Micro Adjust the Rip Fence

dusty · Post by **dusty** » Sat Apr 26, 2008 6:03 pm

During Sawdust Session #18, Nick demonstrated the use of the dial indicator to accomplish a very fine adjustment of the rip fence.

I went to the shop to try out the technique. It worked real good for Nick but I just could not move the rip fence in increments that small (.002" or .003").

Maybe Nick didn't either - he never did show us the dial face. His box joints (finger joints) worked out good though, so he must have made the adjustment he wanted.

But now I want to microadjust my rip fence. I set out to rummage through the bits, parts and pieces that I have carried around for years to see what I could find. I didn't find a microadjuster but I found some parts and some inspiration.

What I have here is just a concept but it'll work - in time.

I hesitate to drill into the fence, so for the moment, I can push the fence one direction but I cannot drag it back. That seems to be a simple problem but we shall see.

Watching the dial indicator, I had good control and could stop at any point. Make sure the fence is firm against the cap nut when I lock down the rip fence and I'm done.

One complete turn of the wing nut pushed the fence 52/1000" (.0052") so I have good adjustability/accuracy.

paulmcohen · Post by **paulmcohen** » Sat Apr 26, 2008 6:22 pm

I am thinking you could use the slot in the rip fence somehow to make it easy to install and remove. In general I love the idea.

Ed in Tampa · Post by **Ed in Tampa** » Sat Apr 26, 2008 7:13 pm

Dusty
You are the man!!!! That is as good a micro adjuster as many that cost 100 times more.
Ed

Nick · Post by **Nick** » Sun Apr 27, 2008 11:49 pm

Let me put on my disguise so I can tell you this incognito -- if you take Dusty's good idea just one step further, you don't need the dial indicator. Replace the bolt in Dusty's jig with an #8-32 bolt -- 32 threads per inch. One turn of the wing nut will move the fence 1/32"; 1/2 turn, 1/64", 1/4 turn, 1/128". If you like working in thousands as I do, 1/8 turn will move the fence within 1/10,000" of .004", and 1/16 turn moves it within 5/100,000" of .002".

With all good wishes,

ryanbp01 · Post by **ryanbp01** » Mon Apr 28, 2008 11:49 am

With all of the discussion that has gone on here as wells as other threads on adjusting within a few thousandths of an inch for a cut, alignment, etc. is all of this micro-adjusting really all that necessary? Is it noticeable to the naked eye? I can see keeping the table at 90 degrees to the blade, but just how close to "perfect" do you have to be? I realize that "close only counts in horseshoes and hand grenades", but I am having a hard time visualizing just how noticeable a cut would be that is .002 or .003 of an inch. Are we talking something the thickness of a piece of paper? Before anyone says anything, no I haven't had the time to look at the sawdust session in question. Spring has sprung and the mowing/planting seaon has begun.

BPR

Ed in Tampa · Post by **Ed in Tampa** » Mon Apr 28, 2008 1:04 pm

BPR

I totally agree and I have voiced that opinion many times. Wood movement alone dictates you must leave some moving around room.

I like to work accurately but frankly it often comes down that judicous trial and error is often faster and better.

I'm real hesitant to bring micrometers, dial indicators and other percision measuring instruments into wood working. I have seen hundreds of things that display super craftsmenship that were built with rules that were only marked to 1/8 inch or story sticks. Most were hand cut with the craftsman's thumb along side the saw acting as fence, rule and laser pointer.

How often have we seen Nick teach us the wood compresses a few thousandth of an inch when it is being cut on jointer, planer, router and such. If we are working in thousandths and the wood compresses a thousands and then it moves thousandth we can end up measuring cutting remeasuring recutting, remeasuring recutting and on and on.

Some how we have it in out thinking unless the pieces fit as if they were die cast, or CNC cut we are being sloppy. I think we can get so caught up in the adjusting, buying something new to work better, trying new designs and such that we never actually do anything but we are always busy.

