Math

Great thread.  I would start at one end, place a picket, use a 2" spacer and so on.  The last piece is cut to fit. The even spacing  makes for a symmetrical appearance and the scribed piece looks good.  [smile]
 
But with sketchep you might not have
to cut that last picket if you spaced it 1 15/16. ;)
 
This is exactly the kind of conflict Ghostfist is after  [tongue] :

waho6o9 said:
I would start at one end, place a picket, use a 2" spacer and so on.  The last piece is cut to fit. The even spacing  makes for a symmetrical appearance and the scribed piece looks good.  [smile]
Click to expand...

In a light hearted way: Waho6o9 I could not DISAGREE with you more!!!
This sort of look, (to me at least) looks far too unbalanced!!!
 
Top Knot said:
This is exactly the kind of conflict Ghostfist is after  [tongue] :

waho6o9 said:
I would start at one end, place a picket, use a 2" spacer and so on.  The last piece is cut to fit. The even spacing  makes for a symmetrical appearance and the scribed piece looks good.  [smile]
Click to expand...

In a light hearted way: Waho6o9 I could not DISAGREE with you more!!!
This sort of look, (to me at least) looks far too unbalanced!!!
Click to expand...

+1  Disagree!  

You could scribe the first and last so its look symmetrical but no way would I just scribe the last one.  Thats a site type of job where its all about profit so you just need to bang it up and go! Not for me!

Edited:  Check my score out -----^ its okay try and beat it in time and score no cheating!  Have a FOG competition! Im going to have another go in a min! I need to do better lol!
 
Best on this computer score and time:
2.81 134 s Mavrik

This is addictive.
I must stop ... I must stop ... I must stop ...
 
Agree, this aspect should be in a different thread but it does have some relevance
to scribing and judging appearance.

Your inaccuracy by category:

Parallelogram 1.0 ---- ----
Midpoint 0.0 ---- ----
Bisect angle 0.7 ---- ----
Triangle center 5.3 ---- ----
Circle center 4.1 ---- ----
Right angle 0.0 ---- ----
Convergence 5.1 ---- ----

Average error:  2.31  (lower is better)
Time taken:  66.4
 
jmbfestool said:
! [big grin]  !

http://woodgears.ca/eyeball/
Best two scores on this computer:
Score Time Name
8.26        77 s JMBjoinery
Click to expand...

Cool little excercise!
Overall score: 4.40
Total time: 113.97

Here’s my approach.  I am usually simultaneously trying to figure out the spacing as well as how many boards I need.
I prefer to plan ahead to the end result, and make a spacer block that is properly determined, rather than just assume 2” is going to result in a nice width for the final boards.  You might start center out and discover that the final boards wind up extremely narrow.  That’d look weird!

For below, I assumed your start and stop points will be a fence board (not a gap).
The SS is deducted on the left side of the equation, because the last board doesn’t get a follow-on spacer.
If you want gaps at the start/end, then ADD the SS to the left side, instead of subtracting it.

First, add up the total lineal distance you need to cover.  
Your specs:  73", 2nd section 76 1/2", and the third is 82 1/8"  =  231.625” lineal distance

Add up the total of your fence boards + spacings and begin to calculate.
Tweak as necessary to arrive at the above figure.

Formula:  ((WW + SS) x YY)  – SS  = LD
WW = width
SS = spacing
YY = number of boards
LD = Lineal Distance

Use the desired approximate gap to solve once for YY, to get an approximate number of boards.
Then substitute YY with the lower integer.
Then re-solve for SS

Example:
Solve for YY:
(5.125” + 2” spacing) x YY number of boards  - 2”  = 231.625
7.125 x YY = 233.625       YY = 32.79 boards
Round this down to 32 boards if you want the spacing over 2”.   (You could also round up if you don’t mind having less than 2”).

Solve again, this time for the spacing SS:
(5.125 + SS) x 32 – SS  = 231.625
(5.125 x 32) + SSx32 – SS  = 231.625
164 + 32SS – SS = 231.625
Move this parts across the equals sign:
 32SS - SS = 231.625 – 164
31SS = 67.625
SS = 2.1814”       The value is between 2-1/8” and 2-3/16”

In this case, it is pretty close to your 2” desired gap.
But, say you had gone with exactly 2”, you would be off by a total of 5.625” at the end, and would have a final board that is ½” wide, or you trim the start and end boards by about half their width…  Not great results IMO.

So, make some spacers 2-3/16” in width and your last board’s width will be only a very minor adjustment.

FYI, if you want to start and end with spacing gaps:  then 2-1/16”

 
I love that little game!

First time I tried it, got 4.24, in 126 seconds. Didn't realise the first time it was against the clock!

