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cutting 1/2" thick aluminum bars on a budget?

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JBL

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Jun 24, 2017, 11:13:25 PM6/24/17
to
I am attempting to make a few "dovetails" which are brackets used to
attach a telescope to a telescope mount. If purchased outright, for the
kind of dovetails I need, the expense is beyond my budget. I recently
acquired some 1/2" aluminum sheet/ bar. The dovetail needs to be 1.75"
wide at the base, with the sides cut at a 15 degree angle. Length can
vary a bit, but usually about 12-14". My plan was to make at least 3
for the various telescopes I have.

I thought I'd be able to get away with an old circular table saw I had.
Last week, I made some 1/4" thick dovetails of a slightly different
design using my table saw fitted with a plywood blade. This went well,
but when I tried to make these thicker 1/2" dovetails today, I ended up
burning out my saw.

Ideas for a cheap way to make these dovetails would be welcome. I've
been watching Craigslist for another circular to replace the burned out
one, but I don't think it's the best tool for this job without a $30
plus blade made to cut metal and even then I'm not sure it will do it.

Thanks in advance for your help,
John

Bob Engelhardt

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Jun 25, 2017, 12:04:01 AM6/25/17
to
I have cut aluminum with circular saws, both hand held and table. The
key is to use carbide tipped blades. I'm pretty sure that your plywood
blade was not carbide.

It will not cut aluminum as fast as it cuts wood (duh?) - so don't force
it. You can also make multiple passes, starting with the blade low and
raising it each pass.

It is much harder on the blade's sharpness than wood is (another duh),
so I keep a separate blade for aluminum.

whit3rd

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Jun 25, 2017, 12:43:49 AM6/25/17
to
On Saturday, June 24, 2017 at 8:13:25 PM UTC-7, JBL wrote:
> I am attempting to make a few "dovetails" which are brackets used to
> attach a telescope to a telescope mount....

> I thought I'd be able to get away with an old circular table saw I had.
> Last week, I made some 1/4" thick dovetails of a slightly different
> design using my table saw fitted with a plywood blade.

You can get metal-cutting (carbide) blades, and can get 'em ground for a
60 degree bevel on the edge, so that the blade cuts one sidewall of a
dovetail socket. It's easier, though, to get a bar and bevel its edges, for
the male half of the dovetail, then another bar beveled at the edges
can be ripped in two, and the halves mounted on a plate to form the
dovetail female.

Don't write off your saw just yet, it could have something simple like
metal shavings in the brushes. A cleaning and some lube can bring it
back to functional.

If a track is what you need, there's suppliers that can deliver it by the millimeter,
with lots of options.
<http://www.igus.com/drylin>

Larry Jaques

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Jun 25, 2017, 12:45:21 AM6/25/17
to
On Sat, 24 Jun 2017 23:13:21 -0400, JBL <J...@ez1.net> wrote:

>I am attempting to make a few "dovetails" which are brackets used to
>attach a telescope to a telescope mount. If purchased outright, for the
>kind of dovetails I need, the expense is beyond my budget. I recently
>acquired some 1/2" aluminum sheet/ bar. The dovetail needs to be 1.75"
>wide at the base, with the sides cut at a 15 degree angle. Length can
>vary a bit, but usually about 12-14". My plan was to make at least 3
>for the various telescopes I have.

Now is the perfect time to learn how to _really_ use a file. This is
your cheapest option and the best way to learn a necessary skill. (Now
watch you scoff at it.)


>I thought I'd be able to get away with an old circular table saw I had.
>Last week, I made some 1/4" thick dovetails of a slightly different
>design using my table saw fitted with a plywood blade. This went well,
>but when I tried to make these thicker 1/2" dovetails today, I ended up
>burning out my saw.

(Burned out your saw? Nasty comments about your IQ suppressed, but
most people know when to quit.) HSS plywood blades won't hack it. Try
carbide.


>Ideas for a cheap way to make these dovetails would be welcome. I've
>been watching Craigslist for another circular to replace the burned out
>one, but I don't think it's the best tool for this job without a $30
>plus blade made to cut metal and even then I'm not sure it will do it.

Drop by Harbor Freight and get some $5 carbide tipped blades. Oops,
they no longer make the cheapies. (Kids are screwing it up, bigtime.)
Too bad. 46231 and 00529 are some I still keep in stock. Depending on
the alloy, these C3 tips can leave a rough cut, but some alloys cut
cleanly. Avanti 10" x 60T blades are $15 at Home Depot. Cut the
angle and file the bottom corner. Or regrind the teeth to 15. This is
if you were overstating the burnout of the table saw motor. <sigh>

Freud carbide tipped dovetail bits for wood are 14-degrees and are $17
at Amazon with free Prime shipping, if you're a member. A router
could make quick work of it for you, if you can make jigs.

