Woodturner's Resource
Woodturner's Resource  
  • Featured Artist    • Websites   Support Wr
Tutorials, Projects & Tips   • Event Calendar   • Tool and Book Store
  Home Page Forum HelpSearch Map TPT Resources LoginRegister
 
Pages: 1 2 3 
Send Topic Print
segmented bowl question (Read 4,376 times)
 
Rodolfo Ceballos
Full Member
**
Offline


WR Rocks!!!

Posts: 87

Gender: male
segmented bowl question
Aug 7th, 2009 at 11:47am
 
So I am tearing my hair out because the math is not checking out.  I modeled the first ring after some tutorial videos by Max Hernik.  The videos are great and the math makes sense,but when I cut my pieces they did not match.  I have a consistent gap of around 9/16.  Because im incredibly stubborn im not adding a small piece that would fill it because I know the math checks out and it should work.  Does anyone have any suggestions as to what I should double check?  I realize im not giving too much info as to what I did, but I know that there must be something that im simply overlooking that I should either be double checking or that I completely did not think about.

Any suggestions?
Back to top
  

Rodolfo
http://facebook.com/tizoc1  
IP Logged
 
Register To Remove Ads
David Hamann
WR Global Moderator
WR Patron
*****
Offline


papadave

Posts: 5,598

Pasco WA, Washington, USA
Pasco WA
Washington
USA

Gender: male

Jet 1014VSI
Re: segmented bowl question
Reply #1 - Aug 7th, 2009 at 12:06pm
 
i use this program: Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register  works great.

others include: Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register

Back to top
« Last Edit: Aug 7th, 2009 at 12:06pm by David Hamann »  

“Be who you are and say what you feel, because those who mind don’t matter and those who matter don’t mind.” - Ted Geisel

Be yourself, after all, everyone else is taken.
 
IP Logged
 
Rodolfo Ceballos
Full Member
**
Offline


WR Rocks!!!

Posts: 87

Gender: male
Re: segmented bowl question
Reply #2 - Aug 7th, 2009 at 12:16pm
 
I actually tried to sample that program but I use a mac and it doesnt appear to be compatible.  Im going to try one more time...  lol.  I used the same mathematical principles to calculate the measurements for a 5'' diameter ring of only 6 segments.  The math checks out but I have to figure out where my error is coming from.  I figure it will be easier to identify with only 6 segments and using my cheap pine rather than wast more of the wood I just bought for the segments.
Back to top
  

Rodolfo
http://facebook.com/tizoc1  
IP Logged
 
Ron Sardo
WR Administrator
WR Patron
*****
Offline


Chief cook and bottle
washer

Posts: 9,263

Drums, Pennsylvania, USA
Drums
Pennsylvania
USA


PM 3520
Re: segmented bowl question
Reply #3 - Aug 7th, 2009 at 1:03pm
 
Rodolfo, Check out

TPT (Tutorials, Projects & Tips) > Woodturning Projects & Techniques > Segmented Turning > Segment Calculator

Back to top
  

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register
WWW  
IP Logged
 
Walt
WR Patron
******
Offline


WR Rocks!

Posts: 1,988

Hanford, California, USA
Hanford
California
USA

Gender: male

PM 3520A
Re: segmented bowl question
Reply #4 - Aug 7th, 2009 at 1:30pm
 
I'm not familiar with Max's video so I can't help with that. 

Where is this 9/16" gap? 

This is what I use.  360 divided by # segments, divided by 2 equals the angle of each cut.  Wether it's a miter saw or table saw.

Diameter of the ring times Pi (3.14) divided by the number of segments equals the long side of the segment.

For a 12 sided ring of 5" diameter it would look like this.
12/360 = 30 /2 = 15 degrees.  5 x 3.14 = 15.7 /12 = 1.308.

All that is left is the thicknes of stock used.  I don't use a program or spreed sheet.  It works for me every time.  Unless I screw up the math.  I double check before I cut wood.  Hope this helps.  Is this what you are doing or is it something else?  I know your pain though! bang head
Back to top
  
 
IP Logged
 
Bob Hamilton
WR Addict
*****
Offline



Posts: 1,118

Forest, Ontario, Canada, Ontario, Canada
Forest, Ontario, Canada
Ontario
Canada

Gender: male
Re: segmented bowl question
Reply #5 - Aug 7th, 2009 at 2:06pm
 
Is your error one of angle or length?  In other words, do the segments meet properly to form a ring of smaller diameter than you want or do you have a 9/16" gap at the inside or outside of the ring when all the segments but the last two are assembled with the miters closed?  The more segments you use the more any tiny error in the angle gets multiplied.

Bob
Back to top
  
WWW  
IP Logged
 
Rodolfo Ceballos
Full Member
**
Offline


WR Rocks!!!

Posts: 87

Gender: male
Re: segmented bowl question
Reply #6 - Aug 7th, 2009 at 3:16pm
 
The gap that I was getting was after the 12 segments were put together.  There was a gap or hole.  The math used was just like the math recommended by Walt, infact the numbers were the same (thanks btw, because it did help confirm that I had the numbers correct). 

After mulling around in the shop a while staring at the failed ring, I tried to look at each factor in the equation and realized that it had to be the degree of the angle between the segments.  I learned that the miter gauge on my bandsaw is definitely not accurate which was why it was off.  Through trial and error I cut scraps before finding the correct 15 degree angle I needed.  I finally cut the wood and created 7 rings.  Im only using 4, but it was good to finally get it.  Now im going to stop for the day and wait until tomorrow to sand and glue.  I think the small break will do me good because the more determined I get, the more I want to finish and the faster I try to work... thats when mistakes happen (sometimes even injury). 

