Custom collets

[Gareth J]

You're welcome to one of these for just postage cost if you can think of a way to glue it into your hole:
http://pages.ebay.com/link/?nav=item.view&id=231984716925&alt=web

Might be adaptable in the right side of hands.

 

[Freddy0309]

what size is the bore of the collet you do have freddy?
if it was big enough you could maybe get a ER collet set and modify the shank on one to suit, but it id want to be a decent enough in the one you have.

Not sure in the bore will measure it when I get home

You're welcome to one of these for just postage cost if you can think of a way to glue it into your hole:
http://pages.ebay.com/link/?nav=item.view&id=231984716925&alt=web

Might be adaptable in the right side of hands.

That's very generous thanks pm incoming

 

[Agroshield]

Someone wrote very early on that you should make the spindle solid. I think that is a mistake. It should be drilled out slightly larger than the capacity of the biggest collet you will use. This will allow you to hold long endmills, taps and drills in the collet.

 

[Freddy0309]

So finally got around to measuring the existing collet it's a 16mm collet so I was wondering if I could use something like http://pages.ebay.com/link/?nav=item.view&alt=web&id=291807466412&globalID=EBAY-GB this and put it through the existing collet?

 

[Agroshield]

So finally got around to measuring the existing collet it's a 16mm collet

A straight shank ER holder would be a great job. Please double check your collet is 16mm and not 5/8". Standard collets are generally quite fussy about the size they hold (and this is why ER is good as it has a relatively large gripping range of 1mm).

 

[Agroshield]

You should never choke any cutting tool so that the cutting edges are held by the collet.

In a professional, production environments, sure. You are correct. However on a 50+ year-old machine used in a hobby environment, maybe not. The machine is small and the biggest limitation will be headroom between the cutter and the workpiece especially when using twist drills. Most people won't have a set of stub drills as well as a set of jobbers. The ability of the ER series to grip on the flutes of a drill or cutter is a big advantage in my book.

There's lots of good advice in this thread but it becomes less useful if the context in which it is to be applied is misunderstood.

 

[Pete.]

So finally got around to measuring the existing collet it's a 16mm collet so I was wondering if I could use something like http://pages.ebay.com/link/?nav=item.view&alt=web&id=291807466412&globalID=EBAY-GB this and put it through the existing collet?

That machine is highly unlikely to have a metric collet with it.

The problem with mounting a collet holder in a collet is the vastly increased stick-out. You wouldn't ever consider buying a machine with a 5/8" spindle, but that's what you're creating if you do this. Your mill was designed to turn decent sized collets at slower speeds, those holders are meant for smaller collects and high rpm on small cnc machines.

I have an idea that might work for you, but it'll have to wait till the weekend for me to check it out.

 

[Freddy0309]

That machine is highly unlikely to have a metric collet with it.

The problem with mounting a collet holder in a collet is the vastly increased stick-out. You wouldn't ever consider buying a machine with a 5/8" spindle, but that's what you're creating if you do this. Your mill was designed to turn decent sized collets at slower speeds, those holders are meant for smaller collects and high rpm on small cnc machines.

I have an idea that might work for you, but it'll have to wait till the weekend for me to check it out.

The bit about the cnc makes a lot of sense. I don't think the collet is original, it's not quite the same as the measurements/pictures online I've found.

I'm grateful for any help or advice I receive as I'm extremely new to all this

 

[Pete.]

Right, I say that OZ collets will work in your spindle (also known as DIN 6388). It would require the taper re-machining and a new nut made but I'm sure they would work. There are several sizes of collet though and you'd need the B form to fit your particular spindle. The collets have several denominations:

OZ20
OZ25-20
DIN 6388 (B)

http://www.e-dvt.com/index.php?route=product/product&product_id=268

ER25 would also probably fit but you'd have to check the taper is shallower than your stock one and the tool capacity is limited to 16mm.

 

[Screwdriver]

The bit about the cnc makes a lot of sense. I don't think the collet is original, it's not quite the same as the measurements/pictures online I've found.

I'm grateful for any help or advice I receive as I'm extremely new to all this

The George Taylor had/has its own proprietary collet system, it is close to but not the same as any of the standard collets. I looked at all of them. Even the one it came with is I think, home made. I reckon it's a 1/2" but we digress. When I was looking at it, I came to the conclusion the best bet was to convert to a standard collet system and iirc R20 looked about the best compromise for sizes. I was considering the idea of having the existing spindle re-ground internally to accept a standard ER20 type collet - then you bought it!

Here's a list of the common ER collet system sizes: https://www.maritool.com/ER-Collets Pick a collet that would fit inside the existing spindle, then have the spindle ground out to accept the precise collet dimensions. Note: The "ER" refers to the type of collet so for example ER20 refers to the dimension shown for the collet body and a set of collets will have a range of sizes it can hold. I don't think you need much more than 1/2" because it is a small precision milling machine.

