Best way to drill through cast iron???

Andy Dingley wrote:

> cutting fluid. The swarf should come off as chips, not twirlies.

Swarf. That's it. So after I just bragged about my perfect little twisty
things, does that mean I did it wrong? Fed too fast?

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
Confirmed post number: 16971 Approximate word count: 509130
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Cast iron is the easiest stuff in the world to drill. More fun that wood, IMHO.
Centerpunch to locate the hole, drill one small pilot hole, then go full-size.
Don't use cutting fluid--it's self-lubricating. A slightly higher speed than
steel for the same bit size is good.

Can't offer any info specific to the project.

GTO(John)


>I'm stumped on a good way to add an outfeed table to my saw. Yet another
>"benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
>thought I'd ask the "Pro's".
>
>If I wanted to attach some brackets to the table saw cast iron top, I think
>I'd be drilling some biggun holes into some purdy thick iron. Would I be an
>idiot to try this? Would it take forever? Would I go through 35 bits? Would
>I need some liquid coolant on the bore? Should I buy eight $15 Black and
>Decker cheapo drills and just burn them up?
>
>Or - should I dimiss this approach and look for another way to attach the
>outfeed table?

it isn't that tuff to drill. You are gonna drill about 1/2 or 7/16 holes? One
bit should do the whole thing. We aren't talking grade 8 material here. Now
that takes a cobalt drill bit, or better.

dave

tnfkajs wrote:

> I'm stumped on a good way to add an outfeed table to my saw. Yet another
> "benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
> thought I'd ask the "Pro's".
>
> If I wanted to attach some brackets to the table saw cast iron top, I think
> I'd be drilling some biggun holes into some purdy thick iron. Would I be an
> idiot to try this? Would it take forever? Would I go through 35 bits? Would
> I need some liquid coolant on the bore? Should I buy eight $15 Black and
> Decker cheapo drills and just burn them up?
>
> Or - should I dimiss this approach and look for another way to attach the
> outfeed table?

tnfkajs wrote:
>
> I'm stumped on a good way to add an outfeed table to my saw. Yet another
> "benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
> thought I'd ask the "Pro's".
>
> If I wanted to attach some brackets to the table saw cast iron top, I think
> I'd be drilling some biggun holes into some purdy thick iron. Would I be an
> idiot to try this? Would it take forever? Would I go through 35 bits? Would
> I need some liquid coolant on the bore? Should I buy eight $15 Black and
> Decker cheapo drills and just burn them up?
>
> Or - should I dimiss this approach and look for another way to attach the
> outfeed table?

Easy to drill, just do it in stages beginning with a 1/8" drill bit then
3/16", etc. until you reach the size you want for your bolts. A little
oil won't hurt but you don't need to slop it on this way.

Scott
--
An unkind remark is like a killing frost. No matter how much it warms
up later, the damage remains.

Cast iron is easily drilled with high speed steel drill bits..

tnfkajs wrote:

>I'm stumped on a good way to add an outfeed table to my saw. Yet another
>"benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
>thought I'd ask the "Pro's".
>
>If I wanted to attach some brackets to the table saw cast iron top, I think
>I'd be drilling some biggun holes into some purdy thick iron. Would I be an
>idiot to try this? Would it take forever? Would I go through 35 bits? Would
>I need some liquid coolant on the bore? Should I buy eight $15 Black and
>Decker cheapo drills and just burn them up?
>
>Or - should I dimiss this approach and look for another way to attach the
>outfeed table?
>
>

