Flat part on router base

[Joe Scharle]

Anyone have any idea why the newer bases are not completely round?

 

[Keye]

Hope someone knows because I have also wondered the same thing.

 

[Bas]

Just a guess: To make it easier to guide it along a straight edge?

 

[thrt15nc]

Let me take a guess at this. If you're routing a dado up against a guide using a router with a round base and the bit isn't perfectly centered to the base, AND you rotate the router a little, it could go out of it's straight line. If you use one with the straight side to the base you'll keep the router in the same placement and you won't have that problem?? Okay, I'm ready. Beat me up!:gar-La; Am I hallucinating?

Tom

 

[Joe Scharle]

I know from use that there's more friction with the flat against a fence. And if the flat moves just slightly away from flush, the bit will swing greatly off track. But if a point on the round base is used as a reference, then less friction and the reference is more forgiving. In fact, I add a round base to my routers that have the flats.

This jig is the main reason I like a round base. The 2 fences are squeezed against a sample of the piece that will fit into the resultant dado regardless of it's thickness. I like to run the router down & back without having to rotate the router, cord & vac hose. BTW, this pic shows the setup for a rabbet, but dado or sliding DT the is same.

 

[McRabbet]

I agree with Joe that is it easier to control round bases for accuracy -- I've had plenty of routers and my only ones without round bases are the little ones (a P-C Trim router and a Trend T3).

 

[Joe Scharle]

Bump

 

[thrytis]

I always thought it was because bases usually aren't perfectly centered, as Tom mentioned. I know i have run into problems before when i've used different points on a round base to guide the router along a fence.

 

[Keye]

I agree with Joe that is it easier to control round bases for accuracy -- I've had plenty of routers and my only ones without round bases are the little ones (a P-C Trim router and a Trend T3).

Funny, the only router I have that does not have a round base is my largest router, 2.5 hp.

 

[Gotcha6]

I think Tom has a valid point about some routers not being perfectly centered on their bases. The downside I see is when you may need to rout to a right angle & turn, you'd overshoot your line on the next cut. It shouldn't be a problem to rout against a circular base & straightedge as long as you aren't twirling the router around and around as you make the cut.
The flat could also be used to cut a dado wider than the bit if the difference between the 2 distances was within the limits and tolerances of what needed to be cut. Just make 1 pass on the flat and another on the circle.

OH! I just thought of the REAL reason. So's you can lay it down on its side & it won't roll off the table!:gar-La;

 

[Alan in Little Washington]

Tom and Dennis

OH! I just thought of the REAL reason. So's you can lay it down on its side & it won't roll off the table!:gar-La;

have it right. Some routers do not have the ability to center the bit.

By the way, you are missing out if you don't have a centering pin. A couple of places sell them. The one I like from Lee Valley has a 1/4" shank on one half and a 1/2" shank on the other. They are good for aligning the bushings and base (if he collars fit tight)

Woodcraft sells this:

Woodworker supply sells this:

I use this one from Lee Valley:

 

[Joe Scharle]

I just asked a sales clerk, and here's the answer. "It's so you don't put the black piece on backwards".
SPARE ME!

Was hoping CharlesM would chime in with a believeable answer.


My big Milwaukee has a round base, my DW625 and Freud2200E have a flat on the base. My small Sears have round bases and the GMC has a flat on he base.

 

[Travis Porter]

How does having a flat keep you from putting the black piece on backwards???:icon_scra

I had never thought of so it doesn't roll off the table. That does make sense, but I don't think I have had one of my round ones roll off anyway. It seems the handles stick out too far to let that happen.

 

[Alex Franke]

Is it a plunge base? My guess is that it provides more friction/accuracy when you're plunging a hole while holding it against a straight edge. You don't want to router to rotate at all along the straight edge when all you want is a hole...

I would center the bit and use the round part to glide, though.

 

[Gotcha6]

I just asked a sales clerk, and here's the answer. "It's so you don't put the black piece on backwards".
SPARE ME!

If you're in the standard BORG the only thing you can find out from a sales clerk is where the restroom is & I already know that real well.:gar-La; I can read the box.
I find customer service in those places nonexistent. I will say that Lowe's has most of their sales clerks trained to tell you which aisle something is on -but they won't take you to it.
Maybe the correct answer to Joe's question is so they could get more bases outa one piece of plastic.:icon_scra

 

[junquecol]

I use this one from Lee Valley:

When I took machine shop, I made several of those. It's an easy turning project.

 

[jeff...]

It's might be something to do with plunge base - I have this Bosch set the plunge base has a flat but the fixed base is round.

but then again my old maktia 3612BR plunge router has a round one.

so the answer is :dontknow:

 

[thrt15nc]

Sorry if my answer sounded flippant Joe, didn't mean it to.

My first router, still have it and it still runs, is a Sears Craftsman from the early 70's. At the time I had no idea what I was doing and I experienced exactly what I described trying to build a set of garage shelves. The bit was so off center and I was turning the router so much while using it that the shelves wouldn't align in the dado. I placed a reference mark on the base to aid me in keeping it "to the edge" so I wouldn't have that problem. Now with my Dewalt, I can center the bit, know not to rotate the router and have better success.

Tom

 

[skysharks]

Very good Question. At First I ignored this post:slap:.
Sorry Joe won't happen again.
But I did go out and check my routers. of the the four that I have It's an equal mixture of flat and completly round.
You got me.
But also got me thinking.

 

[Alex Franke]

But I did go out and check my routers. of the the four that I have It's an equal mixture of flat and completly round.

Are they also only on the plunge bases? I'm convinced that it's there to help make plunged holes more accurate...