Lots of questions about tapping this.

2017 aluminum collar/rod
64 mm length (about 1" will be used)
22 mm outer diameter
8 mm inner diameter

The rod will be pushed into the hub of the skate wheel and the
assembly will screw onto the arbor of the cordless drill. That
looks like a more simple and efficient way to mount the wheel.

http://www.flickr.com/photos/27532210@N04/
http://www.flickr.com/photos/27532210 N04/ (sign removed)

I need to thread the 2017 aluminum collar described above.

For what it's worth, I have this little tap and die set.
http://www.lowes.com/pd_232550-1083-...ductId=1065037

Is the collar's 8mm inner diameter appropriate for 3/8 inch 24
thread?

Otherwise, what size drill bit?

Can the inner diameter be accurately enlarged simply by drilling
into the 8mm collar hole? There was a recent thread about that, I
think, but the discussion was not perfectly clear to me.

Searched Amazon for "3/8 24 thread tap".
(Other online merchant reference links are invited.)

Union Butterfield okay?

The thread length will be 1", or greater if doing the whole 64 mm
collar at one time (I guess not).

The tap finish, like black oxide, makes no difference for tapping
into 2017 aluminum?

A tapered tap is unnecessary since it is a long hole? The main
concern is that the collar/wheel assembly is secure and centered
on the drill arbor, so that the wheel spins without bouncing. A
very close collar & arbor fit would be nice.

Is "H4" better than "H2" for this?

Thanks.




--
If any question is unclear, please either ask for an explanation
or don't bother answering.

On 5/3/2011 3:52 PM, John Doe wrote:
Lots of questions about tapping this.

2017 aluminum collar/rod
64 mm length (about 1" will be used)
22 mm outer diameter
8 mm inner diameter

The rod will be pushed into the hub of the skate wheel and the
assembly will screw onto the arbor of the cordless drill. That
looks like a more simple and efficient way to mount the wheel.

http://www.flickr.com/photos/27532210@N04/
http://www.flickr.com/photos/27532210 N04/ (sign removed)

I need to thread the 2017 aluminum collar described above.

For what it's worth, I have this little tap and die set.
http://www.lowes.com/pd_232550-1083-...ductId=1065037

Is the collar's 8mm inner diameter appropriate for 3/8 inch 24
thread?

Not really.

This tap & drill chart online-
http://www.newmantools.com/tapdrill.htm
says that the standard drill size for 3/8-24 is a #Q drill bit

which this drill chart online-
http://bobmay.astronomy.net/misc/drillchart.htm
says is .332" inch.
Note that it also indicates that a #Q drill is 8.4328 mm diameter, so an
8mm hole is -probably- too small to attempt with a cheap tap.


Otherwise, what size drill bit?

Can the inner diameter be accurately enlarged simply by drilling
into the 8mm collar hole? There was a recent thread about that, I
think, but the discussion was not perfectly clear to me.

Sure, in a lathe.
Possibly close enough, in a milling machine with a coax indicator.
Not freehand.


Searched Amazon for "3/8 24 thread tap".
(Other online merchant reference links are invited.)

For regular-length taps, I like the Hertel spiral-point taps at Enco. A
3/8"-24 is about $7.50. They have a better cutting edge than the usual
China generic straight flute taps, but 8mm is still quite a bit
undersized of a hole.


Union Butterfield okay?

The thread length will be 1", or greater if doing the whole 64 mm
collar at one time (I guess not).

If you can find a thin-shank tap you could tap most of the 64mm length.
A regular 3/8" tap won't go that deep though. You cannot tap in from
both ends, because the threads won't match up in the middle.

You can try to search eBay for 3/8-24 pulley taps, there's some for $10.
You can grind the shank diameters down on a bench grinder. Also note
that many pulley taps are usually plug or bottoming taps, and you may
need to start the threads with a regular-taper tap.

If the threads must be straight, you'll need a machine-guide to do
that,,, a tapping press, a drill press, a mill or a lathe.


The tap finish, like black oxide, makes no difference for tapping
into 2017 aluminum?

tap finish doesn't matter much really, at least for hand tapping


A tapered tap is unnecessary since it is a long hole? The main
concern is that the collar/wheel assembly is secure and centered
on the drill arbor, so that the wheel spins without bouncing. A
very close collar& arbor fit would be nice.

Im not sure of the question, but it sounds like you want a lathe here.


Is "H4" better than "H2" for this?

In taps, the "H" number is the measure of looseness, or oversize of the
tapped threads. Increasing numbers mean increasing looseness. I would
suggest H1 if you can find one, but H2 & H3 are the more common fit
sizes (common zinc-plated hardware store bolts are probably H3-H4 fit).


Thanks.

DougC dcimper norcom2000.com wrote:

John Doe wrote:

2017 aluminum collar/rod
64 mm length (about 1" will be used)
22 mm outer diamete
8 mm inner diameter
http://www.flickr.com/photos/27532210@N04/

Is the collar's 8mm inner diameter appropriate for 3/8 inch 24
thread?

Not really.