Silvan wrote:
>
> Andy Dingley wrote:
>
> >>a pound... Looks like almost a 200:1 ratio unless I'm just demonstrating
> >>how bad Americans are at math.
> >
> > You need to account for the beam inertia too.
>
> I have no idea how to calculate that, so we'll just skip it. It's more than
> plenty enough to throw a baseball. I hate sewing, and I made a sling that
> can't fit anything larger than a baseball, so a baseball it is.
>
> I wonder how you'd factor in the roller bearings when calculating arm
> inertia. I gather these things aren't usually built that way. The arm is
> ~2" wide along the pivot axis, but the contact patch is much narrower,
> since the only bearing surfaces are a couple of 1/4" thick roller bearings.
> Very low resistance; very smooooth. If I put a fixed weight on the bottom
> and give it a good shove, it will rock back and forth for 20 minutes.
>
> >>Tomorrow I'll throw half a brick with the thing and see if I can beat your
> >>50' throw. :)
> >
> > Nearer 200' now - with the big counterweight !
>
> I got to about 70' with half a brick. But your machine is much larger than
> mine. From ground to the top of the hook is 60".
>
> Anyway, there are lots of trebuchets out there in the world that are
> bigger/stronger/faster/cooler than mine, but there's only one like this
> one, and I designed and built the thing myself, and it kicks ass, no matter
> what anybody else says. :)

Constrain the payload to approximate size and mass of a USDA grade A
extra large hen's egg: good aerodynamics, harmless, but still lots
of fun. What range could you achieve with a modest treb?

Hmmm. Flashback from working on heavy equipment!
I used to hate drilling holes in thick cast iron - a realitively thin
table saw should be a cakewalk. We used a 2 HP drill - if the bit bit -
you went for a ride!
My Delta TS has 3 holes drilled on each side for this purpose.
You will need Cobalt Drill Bits. The bigger the drill the better.
Start out with a small bit and work your way up to whatever size you
need. I assume you'll wind up using 3/8" bolts (?).
Optionally you can tap the holes to receive the bolt.
Mark from Pasadena, MD


tnfkajs wrote:
> I'm stumped on a good way to add an outfeed table to my saw. Yet another
> "benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
> thought I'd ask the "Pro's".
>
> If I wanted to attach some brackets to the table saw cast iron top, I think
> I'd be drilling some biggun holes into some purdy thick iron. Would I be an
> idiot to try this? Would it take forever? Would I go through 35 bits? Would
> I need some liquid coolant on the bore? Should I buy eight $15 Black and
> Decker cheapo drills and just burn them up?
>
> Or - should I dimiss this approach and look for another way to attach the
> outfeed table?
>
>

Take the piece off and take to a GOOD machine shop.

tnfkajs wrote:
>
> I'm stumped on a good way to add an outfeed table to my saw. Yet another
> "benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
> thought I'd ask the "Pro's".
>
> If I wanted to attach some brackets to the table saw cast iron top, I think
> I'd be drilling some biggun holes into some purdy thick iron. Would I be an
> idiot to try this? Would it take forever? Would I go through 35 bits? Would
> I need some liquid coolant on the bore? Should I buy eight $15 Black and
> Decker cheapo drills and just burn them up?
>
> Or - should I dimiss this approach and look for another way to attach the
> outfeed table?

"tnfkajs" <[email protected]> wrote in message
news:[email protected]...
> I'm stumped on a good way to add an outfeed table to my saw. Yet another
> "benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
> thought I'd ask the "Pro's".
>
> If I wanted to attach some brackets to the table saw cast iron top, I
think
> I'd be drilling some biggun holes into some purdy thick iron. Would I be
an
> idiot to try this? Would it take forever? Would I go through 35 bits?
Would
> I need some liquid coolant on the bore? Should I buy eight $15 Black and
> Decker cheapo drills and just burn them up?
>
> Or - should I dimiss this approach and look for another way to attach the
> outfeed table?
>
>

Off memory (from when i drilled holes in my bandsaw table for an aftermarket
fence), just use a standard high speed steel twist bit at about 1000rpm (I
used a drill press). A little lube may help disipate the heat produced and
protect the drill bit a little more but apply it only after you have drilled
in a small way, so it doesn't slip while your trying to drill the first few
mm's

--
Regards,

Dean Bielanowski
Editor,
Online Tool Reviews
http://www.onlinetoolreviews.com
------------------------------------------------------------
Latest 5 Reviews:
- Ryobi CDL1802D Pro Series 18v Cordless Drill
- Eze-Lap Diamond Sharpening Stones
- Incra TS-III Table Saw Fence
- Ryobi AP13 Planer/Thicknesser
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------------------------------------------------------------

On Sun, 07 Sep 2003 07:50:24 GMT, "CW" <[email protected]>
wrote:

>Finally, someone speaking reason. Yes, it drills easily and very nicely.
>Tends to clog taps though. Just back out a bit after every couple turns and
>it works fine.

