# Insane router idea



## n00b (Oct 24, 2010)

I don't even own a router, but I'm thinking about buying one. In the meantime, I had an insane idea about how to make a bowl with a router. I'm interested in some feedback. 

The idea: I suspend the router from the rafters over my worktable with strong string, so it can swing in curved (spherical) pattern. And I sweep it through a thick slab of wood from all directions until I've carve out a clean dish shape. The result would be a sort of modern bowl that's just a cavity in a block.

Clearly this would be a misuse of the router. But would it work? Would it be dangerous? What kind of bit would I use? To be clear, I don't propose to let the router swing freely like a pendulum. I would move it in a slow, controlled fashion, using the string as a sort of "jig" to constrain its movement.

Crazy?

- Joe


----------



## Dcase (Jul 7, 2010)

There are ways to make a bowl with a router that are much safer and do work. I think there is a specialty bowl cutting router bit also…. However I have never done and don't know much about. I just remember seeing it in woodsmith or shopnotes magazine.


----------



## brianP (Oct 22, 2010)

Joe,

Consider that suspending the router so high above the workpiece creates a very long radius of curvature. That would have to be one big bowl you're making! And it also sounds extremely dangerous. Controlling the router safely as it passes through the range of thicknesses as it makes its curved passes over the flat workpiece will be more difficult than it sounds. I don't think it's a safe idea.


----------



## Chelios (Jan 2, 2010)

Funny that I had thought about this same idea before. I had seen a video by David Marks where he builds an mdf jig to route a sculpted bowl in a maple slab table that turned out really nice.

I thought suspending the router might be an easier way to accomplish the same effect.

I would say that your safety should be your first concern suspending the router. Also consider that the radius will be huge (not bowl like) unless the string is rather short.

good luck


----------



## TheDane (May 15, 2008)

Joe-It would be, IMHO, almost impossible to control and very dangerous.

The guys on the Woodsmith Shop TV show made a bowl with a router in season 3. Go to their website and you can download a PDF that details how they did it.


----------



## Chelios (Jan 2, 2010)

Joe

Check this video out. It may help you do something that is more controlled. It is the video I mentioned before.

http://www.diynetwork.com/videos/sculpted-maple-bowl-table/39695.html

Best


----------



## DanLyke (Feb 8, 2007)

I think it'd be worth thinking about hard linkages to control the router. The jig described in that video Chelios linked to seems like a good idea, but you could think of other mechanisms that would give you one axis of swing, maybe lockable rotation about that axis, that would let you only have to control one axis of movement at a time, and constrain the router if it got out of control. You don't want a mistaken climb-cut to turn into a router flailing around your workshop…


----------



## richgreer (Dec 25, 2009)

If you have experience with routers you will know that you are dealing with a lot of torque when you start it up. It will be hard to control.


----------



## shipwright (Sep 27, 2010)

Maybe a lockable telescopic pipe arrangement replacing the "string" and a ball and socket joint in the rafters and a good pre-planned escape route for when the aerobatics start. Sounds feasible to me…. if you want a four foot wide bowl. I like the outside the box thinking though.


----------



## bent (May 9, 2008)

have you considered just using a lathe? it might be too heavy to swing from the ceiling, but it would probably work.

sorry, i just couldn't resist.


----------



## miserybob (Jan 24, 2010)

Maybe I'm just tired, bent, but I'm still laughing at that one! Nicely played, sir!


----------



## JoeLyddon (Apr 22, 2007)

Go to WoodSmith.com…

They had a video not too long ago about doing just that… making a bowl with a router…


----------



## davidroberts (Nov 8, 2008)

chairmakers suspend a router on a pole from the "rafters" to gouge out seats. a pole gives you better control, consistency. of course I'm thinking of a shallow bowl, no matter the swing of the router.


----------



## n00b (Oct 24, 2010)

Thanks for all the replies!

I watched the video that Chelios recommended. That's a much more controlled approach - and of course it requires much more work! But the guy in the video mentioned something I hadn't considered: if you sweep the router across the whole diameter of the bowl, on one side it will be making a normal cut and on the other side it will be making a climb cut. That's the sort of think I wouldn't necessarily think about in advance, and I guess that's how you can get injured.

And since davidroberts said that chair makers already use this technique, I did some Googling and found a picture of a setup much like what I had envisioned: http://www.pelwood.com/MakingChairs.html

I think the lesson for me is that I certainly shouldn't be trying anything like this until I'm an expert in the normal use of a router! So for now I'll just hang a circular saw on a string and see how it goes.

Just kidding.


----------



## DanLyke (Feb 8, 2007)

But you can think about how you'd use a table saw at an angle to do a cove cut, and how a circular saw might be able to…

Hmmm… need some shop time…


----------



## bvdon (Feb 22, 2010)

THanks for that link, Joe… good one.

http://www.diynetwork.com/videos/sculpted-maple-bowl-table/39695.html

I am making a router pendulum jig right now. I have the router carriage portion done, just need to figure out how I want to make the frame that it swings from. I plan to use it to make concave cuts. First use will be on the edge of a cutting board for finger grips on each side. The trick will be how I secure the piece being worked on so it is centered and secure. I will post on my projects page and maybe make a video to show it's use.


----------



## knotscott (Feb 27, 2009)

I'd think it would be pretty easy to get a rope and the rafters to flex, leaving a rough cut. Add that to the fact that you're inexperienced, and I smell trouble.