--
The Federal budget is a complex document. However, working
for a President committed to keeping his promises means my
job is as simple as translating his words into numbers.
Mick Mulvaney, Director OMB on Trump

Jim Wilkins

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Jun 25, 2017, 6:09:22 AM6/25/17
to
"JBL" <J...@ez1.net> wrote in message
news:oin9hj$o7v$1...@dont-email.me...
Like these?
http://agenaastro.com/parts-accessories/mounts-tripods-accessories/dovetail-bars-rails.html


JBL

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Jun 25, 2017, 6:55:35 AM6/25/17
to
On 06/25/2017 12:02 AM, Bob Engelhardt wrote:
> I have cut aluminum with circular saws, both hand held and table. The
> key is to use carbide tipped blades. I'm pretty sure that your plywood
> blade was not carbide.

This is the blade I was using:

http://www.homedepot.com/p/Avanti-10-in-x-200-Teeth-OSB-Plywood-Saw-Blade-A10200X/202021698

I think you're right, not carbide.

Jim Wilkins

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Jun 25, 2017, 7:00:26 AM6/25/17
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"whit3rd" <whi...@gmail.com> wrote in message
news:206cf509-9d30-4b2c...@googlegroups.com...
The table saw I chose for cutting aluminum with a carbide blade and
sheet steel with an abrasive disk is an old Craftsman that has the
blade on a fixed arbor which extends out the side to a pulley. The
table tilts instead of the blade. The saw is on a plywood table with
the motor underneath, shielded from metal chips or abrasive particles
and sparks. The motor mount is hinged so its weight tensions the belt
which slips if the saw blade or abrasive disk binds. I jam a hockey
puck under the motor mount to adjust the belt slip.

Since I have more tools than storage space the motor is part of a
belt-disk sander that can be flipped up to use it, or down to use the
saw. Either way gravity tensions the belt. It isn't the fastest
cutting machine but it tolerates jamming well and gives me some
ability to cut metal larger than my more precise machines can handle,
such as 4'x8' sheets.

The hinge it flips around is a pipe across the center of the plywood.
The saw is raised to clear the pipe and make blowing out sawdust
easier when I switch from cutting wood to metal.
-jsw


JBL

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Jun 25, 2017, 7:05:09 AM6/25/17
to
On 06/25/2017 12:45 AM, Larry Jaques wrote:
> On Sat, 24 Jun 2017 23:13:21 -0400, JBL <J...@ez1.net> wrote:
>
>> I am attempting to make a few "dovetails" which are brackets used to
>> attach a telescope to a telescope mount. If purchased outright, for the
>> kind of dovetails I need, the expense is beyond my budget. I recently
>> acquired some 1/2" aluminum sheet/ bar. The dovetail needs to be 1.75"
>> wide at the base, with the sides cut at a 15 degree angle. Length can
>> vary a bit, but usually about 12-14". My plan was to make at least 3
>> for the various telescopes I have.
>
> Now is the perfect time to learn how to _really_ use a file. This is
> your cheapest option and the best way to learn a necessary skill. (Now
> watch you scoff at it.)
>
>
>> I thought I'd be able to get away with an old circular table saw I had.
>> Last week, I made some 1/4" thick dovetails of a slightly different
>> design using my table saw fitted with a plywood blade. This went well,
>> but when I tried to make these thicker 1/2" dovetails today, I ended up
>> burning out my saw.
>
> (Burned out your saw? Nasty comments about your IQ suppressed, but
> most people know when to quit.) HSS plywood blades won't hack it. Try
> carbide.

I was under the impression that the Craftsman I was using just might
have some sort of thermal protection circuit. Unfortunately, turns out
that it did not. It wasn't a huge loss though as I got it surplus.

>
>
>> Ideas for a cheap way to make these dovetails would be welcome. I've
>> been watching Craigslist for another circular to replace the burned out
>> one, but I don't think it's the best tool for this job without a $30
>> plus blade made to cut metal and even then I'm not sure it will do it.
>
> Drop by Harbor Freight and get some $5 carbide tipped blades. Oops,
> they no longer make the cheapies. (Kids are screwing it up, bigtime.)
> Too bad. 46231 and 00529 are some I still keep in stock. Depending on
> the alloy, these C3 tips can leave a rough cut, but some alloys cut
> cleanly. Avanti 10" x 60T blades are $15 at Home Depot. Cut the
> angle and file the bottom corner. Or regrind the teeth to 15. This is
> if you were overstating the burnout of the table saw motor. <sigh>

Yes, I don't see those blades listed at HF. I assume you mean this one
from HD:
http://www.homedepot.com/p/Avanti-10-in-x-200-Teeth-OSB-Plywood-Saw-Blade-A10200X/202021698

The one I used during the burnout was this one:
http://www.homedepot.com/p/Avanti-10-in-x-200-Teeth-OSB-Plywood-Saw-Blade-A10200X/202021698?MERCH=REC-_-rv_nav_plp_rr-_-NA-_-202021698-_-N


I guess $5 more might have saved the saw. Ok, guess I'll start over
looking for another surplus saw and pick up the better blade and try
again. Thanks!

