Hold down alternatives

[MikeDe1025]

I'm looking for some clamping alternatives that will NOT be above board. Either something home made or purchased is fine. What are you guys using?
If it matters, I have the smaller 13" table (I believe) which is made out of MDF.

Thanks,
Mike

[milo30]

When I do not want to use clamps I use screws. Brass screws are good in case your bit hits one. I also sometimes make a jig out of plywood strips. Simply 2 vertical and 2 horizontal. I usually build it in a u shape then slide my workpiece in then use clamps to attach the 4th side to hold the workpiece.

There are several thin clamps others have made. Might try running a search

[Bob]

Mike,
Would this idea help you?
http://www.cncsharktalk.com/viewtopic.p ... lamp#p3138
Bob
and a little more... http://www.cncsharktalk.com/viewtopic.p ... 3&p=84#p84

[MikeDe1025]

Bob, thanks, I have no need for the repeatability though. However, I think in my mind now I can do some sort of take-off of that idea.

Milo-----I like your idea as well.

Bob, while I was following your links around one of them led to me youtube and I saw this little setup. I liked it so well I thought that I would go ahead and link it back to you guys. Check it out.

https://www.youtube.com/watch?v=WmCzWHU ... re=channel

Thanks again, guys,
Mike

[Ner]

I've been pin nailing to a sacrificial board that works really well. Holds really well and removes easy. Otherwise Rockler has some new clamps that push into stops, which will allow you to have nothing on top. They can even push corner to corner.

[rsetina]

Ner,

I saw those at Rockler and found that they didn't have the downward pressure needed to keep the workpiece flat on the table. When I clamped them onto the wood they had there the workpiece lifted up.

[MikeDe1025]

Ya, that downward pressure is an issue all in itself. As your piece loses more and more wood from the carving, it wants to warp and if it's allowed to warp while running then you can pretty much ruin your project because the "Z" 0 will no longer be constant across the board. Even thinking now about the ones I reposted from a youtube video, I have to rethink those now on account of what I just said about downward pressure. In the video the guy was only cutting keyholes in small pieces of wood.

The idea of pinning down your piece onto a sacrificial board I suppose will work but I'd like to have something a bit better than that.
A vacuum setup doesn't really seem to be that easy to do either. Hmmm, I imagine I could screw the work piece to a sacrificial board from the underside of that board and into the underside of the work piece as well thereby eliminating the screw head on the top of the piece. Then clamping with side pressure and no downward pressure seems like it would work in that kind of instance. (Thinking out loud here)

Thanks again guys,
Mike