Everybody goes to great lengths to make their woodworking benches heavy and
strong for stability. But one thing I've always wondered is why there are
no obvious angled supports between the legs and stretchers. The only
triangulation would come from within the widths and thicknesses of the legs
and stretchers.
When I built my drillpress stand, out of 2x4s and 2x6s, I put in additional
boards on the sides going from the front bottom to the back top. It was
very strong front to back, but wobbled a very little bit side-to-side. I
put an additional angled piece on the back (couldn't do the front because of
the drawer and retractable wheel mechanism) and now it behaves as if the
whole thing is made of one block of steel. Super strong! Cabinets work
this way, too, by having the triangles inside the sheet goods used to
surface the frame (if there is one).
So how come nobody adds angled supports to the base, say with angled
mortises and tenons? Lee Valley's bench has this elabourite system of steel
truss rods. I wouldn't think those would be needed at all if there were a
few well placed wooden pieces added to the design. All chance of racking
would be completely eliminated.
When I build another bench I plan to add these pieces to the design, but
since I've never seen it like this before I seriously wonder if I should.
You thoughts please?
Thanks.
- Owen -
On Sat, 13 Aug 2005 08:58:15 -0400, "Owen Lawrence"
<[email protected]> wrote:
>Everybody goes to great lengths to make their woodworking benches heavy and
>strong for stability. But one thing I've always wondered is why there are
>no obvious angled supports between the legs and stretchers.
Because they are heavy enough and strong enough already. Mine's solid
maple, 9' by about 2' 6", 12 drawers, plus two upper wide thinner
drawers, handed to me when I was moving one time. In fact, I'd made
myself a couple of lighter models, and when this was offered, threw
them out to take this one in the moving van. What more do you need if
you have what you need?
On Sat, 13 Aug 2005 08:58:15 -0400, "Owen Lawrence"
<[email protected]> wrote:
>Everybody goes to great lengths to make their woodworking benches heavy and
>strong for stability. But one thing I've always wondered is why there are
>no obvious angled supports between the legs and stretchers. The only
>triangulation would come from within the widths and thicknesses of the legs
>and stretchers.
>
>When I built my drillpress stand, out of 2x4s and 2x6s, I put in additional
>boards on the sides going from the front bottom to the back top. It was
>very strong front to back, but wobbled a very little bit side-to-side. I
>put an additional angled piece on the back (couldn't do the front because of
>the drawer and retractable wheel mechanism) and now it behaves as if the
>whole thing is made of one block of steel. Super strong! Cabinets work
>this way, too, by having the triangles inside the sheet goods used to
>surface the frame (if there is one).
>
>So how come nobody adds angled supports to the base, say with angled
>mortises and tenons? Lee Valley's bench has this elabourite system of steel
>truss rods. I wouldn't think those would be needed at all if there were a
>few well placed wooden pieces added to the design. All chance of racking
>would be completely eliminated.
>
>When I build another bench I plan to add these pieces to the design, but
>since I've never seen it like this before I seriously wonder if I should.
>You thoughts please?
>
>Thanks.
>
> - Owen -
>
Owen,
I wonder exactly the same thing. The work bench I built used doubled
up two by fours for strength but I used diagonal bracing on three
sides for rigidity. See http://tinyurl.com/bqd4k
This bench doesn't move when it's not lifted on its casters.
TWS
On Sat, 13 Aug 2005 15:07:15 GMT, "David Merrill"
<[email protected]> wrote:
>As a retired structural analyst, I've noticed the same lack of wracking
>resistance. It would seem especially important if the bench is to be used
>for tasks such as hand planing where the forces are applied parallel to the
>top surface and not important if the bench is being used primarily for tasks
>where the forces are oriented vertically.
I must be weaker than you? My planes are sharp enough to not meet so
much resistance and are used with a smooth application; certainly not
even remotely close to the forces needed to pull my solid, well-built
workbench apart. If your planes are dull and you try to gouge off
half-inch thick shavings you might have a point.
Steve DeMars wrote:
>
> I believe the reason you do not see triangles on the back of well built
> benches is the same reason you don't see a large 2" pipe bumper surrounding
> a new Jaguar. After all, this would prevent dings, which we all know Jag
> owners fear more than death it self.
>
> It's looks, looks, appearance, style, staying with the old look, etc . . .
