The "Sagulator" is cool, but...

On 10/17/2017 1:44 PM, CruzR wrote:
> replying to Bay Area Dave, CruzR wrote:
> looking at the first few comments it appears you folks have not used
> Sagulator. I use it all the time; it's awesome. Before you use it, it is
> extremely imperative that you read the directions very carefully.



Here is my Sagulator, it is the LFAT model.

https://www.flickr.com/photos/lcb11211/8539981330/in/album-72157622991960362/

replying to Bay Area Dave, CruzR wrote:
looking at the first few comments it appears you folks have not used
Sagulator. I use it all the time; it's awesome. Before you use it, it is
extremely imperative that you read the directions very carefully.

--
for full context, visit https://www.homeownershub.com/woodworking/the-sagulator-is-cool-but-236180-.htm

I agree; I'm not gonna worry about the sag since the shelves
will be supported in dados and secured to the back as well.

dave

j.duprie wrote:

> In general, if a shelf is suported on 3 sides (and I'm working with stock of
> any real thickness - say 3/4" or more), I tend not to worry about shelf sag
> unless the shelf is really wide.
>
> I have some pine bookcases I built about 30 years ago - they're a full foot
> deep, supported on 3 sides (grooves in the plywood back and wood sides),
> 3/4" stock. they've held my dad's engineering library since they were made
> (big, heavy books), and there is a *slight* sag in the middle. Barely
> noticable unless you actually sight along the edge.
>
> YMMV
>
> --JD
>
>
> "alexy" <[email protected]> wrote in message
> news:[email protected]...
>
>>Bay Area Dave <[email protected]> wrote:
>>
>>
>>>I'm building a small wall unit with narrow shelves that will
>>>be attached to the back panel as well as the sides. I doubt
>>>that the "Sagulator"
>>>(http://www.woodbin.com/calcs/sagulator.htm) takes that into
>>>account. Is there another resource on the web or a way to
>>>figure how much additional support is provided by attaching
>>>a shelf to the rear wall? My shelves are going to be quite
>>>shallow; about 5 1/2". In other words, I'd like to
>>>calculate the "sag" for a shelf that is support on 3 edges.
>>
>>Intuitive, non-engineer answer: Too many other variables to be able to
>>answer the question. Some pertinent factors: stiffness of the back,
>>stiffness of the sides, other shelves (which will tend to stiffen the
>>sides, making them less able to twist to accommodate a sag of one edge
>>of the shelf in question). Probably lots of etc's I'm not thinking of.
>>
>>--
>>Alex
>>Make the obvious change in the return address to reply by email.
>
>
>

In general, if a shelf is suported on 3 sides (and I'm working with stock of
any real thickness - say 3/4" or more), I tend not to worry about shelf sag
unless the shelf is really wide.

I have some pine bookcases I built about 30 years ago - they're a full foot
deep, supported on 3 sides (grooves in the plywood back and wood sides),
3/4" stock. they've held my dad's engineering library since they were made
(big, heavy books), and there is a *slight* sag in the middle. Barely
noticable unless you actually sight along the edge.

YMMV

--JD


"alexy" <[email protected]> wrote in message
news:[email protected]...
> Bay Area Dave <[email protected]> wrote:
>
> >I'm building a small wall unit with narrow shelves that will
> >be attached to the back panel as well as the sides. I doubt
> >that the "Sagulator"
> >(http://www.woodbin.com/calcs/sagulator.htm) takes that into
> >account. Is there another resource on the web or a way to
> >figure how much additional support is provided by attaching
> >a shelf to the rear wall? My shelves are going to be quite
> >shallow; about 5 1/2". In other words, I'd like to
> >calculate the "sag" for a shelf that is support on 3 edges.
>
> Intuitive, non-engineer answer: Too many other variables to be able to
> answer the question. Some pertinent factors: stiffness of the back,
> stiffness of the sides, other shelves (which will tend to stiffen the
> sides, making them less able to twist to accommodate a sag of one edge
> of the shelf in question). Probably lots of etc's I'm not thinking of.
>
> --
> Alex
> Make the obvious change in the return address to reply by email.

Bay Area Dave <[email protected]> wrote:

>I'm building a small wall unit with narrow shelves that will
>be attached to the back panel as well as the sides. I doubt
>that the "Sagulator"
>(http://www.woodbin.com/calcs/sagulator.htm) takes that into
>account. Is there another resource on the web or a way to
>figure how much additional support is provided by attaching
>a shelf to the rear wall? My shelves are going to be quite
>shallow; about 5 1/2". In other words, I'd like to
>calculate the "sag" for a shelf that is support on 3 edges.

Intuitive, non-engineer answer: Too many other variables to be able to
answer the question. Some pertinent factors: stiffness of the back,
stiffness of the sides, other shelves (which will tend to stiffen the
sides, making them less able to twist to accommodate a sag of one edge
of the shelf in question). Probably lots of etc's I'm not thinking of.

--
Alex
Make the obvious change in the return address to reply by email.

CruzR <[email protected]> writes:
>replying to Bay Area Dave, CruzR wrote:
>looking at the first few comments it appears you folks have not used
>Sagulator. I use it all the time; it's awesome. Before you use it, it is
>extremely imperative that you read the directions very carefully.
>

Wow! Bay Area Dave! Haven't seen that moniker for a decade or so.

And as for CruzR, whatever that may be, you have no clue. Not about
Usenet, nor about "you folks".