I happen to have a nice Nikken metric boring head that was designed to fit a
26mm BT-flange holder. This boring head has a 26mm dia x 26mm straight
cylindrical shank with two radial holes at 90-deg to accept locking set
screws or pins.

Of course, my mill doesn't have a BT spindle; it has an R8 spindle. So my
idea was to use an end mill holder as an adapter for this boring head. But
that presents its own problems as I have yet to encounter a 26mm end mill
holder. (Anyone know a source for these? I find it amazing that the US
machining industry is still so firmly entrenched in the English system.)

Short of finding a 26mm holder, my next thought would be to buy a 1" end
mill holder (25.4mm) and try to modify it to accept the 26mm shank of my
boring head. I just don't know how successful that plan might be. For one
thing, I suspect that the bore of an end mill holder is hardened and ground,
so I will probably have a tough time trying to bore 0.6mm off the inside
diameter in my lathe. Another possibility would be to use an abrasive
cylinder hone to enlarge the bore of the holder. But that may not be a very
accurate operation as I only have the low-cost, sprung-arm hones that are
common in auto parts stores.

Any thoughts or advice?

Thanks,
Michael

"DeepDiver" wrote in
:

I happen to have a nice Nikken metric boring head that was designed to
fit a 26mm BT-flange holder. This boring head has a 26mm dia x 26mm
straight cylindrical shank with two radial holes at 90-deg to accept
locking set screws or pins.

Of course, my mill doesn't have a BT spindle; it has an R8 spindle. So
my idea was to use an end mill holder as an adapter for this boring
head. But that presents its own problems as I have yet to encounter a
26mm end mill holder. (Anyone know a source for these? I find it
amazing that the US machining industry is still so firmly entrenched
in the English system.)

Short of finding a 26mm holder, my next thought would be to buy a 1"
end mill holder (25.4mm) and try to modify it to accept the 26mm shank
of my boring head. I just don't know how successful that plan might
be. For one thing, I suspect that the bore of an end mill holder is
hardened and ground, so I will probably have a tough time trying to
bore 0.6mm off the inside diameter in my lathe. Another possibility
would be to use an abrasive cylinder hone to enlarge the bore of the
holder. But that may not be a very accurate operation as I only have
the low-cost, sprung-arm hones that are common in auto parts stores.

Any thoughts or advice?

Contact these folks, bet they have one. May not be cheap though.

Lyndex-Nikken, Inc.
1468 Armour Blvd.
Mundelein IL 60060
Phone: 800-543-6237
Fax: 847-367-4815

--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

"Anthony" wrote in message
...

Contact these folks, bet they have one. May not be cheap though.

Lyndex-Nikken, Inc.
1468 Armour Blvd.
Mundelein IL 60060
Phone: 800-543-6237
Fax: 847-367-4815

Thanks for the tip.

I should have mentioned that economy is a factor. Not just because I don't
want to spend a lot of money, but also because I'll probably have to shorten
the end mill holder in order to get one of the set screw positions to line
up with one of the locking holes in the boring head shank. In other words, I
don't want to be cutting on a new, $50+ brand-name end mill holder.

- Michael

I don't have any experience with this (you asked for thoughts or advice);
but I'd think you could bore it on a lathe with a carbide tipped boring
tool; taking very, very light cuts.

Bob Swinney
"DeepDiver" wrote in message
...
I happen to have a nice Nikken metric boring head that was designed to fit
a 26mm BT-flange holder. This boring head has a 26mm dia x 26mm straight
cylindrical shank with two radial holes at 90-deg to accept locking set
screws or pins.

Of course, my mill doesn't have a BT spindle; it has an R8 spindle. So my
idea was to use an end mill holder as an adapter for this boring head. But
that presents its own problems as I have yet to encounter a 26mm end mill
holder. (Anyone know a source for these? I find it amazing that the US
machining industry is still so firmly entrenched in the English system.)

Short of finding a 26mm holder, my next thought would be to buy a 1" end
mill holder (25.4mm) and try to modify it to accept the 26mm shank of my
boring head. I just don't know how successful that plan might be. For one
thing, I suspect that the bore of an end mill holder is hardened and
ground, so I will probably have a tough time trying to bore 0.6mm off the
inside diameter in my lathe. Another possibility would be to use an
abrasive cylinder hone to enlarge the bore of the holder. But that may not
be a very accurate operation as I only have the low-cost, sprung-arm hones
that are common in auto parts stores.