...
And w/ most old, original benches, well crafted, significant sized
mortise/tenon joints that eliminate the need...
On Mon, 22 Aug 2005 01:22:45 -0400, "Owen Lawrence"
<[email protected]> wrote:
>
>
>Don't let the semantics distract you. It's flatness that I'm really
>interested in. If the table support frame is absolutely rigid, unless it
>only has three legs it's going to rock until the fourth leg's length is
>adjusted to meet the floor. It's an overconstrained system. If the frame
>isn't absolutely rigid, it's going to change its shape to match the floor,
>which is also bad.
>
>I already experience this with my new router table. I'm always moving it
>around, and it's very rigid over its four legs. When I need to lower it
>from its wheels I just shim one of the legs (or keep moving it until I find
>a better spot, which is a pain). But a router table is a lot lighter and
>takes less abuse than a workbench so it's not a huge problem. I expect I'll
>get away with an extensible foot if I ever get around to adding one.
>
> - Owen -
>
Ok, I understand. You're right, if the floor is not only tilted but
also not planar then you have lost the advantage of the rigid base -
the rigidity actually works against you. In my case the garage floor
is reasonably planar so I can always find four points of contact by
jockeying it around.
Let me know when you've finished your bench and what you come up with.
TWS
On Sat, 13 Aug 2005 23:34:16 GMT, "CW" <[email protected]> wrote:
>Yep, you really are an asshole. Thanks for the confirmation.
You are merely confirming your own character. Now, I'm not here for
your rubbish; you're kill-filed.
I believe the reason you do not see triangles on the back of well built
benches is the same reason you don't see a large 2" pipe bumper surrounding
a new Jaguar. After all, this would prevent dings, which we all know Jag
owners fear more than death it self.
It's looks, looks, appearance, style, staying with the old look, etc . . .
"Owen Lawrence" <[email protected]> wrote in message
news:[email protected]...
> Everybody goes to great lengths to make their woodworking benches heavy
and
> strong for stability. But one thing I've always wondered is why there are
> no obvious angled supports between the legs and stretchers. The only
> triangulation would come from within the widths and thicknesses of the
legs
> and stretchers.
>
> When I built my drillpress stand, out of 2x4s and 2x6s, I put in
additional
> boards on the sides going from the front bottom to the back top. It was
> very strong front to back, but wobbled a very little bit side-to-side. I
> put an additional angled piece on the back (couldn't do the front because
of
> the drawer and retractable wheel mechanism) and now it behaves as if the
> whole thing is made of one block of steel. Super strong! Cabinets work
> this way, too, by having the triangles inside the sheet goods used to
> surface the frame (if there is one).
>
> So how come nobody adds angled supports to the base, say with angled
> mortises and tenons? Lee Valley's bench has this elabourite system of
steel
> truss rods. I wouldn't think those would be needed at all if there were a
> few well placed wooden pieces added to the design. All chance of racking
> would be completely eliminated.
>
> When I build another bench I plan to add these pieces to the design, but
> since I've never seen it like this before I seriously wonder if I should.
> You thoughts please?
>
> Thanks.
>
> - Owen -
>
>
As a retired structural analyst, I've noticed the same lack of wracking
resistance. It would seem especially important if the bench is to be used
for tasks such as hand planing where the forces are applied parallel to the
top surface and not important if the bench is being used primarily for tasks
where the forces are oriented vertically.
I would also suggest, as an alternative to angled members, the use of
plywood shear panels on the back, sides (and front if no drawers or shelves
are planned). The panels, when rigidly attached to the legs, would provide
wracking resistance in the same manner as does plywood sheathing on house
framing. Many other workshop tables, tool bases and stands could benefit
from the same treatment, e.g. router tables; many of the designs I see in
woodworking magazines, and commercial offerings as well, appear to
completely ignore wracking resistance. Shear panels can easily be retrofit
to existing benches and stands that lack them, greatly increasing their
rigidity.
David Merrill
"Owen Lawrence" <[email protected]> wrote in message
news:[email protected]...
> Everybody goes to great lengths to make their woodworking benches heavy
and
> strong for stability. But one thing I've always wondered is why there are
> no obvious angled supports between the legs and stretchers. The only
> triangulation would come from within the widths and thicknesses of the
legs
> and stretchers.
