I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

On Saturday, March 15, 2014 12:52:22 PM UTC-4, wrote:

I'm building an engraving spindle using a high speed bldc motor made

for a model airplane. So the ER8 holder will be the spindle. Which means the

bearings will have a 10mm ID and a max OD of 30mm in order to fit into

the spindle housing which will fit into a 1.5 ID tool holder.

Eric


I am a retired electronic engineer so my advice is worth what you pay for it.

On 15/03/14 16:52, wrote:
I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

I think you can't be looking very hard on the SKF site as I've always
been able to find the technical information for bearings quite easily.
From Dan's suggestion of a 6200 here is the shielded version
information
http://www.skf.com/uk/products/beari...imperial=false

On Sat, 15 Mar 2014 17:52:17 +0000, David Billington
wrote:

On 15/03/14 16:52, wrote:
I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

I think you can't be looking very hard on the SKF site as I've always
been able to find the technical information for bearings quite easily.
From Dan's suggestion of a 6200 here is the shielded version
information
http://www.skf.com/uk/products/beari...imperial=false
Greetings David,
I spent over an hour last night looking for specific bearings on the
SKF website. I must be blind or stupid because you found it right off.
I was looking for a bearing catalog. I see I should have been looking
at the product tables.
Thanks,
Eric

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

On 15/03/14 19:40, wrote:
On Sat, 15 Mar 2014 17:52:17 +0000, David Billington
wrote:

On 15/03/14 16:52, wrote:
I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

I think you can't be looking very hard on the SKF site as I've always
been able to find the technical information for bearings quite easily.
From Dan's suggestion of a 6200 here is the shielded version
information
http://www.skf.com/uk/products/beari...imperial=false
Greetings David,
I spent over an hour last night looking for specific bearings on the
SKF website. I must be blind or stupid because you found it right off.
I was looking for a bearing catalog. I see I should have been looking
at the product tables.
Thanks,
Eric

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

SKF seem to have reorganised the site somewhat from when I last looked
maybe a year ago but typed 6200 into the search box and got the data. As
you probably now know rooting around in the products menu get you to
deep groove ball bearings and a little more gets a list such as this
http://www.skf.com/uk/products/beari...row/index.html
.. I rarely need to use their site as I have a printed copy of their
bearing catalogue from years back and the information changes little,
the basics being the same. I would be interested to see how your project
progresses.

On Sat, 15 Mar 2014 09:52:22 -0700, wrote:

I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric


First you ought to decide how stiff you'd like your spindle to be.
Simplest and cheapest will be a pair of deep groove bearings with a
spring preload. If you want stiffness more like a milling or grinding
spindle you'll need to go to a precision angular contact pair in order
to get the preload right.

Springs will make setting the preload relatively easy with regular
deep groove bearings, but with a sacrifice of stiffness. Springs =
springy.

And the preload is critical at these speeds.

This would be a suitable angular contact pair. Light preload, 15
degree contact angle.
http://www.ebay.com/itm/FAFNIR-MODEL...-/250320797407

If you use deep groove bearings, I'd suggest SKF's electric motor
quality bearings. They're claimed to be a couple grades higher than
their ABEC1 rating in a few areas, including runout. I think "JEM" in
the SKF number is what you're looking for.

You'll also need to decide whether to use a pair of bearings at the
spindle nose plus a single floating bearing at the tail, or two
bearings separated by spacers. Easy to do with spring preload,
requires substantial care otherwise.

Lubrication will also be critical. Kluber Isoflex NBU15 grease is
probably OK, but Kluber may be able to recommend something else. I've
found them helpful on the phone on a couple occasions.

Barden, NSK, and Fafnir seem to have better info that SKF on precision
and high speed bearings.

By the way, if you're using "dynamic load" as it's presented in the
bearing manuals, I think you're misinterpreting what it means. The
dynamic load rating is used to predict the time to failure of a
bearing by fatigue of the balls or races. The static load rating is
the load that will cause a permanent deformation of a specific
magnitude in the balls and races.

--
Ned Simmons

wrote in message
...
I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric


A cheap accurate off the shelf ER16 spindle that will happily turn 10K all
day long is the one used on the Taig mill. It starts to get warm at about
12K, and that's about its limit with the stock bearings. That being said.
The limitation is not the bearings. It's the seals. The rubber seals on
the lower bearings create friction which is the primary cause of heat
buildup on light duty jobs like engraving. Swap that out for one with a
metal shield and the rating of the same bearings is 15-16K.

