Top or Bottom Bearing

On the table, I prefer top-mounted bearings with my pattern/template atop the work piece. That way any excess bit is below the table instead of sticking out, menacing my fingers.

edit--*I guess in buying, it might officially be a "bottom bearing bit" that i'm using upside down? This is why I use pictures to order from!!

earl

In a table I'd definitely go with a bottom bearing (so the bearing is on top when inverted in the table) as Earl described, much safer.

They do make bits with both bottom and top bearings and if you are having problems with tear out you can route up to the grain change and flip the part lower or raise the bit to use the other bearing and finish cut the part.

Look at this post and the pictures I added, read my post for an explanation.

http://www.routerforums.com/router-bits-types-usage/33080-bit-use.html

The bearing on the top as the cutter is in the table is the most usual way.

Any roundover bit will come that way anyway.
But then if its a straight sided cutter, you have full adjustment on how much cutting edge is shown.

The only cutters i use in the table with the bearing at the bottom are slot or comb joint bits.

MEBCWD said:

They do make bits with both bottom and top bearings and if you are having problems with tear out you can route up to the grain change and flip the part lower or raise the bit to use the other bearing and finish cut the part.

Look at this post and the pictures I added, read my post for an explanation.

http://www.routerforums.com/router-bits-types-usage/33080-bit-use.html

Click to expand...

Do you mean one like this?
https://www.amazon.com/MLCS-Bottom-Bearing-Flush-Pattern/dp/B000LG98TC

Herb

AndyL said:

In a table I'd definitely go with a bottom bearing (so the bearing is on top when inverted in the table) as Earl described, much safer.

Click to expand...

Very confusing but I think I get it

Thanks

J

John Charnock said:

Very confusing but I think I get it

Thanks

J

Click to expand...

It is really quite simple if the router is hand held the bearing on the end of the bit is down so it is a bottom bearing.
If the router is in a table ,the bearing on the end of the bit is sticking up on the bottom of the bit , and the top of the bit is in the chuck of the router in the table.
Makes perfect sense.
Herb

Herb Stoops said:

It is really quite simple if the router is hand held the bearing on the end of the bit is down so it is a bottom bearing.
If the router is in a table ,the bearing on the end of the bit is sticking up on the bottom of the bit , and the top of the bit is in the chuck of the router in the table.
Makes perfect sense.
Herb

Click to expand...

It is simple but also confusing. Did I just say that!!! I think they should say the bearing on the (end) or in the (middle) or both. Would that help???

hawkeye10 said:

It is simple but also confusing. Did I just say that!!! I think they should say the bearing on the (end) or in the (middle) or both. Would that help???

Click to expand...

what makes it more confusing is that when hand routing the template is on the top of the work and when table routing th template is on the bottom of the work with the same bit. or vice versa with the bearing on the other end. My guess is the routers were originally designed to be hand held, and shapers were for table routing.

Herb