Just had a second attempt, got the following:

Your inaccuracy by category:
   
Parallelogram 10.0 4.5 8.0
Midpoint 7.8 7.1 2.8
Bisect angle 3.4 0.1 2.7
Triangle center 2.2 0.8 3.5
Circle center 3.2 3.2 5.0
Right angle 0.4 1.6 5.5
Convergence 8.2 3.2 3.2

Average error:  4.11  (lower is better)
Time taken:  98.5

 
norwegian wood said:
i use the iphone baluster app. works awesome
Click to expand...

What's the app called?  Thank you

I need get a better score take my time abit every body is getting 4 lol I did itmto fast

Jmb
 
Wood_Junkie said:
Here’s my approach.  I am usually simultaneously trying to figure out the spacing as well as how many boards I need.
I prefer to plan ahead to the end result, and make a spacer block that is properly determined, rather than just assume 2” is going to result in a nice width for the final boards.  You might start center out and discover that the final boards wind up extremely narrow.  That’d look weird!

For below, I assumed your start and stop points will be a fence board (not a gap).
The SS is deducted on the left side of the equation, because the last board doesn’t get a follow-on spacer.
If you want gaps at the start/end, then ADD the SS to the left side, instead of subtracting it.

First, add up the total lineal distance you need to cover. 
Your specs:  73", 2nd section 76 1/2", and the third is 82 1/8"  =  231.625” lineal distance

Add up the total of your fence boards + spacings and begin to calculate.
Tweak as necessary to arrive at the above figure.

Formula:  ((WW + SS) x YY)  – SS  = LD
WW = width
SS = spacing
YY = number of boards
LD = Lineal Distance

Use the desired approximate gap to solve once for YY, to get an approximate number of boards.
Then substitute YY with the lower integer.
Then re-solve for SS

Example:
Solve for YY:
(5.125” + 2” spacing) x YY number of boards  - 2”  = 231.625
7.125 x YY = 233.625      YY = 32.79 boards
Round this down to 32 boards if you want the spacing over 2”.  (You could also round up if you don’t mind having less than 2”).

Solve again, this time for the spacing SS:
(5.125 + SS) x 32 – SS  = 231.625
(5.125 x 32) + SSx32 – SS  = 231.625
164 + 32SS – SS = 231.625
Move this parts across the equals sign:
  32SS - SS = 231.625 – 164
31SS = 67.625
SS = 2.1814”      The value is between 2-1/8” and 2-3/16”

In this case, it is pretty close to your 2” desired gap.
But, say you had gone with exactly 2”, you would be off by a total of 5.625” at the end, and would have a final board that is ½” wide, or you trim the start and end boards by about half their width…  Not great results IMO.

So, make some spacers 2-3/16” in width and your last board’s width will be only a very minor adjustment.

FYI, if you want to start and end with spacing gaps:  then 2-1/16”
Click to expand...

[dead horse] [dead horse] [dead horse]

Please give us your address.  We are sending a team of FOG member carpenters over immediately to build the fence for you.  While you're waiting for us, please gather up a lot of cardboard since we are first going to sit down with a bunch of scissors when we arrive, make a test cut of the whole fence in cardboard then set up a dozen MFT's and start the production process.  Some members will be designated to do the scribing of the cardboard onto wood with crayons at the scribing station.  Another group will do the cutting at the cutting station.  We'll set up a routing station just for fun.  Last station will be the painters.  To keep costs down, you'll be doing the installation.

Please respond in a timely fashion as we are on standby for just such carpentry emergencies.
 
Nice, you guys are getting into the geometry game. Really good exercise. the purpose of this thread was to see how many different ways there are to approach this problem, and it looks like we're starting to to a variety of answers. No one's wrong it's just what works for you, and more importantly your clients.

on a side note regarding the geometry test, you guys should take a look at the fella's site who put that up, real interesting character.

http://woodgears.ca/
 
Wow, just had a look at the rest of the site. There's some really cool stuff on there, including a page dedicated to the original question of this thread.

Had a third attempt at the eyeball test too:

Your inaccuracy by category:
   
Parallelogram 4.1 5.7 11.4
Midpoint 1.0 3.6 0.0
Bisect angle 2.3 0.6 1.7
Triangle center 4.3 0.8 2.4
Circle center 2.8 5.0 2.8
Right angle 2.4 2.0 2.8
Convergence 1.0 2.0 1.0

Average error:  2.84  (lower is better)
Time taken:  93.9
 
You must log in or register to reply here.

Similar threads

ericsink
Tenon length for table apron, Domino 700
Replies
13
Views
739
Packard
P
ear3
Cherry armoire
2
Replies
21
Views
1K
smorgasbord
S
S
Murphy Bed in Cherry
Replies
17
Views
1K
luvmytoolz
luvmytoolz
ryanjg117
3D printed upgrades to jointer/planer combo
Replies
4
Views
630
festal
F
rmwarren
Riffing on MFTs & clamping
Replies
1
Views
1K
agehall
A
Back
Top