Don't write it off just because its on a hobby mill either. Its rated for
1/4 HP. Now I know folks who run real VMCs are shaking their head, but with
the tiny little cutters used for engraving you rarely see significantly
measurable horsepower requirements. Heck, a 1/4 HP is enough to do actual
light milling. I think complete replacement spindles for the Taig sell for
about $110-120. While it may not be off the shelf ready for YOUR
application, it might be worth tearing one apart to see if you can learn
anything for making yours. If you need real speed and all you are doing is
engraving almost any of those cheap 3 phase Chinese spindles on ebay will do
ok for that.




---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

On Sat, 15 Mar 2014 21:04:22 -0400, Ned Simmons
wrote:

On Sat, 15 Mar 2014 09:52:22 -0700, wrote:

I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric


First you ought to decide how stiff you'd like your spindle to be.
Simplest and cheapest will be a pair of deep groove bearings with a
spring preload. If you want stiffness more like a milling or grinding
spindle you'll need to go to a precision angular contact pair in order
to get the preload right.

Springs will make setting the preload relatively easy with regular
deep groove bearings, but with a sacrifice of stiffness. Springs =
springy.

And the preload is critical at these speeds.

This would be a suitable angular contact pair. Light preload, 15
degree contact angle.
http://www.ebay.com/itm/FAFNIR-MODEL...-/250320797407

If you use deep groove bearings, I'd suggest SKF's electric motor
quality bearings. They're claimed to be a couple grades higher than
their ABEC1 rating in a few areas, including runout. I think "JEM" in
the SKF number is what you're looking for.

You'll also need to decide whether to use a pair of bearings at the
spindle nose plus a single floating bearing at the tail, or two
bearings separated by spacers. Easy to do with spring preload,
requires substantial care otherwise.

Lubrication will also be critical. Kluber Isoflex NBU15 grease is
probably OK, but Kluber may be able to recommend something else. I've
found them helpful on the phone on a couple occasions.

Barden, NSK, and Fafnir seem to have better info that SKF on precision
and high speed bearings.

By the way, if you're using "dynamic load" as it's presented in the
bearing manuals, I think you're misinterpreting what it means. The
dynamic load rating is used to predict the time to failure of a
bearing by fatigue of the balls or races. The static load rating is
the load that will cause a permanent deformation of a specific
magnitude in the balls and races.
Greetings Ned,
The reason I'm looking at dynamic load is because of the lifetime. I
was surprised to see lifetimes of about 40 hours, and even less, for
some bearings. I would really like to only put in one set of bearings.
I'm not sure how stiff the thing needs to be. It will be used with
standard engraving tools and maybe with endmills up to about .187 max
diameter. But most likely just for engraving.
Thanks,
Eric.

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

On Sat, 15 Mar 2014 21:20:24 -0700, "Bob La Londe"
wrote:

wrote in message
.. .
I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric


A cheap accurate off the shelf ER16 spindle that will happily turn 10K all
day long is the one used on the Taig mill. It starts to get warm at about
12K, and that's about its limit with the stock bearings. That being said.
The limitation is not the bearings. It's the seals. The rubber seals on
the lower bearings create friction which is the primary cause of heat
buildup on light duty jobs like engraving. Swap that out for one with a
metal shield and the rating of the same bearings is 15-16K.

Don't write it off just because its on a hobby mill either. Its rated for
1/4 HP. Now I know folks who run real VMCs are shaking their head, but with
the tiny little cutters used for engraving you rarely see significantly
measurable horsepower requirements. Heck, a 1/4 HP is enough to do actual
light milling. I think complete replacement spindles for the Taig sell for
about $110-120. While it may not be off the shelf ready for YOUR
application, it might be worth tearing one apart to see if you can learn
anything for making yours. If you need real speed and all you are doing is
engraving almost any of those cheap 3 phase Chinese spindles on ebay will do
ok for that.
Greetings Bob,
10,000 is way too slow. The motors I'm looking at will provide enough
hp, more than 1/4, at the speeds I want and in the space I want. Do
you have any experience with the cheap Chinese spindles? How small are
they? Will they, for example, fit into a 1.5 dia tool holder? My
spindle will, if it works the way I think it will. Can you provide
some links please with any units you have direct experience with or
that someone you know has direct experience with? The replies I have
recieved so far are why I posted the message in the first place. I'm
pretty confident that I will be able to do actual precise metal
cutting with a home made 40,000 rpm spindle, which is what this group
is all about.
Thanks,
Eric