JBL

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Jun 25, 2017, 7:35:15 AM6/25/17
to
I just wanted to ask about this possible alternative for cutting the
aluminum:
a neighbor offered to let me use his Craftsman 10" bandsaw. Would this
be able to cut the 1/2" aluminum or not large enough a saw?


dca...@krl.org

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Jun 25, 2017, 8:32:26 AM6/25/17
to
On Sunday, June 25, 2017 at 7:05:09 AM UTC-4, JBL wrote:





> Yes, I don't see those blades listed at HF. I assume you mean this one
> from HD:
> http://www.homedepot.com/p/Avanti-10-in-x-200-Teeth-OSB-Plywood-Saw-Blade-A10200X/202021698
>
> The one I used during the burnout was this one:
> http://www.homedepot.com/p/Avanti-10-in-x-200-Teeth-OSB-Plywood-Saw-Blade-A10200X/202021698?MERCH=REC-_-rv_nav_plp_rr-_-NA-_-202021698-_-N
>
>
>

Do not use a plywood blade. Use a blade with about 8 to 24 carbide teeth. And do not feed too fast. wear eye and ear protection. The plywood blade has too many teeth and since they are not carbide tipped the teeth will get hot and then dull. And being dull will make them get even hotter.

Dan

Jim Wilkins

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Jun 25, 2017, 8:34:56 AM6/25/17
to
"JBL" <J...@ez1.net> wrote in message
news:oio6uh$4s2$1...@dont-email.me...
I used a yellow 10" Craftsman to cut aluminum until I found a used
4"x6" metal bandsaw which cuts much straighter and more accurately.
The Craftman wouldn't cut straight enough unless the blade guides were
in perfect condition and adjusted carefully.

Mine lacked any provision for rip or miter guides until I adapted the
table from a small table saw. You can clamp on guide bars but setting
them simultaneously parallel to the blade and at the right distance is
difficult.

I'd buy the widest blade that will fit, 10 to 14 TPI although 18 will
let you cut thinner metal without catching and stripping off the
teeth. Sharp-edged, incompressible metal chips don't do the wheels any
good.

While the blade speed of a wood-cutting bandsaw is acceptable for
aluminum, steel will ruin the blade instantly.

-jsw


Larry Jaques

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Jun 25, 2017, 9:50:05 AM6/25/17
to
On Sun, 25 Jun 2017 07:05:06 -0400, JBL <J...@ez1.net> wrote:

>On 06/25/2017 12:45 AM, Larry Jaques wrote:
>> On Sat, 24 Jun 2017 23:13:21 -0400, JBL <J...@ez1.net> wrote:
>>
>>> I am attempting to make a few "dovetails" which are brackets used to
>>> attach a telescope to a telescope mount. If purchased outright, for the
>>> kind of dovetails I need, the expense is beyond my budget. I recently
>>> acquired some 1/2" aluminum sheet/ bar. The dovetail needs to be 1.75"
>>> wide at the base, with the sides cut at a 15 degree angle. Length can
>>> vary a bit, but usually about 12-14". My plan was to make at least 3
>>> for the various telescopes I have.
>>
>> Now is the perfect time to learn how to _really_ use a file. This is
>> your cheapest option and the best way to learn a necessary skill. (Now
>> watch you scoff at it.)

Nope, you just completely ignored it. Same, same, so solly.


>>> I thought I'd be able to get away with an old circular table saw I had.
>>> Last week, I made some 1/4" thick dovetails of a slightly different
>>> design using my table saw fitted with a plywood blade. This went well,
>>> but when I tried to make these thicker 1/2" dovetails today, I ended up
>>> burning out my saw.
>>
>> (Burned out your saw? Nasty comments about your IQ suppressed, but
>> most people know when to quit.) HSS plywood blades won't hack it. Try
>> carbide.
>
>I was under the impression that the Craftsman I was using just might
>have some sort of thermal protection circuit. Unfortunately, turns out
>that it did not. It wasn't a huge loss though as I got it surplus.

I see that you did not learn the lesson from that experience.
You're on your own.