I think this is the reason that many of today's "Woodworkers" build very little, they are wood workers that like adjust and recheck their machines, to collect new and "helpful tools" and sometimes they even build jigs that will rarely be used. I don't know what percentage of machines are actually ever used but I tend to hear a lot of stories of machines that were never fully opened or completely assembled. I read a lot of ads in the craigslist and in the paper that says, $1200 saw used twice or never used. I hear stories of guys lucking into Shopsmiths that never had all the packing removed around the headstock.
Ed

woodburner · Post by **woodburner** » Mon Apr 28, 2008 1:10 pm

The reasons you want to make cuts that percise is that it helps with the overall project. If you are making furniture for example, the more accurate each cut is, the less they show in the finished piece.

For example:
Let's say you need to cut fifteen pieces the same size and angle. If each of your cuts are 1/64" off, multiply that by fifteen (one bad cut x1, two bad cuts x2 + x2, etc.), when your done and you are putting your project together, you'll end up about a 1" off (?), and in furniture making, that doesn't look very good.

So yes, cuts this precise are important to the fine woodworker.

woodburner · Post by **woodburner** » Mon Apr 28, 2008 1:27 pm

Sure you can mark your pieces an 1/8", but that was because most saw blades used to be 1/8" thick. Now with the 3/32" inch blades, it requires you to be a bit more precise.
Also, as long as the 1/8" cuts are cut precise, and not 1/8" off, you will have no problem. Can you imagine how unsquare a table would be if each apron was cut 1/8" off. You would never be able to make it square. And forget about lining up a mortise and tenon joint if you are that far off.
Layout and measuring is everything in woodworking. Without it, you couldn't build a thing without something bending, cracking or warping after the piece is built.
The more precise your layout and cuts in the beginnng, the less trouble you'll have down the road (recuts, joints that don't match-up, wasted time & wood, etc.)

Nick · Post by **Nick** » Mon Apr 28, 2008 1:28 pm

"Are we talking something the thickness of a piece of paper?"

No. About half the thickness of a piece of paper.

"...is all of this micro-adjusting really all that necessary?"

When making a finger joint, my 1/4" router bit cuts a groove .254" wide --.004 inches wider than 1/4". That means I have to make the tenons .246" wide for the joint to come out correctly. The sum of the width of the tenon and the width of the mortise must be equal to .500" for the joinery to come out evenly on 3-1/2"-wide adjoining boards. There should be seven full tenons and seven full grooves. If the tenons are also off by .004", then the finger joints will be off by over 1/32" by the time you've cut from one edge of the board to the other. Not much, but noticeable. If the adjoining boards are 6" wide, as the were in the CD/DVD holder that Drew made while he was doing the research for last week Sawdust Session, then the joinery will be off by over 3/32". Now you've got a problem. So, in answer to your question, "Is all this micro-adjusting neccessary?" -- yes, it is for this particular joint.

Can you set up the Shopsmith Router Table to make this particular joint without going digital? Yes, you can. By making several test cuts, you can zero in to the proper setup. The old "cut-and-try" method always works. It takes longer, sometimes a great deal longer, but it always works. I value my own time enough to invest in a digital calipers and a dial indicator to help me get to where I need to be without guesswork.

Does the wood move after you make the cut? Yes it does. But in this example, the adjoining parts move in unision presuming the wood is properly shop-dried. In any event, whether you are working with a dial indicator or cutting and trying, you should always assemble the joinery as soon as possible after cutting it. Waiting so long that the seasons change between joinery and assembly is just asking for trouble.

With all good wishes,

Ed in Tampa · Post by **Ed in Tampa** » Mon Apr 28, 2008 4:06 pm

woodburner wrote:The reasons you want to make cuts that percise is that it helps with the overall project. If you are making furniture for example, the more accurate each cut is, the less they show in the finished piece.

For example:
Let's say you need to cut fifteen pieces the same size and angle. If each of your cuts are 1/64" off, multiply that by fifteen (one bad cut x1, two bad cuts x2 + x2, etc.), when your done and you are putting your project together, you'll end up about a 1" off (?), and in furniture making, that doesn't look very good.

So yes, cuts this precise are important to the fine woodworker.

Woodburner
You talking here about compound mistakes not adjusting to a thousands in the pursuit of accuracy.
Ed