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

On Sun, 16 Mar 2014 15:13:20 -0700, wrote:

On Sat, 15 Mar 2014 21:04:22 -0400, Ned Simmons
wrote:

On Sat, 15 Mar 2014 09:52:22 -0700, wrote:

I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric


First you ought to decide how stiff you'd like your spindle to be.
Simplest and cheapest will be a pair of deep groove bearings with a
spring preload. If you want stiffness more like a milling or grinding
spindle you'll need to go to a precision angular contact pair in order
to get the preload right.

Springs will make setting the preload relatively easy with regular
deep groove bearings, but with a sacrifice of stiffness. Springs =
springy.

And the preload is critical at these speeds.

This would be a suitable angular contact pair. Light preload, 15
degree contact angle.
http://www.ebay.com/itm/FAFNIR-MODEL...-/250320797407

If you use deep groove bearings, I'd suggest SKF's electric motor
quality bearings. They're claimed to be a couple grades higher than
their ABEC1 rating in a few areas, including runout. I think "JEM" in
the SKF number is what you're looking for.

You'll also need to decide whether to use a pair of bearings at the
spindle nose plus a single floating bearing at the tail, or two
bearings separated by spacers. Easy to do with spring preload,
requires substantial care otherwise.

Lubrication will also be critical. Kluber Isoflex NBU15 grease is
probably OK, but Kluber may be able to recommend something else. I've
found them helpful on the phone on a couple occasions.

Barden, NSK, and Fafnir seem to have better info that SKF on precision
and high speed bearings.

By the way, if you're using "dynamic load" as it's presented in the
bearing manuals, I think you're misinterpreting what it means. The
dynamic load rating is used to predict the time to failure of a
bearing by fatigue of the balls or races. The static load rating is
the load that will cause a permanent deformation of a specific
magnitude in the balls and races.
Greetings Ned,
The reason I'm looking at dynamic load is because of the lifetime. I
was surprised to see lifetimes of about 40 hours, and even less, for
some bearings. I would really like to only put in one set of bearings.
I'm not sure how stiff the thing needs to be. It will be used with
standard engraving tools and maybe with endmills up to about .187 max
diameter. But most likely just for engraving.
Thanks,
Eric.

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

Consider that the lifetime means generally the time the spindle is
turning and most often under load. Then consider how much 40 hours of
run time really is on an engraver.

Gunner

--

"
I was once told by a “gun safety” advocate back in the Nineties
that he favored total civilian firearms confiscation.
Only the military and police should have weapons he averred and what did I think about that?

I began to give him a reasoned answer and he
cut me off with an abrupt, “Give me the short answer.”

I thought for a moment and said, “If you try to take our firearms we will kill you.”"

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

wrote in message
...
On Sat, 15 Mar 2014 21:20:24 -0700, "Bob La Londe"
wrote:

wrote in message
. ..
I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric


A cheap accurate off the shelf ER16 spindle that will happily turn 10K all
day long is the one used on the Taig mill. It starts to get warm at about
12K, and that's about its limit with the stock bearings. That being said.
The limitation is not the bearings. It's the seals. The rubber seals on
the lower bearings create friction which is the primary cause of heat
buildup on light duty jobs like engraving. Swap that out for one with a
metal shield and the rating of the same bearings is 15-16K.

Don't write it off just because its on a hobby mill either. Its rated for
1/4 HP. Now I know folks who run real VMCs are shaking their head, but
with
the tiny little cutters used for engraving you rarely see significantly
measurable horsepower requirements. Heck, a 1/4 HP is enough to do
actual
light milling. I think complete replacement spindles for the Taig sell
for
about $110-120. While it may not be off the shelf ready for YOUR
application, it might be worth tearing one apart to see if you can learn
anything for making yours. If you need real speed and all you are doing
is
engraving almost any of those cheap 3 phase Chinese spindles on ebay will
do
ok for that.
Greetings Bob,

10,000 is way too slow.

