Router Planing Fixtures

[/\/\3phist0]

Yeah, I can totally see the usefulness of a sled using linear rails and just manually moving it along the rail path rather than trying to drive it. I know John originally started down that path and quickly fell down the world's deepest rabbit hole. But I think the linear rail would solve a lot of issues regarding rigidity and smooth operation while not solving that one issue of liberating every single dollar I've ever made in my life.

After I get done if it's successful.
I'll create a plan and parts list for others. Each rail set is @ 40 usd.
I'm not following the rabbit hole
Simple functionality, with stability and adjustability . I won't have to be as concerned about holding on to the router, the whirling carbide blades will be well away from tender flesh. Dust collection is designed in and the gantry will take little effort to guide. The blade will be able to be in an accurate perpendicular plane. No friction in guide slots, no chance of the sled going off the rail. No friction / guide surfaces to wear.

 

[dwizum]

And when you're done, it can be flipped over and used as a work bench, drafting table or to eat lunch.
Frikkin genius.

For real! If you had a teeny tiny shop, without much storage, you could just use the one table as your work bench - and then when you needed a router planing jig, you flip it over and put it on top of your work be....

...oh wait...

 

[rudy4444]

In my machine, I need the bridge to be heavy. When I'm making heavy cuts, the bridge is actually slightly floating and lifting up off the rails. I'm pretty sure that's why I was getting those slight steps in the surface sometimes. Experimenting with this rig has made me appreciate that there's some significant force and horsepower involved in routing a path 1 1/2" wide x 1/8" deep. It takes some muscle to pull the bridge along, and that same power is trying to lift the bridge up.

There's a reason why my big pin router has a 3000 lb frame. And why John has to pay attention to the rigidity of the frame of his CNC router. There are forces involved.

Watching the process of your new router sled I'm a bit surprised that the router slows down. I've posted my Safe-T-Planer photos many times, but it's surprising that the planer takes 2-1/2" wide passes by 1/8" depth and doesn't seem to slow down at all. The drill press motor is 3/4 hp, but I guess the physics of the actual cut is significantly different.

Here's a shot of free-handing entire slabbed walnut; you can see it's not a problem to make the passes.

 

[Bruce Johnson]

Yeah, I can totally see the usefulness of a sled using linear rails and just manually moving it along the rail path rather than trying to drive it. I know John originally started down that path and quickly fell down the world's deepest rabbit hole. But I think the linear rail would solve a lot of issues regarding rigidity and smooth operation while not solving that one issue of liberating every single dollar I've ever made in my life.

Yeah, except for one thing: Those linear bearings and rails are very (like, Very) sensitive to dirt and small particles. You must have good wipers and flex hoods on them to keep out the big chips. But even then, fine dust sticking to the rail can get in under the wipers, causing them to lock up solid. Then you have to disassemble them and wash them out.

I have personal experience building machines using linear bearings, back in my Corporate days, and they are troublesome in dirty environments. Like woodworking.

 

[/\/\3phist0]

Yeah, except for one thing: Those linear bearings and rails are very (like, Very) sensitive to dirt and small particles. You must have good wipers and flex hoods on them to keep out the big chips. But even then, fine dust sticking to the rail can get in under the wipers, causing them to lock up solid. Then you have to disassemble them and wash them out.

I have personal experience building machines using linear bearings, back in my Corporate days, and they are troublesome in dirty environments. Like woodworking.

Understand, and experience carries weight. I intend on having dust control as high priority. And compressed air to blow stuff clear, I have rubber wipers to keep most of the Schmutz off the rails.
The open ended rails make for quick easily assembly / disassembly.
I expect some issues and protocols that will need to be followed.

 

[MovinTarget]

Had just enough time to plane one of my joined maple boards. If the figuring weren't so different, you wouldn't be able to tell there is a seam!

I have 3 more to rough plane and then I can thickness plane them to uniformity.

About the only tweak left I really have to make is make the under side of my sled perfectly, uniformly smooth again, there are some slight bulges from when the screws went in. I might just glue some thin hardwood strip to the underside, not trying to add much thickness to the base, just enough that it's nice-n-smooth.