>
> When I built my drillpress stand, out of 2x4s and 2x6s, I put in
additional
> boards on the sides going from the front bottom to the back top. It was
> very strong front to back, but wobbled a very little bit side-to-side. I
> put an additional angled piece on the back (couldn't do the front because
of
> the drawer and retractable wheel mechanism) and now it behaves as if the
> whole thing is made of one block of steel. Super strong! Cabinets work
> this way, too, by having the triangles inside the sheet goods used to
> surface the frame (if there is one).
>
> So how come nobody adds angled supports to the base, say with angled
> mortises and tenons? Lee Valley's bench has this elabourite system of
steel
> truss rods. I wouldn't think those would be needed at all if there were a
> few well placed wooden pieces added to the design. All chance of racking
> would be completely eliminated.
>
> When I build another bench I plan to add these pieces to the design, but
> since I've never seen it like this before I seriously wonder if I should.
> You thoughts please?
>
> Thanks.
>
> - Owen -
>
>
Owen Lawrence wrote:
> Everybody goes to great lengths to make their woodworking benches heavy and
> strong for stability. But one thing I've always wondered is why there are
> no obvious angled supports between the legs and stretchers. The only
> triangulation would come from within the widths and thicknesses of the legs
> and stretchers.
>
> When I built my drillpress stand, out of 2x4s and 2x6s, I put in additional
> boards on the sides going from the front bottom to the back top. It was
> very strong front to back, but wobbled a very little bit side-to-side. I
> put an additional angled piece on the back (couldn't do the front because of
> the drawer and retractable wheel mechanism) and now it behaves as if the
> whole thing is made of one block of steel. Super strong! Cabinets work
> this way, too, by having the triangles inside the sheet goods used to
> surface the frame (if there is one).
>
> So how come nobody adds angled supports to the base, say with angled
> mortises and tenons? Lee Valley's bench has this elabourite system of steel
> truss rods. I wouldn't think those would be needed at all if there were a
> few well placed wooden pieces added to the design. All chance of racking
> would be completely eliminated.
>
> When I build another bench I plan to add these pieces to the design, but
> since I've never seen it like this before I seriously wonder if I should.
> You thoughts please?
>
> Thanks.
>
> - Owen -
>
>
My bench was built from 4x4 legs and 2x4 everything else. I used M&T
joinery throughout. The top is bolted to the undercarriage with 3/8"
bolts (just happened to have a supply). No angled supports at all.
After 8 years, still no movement of any kind.
mahalo,
jo4hn
Oh the pain. Will I ever survive?
"Guess who" <[email protected]> wrote in message
news:[email protected]...
> On Sat, 13 Aug 2005 23:34:16 GMT, "CW" <[email protected]> wrote:
Now, I'm not here for
> your rubbish; you're kill-filed.
>
In article <[email protected]>,
"Owen Lawrence" <[email protected]> wrote:
> Everybody goes to great lengths to make their woodworking benches heavy and
> strong for stability. But one thing I've always wondered is why there are
> no obvious angled supports between the legs and stretchers. The only
> triangulation would come from within the widths and thicknesses of the legs
> and stretchers.
Those diagonal braces interfere with the nice cabinetry
that you build under the bench. Its storage space, in
the most convenient place. Mortise and tenon construction
makes it stiff. I used that, plus the Lee Valley threaded
rods under tension to keep it stiff for my lifetime.
John
You say "staying with the old look". Why didn't people centuries ago
incorperate those things? They knew of the advantages then.
"Steve DeMars" <[email protected]> wrote in message
news:C8oLe.470$Sj1.89@okepread04...
> I believe the reason you do not see triangles on the back of well built
> benches is the same reason you don't see a large 2" pipe bumper
surrounding
> a new Jaguar. After all, this would prevent dings, which we all know Jag
> owners fear more than death it self.
>
> It's looks, looks, appearance, style, staying with the old look, etc . . .
>
>
>
>
>
> "Owen Lawrence" <[email protected]> wrote in message
> news:[email protected]...
> > Everybody goes to great lengths to make their woodworking benches heavy
> and
> > strong for stability. But one thing I've always wondered is why there
are
> > no obvious angled supports between the legs and stretchers. The only
> > triangulation would come from within the widths and thicknesses of the
> legs
> > and stretchers.