How do you get a couple of turns? I've never been able to get more
than a half turn or so before things tighten up enough that I'm afraid
of breaking the tap.

There must be some sort of corrolary to Murphy's Law about this; taps
only break in locations whose position is absolutely essential and for
which no alternative exists. I don't want to fall prey to that...ever.


LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

"Morgans" <[email protected]> wrote in message
news:[email protected]...
>
> I don't have the slightest idea why the above poster said this. Cast iron
> is by far the easiest drilling of all the ferric metals. It has
properties
> that make it self lubricating.
>

I'm the OP - I asked this about a month or two ago...
I asked because I didn't have the slighest idea on what it took to drill
into cast iron.
Now I do... :)

Standard HSS is fine. Cast iron is easy drilling. If you do drill a pilot
hole (recommended) make sure it is smaller than the web diameter of the
larger drill bit or it Will grab. The average 1/2 inch corded drill is
plenty.
"Mark" <[email protected]> wrote in message
news:[email protected]...
> You will need Cobalt Drill Bits. The bigger the drill the better.
> Start out with a small bit and work your way up to whatever size you
> need. I assume you'll wind up using 3/8" bolts (?).
> Optionally you can tap the holes to receive the bolt.
> Mark from Pasadena, MD
>

Finally, someone speaking reason. Yes, it drills easily and very nicely.
Tends to clog taps though. Just back out a bit after every couple turns and
it works fine.
"Morgans" <[email protected]> wrote in message
news:[email protected]...
>
> ""Bo" Mathews" <[email protected]> wrote in message
> news:[email protected]...
> > Take the piece off and take to a GOOD machine shop.
> >
> > tnfkajs wrote:
> > >
> > > I'm stumped on a good way to add an outfeed table to my saw. Yet
> another
> > > "benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
> > > thought I'd ask the "Pro's".
> > >
> > > If I wanted to attach some brackets to the table saw cast iron top, I
> think
> > > I'd be drilling some biggun holes into some purdy thick iron. Would I
> be an
> > > idiot to try this? Would it take forever? Would I go through 35 bits?
> Would
> > > I need some liquid coolant on the bore? Should I buy eight $15 Black
> and
> > > Decker cheapo drills and just burn them up?
> > >
> > > Or - should I dimiss this approach and look for another way to attach
> the
> > > outfeed table?
>
> I don't have the slightest idea why the above poster said this. Cast iron
> is by far the easiest drilling of all the ferric metals. It has
properties
> that make it self lubricating.
>
> Follow good procedures, center punch to start, drill in increasing steps
of
> size, slower for bigger drills.
> --
> Jim in NC
>
>

JackD wrote:

> If you are hauling it in a car, why not bolt a big hook on the front of
> the car and use it as the counterweight?

Be damn hard to crank it up though, I'd think.

Hard on the suspension too.

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
Confirmed post number: 17081 Approximate word count: 512430
http://www.geocities.com/Paris/Rue/5407/

Andy Dingley wrote:

> http://www.swarf.org.uk

I'm offline at the moment, but I'll follow that directly.

>>So after I just bragged about my perfect little twisty
>>things, does that mean I did it wrong? Fed too fast?
>
> That may have been malleable cast iron, rather than grey. Commonly
> used for the better G clamps, but not cheap machine tool tables.

Oh, right, cast iron. I was drilling a piece of railroad track. Whatever
kind of steel that is.

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
Confirmed post number: 17006 Approximate word count: 510180
http://www.geocities.com/Paris/Rue/5407/

On Sat, 09 Aug 2003 15:10:03 -0400, Silvan
<[email protected]> wrote:

>> You need to account for the beam inertia too.
>
>I have no idea how to calculate that, so we'll just skip it.

Download the programs WinTreb or TrebStar

>I wonder how you'd factor in the roller bearings when calculating arm
>inertia. I gather these things aren't usually built that way.

