Router Planing Fixtures

[mistermikev]

This one: https://www.amazon.com/gp/product/B000K2G1WE/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Looking forward to trying it.

right on, that's the one. I use the 1/2 shank 3/4 version of that all the time. used it to do control cavities even because it leaves a nice little rim at the bottom. whiteside is the stuff for sure. used that bit all over the place for quite a few guitars and still nice and sharp. worth every penney.

 

[rudy4444]

Nobody's using the Infinity router planer bits that Nick Offerman uses to create his live edge tabletops?

Mega Dado and Planer Bit - FineWoodworking

Infinity offers smaller versions, the 1-1/2" diameter is less than $50.

Slab flattening article from Infinity's website:

[Invalid or Expired Link Removed]

 

[Gilmourisgod]

I've decided to build a sled using 1-1/2" x 1/8" aluminum angle, I wanted something lighter than a wood box sled design, as it only gets used occasionally. Are there any special considerations using a sled to plane thin stock, like 1/-8" to 3/16" for thinks like cavity covers? I tend to use double-stick tape to fasten things, but it's not entirely trustworthy, and I'm worried about breaking thin stock prying it up off the table when I'm done planing it to thickness. A vacuum table is one obvious solution, but I won't use it enough to justify the expense or build time. Suggestions for fastening down thin pieces, any different bit type required? I could potentially do this by mounting thin stock to a sacrificial board and running through my thickness planer, but I'm afraid it might snipe or tear out and destroy the wood.

 

[Bruce Johnson]

I've decided to build a sled using 1-1/2" x 1/8" aluminum angle, I wanted something lighter than a wood box sled design, as it only gets used occasionally. Are there any special considerations using a sled to plane thin stock, like 1/-8" to 3/16" for thinks like cavity covers? I tend to use double-stick tape to fasten things, but it's not entirely trustworthy, and I'm worried about breaking thin stock prying it up off the table when I'm done planing it to thickness. A vacuum table is one obvious solution, but I won't use it enough to justify the expense or build time. Suggestions for fastening down thin pieces, any different bit type required? I could potentially do this by mounting thin stock to a sacrificial board and running through my thickness planer, but I'm afraid it might snipe or tear out and destroy the wood.

It's tricky to hold down thin pieces while router-planing them. Tape is problematic. A vacuum table is probably the best choice if you are going to do a lot of them. Rob Allen uses custom vacuum fixtures in his CNC machine to hold down thin cover plates as he mills them to thickness and shape.

One trick I've used for one-offs: Make the board oversize and screw it down in the four corners. Then rout the center area down to the desired thickness, leaving the four corners untouched. Unscrew it, and bandsaw off the corners. Be careful not to allow the wood to heat up during routing, or it may buckle upward in the middle.

 

[MovinTarget]

I've decided to build a sled using 1-1/2" x 1/8" aluminum angle, I wanted something lighter than a wood box sled design, as it only gets used occasionally. Are there any special considerations using a sled to plane thin stock, like 1/-8" to 3/16" for thinks like cavity covers? I tend to use double-stick tape to fasten things, but it's not entirely trustworthy, and I'm worried about breaking thin stock prying it up off the table when I'm done planing it to thickness. A vacuum table is one obvious solution, but I won't use it enough to justify the expense or build time. Suggestions for fastening down thin pieces, any different bit type required? I could potentially do this by mounting thin stock to a sacrificial board and running through my thickness planer, but I'm afraid it might snipe or tear out and destroy the wood.

I've only made one vacuum table and I went big (2' x 4') and plenty deep to clear a hole for the vacuum on the side. FWIW, it too less than a day on my first try.

What I'm getting at is you could make one much thinner (top to bottom) if you want to put the vacuum port on one of the facing sides. Then it could be 2-2.5" inches thick and very easy to stow away. Use 3/4" mdf for the internal supports and frame and use 1/2" MDF for faces?

 

[MovinTarget]

It's tricky to hold down thin pieces while router-planing them. Tape is problematic. A vacuum table is probably the best choice if you are going to do a lot of them. Rob Allen uses custom vacuum fixtures in his CNC machine to hold down thin cover plates as he mills them to thickness and shape.