> >
> > When I built my drillpress stand, out of 2x4s and 2x6s, I put in
> additional
> > boards on the sides going from the front bottom to the back top. It was
> > very strong front to back, but wobbled a very little bit side-to-side.
I
> > put an additional angled piece on the back (couldn't do the front
because
> of
> > the drawer and retractable wheel mechanism) and now it behaves as if the
> > whole thing is made of one block of steel. Super strong! Cabinets work
> > this way, too, by having the triangles inside the sheet goods used to
> > surface the frame (if there is one).
> >
> > So how come nobody adds angled supports to the base, say with angled
> > mortises and tenons? Lee Valley's bench has this elabourite system of
> steel
> > truss rods. I wouldn't think those would be needed at all if there were
a
> > few well placed wooden pieces added to the design. All chance of
racking
> > would be completely eliminated.
> >
> > When I build another bench I plan to add these pieces to the design, but
> > since I've never seen it like this before I seriously wonder if I
should.
> > You thoughts please?
> >
> > Thanks.
> >
> > - Owen -
> >
> >
>
>
Yep, you really are an asshole. Thanks for the confirmation.
"Guess who" <[email protected]> wrote in message
news:[email protected]...
Are you really an asshole or do you just play one on the internet?
"Guess who" <[email protected]> wrote in message
news:[email protected]...
>
> I must be weaker than you? My planes are sharp enough to not meet so
> much resistance and are used with a smooth application; certainly not
> even remotely close to the forces needed to pull my solid, well-built
> workbench apart. If your planes are dull and you try to gouge off
> half-inch thick shavings you might have a point.
>
On Sun, 21 Aug 2005 21:45:48 -0400, "Owen Lawrence"
<[email protected]> wrote:
<snip>
>
>One thing I also want to add is an easy (really easy) way of levelling the
>table. No floor I've ever encountered is completely flat, so if you move
>your bench (and if it's got wheels, you will), you have to level it again.
>I haven't thought about it much, but I worry that anything like extensible
>feet would just ruin the structural integrity gained by all those triangles.
>
> - Owen -
>
Owen,
I wanted the bench top to be flat but I see no reason why it needs to
be absolutely level. If it were used to align with another piece of
equipment or table then I could understand why that might be useful
but, to me, the value of having a rock solid feel is significantly
higher than having the table level. As you point out, it will be very
difficult to make levelers that will be as solid as the base with the
diagonal bars. While it is possible I don't see that it is worth the
extra effort.
TWS
I've often wondered the same thing and, like you, have added angled braces
in many structures. The only thing that I've changed over the years is to
fortify my attachment points (more screws. bolts, or whatever than normal).
Other than that, they work extremely well.
BruceT
"Owen Lawrence" <[email protected]> wrote in message
news:[email protected]...
> Everybody goes to great lengths to make their woodworking benches heavy
> and strong for stability. But one thing I've always wondered is why there
> are no obvious angled supports between the legs and stretchers. The only
> triangulation would come from within the widths and thicknesses of the
> legs and stretchers.
>
> When I built my drillpress stand, out of 2x4s and 2x6s, I put in
> additional boards on the sides going from the front bottom to the back
> top. It was very strong front to back, but wobbled a very little bit
> side-to-side. I put an additional angled piece on the back (couldn't do
> the front because of the drawer and retractable wheel mechanism) and now
> it behaves as if the whole thing is made of one block of steel. Super
> strong! Cabinets work this way, too, by having the triangles inside the
> sheet goods used to surface the frame (if there is one).
>
> So how come nobody adds angled supports to the base, say with angled
> mortises and tenons? Lee Valley's bench has this elabourite system of
> steel truss rods. I wouldn't think those would be needed at all if there
> were a few well placed wooden pieces added to the design. All chance of
> racking would be completely eliminated.
>
> When I build another bench I plan to add these pieces to the design, but
> since I've never seen it like this before I seriously wonder if I should.
> You thoughts please?
>
> Thanks.
>
> - Owen -
>
I think that the massive approach builds a bench that is strong, steady, and
. . . dead! The cross-braced approach tends to build a bench that is
lighter, strong, steady, and . . . resonant! I like a bench that doesn't
vibrate so that when something bumps everything on the bench doesn't dance
around. A real monolith would be ideal.
Tim Ellestad
"Owen Lawrence" <[email protected]> wrote in message
news:[email protected]...