My one started with an axle of 3/4" tube, then bent that during
testing. Nw it runs with solid 3/4" steel. Don't underestimate the
forces around that pivot ! (like they did on Scrapheap Challenge)

>there's only one like this
>one, and I designed and built the thing myself, and it kicks ass, no matter
>what anybody else says. :)

Absolutely !

BTW, the last couple I made were mangonels, not trebs (twisted rope,
not a weight) One had a 9" arm, for my 8 year old, and the other had
a 12" arm for a friend's birthday.
http://www.jarkman.co.uk/catalog/random/onager.htm

Andy Dingley wrote:

>>I have no idea how to calculate that, so we'll just skip it.
>
> Download the programs WinTreb or TrebStar

And run them on what?

I haven't found any trebuchet software for Linux. Actually, I just looked
again, and there _is_ something, but SourceForge is being uncooperative at
the moment.

> My one started with an axle of 3/4" tube, then bent that during
> testing. Nw it runs with solid 3/4" steel. Don't underestimate the
> forces around that pivot ! (like they did on Scrapheap Challenge)

Mine is only 5/8" but it's serious stuff. I couldn't drill a hole in it.
When I tried to mark the starter dimple with my center punch, I ruined my
center punch. I never could get a bit into it.

> BTW, the last couple I made were mangonels, not trebs (twisted rope,
> not a weight) One had a 9" arm, for my 8 year old, and the other had
> a 12" arm for a friend's birthday.
> http://www.jarkman.co.uk/catalog/random/onager.htm

I've thought about building one of those myself, but I think I have to draw
the line somewhere, and that's it. Using archaic technology is fun, but
for the scale of machine I have to build, I'd be surprised if a torsion
bundle is worth the effort compared to bungee power.

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
Confirmed post number: 17115 Approximate word count: 513450
http://www.geocities.com/Paris/Rue/5407/

On Mon, 4 Aug 2003 16:06:44 -0600, "tnfkajs" <[email protected]>
wrote:

>I'm stumped on a good way to add an outfeed table to my saw. Yet another
>"benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
>thought I'd ask the "Pro's".
>
>If I wanted to attach some brackets to the table saw cast iron top, I think
>I'd be drilling some biggun holes into some purdy thick iron.

why use big holes? just drill and tap some holes. then you dont have
to worrie with nuts and washers. makes the addition of a table
easy.bolt your brackets directly to the top. i used an old detla saw
table to mount several grinders to in this manner. worked like a
charm. go slow and let the bit do the work.the cast drills easy and 1
bit and 1 tap should do all the holes for you. george

Would I be an
>idiot to try this? Would it take forever? Would I go through 35 bits? Would
>I need some liquid coolant on the bore? Should I buy eight $15 Black and
>Decker cheapo drills and just burn them up?
>
>Or - should I dimiss this approach and look for another way to attach the
>outfeed table?
>

I too have the Jet SuperSaw and I have added an outfeed table to the
back (32"x57" I think), an extention table to the right hand side, a
drawer under the extension table (for push sticks and feater boards) and
a large drawer under the saw cabnet for blades and such.

Drilling through the cast iron was easy (1/4" holes). I used a BD elec
drill, 1/4" 'Bad Dog' bit and a little 3-in-1 oil. Worked like a champ.

If you want more info or some pictures, email me.

Cheers,
john

tnfkajs wrote:
> I'm stumped on a good way to add an outfeed table to my saw. Yet another
> "benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
> thought I'd ask the "Pro's".
>
> If I wanted to attach some brackets to the table saw cast iron top, I think
> I'd be drilling some biggun holes into some purdy thick iron. Would I be an
> idiot to try this? Would it take forever? Would I go through 35 bits? Would
> I need some liquid coolant on the bore? Should I buy eight $15 Black and
> Decker cheapo drills and just burn them up?
>
> Or - should I dimiss this approach and look for another way to attach the
> outfeed table?
>
>

CW wrote:
> Finally, someone speaking reason. Yes, it drills easily and very nicely.
> Tends to clog taps though. Just back out a bit after every couple turns and
> it works fine.
>

If he's going to tap the holes, it's also worth conidering
using a drill jig to assure the hole is perpendicular to the
surface. A block of hardwood 1.5 inches or so thick with a
drill press drilled hole in it makes a good drill jig for
quite a few holes before it wears out. Just clamp the jig in
place and use it to align the drill. Not necessary, but it
makes for a nicer job.