One trick I've used for one-offs: Make the board oversize and screw it down in the four corners. Then rout the center area down to the desired thickness, leaving the four corners untouched. Unscrew it, and bandsaw off the corners. Be careful not to allow the wood to heat up during routing, or it may buckle upward in the middle.

What it the board you are mounting onto was... waffled? I don't know the term, but that it essentially has large enough holes that you could use use a craft glue gun to glue the underside of the piece to the mount through these openings... That may keep the center from vibrating/buckling too much... if that makes sense at all...

 

[Gilmourisgod]

It's tricky to hold down thin pieces while router-planing them. Tape is problematic. A vacuum table is probably the best choice if you are going to do a lot of them. Rob Allen uses custom vacuum fixtures in his CNC machine to hold down thin cover plates as he mills them to thickness and shape.

One trick I've used for one-offs: Make the board oversize and screw it down in the four corners. Then rout the center area down to the desired thickness, leaving the four corners untouched. Unscrew it, and bandsaw off the corners. Be careful not to allow the wood to heat up during routing, or it may buckle upward in the middle.

This is definitely in the "0ne off" category, or at least the Occasional Use category, screwing it down in the four corners and then just avoiding those areas sounds right up my alley. Thanks @Bruce Johnson!

 

[Gilmourisgod]

I've only made one vacuum table and I went big (2' x 4') and plenty deep to clear a hole for the vacuum on the side. FWIW, it too less than a day on my first try.

What I'm getting at is you could make one much thinner (top to bottom) if you want to put the vacuum port on one of the facing sides. Then it could be 2-2.5" inches thick and very easy to stow away. Use 3/4" mdf for the internal supports and frame and use 1/2" MDF for faces?

What it the board you are mounting onto was... waffled? I don't know the term, but that it essentially has large enough holes that you could use use a craft glue gun to glue the underside of the piece to the mount through these openings... That may keep the center from vibrating/buckling too much... if that makes sense at all...

What is your vacuum source, does a shop vac produce enough downward force to hold, or is it a compressor?

 

[Jon Clegg]

Well, you might try a variation on the blue tape and CA trick that some use to attach templates. In this case, you'd apply blue tape to the base of the sled and to the underside of the stock. Use a few drops of CA on the tape to attach the piece to the base.

 

[Bruce Johnson]

What it the board you are mounting onto was... waffled? I don't know the term, but that it essentially has large enough holes that you could use use a craft glue gun to glue the underside of the piece to the mount through these openings... That may keep the center from vibrating/buckling too much... if that makes sense at all...

Yeah, that might work. If you could lightly press the wood against the fixture surface while you applied hot glue from the bottom through the holes. As long as you could get the hot glue to pop loose after routing, without damaging the thin wood. An interesting idea.

 

[MovinTarget]

What is your vacuum source, does a shop vac produce enough downward force to hold, or is it a compressor?

My first vac was a $29 "Buckethead" from Home depot and it worked great until it died. But if you cover all the holes you don't need some massive vacuum source.

 

[MovinTarget]

Yeah, that might work. If you could lightly press the wood against the fixture surface while you applied hot glue from the bottom through the holes. As long as you could get the hot glue to pop loose after routing, without damaging the thin wood. An interesting idea.

I've used cheap craft glue and that might be the key... you don't want it to be TOO good. If its a hardwood, I think it'd be fine, even with MDF I can usually peel it off w/o too much fuss...

 

[dwizum]

Make the board oversize and screw it down in the four corners. Then rout the center area down to the desired thickness, leaving the four corners untouched. Unscrew it, and bandsaw off the corners. Be careful not to allow the wood to heat up during routing, or it may buckle upward in the middle.

That's how I'd done it in the past, and the buckling I got was the reason why I made the little vacuum jig I posted a number of pages back. I got sick of plates coming out all wavy!

The vacuum jig can be as small as you want it. Mine was basically 100% scraps of mdf, maybe $10 worth, and it took 2 or 3 hours to put together. I used a "buckethead" style shop vac too - just about any shop vac will be more than enough suction, especially if you're only working on small panels.

