SCMS cutoff bench - movable mini fence?

[Lynn Kasdorf]

After procrastinating about 10 years, I am finally building my cutoff bench fo rmy Makita 12" SCMS. Soon, I'll need to install a long fence and stop block system. I was planning on buying the Kreg system.

But I ran across this guy's system at lumberjocks:

http://lumberjocks.com/projects/39274

Basically, instead of a fixed fence on the bench, he inlays a long T-track where the fence would go. Then, he has a little sliding block that serves as a fence, and incorporates a flip-down stop for repeated cuts.

The big advantage is that the bench is flat and doesn't have a permanently mounted fence, in case you need that huge flat workbench area for some project.

So, I wonder if a short movable "fence" would work just as well as a long fixed fence. One advantage I can see is when trimming warped stock. A long fixed fence could be a disadvantage in this case.

Opinions?

[Brian Tymchak]

Interesting idea. first thought was about accuracy - wouldn't the T-bolts be a little sloppy in the track, potentially affecting the squareness of the piece wrt the sawblade?

[Bob Vallaster]

Lynn,

Clever idea.

Brian,

Good point. Perhaps fitting a tongue on the short fence to ride in the minor width of the slot? Or short tabs on each end? Either method could eliminate slop and prevent twisting if a single knob/lever is used to clench the fence tight to the table.

BobV

[Brian W Evans]

I like this idea quite a bit. One difficulty in building it would be keeping both sides of the t-track perfectly in line with each other. A fence can be adjusted much more easily than a t-track embedded in the surface.

How would you accomplish this? Would you have to account for wood movement, building movement, etc.?

My initial thought was that I could make the cabinet tops two layers, with the bottom layer attached to the cabinets beneath. The top layer with the t-track in it would be attached to the bottom layer with bolts in slotted holes to allow forward-backward movement to help align or re-align the t-tracks. It would also allow for the surface to be replaced easily if it were damaged. I can't help feeling that there is an easier way to accomplish perfect alignment, though.

[Lynn Kasdorf]

I have a an 8' track-clamp thing that provides a very accurate straightedge. I've been using it to span the gap and align my two benches. This could be used to align the T - track as well.

Actually, my plan is to use 3/4" ply on the benches and then cover with 1/2" MDF. T Track is 1/2 thick (I think? gotta check), so I would not have to rout a slot for the track. I' would just rip the MDF to the proper width (front of bench to track) and then use my big straightedge to align the pieces with each other. Attach the T track, butting against these 1/2" mdf pieces, then cut MDF pieces to go from the T track to the back of the bench. Edit: I'm seeing various thicknesses of t track. For my plan to work, I'd have to match up track thickness with MDF thickness.

I'm thinking that inlaying a T track would be a good idea no matter what type of fence I use. If I want a long fixed fence, I'd attach it using the T track so it could be removed easily.

Where is the best place to buy long sections of T track? Rockler sells 2', 3', 4' sections but it would be nice to have a seamless longer piece.