>>> Ideas for a cheap way to make these dovetails would be welcome. I've
>>> been watching Craigslist for another circular to replace the burned out
>>> one, but I don't think it's the best tool for this job without a $30
>>> plus blade made to cut metal and even then I'm not sure it will do it.
>>
>> Drop by Harbor Freight and get some $5 carbide tipped blades. Oops,
>> they no longer make the cheapies. (Kids are screwing it up, bigtime.)
>> Too bad. 46231 and 00529 are some I still keep in stock. Depending on
>> the alloy, these C3 tips can leave a rough cut, but some alloys cut
>> cleanly. Avanti 10" x 60T blades are $15 at Home Depot. Cut the
>> angle and file the bottom corner. Or regrind the teeth to 15. This is
>> if you were overstating the burnout of the table saw motor. <sigh>
>
>Yes, I don't see those blades listed at HF.

What part of "Oops, they no longer make the cheapies." did you miss?
No, I don't ever use "plywood" blades, preferring a dull box cutter to
those. (that was a joke)


>The one I used during the burnout was this one:
>http://www.homedepot.com/p/Avanti-10-in-x-200-Teeth-OSB-Plywood-Saw-Blade-A10200X/202021698?MERCH=REC-_-rv_nav_plp_rr-_-NA-_-202021698-_-N
>
>
>I guess $5 more might have saved the saw. Ok, guess I'll start over
>looking for another surplus saw and pick up the better blade and try
>again. Thanks!

No, learning to stop trying when a blade isn't cutting is the lesson
you fail to learn. If it's not working, stop and determine what is
wrong. Check the sharpness of the blade, verify rotation, verify
applicability, etc. Plywood blades don't work on metal. Got it?

You're either a troll or not a tool-using human. G'luck!

Larry Jaques

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Jun 25, 2017, 10:02:15 AM6/25/17
to
He offered _after_ finding out that you -intentionally- burned out
your saw? Are you willing to pay for any damages to the tool you
borrow, and will you do so _when_ you break it? Otherwise, do not
borrow tools.

Have you taken into consideration that telescope mounts are curved?
And do you know how to cut that cove on aluminum bar stock? Just save
up the money and buy the proper mount, dude.

Bob Engelhardt

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Jun 25, 2017, 10:20:54 AM6/25/17
to
On 6/25/2017 9:50 AM, Larry Jaques wrote:
...
> You're either a troll or not a tool-using human. G'luck!
>

Hey ... cut him a break. So, he's new and lacks tool savvy, but he's
reading and replying to our posts, which is a good sign.

Bob Engelhardt

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Jun 25, 2017, 10:33:52 AM6/25/17
to
BTW - for cutting something as thin as 1/2", you don't need a 10" blade
- a 7-1/4" blade will do. $5.99 at HF::
https://www.harborfreight.com/7-14-in-24t-framing-circular-saw-blade-62733.html

Things Have Changed

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Jun 25, 2017, 10:44:23 AM6/25/17
to
On Sun, 25 Jun 2017 07:02:13 -0700, Larry Jaques
<lja...@invalid.diversifycomm.com> wrote:

>On Sun, 25 Jun 2017 07:35:12 -0400, JBL <J...@ez1.net> wrote:
>
>>I just wanted to ask about this possible alternative for cutting the
>>aluminum:
>>a neighbor offered to let me use his Craftsman 10" bandsaw. Would this
>>be able to cut the 1/2" aluminum or not large enough a saw?
>
>He offered _after_ finding out that you -intentionally- burned out
>your saw? Are you willing to pay for any damages to the tool you
>borrow, and will you do so _when_ you break it? Otherwise, do not
>borrow tools.


You go easy on your buddy the deadbeat liar, but you're hard on some
guy's DIY project. That makes sense to you?

Jim Wilkins

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Jun 25, 2017, 11:03:29 AM6/25/17
to
"Larry Jaques" <lja...@invalid.diversifycomm.com> wrote in message
news:6afvkcpi5gh9hq184...@4ax.com...
Hold off until he learns to put up with you.


cl...@snyder.on.ca

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Jun 25, 2017, 1:45:31 PM6/25/17
to
On Sat, 24 Jun 2017 23:13:21 -0400, JBL <J...@ez1.net> wrote:

2 words. Band Saw.

cl...@snyder.on.ca

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Jun 25, 2017, 1:48:17 PM6/25/17
to
and wear a full leather suit and a full face mask. Those aluminum
chips are HOT and SHARP and they fly EVERYWHERE. Also make sure to
protect the motor so NO chips can get into it.(Here is where a belt
drive saw with a totallt enclosed motor is highlt recommended!!!)
Yes, experience talking!

cl...@snyder.on.ca

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Jun 25, 2017, 1:50:36 PM6/25/17
to
On Sat, 24 Jun 2017 21:43:47 -0700 (PDT), whit3rd <whi...@gmail.com>
wrote:

