Question about set screw adapters

Green Wheel. silicon Carbide. And yes..its practical. However keep in mind that there is no Grab with the setscrew...it only jams the endmill and prevents it from spinning. Its not really "holding it"..but thats really a moot point

Gunner

"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."

- Onni 1:33

An alternative that may be useful - a bit of hex bar which is through drilled and tapped. Screw the cutter in and use a large grub screw in the back end to lock the cutter. This lets me use cutters in my drill press / lathe. (I don't have a mill). The thread is only in the back half of the adapeter, the first half is machined to the od of the cutter shank. HTH.

rob

======================== Technical/shop name is "Weldon"(TM) or "whistle notch" style shank see

I have done this and found it to be entirely practical.

More of a rounded groove or notch works better for me, although it is harder to get the end mill in the holder into the correct position for the set screw to lock, as it will not only keep the end mill from turning ==>but also prevents it from moving axially thus getting deeper or shallower.

According to rob :

Are you by any chance talking about the Clarkson style end mills, and the holders for them? Note that most endmills in the US don't have the threaded end on the shank that the Clarksons do. (I know, because I have a pair of endmill holders for the Clarkson end mills, but none of the mills (yet). They strike me as an excellent idea, however.

Most US endmills have either a plain cylindrical shank (for holding in normal collets), or one with a flat ground about halfway down, with a specific profile (45 degree angled sides to engage the slight taper on the setscrew (grub screw in your terminology) so the setscrew both prevents the endmill from turning in the holder, it also prevents it being pulled down by the spiral (which can sometimes be a problem with an endmill held by a typical R8 collet.

Enjoy, DoN.

I don't know Don. All the end & slot cutters I have have a threaded posterior - thread runs for say 1.5x diameter. I'm in Australia if that matters. Most of my cutters came from my Dad who taught Fitting and Machining. IIRC the cutters I've seen at work have the same threaded rear. Are the Clarkson cutters more likely to be used used in prototyping / one off jobs?

Mine are like

According to rob :

[ ... ]

While the threaded rear are quite rare in the US.

IIRC, the Clarkson system started in England, and spread to Australia.

As I said above, US endmills are either plain cylindrical shanks, or plain with a flat ground in the side half-way along the shank length (which is called a "Weldon flat".

They are simply more likely to be used in the UK and in Oz, where you are.

That is one *ugly* URL -- 2-3/4 lines of cut-and-paste. And it happens to include information from your *own* session, which they timed out, to protect your "sensitive order information". It is probably not a good idea to post a URL that long, just in case someone may visit it before the session times out and decides to do something like ordering items in your name. :-)

And when I clicked to accept that it had timed out, It took me to the search page, where I would have had to know your search terms to find the same spot.

However, I'll take it as given that what you pointed to was to Clarkson style end mills.

Enjoy, DoN.

Hi DoN,

I had the same problem with the url. Try this one:

or

Hit the View larger image too, the threads show up a whole lot better then...

Interesting cutters, I have limited experience, but I haven't seen anything like them before.

Thanks! That one worked.

[ ... ]

O.K. Those are the certainly Clarkson style endmills.

For those who have never seen them, I'll describe the endmill holders for these which I have. (Mine happen to mount in 40 NTMB taper spindles, such as my Nichols horizontal mill.)

Start with a fairly short collet (the length of the shank) which is threaded at the back end, and slit (as usual) at the front end.

There is a taper from smaller to larger as you go back from the front -- about half way down.

Then there is a recessed diameter.

Then at the bottom is a circular flange with a pair of flats.

The collet slips into a nosepiece which is threaded on the OD, has a slot to accept the circular flange, and an internal taper to clamp the collet.

In the bottom of the socket in the body into which the nosepiece threads is fitted with a hardened center which fits into the female center at the end of the endmill's shank. When you tighten the nosepiece into the body, the center presses on the end of the endmill's shank, pressing it, and through the threads, the collet, into the nosepiece, thus closing the collet. The flats on the collet and the slot in the nosepiece keep the collet from spinning in the nosepiece.