This tap & drill chart online-
http://www.newmantools.com/tapdrill.htm
says that the standard drill size for 3/8-24 is a #Q drill bit

which this drill chart online-
http://bobmay.astronomy.net/misc/drillchart.htm
says is .332" inch.
Note that it also indicates that a #Q drill is 8.4328 mm
diameter, so an 8mm hole is -probably- too small to attempt with
a cheap tap.

Can anyone specify a 3/8-24 tap that might work without enlarging
the hole?

http://www.use-enco.com/CGI/INLMK32?PARTPG=INSRAR2

The 3/8-24 H1 Hertel spiral point tap is back ordered.

In taps, the "H" number is the measure of looseness, or oversize
of the tapped threads. Increasing numbers mean increasing
looseness.

Okay, thanks.

http://www1.mscdirect.com/cgi/NNSRIT...-SearchResults

Description: Hand Sets - Taps Thread Size: 3/8-24 Ground Thread
Limit: H1 Finish/Coating: Bright Material: HSS Overall Length:
2-15/16 Number of Flutes: 4

Is that likely to work as any other hand tool?
Thanks.

On May 3, 7:17*pm, John Doe wrote:


Note that it also indicates that a #Q drill is 8.4328 mm
diameter, so an 8mm hole is -probably- too small to attempt with
a cheap tap.

Can anyone specify a 3/8-24 tap that might work without enlarging
the hole?

No.
But enlarging the hole is not that big a deal. You are not enlarging
the hole by a lot. So even done free hand, the hole will be very
close to centered. And if you get the hole a bit bigger, it should
not be a problem. The ratio of the threaded length to the diameter
is large, so you will have plenty of strength. I would probably use
a H3 tap. A H1 would give you slightly more strength , but with the
ratio of the length to diameter much greater than one, you do not need
the strength.

Dan

On 5/3/2011 4:52 PM, John Doe wrote:
Lots of questions about tapping this.

2017 aluminum collar/rod
64 mm length (about 1" will be used)
22 mm outer diameter
8 mm inner diameter

The rod will be pushed into the hub of the skate wheel and the
assembly will screw onto the arbor of the cordless drill. That
looks like a more simple and efficient way to mount the wheel.

http://www.flickr.com/photos/27532210@N04/
http://www.flickr.com/photos/27532210 N04/ (sign removed)

I need to thread the 2017 aluminum collar described above.

For what it's worth, I have this little tap and die set.
http://www.lowes.com/pd_232550-1083-...ductId=1065037

Is the collar's 8mm inner diameter appropriate for 3/8 inch 24
thread?

Otherwise, what size drill bit?

Can the inner diameter be accurately enlarged simply by drilling
into the 8mm collar hole? There was a recent thread about that, I
think, but the discussion was not perfectly clear to me.

Searched Amazon for "3/8 24 thread tap".
(Other online merchant reference links are invited.)

Union Butterfield okay?

The thread length will be 1", or greater if doing the whole 64 mm
collar at one time (I guess not).

The tap finish, like black oxide, makes no difference for tapping
into 2017 aluminum?

A tapered tap is unnecessary since it is a long hole? The main
concern is that the collar/wheel assembly is secure and centered
on the drill arbor, so that the wheel spins without bouncing. A
very close collar& arbor fit would be nice.

Is "H4" better than "H2" for this?

Thanks.




Handbook says that for a class 3 thread, your minor diameter should be
..330 - .337 , so no, I wouldn't attempt tapping it without enlarging it..
I would just take the hole out to size with a reamer and tap it. Making
sure to put a lead in chamfer on the part so the tap doesn't end up
chipping.

Or you could try a drill, drills tend to not make great reamers, but you
might get lucky in aluminium.

On 5/3/2011 6:33 PM, John Doe wrote:
http://www1.mscdirect.com/cgi/NNSRIT...-SearchResults

Description: Hand Sets - Taps Thread Size: 3/8-24 Ground Thread
Limit: H1 Finish/Coating: Bright Material: HSS Overall Length:
2-15/16 Number of Flutes: 4

Is that likely to work as any other hand tool?
Thanks.

Firstly: That is a set of three taps--a taper, plug and bottoming tap.
Did you want all three? If you don't have any other
metalworking/machinist tools or a drill press--you'll probably never use
a bottoming tap, for instance.

They are also 4-flutes (3 flutes are stronger) and are straight-flutes
(so you have to reverse to break up chips).


If you only wanted one tap, then here is a $12.48 Hertel H1 spiral point
(spiral-point taps don't require reversing to break up chips, normally)
http://www1.mscdirect.com/cgi/NNSRIT...-SearchResults

alternately here is an Interstate brand (imported) H1 spiral-point for
$5.71-:
http://www1.mscdirect.com/cgi/NNSRIT...-SearchResults




When I checked on eBay, all the pulley taps in 3/8-24 that gave a fit
spec were H3. I'd bet somebody makes them in H1 (or you could
custom-order one) but you'd pay $50+ for it, maybe $100+.

tnik kortjester gmail.com wrote:

...put a lead in chamfer on the part so the tap doesn't end up
chipping.