>On Saturday, June 24, 2017 at 8:13:25 PM UTC-7, JBL wrote:
>> I am attempting to make a few "dovetails" which are brackets used to
>> attach a telescope to a telescope mount....
>
>> I thought I'd be able to get away with an old circular table saw I had.
>> Last week, I made some 1/4" thick dovetails of a slightly different
>> design using my table saw fitted with a plywood blade.
>
>You can get metal-cutting (carbide) blades, and can get 'em ground for a
>60 degree bevel on the edge, so that the blade cuts one sidewall of a
>dovetail socket. It's easier, though, to get a bar and bevel its edges, for
>the male half of the dovetail, then another bar beveled at the edges
>can be ripped in two, and the halves mounted on a plate to form the
>dovetail female.
>
>Don't write off your saw just yet, it could have something simple like
>metal shavings in the brushes. A cleaning and some lube can bring it
>back to functional.
Mine got a fatal dose of "indigestion" when the hot sharp aluminum
chips damaged the insulation on the armature and shorted it out. All
the "magic smoke" came out at once - - -.

JBL

unread,
Jun 25, 2017, 1:53:33 PM6/25/17
to
On 06/25/2017 09:50 AM, Larry Jaques wrote:
> On Sun, 25 Jun 2017 07:05:06 -0400, JBL <J...@ez1.net> wrote:
>
>> On 06/25/2017 12:45 AM, Larry Jaques wrote:
>>> On Sat, 24 Jun 2017 23:13:21 -0400, JBL <J...@ez1.net> wrote:
>>>
>>>> I am attempting to make a few "dovetails" which are brackets used to
>>>> attach a telescope to a telescope mount. If purchased outright, for the
>>>> kind of dovetails I need, the expense is beyond my budget. I recently
>>>> acquired some 1/2" aluminum sheet/ bar. The dovetail needs to be 1.75"
>>>> wide at the base, with the sides cut at a 15 degree angle. Length can
>>>> vary a bit, but usually about 12-14". My plan was to make at least 3
>>>> for the various telescopes I have.
>>>
>>> Now is the perfect time to learn how to _really_ use a file. This is
>>> your cheapest option and the best way to learn a necessary skill. (Now
>>> watch you scoff at it.)
>
> Nope, you just completely ignored it. Same, same, so solly.

Completely ignored what? Using a file to achieve the necessary 15
degree angles on both sides of the aluminum. Even you expected I would
"scoff at it" which I did. What was the point anyway?
>
>
>>>> I thought I'd be able to get away with an old circular table saw I had.
>>>> Last week, I made some 1/4" thick dovetails of a slightly different
>>>> design using my table saw fitted with a plywood blade. This went well,
>>>> but when I tried to make these thicker 1/2" dovetails today, I ended up
>>>> burning out my saw.
>>>
>>> (Burned out your saw? Nasty comments about your IQ suppressed, but
>>> most people know when to quit.) HSS plywood blades won't hack it. Try
>>> carbide.
>>
>> I was under the impression that the Craftsman I was using just might
>> have some sort of thermal protection circuit. Unfortunately, turns out
>> that it did not. It wasn't a huge loss though as I got it surplus.
>
> I see that you did not learn the lesson from that experience.
> You're on your own.

What lesson? The saw was burned out yesterday, period. Nothing else
has been done until I researched further, which was the primary reason
for coming to this group.
>
>
>>>> Ideas for a cheap way to make these dovetails would be welcome. I've
>>>> been watching Craigslist for another circular to replace the burned out
>>>> one, but I don't think it's the best tool for this job without a $30
>>>> plus blade made to cut metal and even then I'm not sure it will do it.
>>>
>>> Drop by Harbor Freight and get some $5 carbide tipped blades. Oops,
>>> they no longer make the cheapies. (Kids are screwing it up, bigtime.)
>>> Too bad. 46231 and 00529 are some I still keep in stock. Depending on
>>> the alloy, these C3 tips can leave a rough cut, but some alloys cut
>>> cleanly. Avanti 10" x 60T blades are $15 at Home Depot. Cut the
>>> angle and file the bottom corner. Or regrind the teeth to 15. This is
>>> if you were overstating the burnout of the table saw motor. <sigh>
>>
>> Yes, I don't see those blades listed at HF.
>
> What part of "Oops, they no longer make the cheapies." did you miss?