 

[MovinTarget]

Woot got the other three planed in 1.5 hours as rains were moving in and I work outside!

No swirlies! Almost dead smooth, I can clean up the rest with prep sanding for gluing.
The join lines are all clean and nigh-imperceptible!

Again thanks to all y'all for the ideas in this thread!

p.s. - The vacuum board is super helpful for moving quickly. Since all the boards were near identical in dimensions, I just used painters tape to cover the unused holes and quick swap/flip boards in no time!

 

[Bruce Johnson]

I finally got some time to make another Engineering Improvement to the Super Router Planer Fixture!

I had the problem with the notch bar dragging and jamming on the side rail. So I made up a new, improved notch bar, with a row of small ball bearings. The ball bearings are replacements for rollerblade and skateboard wheels. They are surprisingly cheap: A pack of 8 for $5 on Amazon. A good source if you need a bunch of ball bearings for a machine project. The bearings are about 7/8" OD x 8mm ID x 1/4" wide. Perfect for this application!

I cut a strip of maple and mounted the row of bearings with screws and washers and small bushings inside. I spaced them to leave a 7/16" gap between them. That's the earlier aluminum notch bar in front.

Here it is, mounted on the front of the bridge. While I was at it, I trimmed down the height of the left MDF side rail to get a little more clearance for the bearings.

It works beautifully. Now the bearings roll easily on the sides of the aluminum rail as the bridge slides on the top of the rail. No dragging or jamming at all, even when the bridge gets a little off of perpendicular. Problem solved.

I also cut the pass-through notches in the left rail wider and deeper to clear the bearings.

This machine is ready for some production work. I've got a stack of walnut AMB-2M body blanks waiting for it. The real job I built this machine for. A good test run to see if it needs any other future improvements.

 

[ardgedee]

Fun fact: Skateboard wheel bearings are what they used to make fidget spinners. When that fad died out warehouses in China were full of wheel bearings that nobody wanted to buy. And now they're very cheap.

You can get bearings even cheaper by buying fidget spinners in bulk and knocking the bearings out. They're just press-fitted, and some types of spinners have four bearings per unit.

 

[dwizum]

My bandsaw takes that same bearing size for the guides. Good news, they're easy to get in bulk and very cheap. Bad news, the lower bearings get so much dust on them, it goes through bearings faster than blades.

 

[chinjazz]

I finally got some time to make another Engineering Improvement to the Super Router Planer Fixture!

I had the problem with the notch bar dragging and jamming on the side rail. So I made up a new, improved notch bar, with a row of small ball bearings. The ball bearings are replacements for rollerblade and skateboard wheels. They are surprisingly cheap: A pack of 8 for $5 on Amazon. A good source if you need a bunch of ball bearings for a machine project. The bearings are about 7/8" OD x 8mm ID x 1/4" wide. Perfect for this application!

I cut a strip of maple and mounted the row of bearings with screws and washers and small bushings inside. I spaced them to leave a 7/16" gap between them. That's the earlier aluminum notch bar in front.

View attachment 4362451

Here it is, mounted on the front of the bridge. While I was at it, I trimmed down the height of the left MDF side rail to get a little more clearance for the bearings.

View attachment 4362452

It works beautifully. Now the bearings roll easily on the sides of the aluminum rail as the bridge slides on the top of the rail. No dragging or jamming at all, even when the bridge gets a little off of perpendicular. Problem solved.

View attachment 4362453

I also cut the pass-through notches in the left rail wider and deeper to clear the bearings.

View attachment 4362454

This machine is ready for some production work. I've got a stack of walnut AMB-2M body blanks waiting for it. The real job I built this machine for. A good test run to see if it needs any other future improvements.

Great change up with the bearings!

Anything to make it a less back breaking operation. The top sled is quite large and I’m sure this makes it glide nicely.

 

[chinjazz]

My bandsaw takes that same bearing size for the guides. Good news, they're easy to get in bulk and very cheap. Bad news, the lower bearings get so much dust on them, it goes through bearings faster than blades.

There are higher quality bearings that are sealed better - I think Bones Reds are, but that brings the price up.