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Back up as it starts to get tight, don't wait until it's
tight.

Are you using the right size tap drill for the material?

Don't have good tap drill chart?

Subtract one thread pitch from the nominal screw diameter.
.250-20 Tap drill = .250 -1/20 = .200. Then pick the next
largest actual drill size (assuming you have a complete set
of drills). If you only have a set graduated in 1/16th or
32nds you have a problem.

Also use coarse threads everyplace you can. They are easier
to cut and hold up better in many materials, cast iron and
aluminum being two good examples.

Rico

LRod wrote:
> On Sun, 07 Sep 2003 07:50:24 GMT, "CW" <[email protected]>
> wrote:
>
> >Finally, someone speaking reason. Yes, it drills easily and very nicely.
> >Tends to clog taps though. Just back out a bit after every couple turns and
> >it works fine.
>
> How do you get a couple of turns? I've never been able to get more
> than a half turn or so before things tighten up enough that I'm afraid
> of breaking the tap.
>
> There must be some sort of corrolary to Murphy's Law about this; taps
> only break in locations whose position is absolutely essential and for
> which no alternative exists. I don't want to fall prey to that...ever.
>
>
> LRod


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--
In His Name, be Blessed,

Just drill with steady pressure and low speeds and I use power steering
fluid as a lubercant.. Just watch the chip coming from the hole you are
drilling because it will tell you the correct speed and feed.

God Bless,

Mike

www.cedarworks.1plan.net
www.geocities.com/zuchick
"tnfkajs" <[email protected]> wrote in message
news:[email protected]...
> I'm stumped on a good way to add an outfeed table to my saw. Yet another
> "benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
> thought I'd ask the "Pro's".
>
> If I wanted to attach some brackets to the table saw cast iron top, I
think
> I'd be drilling some biggun holes into some purdy thick iron. Would I be
an
> idiot to try this? Would it take forever? Would I go through 35 bits?
Would
> I need some liquid coolant on the bore? Should I buy eight $15 Black and
> Decker cheapo drills and just burn them up?
>
> Or - should I dimiss this approach and look for another way to attach the
> outfeed table?
>
>

Drill cast iron dry. Hand drill would work just fine.
"Edwin Pawlowski" <[email protected]> wrote in message
news:[email protected]...
> >
> > tnfkajs wrote:
>
> > >
> > > If I wanted to attach some brackets to the table saw cast iron top, I
> think
> > > I'd be drilling some biggun holes into some purdy thick iron. Would I
> be an
> > > idiot to try this? Would it take forever?
>
> If there is a flat surface, you can atach a magnetic drill. Good tool
> rental shops have them, but it will probably be $50 for the day. You
supply
> the bit. Yes, lube as you drill, even if it is only a spray of WD-40.
>
> > > Or - should I dimiss this approach and look for another way to attach
> the
> > > outfeed table?
>
> Anything you can clamp on to?
> Ed
>
>

Dr. Rev. Chuck, M.D. P.A. wrote:

> Constrain the payload to approximate size and mass of a USDA grade A
> extra large hen's egg: good aerodynamics, harmless, but still lots
> of fun. What range could you achieve with a modest treb?

Hmmm... Now why didn't I think of that? We don't eat a lot of eggs, and
I'll bet there are still eggs in the fridge left over from last winter's
cookie baking season. Maybe I'll decorate the gigantic concrete wall
beside my house. :)

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
Confirmed post number: 17116 Approximate word count: 513480
http://www.geocities.com/Paris/Rue/5407/

tnfkajs wrote:
> I'm stumped on a good way to add an outfeed table to my saw. Yet
> another "benefit" of the Jet Supersaw. Before I dimisss this idea
> entirely, I thought I'd ask the "Pro's".
>
> If I wanted to attach some brackets to the table saw cast iron top, I
> think I'd be drilling some biggun holes into some purdy thick iron.
> Would I be an idiot to try this? Would it take forever? Would I go
> through 35 bits? Would I need some liquid coolant on the bore?
> Should I buy eight $15 Black and Decker cheapo drills and just burn
> them up?
>
> Or - should I dimiss this approach and look for another way to attach
> the outfeed table?