Got it. GOT IT. Do YOU get it?
>
>
>> I assume you mean this one from HD:
>> http://www.homedepot.com/p/Avanti-10-in-x-200-Teeth-OSB-Plywood-Saw-Blade-A10200X/202021698
>
> No, I don't ever use "plywood" blades, preferring a dull box cutter to
> those. (that was a joke)

Now for that I stand corrected. The link I asked about above was not
the link for the blade you were referring to for $15. Can our precious
Larry forgive the oversight? Me thinks not and me doesn't give a rats
you know what anyway.
>
>
>> The one I used during the burnout was this one:
>> http://www.homedepot.com/p/Avanti-10-in-x-200-Teeth-OSB-Plywood-Saw-Blade-A10200X/202021698?MERCH=REC-_-rv_nav_plp_rr-_-NA-_-202021698-_-N
>>
>>
>> I guess $5 more might have saved the saw. Ok, guess I'll start over
>> looking for another surplus saw and pick up the better blade and try
>> again. Thanks!
>
> No, learning to stop trying when a blade isn't cutting is the lesson
> you fail to learn. If it's not working, stop and determine what is
> wrong. Check the sharpness of the blade, verify rotation, verify
> applicability, etc. Plywood blades don't work on metal. Got it?
>
> You're either a troll or not a tool-using human. G'luck!

If you weren't prepared for additional questions for what you perceived
as obviously a newcomer, then you shouldn't have responded in the first
place. Fortunately, I don't have time to sit here and argue with a has
been and I am now adding you to my kill file so I will see no more
responses. You ought to take the advice of other group members here and
give people a break. You remind me of a serious narcissist that
probably has some significant issues going on at home that warrant
serious attention. What a pity that this is the only channel you have
to vent your frustrations.... but it will no longer be at my expense.
BYE!

JBL

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Jun 25, 2017, 1:56:33 PM6/25/17
to
Would you happen to know what size band saw? A neighbor has a 10" saw
with 1/8 to 1/4" blades I could borrow.

cl...@snyder.on.ca

unread,
Jun 25, 2017, 1:57:45 PM6/25/17
to
On Sun, 25 Jun 2017 07:35:12 -0400, JBL <J...@ez1.net> wrote:

It will cut it with the right blade if you don't force it. Even a
porta-band will do the job.

JBL

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Jun 25, 2017, 2:00:00 PM6/25/17
to
Ok, thanks for your response.

et...@whidbey.com

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Jun 25, 2017, 3:29:23 PM6/25/17
to
How good does the finish need to be? You could use a vertical band saw
but the finish won't be very good, not really good enough for a
sliding fit if that's what you're looking for. But if you just need
the angle for retaining then a bandsaw would be a fast and easy way to
cut the aluminum. You will need to make some sort of fixturing to hold
the aluminum at the correct angle and width. You could also use a
carbide router bit with a rub collar if you have a router. Carbide
router bits are great, they last a very long time compared to the HSS
ones and are not very expensive.
Eric

cl...@snyder.on.ca

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Jun 25, 2017, 3:49:09 PM6/25/17
to
Remember, when you send a boy to do a man's job, it CAN be done, but
it will be done more slowly. Make sure the "boy" is properly
supervized and not overworked.

dca...@krl.org

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Jun 25, 2017, 3:58:34 PM6/25/17
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On Sunday, June 25, 2017 at 8:32:26 AM UTC-4, dca...@krl.org wrote:


> Do not use a plywood blade. Use a blade with about 8 to 24 carbide teeth. And do not feed too fast. wear eye and ear protection. The plywood blade has too many teeth and since they are not carbide tipped the teeth will get hot and then dull. And being dull will make them get even hotter.
>
> Dan

I forgot to add that you might tell where you are located. Someone here might be close and willing to help you.

Dan

Jim Wilkins

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Jun 25, 2017, 7:05:41 PM6/25/17
to
<cl...@snyder.on.ca> wrote in message
news:5r40lc15rbbv0tbj5...@4ax.com...
Speaking of overworked, I modified my 10" Rockwell (oops, not
Craftsman) bandsaw into a sawmill and cut about two dozen 9" wide by
8' long planks from red oak logs. The best 16 of them are now a wall
of bookshelves. I just couldn't waste the straight, knot-free trunks
as firewood.
Like this:
http://maubow-turnings.blogspot.com/2009/09/bandsaw-joins-in.html

Each gravity-powered pass took 20-30 minutes. The revised version uses
a real Timberwolf sawmill blade running on motorcycle wheels, with a
5.5HP gas engine, and takes about 2 minutes per pass.
-jsw


Larry Jaques

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Jun 25, 2017, 10:33:00 PM6/25/17
to
Yeah, I --much-- prefer hack and bandsaws for cutting aluminum for
that very reason.

Larry Jaques

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Jun 25, 2017, 10:57:44 PM6/25/17
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On Sun, 25 Jun 2017 11:03:42 -0400, "Jim Wilkins"
<murat...@gmail.com> wrote:

>"Larry Jaques" <lja...@invalid.diversifycomm.com> wrote in message
>news:6afvkcpi5gh9hq184...@4ax.com...