I have to say I have always had a deep respect for the art created by woodworkers but I am gaining an even deeper respect for masters at this medium.  Its a completely different craft.  For me right now it is very frustrating, but frustrating in a way that is highly motivating.  Im going to try this first small bowl and keep at it.

Thanks again everyone!
Back to top
  
Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register 6020_565060173079_35804667_33364226_7270748_n.jpg (Attachment deleted)

Rodolfo
http://facebook.com/tizoc1  
IP Logged
 
Walt
WR Patron
******
Offline


WR Rocks!

Posts: 1,988

Hanford, California, USA
Hanford
California
USA

Gender: male

PM 3520A
Re: segmented bowl question
Reply #7 - Aug 7th, 2009 at 3:48pm
 
Good luck and after you get the hang of it you'll look back and laugh.  I did.  I also cut scrap or MDF just to verify angle before cutting expensive wood.
Back to top
  
 
IP Logged
 
Register To Remove Ads
Ron Sardo
WR Administrator
WR Patron
*****
Offline


Chief cook and bottle
washer

Posts: 9,263

Drums, Pennsylvania, USA
Drums
Pennsylvania
USA


PM 3520
Re: segmented bowl question
Reply #8 - Aug 7th, 2009 at 4:35pm
 
On a 12 segment ring I glue three segments together at a time and sand to 90 degrees.
Then I take two 3-segment pieces and glue them to together then sand so I have a perfect half circle.
Then I glue the two half circles together.

Helps eliminate any mistakes in measuring or cutting
Back to top
  

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register
WWW  
IP Logged
 
Rodolfo Ceballos
Full Member
**
Offline


WR Rocks!!!

Posts: 87

Gender: male
Re: segmented bowl question
Reply #9 - Aug 7th, 2009 at 6:09pm
 
Ill definitely do that Ron.  I know that there is still some question as to the accuracy of the rings.  I did have one more question...  What do you guys use as a surface when you glue?  I was going to use the titebond glue and know that im supposed to use a surface that it wont stick to but am not sure what to use.

Thanks!
Back to top
  

Rodolfo
http://facebook.com/tizoc1  
IP Logged
 
David Hamann
WR Global Moderator
WR Patron
*****
Offline


papadave

Posts: 5,598

Pasco WA, Washington, USA
Pasco WA
Washington
USA

Gender: male

Jet 1014VSI
Re: segmented bowl question
Reply #10 - Aug 7th, 2009 at 6:35pm
 
i use wax paper.
Back to top
  

“Be who you are and say what you feel, because those who mind don’t matter and those who matter don’t mind.” - Ted Geisel

Be yourself, after all, everyone else is taken.
 
IP Logged
 
Ron Sardo
WR Administrator
WR Patron
*****
Offline


Chief cook and bottle
washer

Posts: 9,263

Drums, Pennsylvania, USA
Drums
Pennsylvania
USA


PM 3520
Re: segmented bowl question
Reply #11 - Aug 7th, 2009 at 8:12pm
 
Wax paper works

I use newpaper
Back to top
  

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register
WWW  
IP Logged
 
Paul Hinds
Senior Member
****
Offline


the Hobbit

Posts: 262

Gender: male
Re: segmented bowl question
Reply #12 - Aug 8th, 2009 at 7:31am
 
Ron Sardo wrote on Aug 7th, 2009 at 4:35pm:
On a 12 segment ring I glue three segments together at a time and sand to 90 degrees.
Then I take two 3-segment pieces and glue them to together then sand so I have a perfect half circle.
Then I glue the two half circles together.

Helps eliminate any mistakes in measuring or cutting


Yep, that's the intelligent way to do it.  Not surprizing from a master like Ron.

Paul
Back to top
  

Paul (hobbithouse) Hinds
WOOD ID SITE: Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register
BOWLS: Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register
GLOSSARY: Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register
WWW  
IP Logged
 
Jim Curlee
Full Member
**
Offline


WR Rocks!

Posts: 94

Re: segmented bowl question
Reply #13 - Aug 8th, 2009 at 10:06am
 
I do mine a lttle different than Ron. I set my sleds to be dead accurate. That way I can glue the entire ring at one time. On some complicated feature rings, having to true them during the glue up can throw off a pattern. My fault, the wood, stars not aligned right, there are still times I need to true half rings but I try to avoid it if at all possible.
Back to top
  
 
IP Logged
 
Ron Sardo
WR Administrator
WR Patron
*****
Offline


Chief cook and bottle
washer

Posts: 9,263

Drums, Pennsylvania, USA
Drums
Pennsylvania
USA


PM 3520
Re: segmented bowl question
Reply #14 - Aug 8th, 2009 at 11:55am
 
I cut them dead accurate myself. When I dry fit the pieces they are right on.

But stuff happens... like the glue swelling the wood and knocking them out of alignment.

I don't use clamps, I just rub two pieces together until they feel stiff. then lay them on the table. It is also possible that one segment isn't perfectly aligned, knocking the section off. As you know, being 1 degree off can mess things up.

Below is a half of a 6 segment ring that I use for xmas ornaments.
You can see the cuts are dead on target.
Back to top
« Last Edit: Aug 8th, 2009 at 12:02pm by Ron Sardo »  
Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register DSCN0561.jpg (Attachment deleted)

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register
WWW  
IP Logged
 
Pages: 1 2 3 
Send Topic Print