How do I figure out this angle?

[rnt80]

I'm finishing up this tv frame and I can't figure out the angle that I need to cut this trim that wraps around the perimeter of the frame.  The columns are angled at 10 degrees.  I've bevelled the backside of the trim that is on the front of the trim so that the top of the trim remains parallel to the base and top of the unit.  I've tried some trial and error this afternoon but I'm running out of wiggle room with my trim stock.  Any help would be appreciated.

 

[Rob Z]

Hi Russell,

If I understand what you are trying to do with the trim....then the simplest thing to do (if you don't have a compound miter saw) would be to rip some strips of wood on the table saw with the blade set at 10 degrees, then back the piece of trim in the miter saw with the sacrificial strip ripped to 10 degree bevel.  Then, you could cut the outside miters  the regular way.

 

[rnt80]

Rob, I've got a Kapex so the bevel setting is my friend .  The problem I've had thus far is that since I had to bevel the back of the molding that's applied to the front of the frame it is slightly thinner at the top compared to the trim that runs along the side.  Does that make sense?  When I cut the miters the pieces don't match up.  I must be going at this all wrong but I don't know how to fix it yet.

 

[mastercabman]

Why don't you cut both pcs at 5 degree bevel?
That's the way i look at it.

I don't know if it will be a perfect fit but it's worth a try!

 

[Tom Ryan]

I don't really have an answer, but if it were me, I would mill some scrap to "look like" the molding, at least on the faces and edges that meet other faces and edges.  They wouldn't have to be long to get the angles.  Then I'd get the angles right, and finally worry about the length.

Sorry if this is too primitive an answer.  I was trained as a mathematician, and long ago learned that trial and error got the answer faster, and with fewer errors (if you don't cut your boards to short).

If your jpegs are from Sketchup, you can look at the joint from the end, get the angle, and do the same from the front.  This should give your settings for your Kapex, at least for a first approximation to trial and error.

Tom in SE Pennsylvania

 

[mastercabman]

Rob, I've got a Kapex so the bevel setting is my friend .  The problem I've had thus far is that since I had to bevel the back of the molding that's applied to the front of the frame it is slightly thinner at the top compared to the trim that runs along the side.  Does that make sense?  When I cut the miters the pieces don't match up.  I must be going at this all wrong but I don't know how to fix it yet.

Did you bevel the whole back of the trim????  Why?  It will never fit,you need to keep the same thickness of the trim that you are trying to joint.Try what i suggested about cutting yoiur trim at 45 miter and 5 bevel.Or you may need to cut a 3rd pc (transition between the 2 pcs)but usally i do that with cronw molding when the ceilling changes elevationon at a  corner.

 

[rnt80]

I had to back bevel the trim that goes on the front of the cab, if I didn't then it would sit at an angle.  Am I trying the impossible here?  If I bevel the pieces that go along the side then they will angle up.

 

[bionicus]

If I'm looking at this right, you can't bevel the entire backside length of that front strip. Things just won't line up, as I think you've realized. But if that front is, say, 6 inches wide, and you back-bevel just those middle 6 inches of the strip, with the overhanging corners then hugging back around slightly to meet up with the sides at 45 degrees, something very close to the desired effect should be achievable... I think.

Alternatively, if you could carefully notch into the front face, the same effect could be attained without having to bevel the trim piece at all.

Either way, tricky stuff. 

 

[Brice Burrell]

Russell, I've checked it out in SU, it's a compound miter, miter at 52.1 degrees and bevel at 10 degrees (I think but it is getting late here in the East  ;D ). Since the pieces are different thicknesses you aren't going to use a 45 for miter.

[attachthumb=#]

 

[sw1211]

This might help, http://www.csgnetwork.com/sawmitercalc.html

 

[rnt80]

Russell, I've checked it out in SU, it's a compound miter, miter at 52.1 degrees and bevel at 10 degrees (I think but it is getting late here in the East  ;D ). Since the pieces are different thicknesses you aren't going to use a 45 for miter.

[attachthumb=#]

Thanks Brice.  I'll give it shot tomorrow when I get home from school.

 

[cdconey]

Could you just make relief cuts in your column to allow you to use unmodified molding?

From the picture, I'm having a hard time distinguishing where the angle is

 

[Brice Burrell]

Could you just make relief cuts in your column to allow you to use unmodified molding?

From the picture, I'm having a hard time distinguishing where the angle is

It looks like the angle is on the front and the sides are square.

This might help, http://www.csgnetwork.com/sawmitercalc.html

I've only looked briefly at this calculator but I couldn't figure it out. Kinda makes me feel dumb to not be able to figure out how to have a calculator give me the answer.  ;D

 

[AlexThePalex]

I'm pretty good with trigonometry, but seriously, from your description, I got no clue what you're actually trying to do.