 

[Bruce Johnson]

Well, you might try a variation on the blue tape and CA trick that some use to attach templates. In this case, you'd apply blue tape to the base of the sled and to the underside of the stock. Use a few drops of CA on the tape to attach the piece to the base.

That's another interesting technique that I haven't tried. But it sounds like it would work. Cover the underside of the wood with blue masking tape, and then glue the tape down to the fixture surface. The tape's adhesive is all that touches the wood.

 

[Bruce Johnson]

Rob's vacuum fixtures are surprisingly simple. He makes them from some kind of plastic blocks; I forget what the material is. About an inch thick. To hold down, like, a cover plate, he draws the outline of the part on the surface. Then he uses the CNC to rout a worm-like path all around the inside area. Around near the perimeter and back and forth in the center. Like 1/4" wide x 1/4" deep. Not a big pocket; just a zig-zag path that is all connected together. Then he drills a 1/4" hole from the worm path out through one side of the block, taps threads in the hole, and screws in a brass barb fitting.

A small rubber hose plugs onto the barb fitting and runs up to a small vacuum pump sitting up on top of the CNC machine. Teed into the front of the vacuum pump is a small ball valve, which can be opened as an exhaust port, and a vacuum gauge.

In use, the plastic block fixture gets clamped in the vise of the CNC. Plug the rubber hose on the fitting. Turn on the vacuum pump with the exhaust valve open. Lay the wood blank down on the fixture, lining it up on the Sharpie outline. Close the exhaust valve and watch the vacuum gauge until the vacuum reaches a certain level. Punch the Go button on the CNC. When the part is done, open the exhaust valve, lift the part out, lay the next part down, repeat.

The vacuum pump will pull higher levels of vacuum than a shop vac, so you don't need as much surface area to get the holding force. And, cutting the worm-style troughs minimizes the air volume inside the fixture. That minimizes the time it takes for the pump to lock the part down. If I remember right, Rob's fixtures were pulling down tight in just a few seconds.

 

[Gilmourisgod]

Well, you might try a variation on the blue tape and CA trick that some use to attach templates. In this case, you'd apply blue tape to the base of the sled and to the underside of the stock. Use a few drops of CA on the tape to attach the piece to the base.

I keep seeing reference to CA Glue/masking tape trick, and have yet to try it, but I'm wondering why that is any more reliable or less difficult to remove that double-stick tape? Is it because the masking tape has less tack, and is therefore easier to remove?

 

[Jon Clegg]

I keep seeing reference to CA Glue/masking tape trick, and have yet to try it, but I'm wondering why that is any more reliable or less difficult to remove that double-stick tape? Is it because the masking tape has less tack, and is therefore easier to remove?

Yes. Blue-tape pulls off much more easily that double-stick and doesn't leave the residue.

 

[John_Nicholas]

I keep seeing reference to CA Glue/masking tape trick, and have yet to try it, but I'm wondering why that is any more reliable or less difficult to remove that double-stick tape? Is it because the masking tape has less tack, and is therefore easier to remove?

The first place I heard of this method was the Crimson Guitar videos.


Honestly haven't tried it on something small and thin like a cavity cover.

But a vacuum table seems pretty easy to make. Actually not very much different from the Downdraft sanding table I made a few years back out of scrap. I use my 1 hp dust collector for this, which I think would have more suction than a shop vac??

 

[Bruce Johnson]

I use my 1 hp dust collector for this, which I think would have more suction than a shop vac??

No actually not. A dust collector has higher air flow than a shop vac, but lower suction (usually).

 

[John_Nicholas]

No actually not. A dust collector has higher air flow than a shop vac, but lower suction (usually).

I was pretty sure I was wrong, thank you for clarifying and correcting my incorrect assumption!

 

[Beej]

Re: the superglue/masking tape trick and thin pieces. Yes this works much better than using double-sided tape. Due to the strong tack of most DS tape, I've broken some thinly routed pieces when taking them off. Thin being 1/8" thick or thinner. When laying down masking tape on the router template surface as well as the work piece and using superglue, the bond is more than strong enough to hold during the operation, but the tack is low enough that you can peel the work piece off the platen without damage when you're done. Then after it all comes up, you can peel the tape off the work piece. I've successfully used this method to make veneers that are only 1.5mm thick.