Actually I gave you guidelines up to about 16K. Not 10K. Your own stated
test speed was 14.4K. I gave you a cheap alternative that has a proven
track record and hundreds if not thousands of users. Something you could
tear apart and copy into your own footprint.


The motors I'm looking at will provide enough
hp, more than 1/4,

You might be able to provide a hundred or a thousand horsepower, but the
small cutters used for engraving won't stand up to even very small
fractional horsepower forces. Go to Zero Divides website and plug some
cutters into his FS Wizard speed feed calculator and see what it say the HP
requirements are. For cutters engraving size most calculations for
horsepower come up so small it just says zero.

at the speeds I want and in the space I want.

I do not recall you posting speeds you want in the post I replied to. I do
recall you saying you were going to test at 14.4K.


Do
you have any experience with the cheap Chinese spindles?

Yes.



How small are
they?

A typical 24K RPM 1 horsepower is 65 MM. Some of the more powerful ones are
80mm, and some are upto 100mm.

Will they, for example, fit into a 1.5 dia tool holder?

Not unless you make one heck of a mount and have a lot of z clearance. I
could do it. However, most folks use them as a companion spindle on one
side since they are a full motor and spindle in one. I have one that turns
35K RPM.

My
spindle will, if it works the way I think it will. Can you provide
some links please with any units you have direct experience with or
that someone you know has direct experience with?

I can but I feel your reply to my honest attempt to help you is a bit
adversarial so I choose not to take the effort.

The replies I have
recieved so far are why I posted the message in the first place. I'm
pretty confident that I will be able to do actual precise metal
cutting with a home made 40,000 rpm spindle, which is what this group

Over about 15K balance becomes critical. Collets, closer nuts, even the
tools can be an issue. I have run a lot of tools at 28000 to 34000 RPM, and
they work. You may need to find somebody who can dynamically balance your
home made spindle and all your closer nuts after you are finished. I agree
10K is pretty slow by today's standards for engraving, but once you get
about 15-16K trivial forces become important.

is all about.
Thanks,
Eric

You are welcome.




---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

wrote:
I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric


Porter-Cable makes a belt drive offset base for this model router - 1:1
ratio , but you could gear it up or down .
http://www.portercable.com/products/...roductID=11106 And
they're relatively inexpensive .
--
Snag

SNIP

I can but I feel your reply to my honest attempt to help you is a bit
adversarial so I choose not to take the effort.

SNIP
You are welcome.
Greetings Bob,
I see from reading the post you replied to that 40,000 RPM is not
mentioned. Oops. About my reply sounding adverserial I did not mean
it to sound adverserial. But after reading it I can see how it may
have sounded that way. Sorry about that. It was certainly not my
intention to insult or in any other way offend you. I'm not being
flip. Too often folks here insult others when someone has asked or
replied to a question. It may sound stupid to someone but the person
asking the question didn't think it was stupid. My goal with the
spindle is to get something I can hold in the CAT 40 tool holder
without a lot of hang out. I do not want a spindle added to the side
of the main spindle. I did consider this at first and drew up a clamp
arrangement but didn't like it. I also made in the past a spindle that
mounts in an NMTB 40 holder and uses a belt drive to a motor mounted
off to the side. And though it works OK I have really never liked it
much.
Cheers,
Eric

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

"Gunner Asch" wrote in message
...
On Sun, 16 Mar 2014 15:13:20 -0700, wrote:

On Sat, 15 Mar 2014 21:04:22 -0400, Ned Simmons
wrote:

On Sat, 15 Mar 2014 09:52:22 -0700, wrote:

I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric


First you ought to decide how stiff you'd like your spindle to be.
Simplest and cheapest will be a pair of deep groove bearings with a
spring preload. If you want stiffness more like a milling or grinding
spindle you'll need to go to a precision angular contact pair in order
to get the preload right.

Springs will make setting the preload relatively easy with regular
deep groove bearings, but with a sacrifice of stiffness. Springs =
springy.

And the preload is critical at these speeds.

This would be a suitable angular contact pair. Light preload, 15
degree contact angle.
http://www.ebay.com/itm/FAFNIR-MODEL...-/250320797407

If you use deep groove bearings, I'd suggest SKF's electric motor
quality bearings. They're claimed to be a couple grades higher than
their ABEC1 rating in a few areas, including runout. I think "JEM" in
the SKF number is what you're looking for.