> Everybody goes to great lengths to make their woodworking benches heavy
and
> strong for stability. But one thing I've always wondered is why there are
> no obvious angled supports between the legs and stretchers. The only
> triangulation would come from within the widths and thicknesses of the
legs
> and stretchers.
>
> When I built my drillpress stand, out of 2x4s and 2x6s, I put in
additional
> boards on the sides going from the front bottom to the back top. It was
> very strong front to back, but wobbled a very little bit side-to-side. I
> put an additional angled piece on the back (couldn't do the front because
of
> the drawer and retractable wheel mechanism) and now it behaves as if the
> whole thing is made of one block of steel. Super strong! Cabinets work
> this way, too, by having the triangles inside the sheet goods used to
> surface the frame (if there is one).
>
> So how come nobody adds angled supports to the base, say with angled
> mortises and tenons? Lee Valley's bench has this elabourite system of
steel
> truss rods. I wouldn't think those would be needed at all if there were a
> few well placed wooden pieces added to the design. All chance of racking
> would be completely eliminated.
>
> When I build another bench I plan to add these pieces to the design, but
> since I've never seen it like this before I seriously wonder if I should.
> You thoughts please?
>
> Thanks.
>
> - Owen -
>
>
"TWS" <[email protected]> wrote in message
news:[email protected]...
> On Sat, 13 Aug 2005 08:58:15 -0400, "Owen Lawrence"
> <[email protected]> wrote:
>
>>Everybody goes to great lengths to make their woodworking benches heavy
>>and
>>strong for stability. But one thing I've always wondered is why there are
>>no obvious angled supports between the legs and stretchers. The only
>>triangulation would come from within the widths and thicknesses of the
>>legs
>>and stretchers.
>>
>>When I built my drillpress stand, out of 2x4s and 2x6s, I put in
>>additional
>>boards on the sides going from the front bottom to the back top. It was
>>very strong front to back, but wobbled a very little bit side-to-side. I
>>put an additional angled piece on the back (couldn't do the front because
>>of
>>the drawer and retractable wheel mechanism) and now it behaves as if the
>>whole thing is made of one block of steel. Super strong! Cabinets work
>>this way, too, by having the triangles inside the sheet goods used to
>>surface the frame (if there is one).
>>
>>So how come nobody adds angled supports to the base, say with angled
>>mortises and tenons? Lee Valley's bench has this elabourite system of
>>steel
>>truss rods. I wouldn't think those would be needed at all if there were a
>>few well placed wooden pieces added to the design. All chance of racking
>>would be completely eliminated.
>>
>>When I build another bench I plan to add these pieces to the design, but
>>since I've never seen it like this before I seriously wonder if I should.
>>You thoughts please?
>>
>>Thanks.
>>
>> - Owen -
>>
> Owen,
> I wonder exactly the same thing. The work bench I built used doubled
> up two by fours for strength but I used diagonal bracing on three
> sides for rigidity. See http://tinyurl.com/bqd4k
>
> This bench doesn't move when it's not lifted on its casters.
>
Nice. How do the casters work?
- Owen -
Owen Lawrence wrote:
> Everybody goes to great lengths to make their woodworking benches heavy and
> strong for stability. But one thing I've always wondered is why there are
> no obvious angled supports between the legs and stretchers.
<snip>
See my comment about 1/2" CDX gussets in "wood for work bench" post.
Lew
On Sat, 13 Aug 2005 10:28:17 -0500, Duane Bozarth
<[email protected]> wrote:
>Steve DeMars wrote:
>>
>> I believe the reason you do not see triangles on the back of well built
>> benches is the same reason you don't see a large 2" pipe bumper surrounding
>> a new Jaguar. After all, this would prevent dings, which we all know Jag
>> owners fear more than death it self.
>>
>> It's looks, looks, appearance, style, staying with the old look, etc . . .
>...
>
>And w/ most old, original benches, well crafted, significant sized
>mortise/tenon joints that eliminate the need...
Yep. As a poor boy, most of my benches are made from framing stock,
and the racking resistance comes from using a 1.5" x 3" through tenons
mounted through the legs (doubled up two by fours) that are bolted
into place with big lag screws. Solid enough for just about anything-
a M&T joint that size doesn't submit to racking forces very easily.
