizes in the cheap chinese set that I inherited with the mill. The lyndex collets are japanese and have nice fit finish although the 3/4 one seems to be a few tenths large or something as it has to be pretty tight before it grabs the tool.

With Noah's calculation, it's pretty obvious that that little dog point screw is toast if anything even thinks about spinning. Without looking it up, I'd figure a small screw like that loaded in shear is only good (being generous) for somewhat under 1000 psi which is 1% of the computed shear on the collet.

fasto
12-28-2008, 04:11 PM
With Noah's calculation
It's fasto's calculation :D
--
Aaron

John Stevenson
12-28-2008, 04:19 PM
Noah could only do 2 + 2 + 2.....................for calculations

OK I'll get me coat...........................

.

John Stevenson
12-28-2008, 04:35 PM
ER is decidedly unpopular because of extra overhang beyond the spindle bearings, shear market pressure which keeps the price higher due to lack of volume (and so becomes somewhat self limiting),

What's wrong with this scenario ?

http://www.stevenson-engineers.co.uk/files/X3nose1.jpg

ER32 direct into an x3 spindle, exactly the same distance as a R8.

Plus with no drawbar needed you can run sub spindles held direct in an ER collet and drive thru the top.

http://www.stevenson-engineers.co.uk/files/x3nose2.jpg


This way you still get to keep the same 0,0 point. Ideal for engraving and small drills.

http://www.stevenson-engineers.co.uk/files/beltdrive6.jpg

Not staged that's actual spindle speed of 43,786 to the accuracy of the rev counter.

Nearly as fast as Evan's steam engine :cool:

.

BadDog
12-28-2008, 04:59 PM
Certainly not bad in that implementation. And surely far better than an ER adapter in an R8 spindle. But the question quoted was about the reasoning for it's lack of popularity in the US. And my response was that it seems largely historical, economic, and perspective. And that view comes (at least in part, or the genesis of it) from the response given (including yours) for my similar query some years back when I was overwhelmed by the many seemingly arbitrary (and expensive) options in collets...

Yes, what you show does have more overhang than an R8 all but embedded (comparatively) inside the spindle bearings. Exactly how important that difference is depends on what it's doing, and who is commenting on it. It's also a new setup that gives up much of the R8 tooling so readily available in the US, and so goes to my comment on the historical and economic influence.

I agree that ER is a superior modern option to R8. But for most of us in the US, cost and availability (native in a spindle) makes it a non-starter. Once machines like you show become more common in the US, and quality ER collets less expensive and more widely used (so that it's not just another set of collets to add to the 4 other styles) then it will likely start gaining ground. But for now, even the common HSM type new machines from Grizzly, Enco, HF, etc almost universally come with R8, and I think, for the reasons I mentioned...

BadDog
12-28-2008, 05:10 PM
Yes, what you show does have more overhang than an R8 all but embedded (comparatively) inside the spindle bearings.
I just re-read and that didn't come out right. What I meant was relative to the typical turret and bench top mills with R8 spindles. I didn't mean to imply that you are wrong when stating that it is the same as R8 on that machine. Appropriate sized ER could be just as compact and embedded as R8 given a spindle designed for native ER use, but that doesn't exist outside a few new/prototype/custom machines. So the rest must use adapters with considerable hang out.

If I were to pick up a new small CNC mill, I would love to get one of your ER spindle X3s. But if I had my preferences in a larger manual or CNC machine, I would probably chose one with a 30 taper. Direct drive, no slip, and still has reasonably common/inexpensive tooling...

noah katz
12-28-2008, 11:32 PM
"Noah could only do 2 + 2 + 2..."

If you're referring to my questioning “shear force is t = (4 * force) / (3 * area)”, I’d appreciate being educated.

If not, that’s another thing I’m clueless about.

platypus2020
12-28-2008, 11:38 PM
"Noah could only do 2 + 2 + 2...."


Noah, boarded the animals 2 x 2....

fasto
12-28-2008, 11:47 PM
If you're referring to my questioning “shear force is t = (4 * force) / (3 * area)”, I’d appreciate being educated.

Machinery's Handbook 27th edition Pg 213 "Table of Simple Stresses".
The modeling of the pin as a circular column loaded in shear is an approximation, as are the rest of the calculations, but should be close. ;)

Teenage_Machinist
12-28-2008, 11:49 PM
Damn it, we don't need MORE tapers! :mad:


Three c's for the mini-lathes under the sky

Cat-40 for the NC-mills in their bases of stone

R *8 for Brideports old and dry

ER for the new mill on it's dark throne

One collet to rule them all, one taper to find them

One collet to hold them all and in the spindle bind them

In the land of Hardinge where the coolants lie

noah katz
12-29-2008, 04:57 AM
"Noah, boarded the animals 2 x 2..."

Duh, I am dense, thanks :)

"The modeling of the pin as a circular column loaded in shear..."

Ah, well, a column and a beam are two different...animals.

macona
12-29-2008, 07:13 AM
Damn it, we don't need MORE tapers! :mad:


[/COLOR]

Ahh, its not so bad.

Lets see, I have:
ER-16,20,32
TG
Acura-Flex
SK-10,16
5C
2J
3C
1A
Z
DA-100
Precise Spindle Collets
W15
S15

Got rid of all my R8 after I changed to 30 Taper. Did try pulling the set screw. Put it right back in after a collet self tightened on me.

Dont see the issue with overhang with a R8 to ER collet chuck. After all the equivalents are used in CNC all the time.

lazlo
12-29-2008, 07:49 AM
Yes, what you show does have more overhang than an R8 all but embedded (comparatively) inside the spindle bearings.