>> You're either a troll or not a tool-using human. G'luck!
>
>Hold off until he learns to put up with you.

<g>

I was easy on him (helping) until I saw his 3rd post admitting more
and more culpability and tool abuse. He should take your link and run
with it.

JBL

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Jun 26, 2017, 8:17:35 AM6/26/17
to
I just recently picked up a Craftsman router table, but no router yet.
I've never seen a router in use or used one myself and I have started
checking videos on the topic. At some point, I'll pick up a used router.

I suspected the band saw might be a bit problematic for the long angled
cuts I needed unless I added a fence maybe... I'm just going to go with
the carbide blade the others mentioned, go much more slowly and add
small amounts of cutting depth at a time using the table saw. I managed
to find a cheap Craig's List replacement over the weekend. I tried to
salvage the prior saw, but motor windings tested open for continuity and
a replacement motor was far more than I paid for the saw, so just
cheaper to get another used one.

Jim Wilkins

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Jun 26, 2017, 8:46:14 AM6/26/17
to
"JBL" <J...@ez1.net> wrote in message
news:oiqtpp$ce5$1...@dont-email.me...
If you go asking for a used motor, this is called a Resilient mount.
http://www.electricmotorwholesale.com/MARATHON-A279.html
-jsw


William Bagwell

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Jun 26, 2017, 8:48:09 AM6/26/17
to
On Sat, 24 Jun 2017 23:13:21 -0400, JBL <J...@ez1.net> wrote:
(snips)
>Length can vary a bit, but usually about 12-14".

Something that small needs to be clamped down for safety! If they
are going to have any holes I would pre-drill them and bolt or screw
the parts being cut to a scrap of plywood. Can also attach another
scrap as a guide to keep your cut straight.

Agree with all the advice about carbide! Personally prefer a 40
tooth though they are a bit more expensive. Also use stick wax as a
lubricant on the blade. Short as your cuts are you can probably get
away dry cutting. Even candle wax will work once the blade gets warm
enough to melt it. Try some on the second cut and see if it helps.

No current access to a machine shop so I have a bit of experience
with improvised metal working. See
http://www.mysecondbathouse.com/firstmold.html for what can be done
with (mostly) a skill saw.
--
William

Bob Engelhardt

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Jun 26, 2017, 9:47:50 AM6/26/17
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On 6/26/2017 8:17 AM, JBL wrote:
...
> I suspected the band saw might be a bit problematic for the long angled
> cuts I needed unless I added a fence maybe... I'm just going to go with
> the carbide blade the others mentioned, go much more slowly and add
> small amounts of cutting depth at a time using the table saw. I managed
> to find a cheap Craig's List replacement over the weekend. ...

Good choice.

Here's a tip when you're cutting bevels on a table saw: when you're
cutting the second bevel and the 1st one is against the fence, don't
have the "point" of the bevel down. It can slip under the fence and
even just a little slip can ruin the cut and/or jam the work against the
blade.

Having the point up may mean that the fence has to go on the other side
of the blade, but that shouldn't be a problem.

Gerry

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Jun 26, 2017, 11:40:10 PM6/26/17
to
On Sun, 25 Jun 2017 00:02:59 -0400, Bob Engelhardt
<BobEng...@comcast.net> wrote:

>I have cut aluminum with circular saws, both hand held and table. The
>key is to use carbide tipped blades. I'm pretty sure that your plywood
>blade was not carbide.
>
>It will not cut aluminum as fast as it cuts wood (duh?) - so don't force
>it. You can also make multiple passes, starting with the blade low and
>raising it each pass.
>
>It is much harder on the blade's sharpness than wood is (another duh),
>so I keep a separate blade for aluminum.
I have cut 3/4" aluminium with my wood cutting band saw, 1/2" 5T.blade
which I use for general shop work. Bonus - you can tilt the table
rather than the blade.

Mark Storkamp

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Jun 27, 2017, 2:57:45 PM6/27/17
to
In article <oiqtpp$ce5$1...@dont-email.me>, JBL <J...@ez1.net> wrote:

> On 06/25/2017 03:35 PM, et...@whidbey.com wrote:
> > On Sun, 25 Jun 2017 13:56:31 -0400, JBL <J...@ez1.net> wrote:
> >
> >> On 06/25/2017 01:45 PM, cl...@snyder.on.ca wrote:
> >>> On Sat, 24 Jun 2017 23:13:21 -0400, JBL <J...@ez1.net> wrote:
> >>>
> >>>> I am attempting to make a few "dovetails" which are brackets used to
> >>>> attach a telescope to a telescope mount. If purchased outright, for the
> >>>> kind of dovetails I need, the expense is beyond my budget. I recently
> >>>> acquired some 1/2" aluminum sheet/ bar. The dovetail needs to be 1.75"
> >>>> wide at the base, with the sides cut at a 15 degree angle. Length can
> >>>> vary a bit, but usually about 12-14". My plan was to make at least 3
> >>>> for the various telescopes I have.


