Routing the outline of an 8 pointed star

[H12]

Greetings:

Can anyone suggest a good way of routing the outline of an 8 pointed star commonly found in Arabic architecture?

(Since I haven't figured out the posting of images yet..)  Think of the outline of two squares overlayed on each other, with one rotated 45 degrees from the other.  Trick is I just want the outer trace.  Could an MFS be employed for such a thing?  Especially with the need to scroll around 8 each outside angles of the star, I'm worried about wandering off a normal template and ruining the piece.  Any other wild ideas would be appreciated.

The project is a side table for an Iraqi Brigadier General I spent the last year working with in Baghdad.  Among other things, I ate dinner with him everyday (and drank hundreds of gallons of tea it seems...) on a pair of wobbly side tables and have promised him I would build him a table as a gift.  I intend to route the outline of an 8 pointed star in Cherry ply, fill with black walnut strips, inlay the the country of Iraq with maple veneer into the interior field,  outline the trace of the Tigris and Euphrates rivers with blue/green tinted epoxy, and mark Baghdad with a plug or stone of some sort.  Detachable legs will cut on the APO shipping costs to my successor in the job.  I know there are a lot of issues related to the war in Iraq and would prefer this not become a political thread; after a year standing shoulder to shoulder with this man in a combat zone, he is my brother.

Thanks.

//s//

Bill.

 

[Frans]

First off, I hope I understood what you're trying to achieve.

I'd make two templates and stick these on the tabletop with doublesided tape. Mount a copying ring in your router and blaze away. The space between the two templates should be the required groove width minus the bit thickness plus the outer diameter of the copy ring. Fix up the corners width a chisel.
I hope the included drawing makes it clear.

Frans

 

[nickao]

First off, I hope I understood what you're trying to achieve.

I'd make two templates and stick these on the tabletop with doublesided tape. Mount a copying ring in your router and blaze away. The space between the two templates should be the required groove width minus the bit thickness plus the outer diameter of the copy ring. Fix up the corners width a chisel.
I hope the included drawing makes it clear.

Frans

That is a really good way to make it. I like your drawing!

Nickao

 

[Brice Burrell]

Bill, I'd use the MFS to make a template.

 

[Frans]

That is a really good way to make it. I like your drawing!

Nickao

Wanna buy the copyrights? ;D

 

[nickao]

How about a pat on the back for helping a newbie. I'll post pics of a simple way to make the template without a fancy jig. You can easily only use one of the two template pieces, you do not need both .

It is much simpler to make the center template piece. Then if you want the negative image you can use the positive image as your guide to make the negative image with a router.

Or just use the center template  affixed to the wood you are cutting(also fixed down) and cut around it with a router, pop the top template piece off and clean up the tips with a chisel.

Nickao

 

[H12]

Ahh....

I had gotten so fixed on using the inner template that I hadn't considered the advantages of using an outer template. 

In practice with the inner template, I was having problems going around the tips of the stars without periodically "jumping" off the template a bit on the tip thereby ruining it  - and with 8 of them to trace, the odds of getting all of them flawless was getting pretty small.  I think the outer template will solve some of those problems.

I do appreciate the assistance of a variety of individuals, and I look forward to posting a picture of the project upon completion.  Heck, I might even get a picture of BG Kareem drinking chi from it in his office if I'm lucky.

VR.

//s//

Bill.

 

[johne]

maybe a stupid question but if you use a template outer or inner you can use a chisel to straigthen the points of the star
but wont the inside corners (marked with the red dot on pic) be rounded too? How do you clean these up?

 

[nickao]

maybe a stupid question but if you use a template outer or inner you can use a chisel to straigthen the points of the star
but wont the inside corners (marked with the red dot on pic) be rounded too? How do you clean these up?

No the corners you marked can come out pointed. Image cutting a line with a router, then cutting a 45 degree line right through it. That will leave you a tip of a triangle beneath the intersection of the two lines. Even if it is rounded ever so slightly it will not be to a point that is detrimental.

If you really do not want it rounded at your marked point use a flush cut bit with a bearing to ride the outer template. The point opposite your mark will be rounded because the entire cut of both the left side and right side of the round spinning bit does not pass through the entire width of both lines.

Am I making sense to you?

I need to take a pic or two to make the explanation simpler.

I tried to explain it in words and I can not write a short concise answer to convey the concept. Somebody else maybe can put it in words.?

Nick

 

[johne]

Nickao, I am still racking my brain over your explanation, maybe a square outer template would work also, easier to make but harder to route. Route the corners
rotate template 45 degrees route 4 more corners. Inside corners would be straight outside corners can be chiseled. Maybe  a bit tricky?

 

[johne]

to clarify last post

 

[nickao]

to clarify last post

Well this pic shows outside intersection of the inside points, the side toward the outer template, will be pointed , while the inner points will be humps. And vice versa for the outside tips, Nice.

 

[spikfot]

Nickao is right, In the template scenario the outside corners will remain pointed. in application, you must read the grain closely.    sometimes it is best to stop and replunge as opposed to round corners.  spiral bits are best .  the sharper an outside corner is, the easier it can blow out.    One can also cut a strip of  hardwood a hair under your jig/cutter offset and use it as jig to pre cut/backcut the points with a  razor edge,
     

  Hope i'm not repeating what you allready know. 

 

[Eli]

I commend you Bill, for your efforts to remain close to a person, not politics.

May I humbly suggest that since it was two side tables you ate off of, should it not be two side tables that replace them? Since the star has eight points, which are two rectangles overlaid, could you not visually make the same symbol with two stacking tables easily?

Otherwise, I'd stop after the walnut inlay, and not place the country, rivers or Baghdad marker. It will have a much more timeless look. I'm only offering my opinion, don't mean to offend. 

 

[H12]

Eli:

I can hardly take offense when someone comments on design!  In fact, I like the idea of a pair of table - perhaps it will be one of each.  I certainly agree that just having the 8 pointed star will be more timeless; I have to admit to a little vanity and desire to do some things I haven't done before on the more extensive design.

I'm currently planning on using a single, outside, 90 degree template with stop blocks to route the inlay.  I will test out my ability to lay it down on a line and cut to the inside corners, then pick it up and repeat seven more times.  I think I'm a little too cheap to buy enough MFS components to have a set up that completely captures a copy ring without any slop, though now that I think about it, I don't know why I don't build the jig that way anyway.... hmm.

Still, it's been sweet just to have my hands on the tools (Festools in particular) after a long absence.

VR.

//s//

Bill.

 

[nickao]

Have fun!