I use rare earth magnets epoxy'd to the table that attach them selves and
hold pretty well. You can find these in any old hard drive or do a web
search for rare earth magnets.

Someone a long while back (it's been 8 months since I've been on the wreck)
posted this message and had a web site showing it. Works great!

Mike

I'd use oil, slow speed, and not over 1/4".
Drill a hole in some iron, or maybe use one of your rails, and clamp it so
the hole is where you want to drill. That will get you started and keep the
bit from skating.
Wilson
"tnfkajs" <[email protected]> wrote in message
news:[email protected]...
> I'm stumped on a good way to add an outfeed table to my saw. Yet another
> "benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
> thought I'd ask the "Pro's".
>
> If I wanted to attach some brackets to the table saw cast iron top, I
think
> I'd be drilling some biggun holes into some purdy thick iron. Would I be
an
> idiot to try this? Would it take forever? Would I go through 35 bits?
Would
> I need some liquid coolant on the bore? Should I buy eight $15 Black and
> Decker cheapo drills and just burn them up?
>
> Or - should I dimiss this approach and look for another way to attach the
> outfeed table?
>
>

Andy Dingley wrote:

>>a pound... Looks like almost a 200:1 ratio unless I'm just demonstrating
>>how bad Americans are at math.
>
> You need to account for the beam inertia too.

I have no idea how to calculate that, so we'll just skip it. It's more than
plenty enough to throw a baseball. I hate sewing, and I made a sling that
can't fit anything larger than a baseball, so a baseball it is.

I wonder how you'd factor in the roller bearings when calculating arm
inertia. I gather these things aren't usually built that way. The arm is
~2" wide along the pivot axis, but the contact patch is much narrower,
since the only bearing surfaces are a couple of 1/4" thick roller bearings.
Very low resistance; very smooooth. If I put a fixed weight on the bottom
and give it a good shove, it will rock back and forth for 20 minutes.

>>Tomorrow I'll throw half a brick with the thing and see if I can beat your
>>50' throw. :)
>
> Nearer 200' now - with the big counterweight !

I got to about 70' with half a brick. But your machine is much larger than
mine. From ground to the top of the hook is 60".

Anyway, there are lots of trebuchets out there in the world that are
bigger/stronger/faster/cooler than mine, but there's only one like this
one, and I designed and built the thing myself, and it kicks ass, no matter
what anybody else says. :)

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
Confirmed post number: 17108 Approximate word count: 513240
http://www.geocities.com/Paris/Rue/5407/

On Sat, 09 Aug 2003 02:27:05 -0400, Silvan
<[email protected]> wrote:

>I shoot a 5 oz baseball, so that's... Well, more math than I want to do
>after all this beer. Let's see... 16 ounces to a pound, so I have 5/16 of
>a pound... Looks like almost a 200:1 ratio unless I'm just demonstrating
>how bad Americans are at math.

You need to account for the beam inertia too.


>Tomorrow I'll throw half a brick with the thing and see if I can beat your
>50' throw. :)

Nearer 200' now - with the big counterweight !

On Mon, 4 Aug 2003 16:06:44 -0600, "tnfkajs" <[email protected]>
wrote:

>If I wanted to attach some brackets to the table saw cast iron top, I think
>I'd be drilling some biggun holes into some purdy thick iron. Would I be an
>idiot to try this? Would it take forever?

No idea. Well behaved cast iron is easy to drill, "chilled" iron can
be a nightmare. Give it a go, you'll probably find it drills very
easily. Use a sharp twist drill and you don't need lubricants or
cutting fluid. The swarf should come off as chips, not twirlies.

