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Forum topic by Tim Suess posted 01-03-2010 05:17 AM 1512 views 0 times favorited 17 replies Add to Favorites Watch
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Tim Suess

12 posts in 3170 days


01-03-2010 05:17 AM

Topic tags/keywords: question joining

I am attempting to construct a candy bowl but I have been running into a geometry problem which I cannot figure out. The dish is essentially an upside down pyramid with the tip cut off, and obviously hollow for delicious treats.

I cut a 15 degree bevel on each edge (so the top an bottom are parallel). I then cross cut each end at 15 degrees with the blade set to 45 degrees and when putting all the pieces together I get a gap on the inside of the compound miter. If your looking at it form the top the gap is on the short side of the miter. What am I doing wrong any tips or tricks that would be helpful? Of all the bowls on the website I couldnt find a non-turned bowl/dish so here is a ceramic example of what I am trying to create http://www.jewishbazaar.com/ceramic-hanukah-candy-dish.htm
Thanks!

-- T. Suess


17 replies so far

View kolwdwrkr's profile

kolwdwrkr

2821 posts in 3053 days


#1 posted 01-03-2010 05:28 AM

If all the miters are off then I would say that your saw isn’t set at a true 45. You also need to make sure that the material is sitting flat on the saw, and that you are using a stop of some sort to ensure that each piece is cut to exactly the same size. Other then that I’d have to see it.

-- ~ Inspiring those who inspire me ~

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Tim Suess

12 posts in 3170 days


#2 posted 01-03-2010 05:30 AM

I am using a stop to get all of the pieces to the same length

-- T. Suess

View j_olsen's profile

j_olsen

155 posts in 2635 days


#3 posted 01-03-2010 05:31 AM

Tim
Sounds like you haven’t got a true 45 set on your saw tilt

Are you using a digital guage or some other form of reference when setting up the tilt?

-- Jeff - Bell Buckle, TN

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a1Jim

115202 posts in 3040 days


#4 posted 01-03-2010 07:30 AM

If you have true 45s then your parts are not equall in size.

-- http://artisticwoodstudio.com Custom furniture

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TopamaxSurvivor

17671 posts in 3139 days


#5 posted 01-03-2010 07:54 AM

I agree, your miter is off of 45. Get a drafting square to check it or layout a prefect square. You can do that with a compass. strike arcs on a straight line. Expand your compass and strike intersecting arcs on one side of the line. Draw a line from the first center point to the intersecting arcs on the side. Now, you should have a perfect 90. Strike arcs on the lines that form the 90 angle from the intersection. Connect those to arcs. Now you have a perfect 90 and 45*. Use that to check your saw and miters. Good luck:-)

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

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scrappy

3506 posts in 2894 days


#6 posted 01-03-2010 07:59 AM

That looks the same as a segmented turning just not run on the lathe. If the bottom and top are NOT the same size(like the pic shows) I believe you should NOT have a 45 deg angle.

Here is a link to a site that will calculate the correct angle to be cut.http://www.blocklayer.com/CompoundMiterEng.aspx

You can put in as many sides as you need (4 in this case) and the angle that your sides are on, and it will calculate the cut angle for you. A 15 deg angle on the sides with 4 sides will require a 46.0 deg cut.

Hope this helps..

Scrappy

-- Scrap Wood's the best...the projects are smaller, and so is the mess!

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TopamaxSurvivor

17671 posts in 3139 days


#7 posted 01-03-2010 08:44 AM

The angle on the piece of wood has to be 45 to add up to 90 and eventually 360. I asumed it to be being cut on a table saw since there was no mention of a saw type. On a table saw the blade needs to be at 45 and teh miter gauge needs to be at 15*. For a compound miter saw, I have no idea where to set it, don’t have one :-))

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

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TopamaxSurvivor

17671 posts in 3139 days


#8 posted 01-03-2010 08:46 AM

What make some of those words show up in bold face??

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

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TopamaxSurvivor

17671 posts in 3139 days


#9 posted 01-03-2010 08:57 AM

Scrappy, that calculator is for the compound miter saw setttings to get 45 and 15 on the wood.

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

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scrappy

3506 posts in 2894 days


#10 posted 01-03-2010 09:09 AM

Topmax, According to the pic, The Miters being cut should be compound miters. Just like on my Purpleheart segmented turning With the top and bottom NOT the same size the angle on the cut surface changes. It is no longer an even 45 deg when cut flat. After you put them together on the slant, it will be a 90 deg corner.

Scrappy

-- Scrap Wood's the best...the projects are smaller, and so is the mess!

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TopamaxSurvivor

17671 posts in 3139 days


#11 posted 01-03-2010 09:32 AM

Scrappy, Did you cut it with a compound miter saw or a table saw? What bentlyj says is why the angles are not 15 and 45 in the calculator.

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View stefang's profile

stefang

15512 posts in 2797 days


#12 posted 01-03-2010 09:03 PM

If the piece you are cutting is being held at a 15 degree angle while you are running it through the saw, then you only need to cut it at 45 degrees. That sounds like the case here. That means it could be that the saw blade or miter gage if a table saw is not set at 45 degrees or the 15 degree cuts on the edges are not correct or if it is a mitersaw it is also possible that the saw blade is not at exactly 90 degrees. The same would apply for a table saw blade. My suggestion Tim is to make sure all the above mentioned angles are correct. I don’t think there is anything wrong with your basic method.

-- Mike, an American living in Norway.

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scrappy

3506 posts in 2894 days


#13 posted 01-04-2010 08:42 AM

Hey Bently, THAT is how you show your calculations are correct! haha

Thanks for the info.

Scrappy

-- Scrap Wood's the best...the projects are smaller, and so is the mess!

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kolwdwrkr

2821 posts in 3053 days


#14 posted 01-04-2010 09:02 AM

Nice job Bently

-- ~ Inspiring those who inspire me ~

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TopamaxSurvivor

17671 posts in 3139 days


#15 posted 01-04-2010 09:17 PM

That is 3,000 yrs of accumulated knowledge :-)) We still don’t know if the cutting is on a flat surface (TS) or compound miter saw, makes a big difference!!

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

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