[since1492]

hi i will do my best explaining, I need to get a perfectly rounded end on a 2x4. is there a better way to do it than with a jigsaw? the jigsaw cut are not coming out perfect enough and are to hard. thanks. here a drawing of what i need.

 

[Stick486]

you say end...
is it really the edge and do you want a round over the the full thickness of the 2by???
how large is the piece??

at a guess from what you show/say you want a 1½'' radius router bit...
do you have a router??

 

[since1492]

yes the full thickness of the 2x4 and the image is a side view, and I've got 2 routers but can explain what a 1½'' radius router bit is and how it can help me? thanks.

 

[since1492]

I think I am starting to understand what you are saying. you mean I should route it from the top and let the router make the curve? that is brilliant! is that what you mean?

 

[MT Stringer]

How long is the 2x4? And you want to round over the entire length, right?

 

[Stick486]

I think I am starting to understand what you are saying. you mean I should route it from the top and let the router make the curve? that is brilliant! is that what you mean?

yup...
the bit looks like this....

..

 

[Stick486]

now we need more information as in details in order to help you proceed safely...

how long are the pieces???

 

[since1492]

How long is the 2x4? And you want to round over the entire length, right?

no the width. the 2x4 is about 3 feet long but I need just that end to be rounded. i will add dimensions to the image. this is an image of the side of the 2x4.

 

[JOAT]

I would likely cut it a tad oversize, then sand it to final shape.

 

[since1492]

so according to what I am understanding I will need a 3½ inch radius bit, correct? does that even exist?

 

[MT Stringer]

no the width. the 2x4 is about 3 feet long but I need just that end to be rounded. i will add dimensions to the image. this is an image of the side of the 2x4.

One last question...
Is this for one board or many?

I have done round overs like this by cutting with a jig saw first, then sanding smooth with a ROS. For a more heavy duty sanding job, a hand held belt sander and your skill at using it should be good enough. :grin:

In my case, I rounded the corners of the table top (see pictures). Similar but not exactly the same but you get the idea. Cut it close first, then sand smooth to the line.

 

[Stick486]

so according to what I am understanding I will need a 3½ inch radius bit, correct? does that even exist?

correct..
the bit, actually a cutter, does exist but that will take a shaper to turn it... not a router..
what you are showing is the face of the 2by and the ends...
the edge is 1½'' thick...

rough cut it to size and sand to final...
an ROS will do it...
as well as a disk, belt or drum sander...
a disk sander will do the best job..
2nd choice is the belt sander...
make the tool stationary and move/rotate the wood over the sanding surface...
all w/ a little practice you'll get what you are looking for...

 

[denis lock]

This is a job for a bandsaw (or a jig saw) and a disk or belt sander. You will NOT get a round-over bit with a radius of 3-1/2": that's a bit with a diameter of over 7". Instead of sanding you could pattern rout it. You would need a 1/2" collet router and a flush-trim bit with a cutting edge of 2". If the 4x2 is in fact only 3-1/2 x 1-1/2 you could do it in two passes: the first with the pattern and a pattern (shank-mounted bearing) bit with a 1" cutting edge and a second pass (from the opposite face) with a flush-trim bit.

Denis Lock - "Routing with Denis"

 

[MT Stringer]

I think this is the end result he is after.

 

[Stick486]

I think this is the end result he is after.

no...
he wants a 3½'' radius..
so that's edge to edge, not face to back as you show...
rotate it 90°...

http://www.routerforums.com/1673897-post8.html

 

[TenGees]

Maybe put two boards together and use a circle cutting jig for the jigsaw. Then sand 'em. ???

 

[Herb Stoops]

Use a template and a pattern bit. rough cut it 1/8" larger then finish with a router either hand held or a router table.

Industrial router bits-Pattern router bits, long series-CMT tools

http://www.cmtutensili.com/show_items.asp?pars=RB~7/8/906~2~2~3

Herb