leveling work bench/router table - novice question

[Dave Lame]

I have an excellent workbench. Want to build router table at exact (+/- .002) same height. Router table will be on casters. What is best method of fine adjustment to bring router table and workbench to same height?

[Jamie Buxton]

You could use leveling casters on the router table. Leveling casters include the caster wheel and an up-down jack. Google that term if you don't recognize it.

But if you really need +/- two thousandths, I think you'll find the leveling casters frustrating. To achieve that precision, I think you'll need to re-adjust the casters each time you move the table. Instead, I'd build some scheme on to the workbench that positively and repeatably holds the router table, and does it to that precision. The router table also has some casters on it so you can roll it around, but they don't support the table when it is hooked to the bench. You might need to lift the table a bit to get it to engage the workbench as you roll it into place. The holding scheme could be a cleat on the side of the workbench. Or it could be arms sticking out from the bench to support the table in exactly the right position.

[Charles Lent]

+-.002" ?? Really? Wood can change in thickness more than that from day to day due to moisture changes in the air. If you want it that precise you had better make them both from aluminum jig plate and have alignment pins and clamps to lock them together.

[Doug Hepler]

Dave,

The way to do this is to make the router table the height you want. (I can't address the tolerance you want to achieve.) Then attach the kind of mobile base that raises the table to move it and then lowers it back on its own feet. (These could have adjustable levelers on them if you like) Many vendors sell these, I think, but they are not hard to make. You buy the foot lever for one end and install wheels on the opposite side, just touching the floor. When you raise one side with the foot lever, it tilts the table just enough that the wheels raise the other side. It this isn't clear write again. 329723
You could use two of these: http://www.amazon.com/WORK-BENCH-CASTER-SET-PKG/dp/B00CPTFQ58
Here are two more ideas from Chris Schwarz http://www.popularwoodworking.com/workbenches/schwarz-workbenches/the-easiest-way-to-make-your-bench-mobile
http://www.popularwoodworking.com/workbenches/schwarz-workbenches/making-workbenches-mobile-and-immobile
Doug

[Andrew Pitonyak]

I bolted one to a table saw at the correct height, then I used the adjustable legs to lower the feet until they supported the table correctly.

[Keith Weber]

I think you're a little over-ambitious with your requirement to maintain tolerances within 0.002". For starters, leveling a wooden workbench to a mobile router table to those kind of tolerances is going to be impossible without daily tweaking. Maybe with a heavy steel workbench and a fixed steel router table you could do it, but you'd have to have them both professionally ground for it to be even worth trying. Neither your router table top or your wooden workbench will be likely to have anywhere near those tolerances, so I don't understand why the gap between them would need that amount of precision.

If anything, I would make the router table slightly proud of the workbench. As long as the piece being routed is held firmly against the router table in the vicinity of router bit, it doesn't matter if the far end of a long piece of trim sags a bit.

My sliding table outfeed butts up against the right side of my miter saw table. The miter saw table sits pretty much flush with, but slightly below (maybe 0.010", maybe more) the slider outfeed table. As I'm pushing something through the slider, the last thing I want is for it to catch on the miter saw table midway through the cut. With it ever so slightly lower, it won't. When cutting a board on the miter saw that's long enough to rest on the slider's outfeed table, it's irrelevant that it might be raised up 0.010" or so, because it's 4 feet away from the miter saw blade, and there's more than enough flex in the board so that will lay flat where it's getting cut.

By having your router table proud of everything else by a bit, the workpiece won't catch on anything.

If you needed 0.002" tolerances on all your machines in order to make furniture, then most of the Asian import woodworking machinery companies would soon go out of business.

[Art Mann]

If you needed 0.002" tolerances on all your machines in order to make furniture, then most of the Asian import woodworking machinery companies would soon go out of business.
I think the original poster must have been exaggerating to make a point. There is no woodworking equipment on earth with work surfaces machined to that tolerance. Seasonal warpage of the cast iron is greater than that. There is no hope of building a work table out of wood that is within 10 times that tolerance. What happens if your casters roll up on a grain of sand?

[Jim Dwight]

Not only does wood move but the floor is not that flat. If it is a concrete garage floor, as mine is, it is not close. They deliberately slope to the door if they are made right (mine has a low spot).

I like everything the same height as my table saw and I put it and most of the tools, including the workbench, on totally locking casters. I do not have the space to give each tool a permanent home. Anyway, what works for me is to build things a little short and then put pads under the casters to get things to line up. My pads are around 1/4 inch but I see no problem planning thicker ones. It is much harder to shorten a cabinet than to plane up a thinner or thicker pad for the caster.

The only one I missed big time on is the one with a rotating top for my planner and mortiser. The mortiser requires a lot of clearance for the handle and I ended up a bit high. I am not going to worry about it. I have to move it out of the way sometimes when using my CMS or RAS (it stores along that wall) but that is no huge deal.

So my advice is to aim short and make shims to get where you need to be. And realize in a different part of your shop, your tool will be a different height. (not really but the floor will make it seem like that and potentially not line up right with other tools). If you have a wooden floor, this effect should be less.

[Jim Becker]

The way to do this is to make the router table the height you want. (I can't address the tolerance you want to achieve.) Then attach the kind of mobile base that raises the table to move it and then lowers it back on its own feet.


This. For. Sure.

And since the bench is stationary and (presumably) the router table will always locate in the exact same spot, once it's dialed in as precise as you can, it's going to register the same every time unless something is knocked out of adjustment for other reasons.

That said, the comment early in the thread about wood movement is spot on...OP, get as close as you can but know that from day to day the material you are working with with change, sometimes noticeably.

[Dave Lame]

OK, so .002 is not good number. Then the question becomes what is good number?

Bench Dog claims .008 for their steel router table top. Incra says .024 good for their tables. Since I will use Incra LS positioner I will go with .024.

Thanks for the useful suggestions on technique.

[Jim Becker]

The actual router table surface really should be held to greater tolerances. It's harder to do that when you want to mate it up with another surface. If anything I'd allow that "other surface" to be slightly lower (and I mean really slightly) if you're going to have a variance as that will interfere less with the cutting area accuracy, especially if you're using hold-downs to keep your cuts clean.

[Frederick Skelly]

Do you really mean 2 thousandths if an inch, in wood? If so, I'd build it 1/16" over the final desired height and try to hand plane it to the tolerance you want.

IMHO, I think you're in for a ton of work for very little gain. I busted my hump to flatten a bench to a couple hundredths about 18 mos ago, and it didn't stay that way long.

Edit: What's driving you to match the bench height pretty precisely? Could you match the bench height to say 1/10th of an inch? My method would definitely work for that.

[Pete Janke]

Dave,

The way to do this is to make the router table the height you want. Then attach the kind of mobile base that raises the table to move it and then lowers it back on its own feet.
Rockler sells these. I have them on my workbench. They are pictured holding the bench up. You kick the lever up to seat the bench on its legs. 330005330004