 

[cdconey]

Could you just make relief cuts in your column to allow you to use unmodified molding?

From the picture, I'm having a hard time distinguishing where the angle is

It looks like the angle is on the front and the sides are square.

This might help, http://www.csgnetwork.com/sawmitercalc.html

I've only looked briefly at this calculator but I couldn't figure it out. Kinda makes me feel dumb to not be able to figure out how to have a calculator give me the answer.  ;D

TS55 and guide rail, set TS55 to 10 degrees and cut a relief.

 

[RONWEN]

Russel,
I can't tell from your sketches, I assume that the columns are angled 10 degrees just on the front face and on the outside ends of the cabinet?  The column faces next to the TV and (of course) on the cabinet rear are plumb?  Is that correct? 

 

[Brice Burrell]

Russel,
I can't tell from your sketches, I assume that the columns are angled 10 degrees just on the front face and on the outside ends of the cabinet?  The column faces next to the TV and (of course) on the cabinet rear are plumb?  Is that correct? 

Ron, don't think so, look carefully at the drawing, I'm pretty sure it's just the front face that is angled. The front piece is a rectangle so the sides aren't angled. 

 

[RONWEN]

Russel,
I can't tell from your sketches, I assume that the columns are angled 10 degrees just on the front face and on the outside ends of the cabinet?  The column faces next to the TV and (of course) on the cabinet rear are plumb?  Is that correct? 

Ron, don't think so, look carefully at the drawing, I'm pretty sure it's just the front face that is angled. The front piece is a rectangle so the sides aren't angled. 

It might be a bit of a task blending the trim widths if one piece is sitting at a 10 degree angle and the others are plumb.  They will in effect need to be different widths, probably easiest by ripping a slight amount off the plumb trim at the bottom edge.

 

[rnt80]

Russel,
I can't tell from your sketches, I assume that the columns are angled 10 degrees just on the front face and on the outside ends of the cabinet?  The column faces next to the TV and (of course) on the cabinet rear are plumb?  Is that correct? 

I obviously haven't done a good job of explaining my predicament, sorry for any confusion.  I've included some more pictures in hopes that it will clarify things.  Brice was correct when he stated that the columns are only angled on the front face.  The two sides are straight up and down.  The other part that is angled at ten degrees is the stretcher that runs between the two columns.  The molding that I'm applying runs along the stretcher and then runs around three sides of the column (it doesn't wrap around the back).  The issue is that in order for the top part of the molding to remain parallel to the base of the cabinet the back of the molding has to be bevelled at ten degrees.  The moulding that is applied to the side of the columns is not bevelled, if it were then the top part of the profile would angle up.  I think Brice is on the right track with his SU model.  Since the pieces are of different thickness the miter angle will not be two 45's.  I didn't have a chance to try his calculations today but I should have some time tomorrow.

 

[Michael Kellough]

If only the front plane of the column is angled out...
your joints will be the usual 45 degrees, but
the front piece of moulding does need to be back beveled 10 degrees +.

Miter your unaltered stock at the usual 45 degrees but measure the lengths
for the lower edge of the miter joint, not the top because you're going to have
to relieve the top/back of the front stick so the piece can fit tight at the bottom.
The top of the actual miter will be a little behind the front face of the column.

I'd probably assemble the pieces first and do the fine tuning of the back bevel
with a small belt sander or rigid sanding block. To make it easier to fine tune
make a heavy hollow ground back bevel on that front piece before assembly.

EDIT

Okay, the above is only good for the pieces that wrap around the column.
I didn't realize you have a stick crossing the similarly angled stretcher but
the process is still similar unless I've missed something else.

For the sticks to fit as mitered joints they haver to be cut as if they are are
identical in shape. I think I read that you've already back beveled the stock?
If so, you going to have to figure out a way to support the molding from it's face.
When you figure that out you'll be back to making all the miters 45 degrees again
and measuring lengths for the bottom of the molding.

Hopefully you have some unaltered stock left. If you do I'd use some fast setting
goo like plumbers two part putty epoxy to mold an impression of the face of the
molding while it is sitting up perfectly square (in back) to the table. Use something
as a release so the epoxy can be popped off the molding. Make a long enough mold
that you can cut it in two so each half can support the back beveled molding securely
while it is being cut.

Remember, for the faces of the molding to fit right they have to both be cut standing
upright regardless of the condition of the backsides. You can't lean one stick forward
and get a good fit. Similarly, if you've already back-beveled a stick already you have
to find a way to keep it from leaning back while it's cut. Also, the very short sticks
on the inside faces of the columns will need a small trimming after assembly since
they will but into a plane that is leaning 10 degrees.

Another EDIT

If you've already back-beveled your stock all you have to do is rip an off-cut from
some other square stock that has that same bevel and stand that against the fence
and push your molding against the off-cut strip so the stock is supported at the normal
orientation.