>
> I just recently picked up a Craftsman router table, but no router yet.
> I've never seen a router in use or used one myself and I have started
> checking videos on the topic. At some point, I'll pick up a used router.
>

Don't try to route aluminum. At work we do have a Biesse CNC router and
a 35' 4 axis router that we do aluminum on every day, but that Craftsman
will be too fast for the diameter of cutter you're likely to use, and
doesn't support the work firmly enough. You'll probably end up sending
the work piece through a wall, and anybody standing between it and the
wall. A carbide tipped blade in a table saw will probably be the best
tool at your disposal. The cutting force from the saw is mostly in a
vector down toward the table and isn't trying as hard to launch the
piece as a router would be.

Bob La Londe

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Jun 27, 2017, 4:53:35 PM6/27/17
to
"JBL" wrote in message news:oin9hj$o7v$1...@dont-email.me...

I am attempting to make a few "dovetails" which are brackets used to
attach a telescope to a telescope mount. If purchased outright, for the
kind of dovetails I need, the expense is beyond my budget. I recently
acquired some 1/2" aluminum sheet/ bar. The dovetail needs to be 1.75"
wide at the base, with the sides cut at a 15 degree angle. Length can
vary a bit, but usually about 12-14". My plan was to make at least 3
for the various telescopes I have.

I thought I'd be able to get away with an old circular table saw I had.
Last week, I made some 1/4" thick dovetails of a slightly different
design using my table saw fitted with a plywood blade. This went well,
but when I tried to make these thicker 1/2" dovetails today, I ended up
burning out my saw.

Ideas for a cheap way to make these dovetails would be welcome. I've
been watching Craigslist for another circular to replace the burned out
one, but I don't think it's the best tool for this job without a $30
plus blade made to cut metal and even then I'm not sure it will do it.

Thanks in advance for your help,
John

***

While not ideal for it I have severed a lot of 1/2 aluminum flat bar (and
thicker) with a 10" table saw. With plenty of lubrication it does ok
actually. I wouldn't saw any old carbide blade would do, because I had a
couple cheap ones that ripped off all the teeth in one pass, but most name
brands do ok for atleast a few cuts. Now I wouldn't put this on an elcheapo
table saw, but my Ridgid contractor saw Is only middle of the pack as saws
go. I've used it for 13-14 years or so for all kinds of projects. For a
couple years it was my dedicated aluminum hacker. Now it only gets used for
wood since I bought a horizontal bandsaw for the metal shop.

I don't know if I would venture to cut dovetails with it, but I suppose it
might be possible some care and proper feeding. (pun intended) The problem
is going to be keeping the blade lubricated Maybe if you could figure out
how to make multiple passes you could fill the slot with cutting oil
between.

I think a variable speed router and a router table Might be the next totally
wrong for it option to consider. I used router as spindles on my early CNC
machines. They didn't last long, but one would probably last long enough
for the job your describe. Be pretty dangerous too.

The right tool of course is a milling machine and a dovetail cutter. Could
probably still use a carbide router bit if you plan lubrication and chip
clearance.

Bob La Londe

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Jun 27, 2017, 4:54:59 PM6/27/17
to
"Bob Engelhardt" wrote in message news:oiohq...@news6.newsguy.com...

BTW - for cutting something as thin as 1/2", you don't need a 10" blade
- a 7-1/4" blade will do. $5.99 at HF::
https://www.harborfreight.com/7-14-in-24t-framing-circular-saw-blade-62733.html

********

Maybe they are better now, but I think the blades I ripped all the teeth off
of described in my other post came from HF. They were 10" blades.


JBL

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Jun 27, 2017, 8:07:46 PM6/27/17
to
Thanks. Well, for now, it's all on hold. I've run out of money for
this hobby stuff and will have to now wait until the next paycheck to go
any further. I actually did manage to properly cut one of the dovetails
on the first table saw before it burned out. It wasn't easy and I
probably should have tried lub as you and the other suggest, plus it
wasn't the right blade. This time, I'll start off with a better blade,
more careful and slower cutting, and some lub. That is, when I acquire
the spare funds. The idea was to make myself several dovetails first
and then use those as templates to make a few more maybe to sell to
others. I lack a drill press too, which is a major stumbling block
since holes need drilled into the dovetails. I do have one of those
small drill holders that accepts a drill and then can drill straight
holes. This can actually work before I start cutting any dovetails, but
once the much smaller dovetails are cut, there just isn't enough surface
area left for the device to line up correctly.
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