The existing spindle is super accurate, hardened and ground. It's a gem. Be careful who you farm it out to for modification. You'll also need to modify or make up a new "collet closer" to suit. Hope that helps. While I was looking at getting it sorted, a full size Bridgeport turned up at a price I could afford so....

S.

 

[Freddy0309]

The George Taylor had/has its own proprietary collet system, it is close to but not the same as any of the standard collets. I looked at all of them. Even the one it came with is I think, home made. I reckon it's a 1/2" but we digress. When I was looking at it, I came to the conclusion the best bet was to convert to a standard collet system and iirc R20 looked about the best compromise for sizes. I was considering the idea of having the existing spindle re-ground internally to accept a standard ER20 type collet - then you bought it!

Here's a list of the common ER collet system sizes: https://www.maritool.com/ER-Collets Pick a collet that would fit inside the existing spindle, then have the spindle ground out to accept the precise collet dimensions. Note: The "ER" refers to the type of collet so for example ER20 refers to the dimension shown for the collet body and a set of collets will have a range of sizes it can hold. I don't think you need much more than 1/2" because it is a small precision milling machine.

The existing spindle is super accurate, hardened and ground. It's a gem. Be careful who you farm it out to for modification. You'll also need to modify or make up a new "collet closer" to suit. Hope that helps. While I was looking at getting it sorted, a full size Bridgeport turned up at a price I could afford so....

S.

Lots of good info to read through, according to two different companies that responded there isn't a way to safely ground to accept collets so looking at getting a new spindle made but was looking at a short term fix to get it up and running so I can have a play

 

[Pete.]

Lots of good info to read through, according to two different companies that responded there isn't a way to safely ground to accept collets so looking at getting a new spindle made but was looking at a short term fix to get it up and running so I can have a play

That's just because they don't want to do it. Of course the spindle can be ground, or hard-turned and finish-ground. My hardened spindle was turned on a lathe then modified for R8 taper and it's seen plenty of use with a non-hardened nosepiece. As a hobbyist machinist you don't need the hardened nose of the original machine.

 

[Pete.]

The machine is not original. The flat belt is gone, vee pulleys fitted and a modern motor on a different mount. What counts is that it can be used.

 

[Screwdriver]

The original bits are there but you're never going to run it with a belt!

Agree they say no because they don't want the business. Why not ping the company I link to in my table bed regrind? They were exceptionally friendly and helpful Very rare sadly so well worth a looksee. I really think it is worth having the existing spindle ground out because it is both the heart of the machine and an exceptionally fine piece of precision engineering. It is redundant if you can't get a collet set for it. Option 2 of course would be to buy a complete collet set that's slightly too big and have the entire set ground down to fit your existing set up

Actually, you know what? I wish I'd thought of that earlier!

S.

 

[tinman123]

pete is right about the stick out, its something you dont want much of when you hanging a 12mm cutter off it.
he could and probably is right about the 5/8, more likely that than 16mm, you might get away with a 16mm er chuck like you linked to but its only an er11 which would mean its max size id be 7mm iirc.
but if thats good enough and your just looking at getin up and runnin for a play then it ill work good enough as a trial run.

id also agree with the lads, id be lookin at getin a price off someone to make or grind the spindle, there is bound to be a medium sized good engineering shop not far from you.

 

[Freddy0309]

Lots of information to wade through but the interest in hospital absolutely sucks it's taken nearly 25 mins just to get this far but hopefully will be coming home tonight so I will be able to look through it properly

 

[ukracer]

Well that's obviously nonsense. You looked at 12.61mm and it was "obviously wrong"? Rubbish. The 12.61mm is the precise figure, quite how you dare to suggest it must be wrong because it's nearly but not quite 1/2 inch I honestly don't know. You must be some sort of psychic. Predicting that it really should be 1/2 inch (which I posted later). The crude inch measurements are pretty much all wrong I should expect.

As are you.

I thought 1/2 inch ws 12.54??

 

[ukracer]

12.7mm


25.4mm = 1"

Ignore my ramblings on an untrained mind..lol

Another person who likes to use metric despite being nearly 60. you now see why..

 

[Screwdriver]

It doesn't matter what half an inch is, it measures 12.61 mm.

End of story. Anyone who wants to say I am "obviously wrong" just because it doesn't translate into fractional inches is in fact, obviously wrong.

S.

 

[ukracer]

Ding Ding round 2?

How did the mods not weed this thread...... How did I miss it ad I have a George Taylor with exactly the same problem.


On further inspection I liked a post so I must have seen it...... Perhaps its an age problem.