You'll also need to decide whether to use a pair of bearings at the
spindle nose plus a single floating bearing at the tail, or two
bearings separated by spacers. Easy to do with spring preload,
requires substantial care otherwise.

Lubrication will also be critical. Kluber Isoflex NBU15 grease is
probably OK, but Kluber may be able to recommend something else. I've
found them helpful on the phone on a couple occasions.

Barden, NSK, and Fafnir seem to have better info that SKF on precision
and high speed bearings.

By the way, if you're using "dynamic load" as it's presented in the
bearing manuals, I think you're misinterpreting what it means. The
dynamic load rating is used to predict the time to failure of a
bearing by fatigue of the balls or races. The static load rating is
the load that will cause a permanent deformation of a specific
magnitude in the balls and races.
Greetings Ned,
The reason I'm looking at dynamic load is because of the lifetime. I
was surprised to see lifetimes of about 40 hours, and even less, for
some bearings. I would really like to only put in one set of bearings.
I'm not sure how stiff the thing needs to be. It will be used with
standard engraving tools and maybe with endmills up to about .187 max
diameter. But most likely just for engraving.
Thanks,
Eric.

---
This email is free from viruses and malware because avast! Antivirus
protection is active.
http://www.avast.com

Consider that the lifetime means generally the time the spindle is
turning and most often under load. Then consider how much 40 hours of
run time really is on an engraver.


Maybe only as long as a few weeks on a busy machine. Somebody programming
engraving is going to want to keep the cutter engaged as much as possible to
get he job done and get on to the next job.






---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

On Tue, 18 Mar 2014 00:09:04 -0700, "Bob La Londe"
wrote:

"Gunner Asch" wrote in message
.. .
On Sun, 16 Mar 2014 15:13:20 -0700, wrote:

On Sat, 15 Mar 2014 21:04:22 -0400, Ned Simmons
wrote:

On Sat, 15 Mar 2014 09:52:22 -0700, wrote:

I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric


First you ought to decide how stiff you'd like your spindle to be.
Simplest and cheapest will be a pair of deep groove bearings with a
spring preload. If you want stiffness more like a milling or grinding
spindle you'll need to go to a precision angular contact pair in order
to get the preload right.

Springs will make setting the preload relatively easy with regular
deep groove bearings, but with a sacrifice of stiffness. Springs =
springy.

And the preload is critical at these speeds.

This would be a suitable angular contact pair. Light preload, 15
degree contact angle.
http://www.ebay.com/itm/FAFNIR-MODEL...-/250320797407

If you use deep groove bearings, I'd suggest SKF's electric motor
quality bearings. They're claimed to be a couple grades higher than
their ABEC1 rating in a few areas, including runout. I think "JEM" in
the SKF number is what you're looking for.

You'll also need to decide whether to use a pair of bearings at the
spindle nose plus a single floating bearing at the tail, or two
bearings separated by spacers. Easy to do with spring preload,
requires substantial care otherwise.

Lubrication will also be critical. Kluber Isoflex NBU15 grease is
probably OK, but Kluber may be able to recommend something else. I've
found them helpful on the phone on a couple occasions.

Barden, NSK, and Fafnir seem to have better info that SKF on precision
and high speed bearings.

By the way, if you're using "dynamic load" as it's presented in the
bearing manuals, I think you're misinterpreting what it means. The
dynamic load rating is used to predict the time to failure of a
bearing by fatigue of the balls or races. The static load rating is
the load that will cause a permanent deformation of a specific
magnitude in the balls and races.
Greetings Ned,
The reason I'm looking at dynamic load is because of the lifetime. I
was surprised to see lifetimes of about 40 hours, and even less, for
some bearings. I would really like to only put in one set of bearings.
I'm not sure how stiff the thing needs to be. It will be used with
standard engraving tools and maybe with endmills up to about .187 max
diameter. But most likely just for engraving.
Thanks,
Eric.

---
This email is free from viruses and malware because avast! Antivirus
protection is active.
http://www.avast.com

Consider that the lifetime means generally the time the spindle is
turning and most often under load. Then consider how much 40 hours of
run time really is on an engraver.


Maybe only as long as a few weeks on a busy machine. Somebody programming
engraving is going to want to keep the cutter engaged as much as possible to
get he job done and get on to the next job.