So -- when it is firmly tightened, there is no chance of pulling the endmill out with aggressive cuts -- something which can happen with an R8 collet and a fairly large endmill with spiral flutes. This pulling has the disadvantage of plunging the endmill deeper into the workpiece than was intended -- often spoiling the workpiece.

As I said -- I have the holders -- now all I need is the endmills without having to order them across some big pond or other. My choices seem to be either the UK, or Australia, neither of which is very close, and both of which offer problems with money exchange. :-(

Enjoy, DoN.

Tried KBC Tools online? A quick search of the term Clarkson gets a small pile of end mills. Not cheap, but quality isn't.

Clarckson end mills are pretty common in Canada. Dunno why they really have not seemed to get any common acceptance in the US.

I have a large Vidmar bin full of (mainly) threaded shank endmills at work, with IIRC 4 or 5 sets of holders and a whack load of ER collet holders for our mills. Mainly the Clarkson EMs are in HSS while the carbides are straight shank. Very few Weldon shank EMs in use there.

Why is money exchange a problem? Buying power is buying power, regardless of location. Use a credit card number and the CC co. does the whole thing, and usually does not do you over as bad as the banks do for the exchange rate. My greif with both those locations is shipping costs. The distance drives that way up.

FWIW, a keen young fella could put his own threads on end mills if so inclined. They are stanardized at 20 tpi throughout the size range IIRC. Wouldn't have to be too fancy, as long as they threaded into the collet.

That would involve setting up to grind threads, but might be do-able.

In any case, the US dollar is still higher than the Canadian one, so it may be worthwhile to check around online.

Too bad I am no longer in the Montreal area. There was (IS?) a tool dealer in St. Janvier, just north of Dorval, that had excepional prices on end mills. Typically he was charging $5-6 for new end mills under 1/2 inch, and half the new price for resharps. His deal was that he bought large lots at auction and resold as much as he could to industrial users. He also did the sharpening in house, so he was essentially making money off unsaleable goods.

Cheers Trevor Jones

Thanks! That works indeed. I hadn't dealt with them. (Now all I need to do is to afford the ones which I want -- in the 3/4" and 1" range. :-)

It is interesting that these are marked as "Made in England".

And I sort of expected the ratio of imperial vs metric sizes to change when I clicked on the Canadian vs the US entry points -- but it only changes the prices -- even in the PDF images of the catalog pages.

While the Weldon shank are the more common here, by far. :-)

Well ... I've bought English system concertinas from both locations, one new, made for me in Scotland, and the other of about

1902 vintage (a big old contrabass), and the money exchange both times was a real pain -- more so with the Australian route, as there was no international agreement between them for international postal money orders, unlike with England.

But I did not even *think* of using my wife's credit card with either purchase. Now, the credit card is in my name, and I might think differently.

Agreed.

Hmm ... I might be able to do that with the toolpost grinder and careful dressing of the stone before I start. Of course, I don't resemble "young" fella these days by quite a bit. :-)

And both prices are affected by them being imported from England. It was amazing the price difference. I remember when US and Canadian money was a lot closer -- and sometimes I believe that the Canadian had the higher value.

That would have been nice.

Thanks, DoN.

Oooops! Sorry about that - I gotta check out that tinyurl stuff & find out how it works.

I should be safe on the personal info/ordering thing - I was using their site anaonymously and don't have an acct with them. Thanks for the heads up anyway.

cheers rob

According to rob :

That would make it easier for me to find out that the URL had expired -- but still would not get me the actual data. :-)

You're welcome. Essentially, it is a site which makes it a pain to bookmark things of interest, because everything is treated as a potential sale, so they want to hold on to associated visit information. :-)

As it works out, someone else posted a URL which showed the proper images -- or was that you in another branch of the thread?

Anyway - they are certainly Clarkson style end mills. And you won't find them common in the US, so my original warning stands --that your advice, while excellent for someone with ready access to the Clarkson style endmills would not work for most here in the USA.

Enjoy, DoN.