----------



## 33706 (Mar 5, 2008)

I recall working in a sweat-shop plastics factory that made vacuum-molded swimming pools for small children. The trimmings were cut away with a stationary router that smoothed the cut edge as the pool itself rotated in a fixture. Then, they created a pool shaped like a little tugboat. The only way to trim the waste around the edge effectively was with a router suspended from the ceiling, with a pattern-following bit. It easily chewed through 1/4" thick polyethylene. Though, in your case, I'd look for some sort of gimbal device to suspend your router for making broad sweeping curves. I've seen them for bowl making, but not in several years.


----------



## TheDane (May 15, 2008)

American Woodworker Issue #152 ( http://americanwoodworker.com/blogs/resources/archive/2010/05/03/web-extras.aspx ) has an article that deals with a gimbal jig.

This one is similar to the one David Marks used in his video, but is used for chair seats. The principle is the same.

-Gerry


----------



## 33706 (Mar 5, 2008)

Thanks, Gerry!


----------



## JoeLyddon (Apr 22, 2007)

Yep, I would also go with other ways as posted.

I would NOT use "string" or "rope"... I would use Three chains…
... actually, I would NOT use any of that stuff…
... TOO dangerous & flimsy.


----------



## Loren (May 30, 2008)

I've made dished forms for putting curves in guitar backs using a router
jig with a 15' radius. At the time I used a steel cable (doesn't stretch
much) to draw the curve on a piece of hardboard. These days, computer
programs would make plotting the curve easier.

Once I was satisfied with my drawn curve, I cut it out and fixed it with 
a file. Then I used the hardboard as a template to route two guides for
my router to ride on when carving the dish. The guide was screwed to
a sheet of plywood and the dish was rotated on a center axis beneath
the guides.

The limit to doing this is in depth.

Another thing to consider is that a uniform curve is not a very interesting
shape for a dish, aesthetically speaking. I used the technique to make
a form to build something else (a guitar) that has structural need to
be curved, but the hollow forms are not very interesting from an artistic
point of view, and they were fairly time-consuming to make.


----------



## BobG (Apr 17, 2010)

Laies and Gentlemen!!! The first string router!!


----------



## DrDirt (Feb 26, 2008)

As others mentioned this isn't so optimal for bowls. This method is used by many for making dished forms like large platters, but I usually see a ball jig for dishing barstool tops.


----------



## Sarit (Oct 21, 2009)

I think I have a solution that may actually work!

Rather than using the string to support the router, use it as a limiter to the radius your router can move.
First, attach a large aux base to your router so that it doesn't dip into the bowl. Then attach the string to the part of the router that plunges up and down. 
When your router is in the highest postion, the string will have the most slack and therefore allow you to route the largest circle. As you plunge, your radius gets smaller. If you plunge and route in small increments then, you should have a reasonably smooth bowl.

You might want to start with a bowl making bit to hog out most of the material, then switch to a cove bit to smooth the ridges, but you'll probably have to adjust the string length after the bit change.

As others have mentioned the string and whatever it is attached to must not stretch/flex at all.


----------



## traupmann (Oct 8, 2010)

Why not take the 'sky hook' to your belt and fly about the shop? You'd be safer.

Everything stretches, routers are hard enough to control when you are only going in 2 directions on a solid foundation. With your idea, you'd have no consistent control. Instead of a hospital bill, you could get a CNC router, or have a wood-wright build you a really great jig.


----------



## 33706 (Mar 5, 2008)

To all the nay-sayers, let me say this: As I mentioned above it not only CAN work, but it does. The suspended router unit I mentioned above not only worked safely, it worked effectively. We were able to put a nice, smooth 1/4" round radius on the edge of those vacuum-formed polyethylene pools with that suspended router. It would be prudent to believe that anyone who thinks it impractical, has never had an opportunity to experience it oneself.


----------



## n00b (Oct 24, 2010)

Update from the original poster: I now have a router, and as expected, as a new woodworker I find that I need to ramp up slowly and deliberately. I experienced my first unintended climb cut, and I learned something. I experienced the problem of creating so much debris that it started to impede the bit, and I learned something there. So even though I might try this swinging router technique in the future, I won't do it any time soon.

In the meantime, I'm glad I sparked a debate. It means my question wasn't so dumb.


----------



## JoeLyddon (Apr 22, 2007)

nOOb…

Glad you saw the light…

Glad you asked… It was NOT a dumb/stupid question!


----------



## crank49 (Apr 7, 2010)

Been done with a jig that had a couple of 1×4s with a shaft and flange bearings on the top and a cross piece on the bottom made of 1/2" Lexan (kinda like a trapeeze). The router was mounted on the "Lexan seat". We used this years ago in a pattern shop to make some large radius shapes. The sides were split and lapped so we could adjust the length (radius).


----------



## docholladay (Jan 9, 2010)

I once saw a jig where a guy made a jig for hollowing out seats on bar stools. He had the router sanza base atached to what looked like a broom handle. He had made a clamp type mechanism that clamped the router. Anyway, it was attached in such a way as to allow the router to swing in an arc in all directions. I would not suggest using a string. That simplly is not rigid enough. That sounds dangerous.

Doc


----------



## DrDirt (Feb 26, 2008)

The seat shaping was shown in Fine woodworking - Brad Smith does this regularly - you see in the picture, that you route using a spiraling pattern from the outside in. 
His set-up is on a 4 foot shaft

http://www.finewoodworking.com/item/20832/brad-smith-story-of-a-stool
I would check out his slideshow, as there are a number of clever fixtures he shows to make his furniture.


----------



## JoeLyddon (Apr 22, 2007)

That shaft with a Ball at the end like a pendulum osunds like a safe way of doing it…
... very clever too.

Thank you.


----------

