How too router a circular disc?

[woodbloke]

One way of reducing (not eliminating) the risk of kickback when doing this taks is to make a curved fence.

Take a piece of 18mm MDF and bandsaw a curve out of it. The radius should be a tad bigger than your disk, and the cutout can be, say, a quarter of the size of your disk. A bit like someone has taken a bite out of the side.

In the centre of that curve, drill a hole big enough for your roundover bit.

Glue an upright to the straight side so you can clamp it to you router table fence.

Set its position so that the router cutter in in the hole and your workpiece contacts the router cutter bearing and the curved fence.

You can then rout away with considerably more support and control.

Cheers
Steve

Nice idea Steve, but I can't visualize this...pic perhaps? - Rob

 

[Steve Maskery]

Mutter, mutter, grumble, things to do, places to go, grumble, mutter, mutter...

Something like that, anyway.
S

 

[Mr Ed]

Personally I don't like bearing guided cutters and templates, so would not use the table.

Ed

In the trade Ed, they are the most used cutters, specially straights - Rob

Never having been in the trade I wouldn't know, but even if you are right in what you say, that fact alone doesn't necessarily make it good advice.

Ed

 

[woodbloke]

Personally I don't like bearing guided cutters and templates, so would not use the table.

Ed

In the trade Ed, they are the most used cutters, specially straights - Rob

Never having been in the trade I wouldn't know, but even if you are right in what you say, that fact alone doesn't necessarily make it good advice.

Ed

If you walk into almost any pro 'shop, you'll more often as not see dozens of templates hanging up...'specially true in places where chairs for example are done. Bandsaw the roungh shape, wack on the template and bearing cut to the edge. Although makers will have dozens of profiles at hand, they always (in my experience) have plenty of top and bottom bearing cutters at their disposal - Rob

 

[Chems]

Yes I agree with Olly and Jim here, hand held is the way to go. And you'll need to back route parts of it so you don't catch the end grain. Someone should do a little tutorial on this, cause although I can visualize it nearly in my head I couldn't explain it for the life of me!

 

[Harbo]

Steve - that was what I was effectively doing with the Woodrat - it did not stop the wood catching and whizzing round.

I did as Mr Ed better described with the wood held firm.

Rod

 

[Chems]

Yes nice idea Steve but I think in this instane your just jig crazy! One of the operations that is better to do hand held than mounted.

 

[Steve Maskery]

Chems, actually I agree with you, but my understanding was that he wanted to do it on the router table.

S

 

[Chems]

What would make your jig pretty good would be if you had some sort of rubber blocks on it to give you a big of grip. Stop the piece spinning away from you. Perhaps some high grit paper would be better as it would stop movement completely.

 

[jimi43]

Routing with a circle jig is all well and good for a circle but when you are trying to put a binding channel on a guitar body then you use a bearing guide...so I guess I am more used to using them.

The key with ANY routing is to take small passes...very small passes...and do it progressively. Think of it as a plane. You wouldn't try to shave off 1/2" of wood in one go so why expect a clean job just because it is a machine tool.

To do that much damage to the wood...and your fingers Harbo I would guess that the cut was far too deep. That being said...freehand is not advisable as I said earlier. Steve's jig is an improvement on my suggestion of running it up against a fence...in his jig...the fence is also the guide and the stabilising element but still use fine passes.

And...of course use a quality, sharp cutter. We have discussed this before about cheap cutters...and some poo pooed the suggestion that they were crap...well IMHO you pays for what you get...there is a reason expensive cutters are expensive...and still sell! I use CMT but there are many good ones out there.

Jim

 

[Harbo]

Jimi43 said

To do that much damage to the wood...and your fingers Harbo I would guess that the cut was far too deep.

No I was taking very light cuts - I had cut it quite close on the bandsaw and was using the approved Woodrat method - the timber rotating round a pin held on a timber support. The deep cut was caused when it had spun round violently and dislodged the support. My fingers were there supposedly controlling the rotation?
At that stage I was using a straight cutter - I was going to round it over later.
Having got Mr M's DVD I will make his jig for doing the first stage on my BS in the future.

Rod

 

[jimi43]

Jimi43 said

To do that much damage to the wood...and your fingers Harbo I would guess that the cut was far too deep.

No I was taking very light cuts - I had cut it quite close on the bandsaw and was using the approved Woodrat method - the timber rotating round a pin held on a timber support. The deep cut was caused when it had spun round violently and dislodged the support. My fingers were there supposedly controlling the rotation?
At that stage I was using a straight cutter - I was going to round it over later.
Having got Mr M's DVD I will make his jig for doing the first stage on my BS in the future.

Rod

Wow Rod...that is a huge amount of tearout. I see what happenened now..it turned into a deep cut pretty quickly!.

Yes...any fence -even a straight one...with little of the cutter poking out...will inherently prevent this grab.....Steve's is an even more secure refinement if you are just doing circles.

You were very lucky my friend...

Jim

 

[Mr Ed]

Keep the wood still and rotate the router is the easiest and safest way to do circles in my view. Thats how this was done;

I don't fancy holding the round bit of wood against the cutters rotation personally.

Ed

 

[wizer]

I can do better than that! :lol:

I think I'd also prefer to do it hand held. But preferable with a small router. The big triton (if that's what you've got), can be unwieldy routing small circumferences.