RAS Top

I picked up a Dewalt 740 / 7740 RAS (the arm says 740, the base 7740). It needs a new top, but I expected that.

I'm planning on using 3/4" MDF with a melamine coating. I haven't decided whether to try a double-layer top right off, or go with just the one and get some experience. I'm leaning towards the simple single-layer design, then working on a more complex design after I get a feel for the saw. The frame is 20" wide.

How far can I extend the top without adding more support? I think 6" on either side would be ok, but would 10" work?

Puckdropper

Reply to
Puckdropper
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Sure, so would 20". So would 40". It doesn't much matter because whatever you are cutting is going to be supported by the central portion of the top and that is supported by the saw's frame.

If you have the room, the ideal (IMO) is side extensions that are about

10-12" wide and 96" long. The length is nice because RAS are basically crosscutting machines and the length lets you put a stop anywhere along it.

The table hanging out from the front of the saw doesn't need to be any wider than what the saw can cut. However, if you plan to ever cut anything wider by cutting, flipping over and cutting the rest, a table hanging over more can be handy...you can mark the trace of the blade on it and after you flip, line up the kerf with that trace.

Reply to
dadiOH

Melamine is a tad slippery for my taste, I'd stick with plain MDF. Even with a "try it out and see how it goes" top, I would add a sacrificial layer on top - quarter inch plywood, hardboard or luan. "Temporary" lash-ups tend to last longer than originally planned, and a new layer can be essential to a clean cut, acting much like a zero clearance insert on a table saw.

Lots of good tune up info available in the FAQ's here:

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Also lots of good knowledgeable people to answer questions in that forum.

Reply to
Larry Kraus

"Larry Kraus" wrote

Agreed, with the MDF as my first choice. I use two layers of 3/4" or 5/8" MDF. The top layer is the sacrificial, screwed onto the saw from below and through the bottom layer. The top layer can then be flipped over for a fresh surface, and the bottom can also be cycled up to the top. You can get

2 - 2' x 8' strips out of one sheet, and 4 fresh surfaces for the saw top, that way.
Reply to
Morgans

Larry Kraus wrote in news:F65Fv.493575$ snipped-for-privacy@fx23.iad:

I've got the Melamine, it's been waiting for a project. In this case, a material I already have is better than a material I'd need to buy. We'll see how that goes, though. I might have to make changes...

Good point about the temporary being rather permanent. I've been meaning to do a couple projects for some time now, but have others that are getting in the way.

I'm getting some good answers here. Looks like that forum requires registration to even read, which makes it hard to get in to.

Puckdropper

Reply to
Puckdropper

On 8/9/2014 12:18 AM, Puckdropper wrote: snip

Well, it is a moderated forum. Upside is the S-N ratio is pretty good, and I cannot blame my registration for any spam.

Reply to
Larry Kraus

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