How would you cut a 3/4″ 4×8 sheet of plywood into an oval?
Got a friend who is plotting to make a race-track style poker table. I may or may not help him. Most of the how-to’s he has been finding online show guys using a jigsaw to cut the oval. Personally, I like the precision (and repeat-ability) of the table saw and miter saw, so I’m less excited about a free hand jigsaw cut.
An example of ones he’s seen online:
http://www.junell.cc/pokertable/
Wonder if you could use a router and piece of string or some such, but it isn’t something I’ve tried.
So, how would you do it?
jt8
“The early bird gets the worm, but the second mouse gets the cheese.” –Dave Barry
Replies
By "oval" do you mean an ellipse? The table in the photo is not an ellipse, it just has radiused corners.
It's easy to draw an ellipse using a string and two nails, but I've never tried to cut one other than freehand or on a CNC router.
By "oval" do you mean an ellipse? The table in the photo is not an ellipse, it just has radiused corners.
He wants the shape they have on that site. Looks like rounded corners to me. But on some of them they've rounded the corners to create the outside oval and then cut another oval inside (which is felted). So the cut needs to be fairly clean or it will be visible.
I like the all felt look, but friend likes the one with the cup holders. It is his project, so I guess it will be like the first pic.
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It's easy to draw an ellipse using a string and two nails, but I've never tried to cut one other than freehand or on a CNC router
Yeah, you can draw it with a pencil and piece of string pretty easy, but I can't think of a time when I've jigsaw'ed something on that scale and had it look really clean. I can't help but think there is a way to make the cut that will provide a VERY clean cut and one that could be repeated later (for instance if you wanted to make another table a month later). CNC would be a little much for this project. :)
There are several different links to tables here, but most use freehand jigsaw.
http://www.homepokertourney.com/tables_build.htm
jt8
"The early bird gets the worm, but the second mouse gets the cheese." --Dave Barry
Edited 11/9/2007 2:40 pm by JohnT8
The rounded corners (I assume no ellipse needed) can be cut with a jigsaw and a radius arm. Don't discount the CNC router. If there's a cabinet shop in your area with a CNC machine, they might cut your sheets for less than $30.
Ditto the CNC shop, that's probably the most precise way. However, if you are looking for repeatability in the end.... create the oval on a sheet of MDF and freehand it proud of the line, use a belt sander to get it right down to the line so that it looks good, and the use a router and bearing-guided bit on the plywood, using the MDF as a template.
http://www.woodweb.com/knowledge_base/A_Jig_for_Drawing_or_Cutting_Ellipses.html
The jig in your link is exactly what I have used many times for trim for eliptical openings between rooms, and garage door heads. I don't use just a pencil, I attach my router to it. As long as you don't get to greedy with your cut the resulsts are excellent.
You could probably get the shape you want by making a pattern from some MDF then using a top bearing flush cutting router bit to follow the pattern and cut a clean line.
I would lay out my oval (or whatever) on the MDF and rough cut it with a jig saw - leaving ~1/16" past the line. Then take a couple of hours sanding, filing, and smoothing to the line. This makes your template.
Use the template to mark the shape on the table top and rough cut with a jig saw - leaving ~1/8" - !/4". Attach the template to the rough cut top and use the router to cut the top to the final size. Piece of cake, right?? - lol
If you want repeatability, make a template and use a straight cut router bit with a bearing to cut all the rest.
Let's not confuse the issue with facts!
Could you use something like this to make a template http://www.arcusblade.com/ and then slightly over cut additional pieces and trim with a flush cut router bit if you're looking for more than one? I've used this blade on decks and it works great. To make the curve I usually use an electricians snake or rip a piece of wood about 1/4 to 3/8 thick and up to 16' long. I've seen people use garden hoses and other techniques as well. Hope this helps.
If the sides are going to be straight with 1/2 circles on the ends. I'd set up a trammel and router.
Quick, easy, accurate.
If the sides are going to be straight with 1/2 circles on the ends. I'd set up a trammel and router.
So on the oval within an oval:
1. trammel the corners off the 4x8 sheet to get the outside oval
2. shorten the radius and trammel the rounded ends of the inner-oval
3. clamp a straight edge down and do the straight-aways on the inner oval.
?jt8
"The early bird gets the worm, but the second mouse gets the cheese." --Dave Barry
Do you know of a CNC shop in your area?
A CNC router would whack this in time counted in seconds, and your part would have smooth edges.
A handheld router working with a circle jig will make the cut for you, too.
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I'm on board with you and Niel, a trammel and a router is fast and easy.Spheramid Enterprises Architectural Woodworks
"If you want something you've never had, do something you've never done"
John
Count me in on the way that Neil and Sphere mentioned.
Trammel and router, quick, accurate, easy and repeatability.
Doug
Edited 11/10/2007 10:10 pm ET by DougU