That being said, I've got some older ones that do have cross-bracing
because I just screwed some single two by fours to the corners of the
tops, and the things wobbled like crazy until they were braced. It
all just depends on how you've built it in the first place, and
whether or not you like the look of the bracing in the back-
everything has it's place.
David Merrill wrote:
> As a retired structural analyst, I've noticed the same lack of wracking=
> resistance. It would seem especially important if the bench is to be u=
sed
> for tasks such as hand planing where the forces are applied parallel to=
the
> top surface and not important if the bench is being used primarily for =
tasks
> where the forces are oriented vertically.
>=20
> I would also suggest, as an alternative to angled members, the use of
> plywood shear panels on the back, sides (and front if no drawers or she=
lves
> are planned). The panels, when rigidly attached to the legs, would pro=
vide
> wracking resistance in the same manner as does plywood sheathing on hou=
se
> framing. Many other workshop tables, tool bases and stands could benef=
it
> from the same treatment, e.g. router tables; many of the designs I see =
in
> woodworking magazines, and commercial offerings as well, appear to
> completely ignore wracking resistance. Shear panels can easily be retr=
ofit
> to existing benches and stands that lack them, greatly increasing their=
> rigidity.
>=20
> David Merrill
I added those shear panels to one bench I made -- they actually formed a =
"drawer box -- complete with drawers :-) " -- and they certainly do=20
increase the rigidity of the table. I also added them to the saw=20
out-feed table -- it allowed me to use light materials and have a rigid=20
table.
It makes a big difference if the bench is built with "light" materials=20
-- 2X4's and MDF as was my original work bench. The panels do increase=20
the "stiffness" greatly. Not so sure it would do much for a properly=20
made work bench -- which my first one wasn't.
> "Owen Lawrence" <[email protected]> wrote in message
> news:[email protected]...
>=20
>>Everybody goes to great lengths to make their woodworking benches heavy=
>=20
> and
>=20
>>strong for stability. But one thing I've always wondered is why there =
are
>>no obvious angled supports between the legs and stretchers. The only
>>triangulation would come from within the widths and thicknesses of the
>=20
> legs
>=20
>>and stretchers.
>>
>>When I built my drillpress stand, out of 2x4s and 2x6s, I put in
>=20
> additional
>=20
>>boards on the sides going from the front bottom to the back top. It wa=
s
>>very strong front to back, but wobbled a very little bit side-to-side. =
I
>>put an additional angled piece on the back (couldn't do the front becau=
se
>=20
> of
>=20
>>the drawer and retractable wheel mechanism) and now it behaves as if th=
e
>>whole thing is made of one block of steel. Super strong! Cabinets wor=
k
>>this way, too, by having the triangles inside the sheet goods used to
>>surface the frame (if there is one).
>>
>>So how come nobody adds angled supports to the base, say with angled
>>mortises and tenons? Lee Valley's bench has this elabourite system of
>=20
> steel
>=20
>>truss rods. I wouldn't think those would be needed at all if there wer=
e a
>>few well placed wooden pieces added to the design. All chance of racki=
ng
>>would be completely eliminated.
>>
>>When I build another bench I plan to add these pieces to the design, bu=
t
>>since I've never seen it like this before I seriously wonder if I shoul=
d.
>>You thoughts please?
>>
>>Thanks.
>>
>> - Owen -
>>
>>
>=20
>=20
>=20
--=20
Will R.
Jewel Boxes and Wood Art
http://woodwork.pmccl.com
The power of accurate observation is commonly called cynicism by those=20
who have not got it.=94 George Bernard Shaw
>>One thing I also want to add is an easy (really easy) way of levelling the
>>table. No floor I've ever encountered is completely flat, so if you move
>>your bench (and if it's got wheels, you will), you have to level it again.
>>I haven't thought about it much, but I worry that anything like extensible
>>feet would just ruin the structural integrity gained by all those
>>triangles.
>>
>> - Owen -
>>
> Owen,
> I wanted the bench top to be flat but I see no reason why it needs to
> be absolutely level. If it were used to align with another piece of
> equipment or table then I could understand why that might be useful
> but, to me, the value of having a rock solid feel is significantly
> higher than having the table level. As you point out, it will be very
> difficult to make levelers that will be as solid as the base with the
> diagonal bars. While it is possible I don't see that it is worth the
> extra effort.
