Machine gloat

[Robert gree]

I have been looking for a dewault RAS but i wont complain about picking this gem up for 400.

I make repetive kerfs in MDF to make curved panesl sometime 60-100 cuts 3/8 apart. And this will be much better than doing it with a crosscut sled. AS well as cutting 2x12's for picnic tables.

http://i106.photobucket.com/albums/m244/F3RR3T_01/DeltaRAS1.jpg

[Michael Dunn]

Good find, so how do you quickly move from kerf to kerf? In other words, do you have some sort of a stop set up so you don't have to eyeball the 3/8"?

Thanx,

shotgunn

[Robert gree]

Good find, so how do you quickly move from kerf to kerf? In other words, do you have some sort of a stop set up so you don't have to eyeball the 3/8"?

Thanx,

shotgunn

i used to do this on the table saw. make a cut pull piece back move fence 3/8 repeat, I will be making some sort of stop i havnt figured that part out yet

[Chip Lindley]

WTG Robert! Nice RAS! A decent radial-arm is indespensible in the shop IMO.

[Michael Dunn]

The jig will probably be pretty detailed, but it should speed up you operation. The trouble is that you are not making a through cut.

The stop will obviously have to move. Perhaps you could make some sort of a 'toothed' piece of hardwood. Space the 'teeth' 3/8" apart. This would look similar to those wooden gates for keeping your dog out of the living room (or my kids out of anywhere room!!!) With each cut you could pull (or push, depending on your direction) the 'toothed hardwood' through a mating piece and hold it down with some type of latching mechanism.

Make sense?

shotgunn


i used to do this on the table saw. make a cut pull piece back move fence 3/8 repeat, I will be making some sort of stop i havnt figured that part out yet

[Robert Reece]

Nice RAS Robert. I go back and forth on whether I want a RAS or not.

For the 3/8" on-center kerfs. I wouldn't think they would have to be done to 0.001" accuracy since you are using them to relieve the back side of a curve. If that is true, then I would simply use a dedicated fence on the RAS that had two saw kerfs. One kerf would be for the blade, the other kerf would be offset 3/8" from the other kerf. Then you could simply eyeball it to line up the kerfs. If you needed more accuracy, you could make a little key that was a 1/64" narrower than your kerf and use that to line them up.
Actually, now that I think about it, instead of a 2nd kerf, you should glue a small finger into that second kerf. Make sure the front edge is rounded so it will slide easily into the MDF kerf. If that finger protruded from the fence 1/4", you would only have to pull that MDF forward a little bit, then over, then back to the fence. I think the key is to round the front of your finger.

[Michael Dunn]

A beveled key might be even better than a round over. It seems like that may be a bit easier to slide for the next kerf.

Just a thought.


Nice RAS Robert. I go back and forth on whether I want a RAS or not.

For the 3/8" on-center kerfs. I wouldn't think they would have to be done to 0.001" accuracy since you are using them to relieve the back side of a curve. If that is true, then I would simply use a dedicated fence on the RAS that had two saw kerfs. One kerf would be for the blade, the other kerf would be offset 3/8" from the other kerf. Then you could simply eyeball it to line up the kerfs. If you needed more accuracy, you could make a little key that was a 1/64" narrower than your kerf and use that to line them up.
Actually, now that I think about it, instead of a 2nd kerf, you should glue a small finger into that second kerf. Make sure the front edge is rounded so it will slide easily into the MDF kerf. If that finger protruded from the fence 1/4", you would only have to pull that MDF forward a little bit, then over, then back to the fence. I think the key is to round the front of your finger.

[Robert gree]

Hmm time to start looking for a blade

[Rick Markham]

How about a "fence" with a clamped stationary board, with two dowels sticking out of it (to prevent the top from rotating on a single dowel), then another board that rides on top with a stop extending out of one end with holes drilled every 3/8" apart, it can be as long or as short as you want to make it. cut a kerf, move the top part of the fence to the next stop then slide the workpiece. :D very simple.

I have another idea too, but it is a little more complex, it would involve the top board sliding on a cleat on the bottom board (bottom board has holes drilled every 3/8"), then you stick the dowel in at the next stop, Heck you could even spring load the stop, that way you don't lose your dowel. Since you will use it a bunch, that might be the ticket! actually would be pretty easy to make. Feel free to PM me if you want me to better explain myself ;)

[Robert gree]

How about a "fence" with a clamped stationary board, with two dowels sticking out of it (to prevent the top from rotating on a single dowel), then another board that rides on top with a stop extending out of one end with holes drilled every 3/8" apart, it can be as long or as short as you want to make it. cut a kerf, move the top part of the fence to the next stop then slide the workpiece. :D very simple.

I have another idea too, but it is a little more complex, it would involve the top board sliding on a cleat on the bottom board (bottom board has holes drilled every 3/8"), then you stick the dowel in at the next stop, Heck you could even spring load the stop, that way you don't lose your dowel. Since you will use it a bunch, that might be the ticket! actually would be pretty easy to make. Feel free to PM me if you want me to better explain myself ;)

I LIKE THE SECOND IDEA. Nice to know you are fairly local also im in ocala

[Rick Markham]

Nice to meet ya Robert! It's good to meet "local" folks around here! Let me know how the jig turns out! ;)


I LIKE THE SECOND IDEA. Nice to know you are fairly local also im in ocala

[Bob Carreiro]

You guys are getting way too fancy without the accuracy. There's a simpler method: use a "bowed stop-block" to easily and accurately repeat these kinds of cuts.

1. Cut a square 1" x 1" with a thickness just less than the width of a kerf cut so the square slides in and out of a kerf cut easily.
2. Attach it to a 1" edge of a 3/4" x 1" x 3" so it sits 1/4" proud along one face.
3. To the top face of the 1x3 (opposite face of 1/4" lip), along its length, attach a 1/4" strip of ply about 1" x 12" cut cross grain so its length flexes easily.
4. Attach the other end of the ply strip to the underside of a block that will clamp to you saw fence at a height that allows your boards to pass under it, while at the same time, puts a downward pressure on the ply strip to force the 1/4" lip at the other end into a kerf cut.
5. Make your first cut and slide your board to align it to the blade for the second cut.
6. Position the stop-block laterally so the 1/4" lip is forced into the kerf cut you just made and make your second cut.
8. Lift the strip up, slide the board and continue.

This is really easy to do and has many adaptations, but is difficult to explain w/o a drawing. I've used this "bowing stop block" for making datos - which is really what you're doing... yours are just "narrower" - and it works great. Hope this helps you.

[Van Huskey]

You guys are getting way too fancy without the accuracy. There's a simpler method: use a "bowed stop-block" to easily and accurately repeat these kinds of cuts.




That is a very cool and useful jig.

For the OPs thin "dado" metal might work better than wood and be more durable since it has to be thin.

[Richard Dragin]

Rick,
I would go outside of Robert's house and wait, you might get a free saw!

[Rick Markham]

Richard, LOL!!! I have neither the room, need, or the desire to own a radial arm saw... Now if anyone is gonna toss out a Euro slider I am more than willing to throw out all of my living room furniture to squeeze it in to my house :D

...didn't think so :p