Any thoughts or advice?

Thanks,
Michael

I'd probably take the collet to an auto machine shop and have them hone it
to the desired size with an abrasive hone. You'll want to put the collet in
a holder and put some brass in the slots so that it doesn't compress.

--
Why do penguins walk so far to get to their nesting grounds?

"Bob May" wrote in message
...
I'd probably take the collet to an auto machine shop and have them hone it
to the desired size with an abrasive hone. You'll want to put the collet
in
a holder and put some brass in the slots so that it doesn't compress.

Actually, I was referring to a solid end mill holder, not an R8 collet. Not
that I have anything against R8 collets, it's just that I don't think a
collet would be a good choice for this particular application.

But it might not be a bad idea to take the 1" end mill holder to an auto
machine shop for honing to 26mm.

- Michael

In article , no-
says...
I happen to have a nice Nikken metric boring head that was designed to fit a
26mm BT-flange holder. This boring head has a 26mm dia x 26mm straight
cylindrical shank with two radial holes at 90-deg to accept locking set
screws or pins.

Of course, my mill doesn't have a BT spindle; it has an R8 spindle. So my
idea was to use an end mill holder as an adapter for this boring head. But
that presents its own problems as I have yet to encounter a 26mm end mill
holder. (Anyone know a source for these? I find it amazing that the US
machining industry is still so firmly entrenched in the English system.)

Short of finding a 26mm holder, my next thought would be to buy a 1" end
mill holder (25.4mm) and try to modify it to accept the 26mm shank of my
boring head. I just don't know how successful that plan might be. For one
thing, I suspect that the bore of an end mill holder is hardened and ground,
so I will probably have a tough time trying to bore 0.6mm off the inside
diameter in my lathe. Another possibility would be to use an abrasive
cylinder hone to enlarge the bore of the holder. But that may not be a very
accurate operation as I only have the low-cost, sprung-arm hones that are
common in auto parts stores.

Any thoughts or advice?


It'd be a lot easier to turn the shank down to 1" to fit an
end mill holder, or 3/4" to fit an R8 collet, than to bore
the holder. The shank is likely hardened, but probably not
too hard to turn with carbide. Depending on the material it
may work harden, so I wouldn't count on being able to
remove small increments on the diameter.

Worst case, if you make a mess, is to have it ground to the
desired size.

Ned Simmons

"Ned Simmons" wrote in message
...
In article , no-
says...
I happen to have a nice Nikken metric boring head that was designed to
fit a
26mm BT-flange holder. This boring head has a 26mm dia x 26mm straight
cylindrical shank with two radial holes at 90-deg to accept locking set
screws or pins.

Of course, my mill doesn't have a BT spindle; it has an R8 spindle. So my
idea was to use an end mill holder as an adapter for this boring head.
...


It'd be a lot easier to turn the shank down to 1" to fit an
end mill holder, or 3/4" to fit an R8 collet, than to bore
the holder.

I realize that's an option. But I am opposed to cutting or grinding the
shank on this beautiful precision tool, not so much for practical reasons,
than on principle. The way I look at it, an adapter is a consumable part
that is subject to change over time (as a tool migrates from machine to
machine, or as the adapter wears). So it makes more sense to me to modify
the adapter than it does to modify the tool.

- Michael

DeepDiver wrote:
"Ned Simmons" wrote in message
...

In article , no-
says...

I happen to have a nice Nikken metric boring head that was designed to
fit a
26mm BT-flange holder. This boring head has a 26mm dia x 26mm straight
cylindrical shank with two radial holes at 90-deg to accept locking set
screws or pins.

Of course, my mill doesn't have a BT spindle; it has an R8 spindle. So my
idea was to use an end mill holder as an adapter for this boring head.
...


It'd be a lot easier to turn the shank down to 1" to fit an
end mill holder, or 3/4" to fit an R8 collet, than to bore
the holder.


I realize that's an option. But I am opposed to cutting or grinding the
shank on this beautiful precision tool, not so much for practical reasons,
than on principle. The way I look at it, an adapter is a consumable part
that is subject to change over time (as a tool migrates from machine to
machine, or as the adapter wears). So it makes more sense to me to modify
the adapter than it does to modify the tool.

- Michael


Lyndex-Nikken has R8 1.25 end mill holders, standard and stub. How about
getting one and making a bushing? Maybe you can get a different shank
for the head, unless it is integral. I would probably turn it down myself.

michael

"michael" wrote in message
...