>
> tnfkajs wrote:

> >
> > If I wanted to attach some brackets to the table saw cast iron top, I
think
> > I'd be drilling some biggun holes into some purdy thick iron. Would I
be an
> > idiot to try this? Would it take forever?

If there is a flat surface, you can atach a magnetic drill. Good tool
rental shops have them, but it will probably be $50 for the day. You supply
the bit. Yes, lube as you drill, even if it is only a spray of WD-40.

> > Or - should I dimiss this approach and look for another way to attach
the
> > outfeed table?

Anything you can clamp on to?
Ed

Depends on the circumstances. You're doing it right though. If you feel
excess resistance, clear the chips.
"LRod" <[email protected]> wrote in message
news:[email protected]...
> On Sun, 07 Sep 2003 07:50:24 GMT, "CW" <[email protected]>
> wrote:
>
> >Finally, someone speaking reason. Yes, it drills easily and very nicely.
> >Tends to clog taps though. Just back out a bit after every couple turns
and
> >it works fine.
>
> How do you get a couple of turns? I've never been able to get more
> than a half turn or so before things tighten up enough that I'm afraid
> of breaking the tap.
>
> There must be some sort of corrolary to Murphy's Law about this; taps
> only break in locations whose position is absolutely essential and for
> which no alternative exists. I don't want to fall prey to that...ever.
>
>
> LRod
>
> Master Woodbutcher and seasoned termite
>
> Shamelessly whoring my website since 1999
>
> http://www.woodbutcher.net

tnfkajs wrote:

> I'd be drilling some biggun holes into some purdy thick iron. Would I be
> an idiot to try this? Would it take forever? Would I go through 35 bits?
> Would
> I need some liquid coolant on the bore? Should I buy eight $15 Black and
> Decker cheapo drills and just burn them up?

What do you consider a big hole? FWIW I drilled a 1/2" hole through a piece
of railroad track (just under the rail head, where it was maybe 1" thick).
I used 3-in-one oil to lubricate it, because that's what was within reach.
I set the speed on my drill press according to the chart, and wound up
using the lowest speed I had for the job, but it came out fine. I got two
perfect little twisty thingies (dang, what are those called?), and the bit
is fine. The only problem was when the bit started to break through to the
other side, grabbed, and tried to spin the 60-pound piece of track. I
smoked the belts on the drill press a couple of times before I managed to
find just the right light touch to get through without it grabbing.

Cast iron would be even easier to drill, though you have the dual problems
of keeping the drill perpendicular to the table surface and maintaining a
good, low speed. Maybe use a dowling jig?

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
Confirmed post number: 16970 Approximate word count: 509100
http://www.geocities.com/Paris/Rue/5407/

On Thu, 07 Aug 2003 19:04:01 -0400, Silvan
<[email protected]> wrote:

>Your mention of chips good, twisties bad (in reference to cast iron)

I never said "good" or "bad", just that it's how CI behaves. Twisty
swarf certainly isn't bad, it's just that you won;t get it, except for
the most sophisticated grades of CI.

The other thing about CI is that it contains loose carbon between the
iron crystal grains. This acts as a lubricant, so you don't need to
add one yourself.

>One way or the other, the hole is drilled, the rod installed, the chain
>attached, and the railroad track segment serves as the counterweight for my
>trebuchet. :)

Doesn't really sound heavy enough !

My 8' beam car-portable treb
<http://www.jarkman.co.uk/toys.htm>
began life with a 12 brick counterweight and was pathetic. With a 20
brick counterweight it got much more interesting. You need at least
20:1 weight ratio to make a treb start to behave.

On Wed, 06 Aug 2003 20:41:43 -0400, Silvan
<[email protected]> wrote:

>Oh, right, cast iron. I was drilling a piece of railroad track. Whatever
>kind of steel that is.

Steel isn't the same as iron. Not by a long way !

We no longer see much iron in use, just cast iron. And even that's
getting rarer. Before the late 19th century and the Bessemer
converter though, steel was a rare and expensive alloy used only for
hard edges. Most things we'd now use mild steel for were made of
wrought iron, of various grades. These days, decorative smiths can
hardly buy wrought iron anywhere. There are only three (?) bloomeries
left making it world-wide, and these are solely for the "arts and
crafts" market.