That almost looks like an adapter, and not a natively-ground ER-32 spindle.
John, why is there a second ER-Nut on the spindle??

This is my R8->ER-40 collet chuck on my Millrite, and the additional overhang is about the same as an endmill holder (about the length of an ER-40 collet ~= 1.5").
If you re-ground this R8 spindle for ER-32 (which is almost exactly the same dimensions), the clamp nut should be level with the tip of the spindle (where it's tapering right before the ER collet chuck):

http://i164.photobucket.com/albums/u15/rtgeorge_album/Servo%20Plate/ServoPlate015.jpg


It's also a new setup that gives up much of the R8 tooling so readily available in the US, and so goes to my comment on the historical and economic influence.

Yes, but a smaller set of ER spring collets will grip a large range of straight shank tools, so all you're really losing is the native R8 tooling. For me, it's primarily the facemill arbors that force me to take the ER chuck off -- everything else, including most of my boring heads, I've standardized on a 3/4" straight shank.

lazlo
12-29-2008, 08:09 AM
R *8 for Brideports old and dry

John likes to complain about Bridgeports and R8, but it works fine for most people. :) Bridgeport does make a 30 Taper spindle, and they sell practically for free on Ebay, because no one wants them: the R8 collet is not the limiting factor on a 1 1/2 HP, light milling machine like the Bridgeport.

I've never had an R8, 5C, or ER collet pull out. Maybe it's karma :)


One collet to rule them all, one taper to find them

That's like asking for a single standardized screw thread. For what size machine?

3C, 4C, and 5C are the same collet series sized for the corresponding spindle. If you wanted 5C capability on an Atlas, for example, you'd need a much larger spindle, which would be out of proportion to the rest of the machine.

If you wanted to standardize on the ER collet system, for example, there's a whole family of them from ER-8 up to ER-50, and the collets don't interchange.

Then there's also the issue of drawbar system collets like the 3C, 4C, 5C series versus non drawbar collet systems like the ER's. A 5C collet is threaded (outside and in), so the hollow drawbar locks onto the collet itself, and you have through-hole capability. 5C's also have square, hex and emergency (solid, machineable) collets, which the double-angle spring collets can't do.

John took a 5C emergency collet and bored it out for the ER-32 collet chamber, and thus made an ER to 5C adapter. That's about the closest you're going to get to collet Nirvana.

But the reality is that you're going to find several collet systems in a typical shop, since each has it's unique features. I use 5C, R8, ER-40, and ER-16 in my shop.

Teenage_Machinist
12-29-2008, 03:19 PM
Really more a joke on just how many there are than that there should be only one---


I say we need: A work collet series- 5C along with less common 3C and other C's. Only the smaller lathes used by HSMs cannot hold 5C and it takes a really small lathe- smaller even than a mini-lathe- to reject a 5c spindle nose chuck. 3c fits in a #3MT and you could have a bigger C for big lathes, ect.

A Milling Machine Taper Series: Either pinless R8 or a NMTB such as Cat-40 would be good. Both can take drawbars which work for both manual and power drawbars. Both are good for shanked tools, and both are somewhat stick-resistant. R8 has the advantage of being good for collets while Cat-40 is good for CNC as it has height repeatability (or so I think).

A Self Holding Taper Series: Use Morse, B+S:p , or Jarno (?) taper, I would say Morse just as it is more common, but the others could work. This may actually be getting a bit obsolete. I have seen self holding tapers only on lathe head/tail spindles, and on drillpresses/chucks, and for tiny or odd mills. It seems like this taper might decline.

A Wide-Range/ Push-In taper- THERE ARE TOO MANY OF THESE!
Let's use the ER's which have a great collapse. ER 32 would be most used with others for odd sizes.




That means 3 common tapers- 5c for work holding, R8 or 40 for milling machines and tool holding/ shanks, and ER 32 for wide range, self ejecting ect. Then there would be 3C and others for work holding, larger and smaller tapers for milling machines, and the large and small ER's. And then different sizes of MT for lathes and drills. But until standardization really happens, there are

TOO MANY TAPERS!

noah katz
01-04-2009, 07:31 PM
"3) Look at the ring on the end of the quill. There are two holes, one on each side. Find/Make a spanner to fit those holes and turn it off like a common right hand nut."

Anything the matter with tapping in the holes with a pin punch?

BadDog
01-04-2009, 07:52 PM
Two big guys in black suits will be there in a few moments. Don't worry, they are there to "help" you resolve this matter...

I would like to find all the guys who used punches to foobar at least half of every non-hex nut in my shop, including the one on my mill... The results would NOT be pretty...

Fasttrack
01-04-2009, 09:51 PM
Two big guys in black suits will be there in a few moments. Don't worry, they are there to "help" you resolve this matter...

I would like to find all the guys who used punches to foobar at least half of every non-hex nut in my shop, including the one on my mill... The results would NOT be pretty...


Hahaha - you should see the B&S surface grinder at the FSAE shop. Spanner wrench is long gone and the spindle nut is all buggered up from people hammering the nut off. Its a left handed thread and that confuses alot of people. Yep, you read that right, people hammering away on a precision grinding spindle :rolleyes: I was angry at first, but then decided life is too short to be angry at people's mistakes, there are too many of them :D

lunkenheimer
01-04-2009, 09:56 PM
Just to clarify from the preceding posts-
1. hammering on a precision spindle is ALWAYS a bad idea
2. You'll bung up the nut and then the proper wrench will not fit
3. Only do use the punch trick if all else fails (not because it's more convenient than finding the correct wrench)