 

[rudy4444]

Roller blade bearings have lots of good uses. I use two pair of them, each pair spaced apart by a washer, to make up the non-driven end of my fret bender. The washer is selected so the tang just fits between the pairs, the crown rides on the tiny radius of the outer race edge.

 

[MPU]

My pickup winder has roller skate bearings. They really are multi purpose bearings.

 

[Bruce Johnson]

Yes, roller skate bearings are very useful for all kinds of shop projects. They are a standard metric bearing size, 8mm ID x 22mm OD x 7mm wide. They are packed with grease and fully shielded against dirt. They are the same general form as the common industrial Machine Bearings aka Motor Bearings.

The roller skate bearings are cheap because they are made to lower tolerance levels. The final fit of the balls and races is much looser than common Motor Bearings. So, they have much lower load and speed capacity. They are good for maybe 100 lbs side load at 300 rpm. In comparison, the same size Motor Bearing may be good for 500 lbs at 3000 rpm. An expensive Precision Bearing of the same size can handle 2000 lbs at 20,000 rpm. That's what goes in the spindle of a milling machine. A $300 ball bearing.

The roller skate bearings are great for many of our light duty, low speed machine things.

 

[Bruce Johnson]

The Super Router Planer Fixture gets some production use!

Jeremy (aka Freekmagnet) came into the Lab this afternoon used it to thickness cut the poplar bodies and tops for three of his Sirena basses. This is the first use of the machine with the new ball bearing notch bar. It worked well. It took him about 15 minutes to do the front and back surfaces of each 15" x 22" board. He was able to get the thickness consistent to within about 0.005".

It slides smoothly, but he agreed that it is some physical exercise to pull that bridge back and forth. It would be cool to add some kind of power drive system eventually.

 

[Freekmagnet]

The Super Router Planer Fixture gets some production use!

Jeremy (aka Freekmagnet) came into the Lab this afternoon used it to thickness cut the poplar bodies and tops for three of his Sirena basses. This is the first use of the machine with the new ball bearing notch bar. It worked well. It took him about 15 minutes to do the front and back surfaces of each 15" x 22" board. He was able to get the thickness consistent to within about 0.005".

It slides smoothly, but he agreed that it is some physical exercise to pull that bridge back and forth. It would be cool to add some kind of power drive system eventually.

View attachment 4376608

haha yeah, I was actually pretty tired after planing six blanks. That fixture is heavy!

 

[MovinTarget]

haha yeah, I was actually pretty tired after planing six blanks. That fixture is heavy!

I don't have all the bearings and stuff and just let is free-slide on my rails and yeah, its a good upper body workout... but it also gets a very hard job done faster and easier!

 

[BishopJP]

Finally built myself a fretboard radius jig! apologies in advance for terrible pictures...

Based on the pics and descriptions Bruce has helpfully provided earlier in this thread, though not nearly as elegant as his.

I used clamps to squeeze the sides, compressing the blocks and holding the neck in place.
Here with the neck in the fixture...

As is usually the case, the process of assembling the fixture made me think of ways to improve the next one...

I do not have a function to raise/lower the central beam that holds the neck-blocks, so I used wedges to raise the neck to the appropriate height. I plan to build a height adjust mechanism, but it may be on the next iteration.

The radius sled is screwed together, still need to add some handles. At the moment, the router just drops in.

And the results...!

It works!

Thanks to @Bruce Johnson for sharing your fixture designs!

 

[eddododo]

The Super Router Planer Fixture gets some production use!

Jeremy (aka Freekmagnet) came into the Lab this afternoon used it to thickness cut the poplar bodies and tops for three of his Sirena basses. This is the first use of the machine with the new ball bearing notch bar. It worked well. It took him about 15 minutes to do the front and back surfaces of each 15" x 22" board. He was able to get the thickness consistent to within about 0.005".

It slides smoothly, but he agreed that it is some physical exercise to pull that bridge back and forth. It would be cool to add some kind of power drive system eventually.

View attachment 4376608

I could picture integrating drawer slides, or even strips of ball bearings to make the friction negligible.. that way the only real force is the inertia in the horizontal plane..

I have some drawer slides from large production printers that are extremely flat and rigid that I’ve used for jigs and router lifts that would work great for this.. been meaning to get around to making a more sophisticated router planing jig