« back to Designing Woodworking Projects forum
Forum topic by Angela  posted 07262011 02:41 AM  2252 views  0 times favorited  15 replies 
07262011 02:41 AM 
Topic tags/keywords: question joining tablesaw mahogany design designing math formula I’m designing a stand for my TV. I figure there must be a math formula I could use to determine what angles I need to cut. There are the two side pieces which will be at an angle and the rear side piece will be at an angle with the back piece. I figure that once I can determine the angles, then I can determine the dimension of the front. I added the image because there’s no way I can explain what I’m talking about. It’s not the best image but I didn’t know I’d be posting it online. Thanks  www.WoodWorkersWebsite.com  Helping other woodworker's 
15 replies so far
#1 posted 07262011 02:46 AM 
I can figure this out quickly for you, but I need to know how you are laying out the front, do you have a width you need, a depth from the widest point to the front, or an angle. you just dont have enough info there to determine. 
#2 posted 07262011 03:31 AM 
I drew it up with the front sides at 45* to the horizontal of the drawing. though bentlyj’s suggestion seems good to simplify things. 
#3 posted 07262011 04:35 AM 
Thanks so much I’m going to have to study your drawings but thanks I didn’t know I’d get such great answers. So the 165/16 isn’t set right? If that is changed then all the others would change. Is that what you ment about missing info? Instead of the 165/16” I would like the depth to be 22” or somewhere around there. Thanks again I’m at awe with your guys drawings.  www.WoodWorkersWebsite.com  Helping other woodworker's 
#4 posted 07262011 05:00 AM 
After looking at my diagram and looking at the TV I have I think I’m going to have to change the dimensions. I would like the total depth 25”. After looking at the sizes of the sides I have would make the angles pretty severe. If you guys would be so kind, I would like to get better measurements then ask you about the angles. Angela  www.WoodWorkersWebsite.com  Helping other woodworker's 
#5 posted 07262011 06:13 AM 
bentlyj ,,,,,,,,,,, you sure are a nice guy  rick 
#6 posted 07262011 09:13 AM 
Oh God,this is so complicated :/ 
#7 posted 07272011 12:16 AM 
OK I’ve made a pattern and good thing or it wouldn’t have worked but here’s the final design with measurements. I hope I provided all the ones you need.  www.WoodWorkersWebsite.com  Helping other woodworker's 
#8 posted 07272011 12:40 AM 
I took a stab at it. I indicated the miter setting and not the angle. But I was wondering if I’m even close.  www.WoodWorkersWebsite.com  Helping other woodworker's 
#9 posted 07272011 02:26 PM 
Angela Why are you making the cabinet this shape (i.e. six sides)? Is this to go into a corner of a room? If so, the angles given to you by Bentlyj in post #6 are essentially correct as they will give you two sides parallel to the two walls, to sides at right angles to the walls and two sides (the front and back) across the corner at 45° to the room. If you then accept that those angles are correct, all you can do to dimension the unit to fit the TV is decide the width of the front, the depth of the sides perpendicular (or at right angles if you prefer) to the walls and the depth of the unit (with some tradeoff between size of the perpendicular sides and the depth). Hope this helps. I’m sure I could explain further if you need me to.  I may have lost my marbles, but I still have my love of woodworking 
#10 posted 07312011 12:41 AM 
Bentyj – Thanks for your help. I’m interested to see how everything comes out. Tootles – Thanks for the info but it’s not going into a corner. Anyway that would make this too easy and I’m ready for a challenge. Thanks everyone  www.WoodWorkersWebsite.com  Helping other woodworker's 
#11 posted 07312011 01:39 PM 
That’s great Angela, a challenge is always a wonderful thing. Calculating the angles mathematically, I get one angle a little different to Bentlyj – I get 129.3 instead of 127.8 (and so the 121.9 becomes 120.4) but, when I plot it on Sketchup, my dimensions come out entirely wrong and I agree wiith Bentlyj’s numbers – so I’m a touch confused as to what’s going on there. That suggests a third method might be even better for marking out and measuring, which works something like this: 1. Mark out the front line (36 1/2 “) Alright, enough said. Go enjoy your challenge!  I may have lost my marbles, but I still have my love of woodworking 