Thanks for the tip. That is useful also for cramming a rod into an
aluminum tube. Infrequently done here, but I need to remember that
one.

DougC dcimper norcom2000.com wrote:

If you only wanted one tap, then here is a $12.48 Hertel H1
spiral point

Plus that much more for tax and shipping, but I did not find it
anyplace else. And the local megastore has a relatively very
limited selection of tools. I guess the old-fashioned way would be
to have some local store special order the thing.

And thanks also for the tip about the type of tap, I was confused
about that one.





--
Thanks to the replies.

On 5/4/2011 10:45 AM, John Doe wrote:
tnikkortjester gmail.com wrote:

...put a lead in chamfer on the part so the tap doesn't end up
chipping.

Thanks for the tip. That is useful also for cramming a rod into an
aluminum tube. Infrequently done here, but I need to remember that
one.

Yea, I normally go a bit bigger, about .015 - .02 per side, than the OD
of the tap.. eg. for a 3/8 tap, I would go with ~ .405-.415 chamfer.

On May 3, 1:52*pm, John Doe wrote:
Lots of questions about tapping this.

2017 aluminum collar/rod
64 mm length (about 1" will be used)
22 mm outer diameter
8 mm inner diameter

The rod will be pushed into the hub of the skate wheel and the
assembly will screw onto the arbor of the cordless drill. That
looks like a more simple and efficient way to mount the wheel.

http://www.flickr.com/photos/2753221...s/27532210N04/ (sign removed)

I need to thread the 2017 aluminum collar described above.

For what it's worth, I have this little tap and die set.http://www.lowes.com/pd_232550-1083-...ductId=1065037

Is the collar's 8mm inner diameter appropriate for 3/8 inch 24
thread?

Otherwise, what size drill bit?

Can the inner diameter be accurately enlarged simply by drilling
into the 8mm collar hole? There was a recent thread about that, I
think, but the discussion was not perfectly clear to me.

Searched Amazon for "3/8 24 thread tap".
(Other online merchant reference links are invited.)

Union Butterfield okay?

The thread length will be 1", or greater if doing the whole 64 mm
collar at one time (I guess not).

The tap finish, like black oxide, makes no difference for tapping
into 2017 aluminum?

A tapered tap is unnecessary since it is a long hole? The main
concern is that the collar/wheel assembly is secure and centered
on the drill arbor, so that the wheel spins without bouncing. A
very close collar & arbor fit would be nice.

Is "H4" better than "H2" for this?

Thanks.

--
If any question is unclear, please either ask for an explanation
or don't bother answering.

OK but why 2017? It machines OK annealed but might be a bit crumbly
at the T4 temper. Also the screw that threads in might end up
stripping out the threads as you start and stop. You shouls also
consider what happens when the wheel is turning and the motor stops,
In a threaded drive like you describe it is likely to unscrew I
think.

If you are trying to make a drive to attach a motor, why not press in
a socket to the wheel and then either use the hex or the square end to
interface with the drill motor. what might work pretty good is a ball
end Allen wrench that would tolerate some misalignment.

Roger Shoaf

RS at work rogershoaf gmail.com wrote:

John Doe wrote:

2017 aluminum collar/rod
64 mm length (about 1" will be used)
22 mm outer diameter
8 mm inner diameter

The rod will be pushed into the hub of the skate wheel and the
assembly will screw onto the arbor of the cordless drill. That
looks like a more simple and efficient way to mount the wheel.

http://www.flickr.com/photos/27532210@N04/
http://www.flickr.com/photos/27532210 N04/ (sign removed)

....

OK but why 2017? It machines OK annealed but might be a bit
crumbly at the T4 temper.

Because that was available to this layman.

Also the screw that threads in might end up stripping out the
threads as you start and stop.

The current motor is not really very powerful, but I will keep
that in mind.

You shouls also consider what happens when the wheel is turning
and the motor stops, In a threaded drive like you describe it is
likely to unscrew I think.

Yes, for sure. The arbor has a reverse threaded screw. If the
arbor is long enough, the screw might solve that problem.

If you are trying to make a drive to attach a motor, why not
press in a socket to the wheel and then either use the hex or
the square end to interface with the drill motor.

Yup, in another design. At the moment, this ultralight version has
the scooter wheel attached directly to the drill arbor with no
support on the other side of the hub.

FWIW.

There is some unusual sideways pressure on the DeWalt right angle
drill arbor bearing, but that is a big bearing and it is doing
well so far. Also, this next one will have the wheel even closer
to that bearing.

Regular drills have a small bearing at the arbor, but they include
a clutch. This right angle drill has a big bearing at the arbor,
but has no clutch. A clutch would be very useful even though it
slightly increases the weight. I could use a regular drill and
have it sticking out sideways from the wheel without a right angle
gear, if the wheel is at least 7 inches diameter. That will
require a sturdy attachment to the drill case up forward near the
arbor. But they might not be as tolerant to sideways pressure on
the chuck.
--












what might work pretty good is a ball
end Allen wrench that would tolerate some misalignment.

Roger Shoaf