>
> TWS
Don't let the semantics distract you. It's flatness that I'm really
interested in. If the table support frame is absolutely rigid, unless it
only has three legs it's going to rock until the fourth leg's length is
adjusted to meet the floor. It's an overconstrained system. If the frame
isn't absolutely rigid, it's going to change its shape to match the floor,
which is also bad.
I already experience this with my new router table. I'm always moving it
around, and it's very rigid over its four legs. When I need to lower it
from its wheels I just shim one of the legs (or keep moving it until I find
a better spot, which is a pain). But a router table is a lot lighter and
takes less abuse than a workbench so it's not a huge problem. I expect I'll
get away with an extensible foot if I ever get around to adding one.
- Owen -
On Sat, 13 Aug 2005 10:32:01 -0400, Bruce T wrote:
> I've often wondered the same thing and, like you, have added angled braces
> in many structures. The only thing that I've changed over the years is to
> fortify my attachment points (more screws. bolts, or whatever than normal).
> Other than that, they work extremely well.
>
> BruceT
>
>>
>> So how come nobody adds angled supports to the base, say with angled
>> mortises and tenons? Lee Valley's bench has this elabourite system of
>> steel truss rods. I wouldn't think those would be needed at all if there
>> were a few well placed wooden pieces added to the design. All chance of
>> racking would be completely eliminated.
>>
>> When I build another bench I plan to add these pieces to the design, but
>> since I've never seen it like this before I seriously wonder if I should.
>> You thoughts please?
>>
>> Thanks.
>>
>> - Owen -
Here's the reason ... the full reason: the braces and sheer panels aren't
used because they aren't needed. The massive construction typically used
provides inertial resistance to sudden loads and the rigid joinery
privides resistance against sustained loads.
If you build a light weight workbench you may need braces. If you build a
bench with so much wood that it leaves a gap in the forest visible
from space, bracing is probably wasted effort.
Since the wood is subject to a lot of different stresses, such as being
used as a vise from various angles and having lots of things whacked on
it, I opt for a workbench so heavy it leaves marks in my concrete floor.
Bill
On Sat, 13 Aug 2005 19:53:42 GMT, "CW" <[email protected]> wrote:
>Are you really an asshole or do you just play one on the internet?
No, but you surely are. I was being serious, and my reply was not to
you in any case, so mind your own damned business. He seemed to think
that it was necessary to state being a structural analyst, as if that
made a difference. That was not at all necessary, since the forces
are in fact so relatively small, so what in hell does force of planing
have to do with the strength of a well-made workbench, and why do you
need to be some sort of expert to explain it? I have a degree in
math and physics, and that makes no difference either. Anyhow, I need
not explain myself to someone so obviously too stupid to understand.
Stick to your woodworking, if in fact you do any. I'm done here.
On Sun, 21 Aug 2005 08:35:37 -0400, "Owen Lawrence"
<[email protected]> wrote:
>Nice. How do the casters work?
>
> - Owen -
>
The short answer is that the lever in the front of the workbench
twists an angle iron under the bench, which, in turn, pushes up on 4
2x4s that act as lever arms to press the casters to the floor. When
retracted the casters fully retract so the bench is sitting on solid
wood feet. When lifted up the feet are raised a little over 1/4 inch
and the bench is moveable. If you want the gory details, email me and
I'll send you a more detailed description. You can find my email
address on my website.
TWS
>>Nice. How do the casters work?
>>
> The short answer is that the lever in the front of the workbench
> twists an angle iron under the bench, which, in turn, pushes up on 4
> 2x4s that act as lever arms to press the casters to the floor. When
> retracted the casters fully retract so the bench is sitting on solid
> wood feet. When lifted up the feet are raised a little over 1/4 inch
> and the bench is moveable. If you want the gory details, email me and
> I'll send you a more detailed description. You can find my email
> address on my website.
I think I understand your explanation. I will definitely have some sort of
retractable wheel mechanism on my next bench, and your way gives me one more
possible approach.
One thing I also want to add is an easy (really easy) way of levelling the
table. No floor I've ever encountered is completely flat, so if you move
your bench (and if it's got wheels, you will), you have to level it again.
I haven't thought about it much, but I worry that anything like extensible
feet would just ruin the structural integrity gained by all those triangles.
- Owen -