#12 posted 07312011 02:35 PM 
For anyone that is interested, there is an excellent CAD program that is not very expensive yet has a lot of features. It’s called Turbocad and at $129 it is a bargain. It will give you professional looking drawings and will help you perform mathematical problems. Plus it comes with all kinds of symbols that can be used in drawings. I use it at home and in the machine shop at the plant. It also runs a CNC router that we use at the plant to make templates that we use to grind our molder tooling with. I’ve never needed any other CAD program and we occasionally build special machines for the plant.  If a man does not keep pace with his companions, perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured or far away. Henry David Thoreau 
#13 posted 08022011 08:22 PM 
Tootles I also got 129.3 for the measurment but I figured Bentlyj was more exact so I went ahead with his measuements and so far so good. Everything fits together nicely. My next step is securing the miter corners. I first thought of biscuits but then after doing some reading I settled on splines. I’ve use biscuits before but never splines. I’ll also be using dowels or tenons for some of the other joints. I haven’t used either so far in a project so each step is new for me and I thank everyone for posting their comments and helping me. Angela  www.WoodWorkersWebsite.com  Helping other woodworker's 
#14 posted 08032011 05:50 AM 
Bentlyj, I agree, I could come up with no sensible explaination why Sketchup should be wrong. On the other hand, I could come up with no reason why the answer calculated using trigonometry should be wrong either. As both an engineer and a future maths teacher, that worries me. Fortunately, although it took me a while, I do have an answer. I worked off the following 6 dimensions: Put simply, these dimensions cannot all be achieved if the front and back are parallel – only five of the six are achievable. Plotting the shape using the angles I caclulated using trigonometry results in the distance fronttoback being about 3/8” short of 23”. Plotting it as I suggested using a compass rsults in the distance pointtopoint being about 3/4” short of 46” (according to Sketchup). And plotting it as you did in Sketchup extends the length of one side by 1/4”. Any one of these solutions is viable, it’s Angela’s choice which dimensions are most important and which one she doesn’t mind altering. So Angela, you have done the right thing by just picking one method on the basis that you don’t mind the side being that 1/4” longer and running with it. In fact, since Bentlyj’s method is the only one that enlarges the shape overall, I think you made the best choice. Bentlyj, not that you didn’t have this already, but let me say publicly that you have my respect. Angela, keep on having fun and good luck with the joints. I wil be keeping an eye out for the project when you get it done.  I may have lost my marbles, but I still have my love of woodworking 
#15 posted 08052011 11:35 PM 
Bentlyj I did use your angles and they worked great. I see in the drawing you have 18 and not 181/4” which you mention in a later posting. It’s interesting because I ended up using 181/4”. I’ll have to check the other side measurement because I can’t remember if it’s 71/2” or 73/4” I thank everyone for their help. I’ve started a blog regarding the problems I’ve had so far with this project.  www.WoodWorkersWebsite.com  Helping other woodworker's 
Have your say...
You must be signed in to reply.

Forum  Topics 

Woodworking Skill Share

11817 
Woodturning

1931 
Woodcarving

407 
Scrollsawing

320 
Joinery

1267 
Finishing

4643 
Designing Woodworking Projects

6457 
Power Tools, Hardware and Accessories

27071 
CNC Woodworking

187 
Hand Tools

5205 
Jigs & Fixtures

1358 
Wood & Lumber

5990 
Safety in the Woodworking Shop

1333 
Focus on the Workspace

2058 
Sweating for Bucks Through Woodworking

1163 
Woodworking Trade & Swap

4640 
LumberJocks.com Site Feedback

2169 
Coffee Lounge

8652 