---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com
Right now I have three jobs for the engraver. Actually two engraving
and 1 micro milling job. The milling job took over 30 hours the last
time I ran it. I can easily cut that in half with a faster spindle.
Eric

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

wrote in message
...
On Tue, 18 Mar 2014 00:09:04 -0700, "Bob La Londe"
wrote:

"Gunner Asch" wrote in message
. ..
On Sun, 16 Mar 2014 15:13:20 -0700, wrote:

On Sat, 15 Mar 2014 21:04:22 -0400, Ned Simmons
wrote:

On Sat, 15 Mar 2014 09:52:22 -0700, wrote:

I'm building an engraving spindle using a high speed bldc motor made
for a model airplane. Today I'll be testing the first iteration at
about 14,400 rpm. This is the highest speed my motors will go. If the
test goes OK I'll be buying higher speed motors and will need
bearings. My plan is to use ER8 collets in an ER8 holder that has a
10mm OD. So the ER8 holder will be the spindle. Which means the
bearings will have a 10mm ID and a max OD of 30mm in order to fit into
the spindle housing which will fit into a 1.5 ID tool holder. I think
what I want is a couple deep groove bearings. The axial and radial
loads will be small but the RPM so high that the dynamic load may be
high. I will try using the load calculator at the SKF website but
would also appreciate advice from folks here who do this kind of thing
and can steer me in the right direction. Even though the SKF website
has all sorts of great info I have been unable to find an SKF ball
bearing catalog online. I need this in order to plug the right SKF
part number into the bearing calculator.
Thanks,
Eric


First you ought to decide how stiff you'd like your spindle to be.
Simplest and cheapest will be a pair of deep groove bearings with a
spring preload. If you want stiffness more like a milling or grinding
spindle you'll need to go to a precision angular contact pair in order
to get the preload right.

Springs will make setting the preload relatively easy with regular
deep groove bearings, but with a sacrifice of stiffness. Springs =
springy.

And the preload is critical at these speeds.

This would be a suitable angular contact pair. Light preload, 15
degree contact angle.
http://www.ebay.com/itm/FAFNIR-MODEL...-/250320797407

If you use deep groove bearings, I'd suggest SKF's electric motor
quality bearings. They're claimed to be a couple grades higher than
their ABEC1 rating in a few areas, including runout. I think "JEM" in
the SKF number is what you're looking for.

You'll also need to decide whether to use a pair of bearings at the
spindle nose plus a single floating bearing at the tail, or two
bearings separated by spacers. Easy to do with spring preload,
requires substantial care otherwise.

Lubrication will also be critical. Kluber Isoflex NBU15 grease is
probably OK, but Kluber may be able to recommend something else. I've
found them helpful on the phone on a couple occasions.

Barden, NSK, and Fafnir seem to have better info that SKF on precision
and high speed bearings.

By the way, if you're using "dynamic load" as it's presented in the
bearing manuals, I think you're misinterpreting what it means. The
dynamic load rating is used to predict the time to failure of a
bearing by fatigue of the balls or races. The static load rating is
the load that will cause a permanent deformation of a specific
magnitude in the balls and races.
Greetings Ned,
The reason I'm looking at dynamic load is because of the lifetime. I
was surprised to see lifetimes of about 40 hours, and even less, for
some bearings. I would really like to only put in one set of bearings.
I'm not sure how stiff the thing needs to be. It will be used with
standard engraving tools and maybe with endmills up to about .187 max
diameter. But most likely just for engraving.
Thanks,
Eric.

---
This email is free from viruses and malware because avast! Antivirus
protection is active.
http://www.avast.com

Consider that the lifetime means generally the time the spindle is
turning and most often under load. Then consider how much 40 hours of
run time really is on an engraver.


Maybe only as long as a few weeks on a busy machine. Somebody programming
engraving is going to want to keep the cutter engaged as much as possible
to
get he job done and get on to the next job.


Another potential off the shelf engraving tool is one of the higher end
Foredom rotary hand pieces. Still not 40K, but in that 15-18 K range. Not
the ones that sell for 50-75 ones. They are fitted to losse so they can
keep the price down and have modestly long life You want the one that sell
for around 150-175 if you want to try that. Contact Foredom first to get
the model number of the heavy duty one. You might be able tot fit that one
in your tool holder if you can figure out how to drive it.






---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com