Railway line is awkward stuff. Old rails tended to be fairly simple
alloys, but modern ones are quite complex. They may even be a harder
steel head welded to a less brittle rail, or a flame carburisation
process where the alloy of the wear surface is changed. Some of these
are damn near undrillable.

Around 1910, Newcastle Upon Tyne was noted for two things; the huge
shipyards building armoured battleships, and the world's largest
railway crossing at one end of Central station. Crossings and points
are always awkward, as the "frog noses" (the pointy bit) wear rapidly.
The solution to regular replacement and traffic disruption was to
replace the frogs in this crossing by a specialised manganese steel,
drawing on the shipyard's armour knowledge.

On Sun, 7 Sep 2003 10:41:06 -0700, D.B. <[email protected]> wrote:

>Back up as it starts to get tight, don't wait until it's
>tight.

I do that. It just doesn't take very long; certainly not two turns.

>Are you using the right size tap drill for the material?

Yes.

>Don't have good tap drill chart?

I do.

>Subtract one thread pitch from the nominal screw diameter.
>.250-20 Tap drill = .250 -1/20 = .200. Then pick the next
>largest actual drill size (assuming you have a complete set
>of drills).

If I can remember all that, I'll try to use it if my chart isn't
handy.

>If you only have a set graduated in 1/16th or
>32nds you have a problem.

I have fractional and numbered, but I don't have letter size. Most of
the time I'm tapping sizes that need number sized bits. No problem
there.

>Also use coarse threads everyplace you can. They are easier
>to cut and hold up better in many materials, cast iron and
>aluminum being two good examples.

Probably stainless, too, I would think, because of the ease of
galling.

Thanks for your thoughts.


LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Andy Dingley wrote:

>>One way or the other, the hole is drilled, the rod installed, the chain
>>attached, and the railroad track segment serves as the counterweight for
>>my
>>trebuchet. :)
>
> Doesn't really sound heavy enough !

It isn't, but it's the most weight I could come up with without having to
scrap the entire thing. Started life using part of an old weight set for
weight. Came to 26 pounds. It was miserable.

The track weighs 62 pounds, so it does better. Track works because it's
narrow enough to fit into the frame that I built to accommodate the
original weights. Any wider, and I have to replace my nice hardened steel
Nordic Trac axle with something else, and pretty much rebuild the entire
thing from there.

> My 8' beam car-portable treb
> <http://www.jarkman.co.uk/toys.htm>
> began life with a 12 brick counterweight and was pathetic. With a 20
> brick counterweight it got much more interesting. You need at least
> 20:1 weight ratio to make a treb start to behave.

I shoot a 5 oz baseball, so that's... Well, more math than I want to do
after all this beer. Let's see... 16 ounces to a pound, so I have 5/16 of
a pound... Looks like almost a 200:1 ratio unless I'm just demonstrating
how bad Americans are at math.

No pictures. I haven't gotten around to taking any yet. It's a good bit
smaller than yours, and much more heavily built. Maybe I over-built it,
but it sure has lasted well. I have it strapped to a hand truck so I can
roll it across to the big parking lot across the street. If I ever get to
take it anywhere, I can probably fit it into the back of a van without
taking it apart, though I will want to un-hook the weight first I should
think. :)

Maximum range on those baseballs is about 100' I'm afraid. I've heard
accounts of smaller/lighter trebs doing better, so maybe I don't have mine
properly tuned yet.

Tomorrow I'll throw half a brick with the thing and see if I can beat your
50' throw. :)

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
Confirmed post number: 17080 Approximate word count: 512400
http://www.geocities.com/Paris/Rue/5407/

"tnfkajs" <[email protected]> wrote:

>I'm stumped on a good way to add an outfeed table to my saw. Yet another
>"benefit" of the Jet Supersaw. Before I dimisss this idea entirely, I
>thought I'd ask the "Pro's".
>
[snip]

Cast drills ez. Drill a pilot hole to make it easier though.
Lubricants not needed.

Wes
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