Lyndex-Nikken has R8 1.25 end mill holders, standard and stub.
How about getting one and making a bushing?

Thanks Michael. Actually, that's an excellent idea. I had already considered
making adapter bushings to fit some English-sized boring bars into the 16mm
bar holding holes in this boring head, but I hadn't considered making a
bushing for the shank. I don't know why I overlooked this.

And there are a number of sources of 1.25" and 1.5" end mill holders,
including Bison (a brand I prefer for their combination of both precision
and economy). I'll probably use a 1.5" end mill holder so the bushing has
more "meat". That way, I can add set screws to match the locking holes in
the existing shank, as well as a Weldon flat to lock the assembly in the end
mill holder.


Maybe you can get a different shank for the head,
unless it is integral.

Yes it is integral. The body and shank are precision ground from a solid
billet. (It's a really nice boring head -- another reason why I don't want
to turn down the shank.)

Had it not been integral, then I would have made a custom shank from an R8
arbor (as I did for another metric boring head I have that does have a
threaded hole to accept a shank).

- Michael

http://cgi.ebay.com/ER40-COLLET-CHUC...QQcmdZViewItem

Then buy collets as required.
DeepDiver wrote:

I happen to have a nice Nikken metric boring head that was designed to fit a
26mm BT-flange holder. This boring head has a 26mm dia x 26mm straight
cylindrical shank with two radial holes at 90-deg to accept locking set
screws or pins.

Of course, my mill doesn't have a BT spindle; it has an R8 spindle. So my
idea was to use an end mill holder as an adapter for this boring head. But
that presents its own problems as I have yet to encounter a 26mm end mill
holder. (Anyone know a source for these? I find it amazing that the US
machining industry is still so firmly entrenched in the English system.)

Short of finding a 26mm holder, my next thought would be to buy a 1" end
mill holder (25.4mm) and try to modify it to accept the 26mm shank of my
boring head. I just don't know how successful that plan might be. For one
thing, I suspect that the bore of an end mill holder is hardened and ground,
so I will probably have a tough time trying to bore 0.6mm off the inside
diameter in my lathe. Another possibility would be to use an abrasive
cylinder hone to enlarge the bore of the holder. But that may not be a very
accurate operation as I only have the low-cost, sprung-arm hones that are
common in auto parts stores.

Any thoughts or advice?

Thanks,
Michael

"Eddy Sams" wrote in message
...
http://cgi.ebay.com/ER40-COLLET-CHUC...QQcmdZViewItem

Then buy collets as required.

Yes, the ER40 does go to 26mm. But I like Michael's bushing idea better for
adapting the shank to a larger end mill holder.

As for the Ebay source linked above...

Unfortunately, "800watt" is one of the few sellers on Ebay who carries a
wide range of inexpensive new import tooling (like the Morse taper collets
I've been looking for). But his feedback rating is questionable, with lots
of negatives for non-delivery after payment and no replies to email. And he
pads his sales with his S&H fees. From what I understand, his idea of
combining shipping is to just knock one or two dollars off the per item S&H
fee.

I myself have tried contacting him and have not been impressed with his
communication (more specifically, his lack thereof). I prefer to avoid Ebay
sellers like that.

I don't know the guy from Adam but a 97.7% positive feedback on 46,400 transactions is not to shabby especially on a $ 25 item. Mind you, I am
not endorsing anyone and I was not trying to steer you to this particular seller, just "the means" of doing what you wanted to get done.


33632
Positive Feedback:
97.7%

Members who left a positive:
34404
Members who left a negative:
801

All positive feedback received:
46433


DeepDiver wrote:

"Eddy Sams" wrote in message
...
http://cgi.ebay.com/ER40-COLLET-CHUC...QQcmdZViewItem

Then buy collets as required.

Yes, the ER40 does go to 26mm. But I like Michael's bushing idea better for
adapting the shank to a larger end mill holder.

As for the Ebay source linked above...

Unfortunately, "800watt" is one of the few sellers on Ebay who carries a
wide range of inexpensive new import tooling (like the Morse taper collets
I've been looking for). But his feedback rating is questionable, with lots
of negatives for non-delivery after payment and no replies to email. And he
pads his sales with his S&H fees. From what I understand, his idea of
combining shipping is to just knock one or two dollars off the per item S&H
fee.

I myself have tried contacting him and have not been impressed with his
communication (more specifically, his lack thereof). I prefer to avoid Ebay
sellers like that.