Stop Block help!

[mackmack]

I have looked all over the net and I can't find how to set up a stop block on my rip fence. I realize it's not to complicated and I understand the basic fundamentals but I would just like to see the right way of doing.

For example, I cut mainly MDF, but what would be the best wood to use for a stop block? I am thinking pine because it is so smooth and dense.

Also the clamp, should I be clamping the wood to the fence or to the underside of the table? Is there any special clamp I should use?

Lastly, I will be cutting as small as .7" to about 7" in cross cut lengths. Should I be using a larger stop block for the smaller cuts to keep the fence as far away as possible? and if so, how far should the fence be? Thanks for any help.

[crokett]

Any wood is fine for a stop block. Unless you are Rod Kirby and it is not just a stop block but a work of art.

As far as attaching to the rip fence, I used to clamp it with a quick-release type clamp. The problem is that the fence is not tall. After the clamp is on you don't have a lot of room underneath it for wood clearance. My solution was a stop block that slips over the fence and has a bolt through the back that locks it to the fence.

[LarryG]

I have a couple stop blocks, one made of pine, one of MDF. Species doesn't really matter since there's not enough friction to matter; probably less than from the rip fence when ripping, for instance. But if it is a problem, a light coat of wax will do the trick.

Dimensions are about 3" long x 2" wide, by exactly 1" thick. The first two aren't critical. The last dimension makes it easy to calculate where the fence goes to get the cut length I want (i.e., just add one full inch to the actual measurement).

Attachment to the fence is via the smallest-size T-nut from Jeff's Nuts, into the slot on the fence side, facing the blade. But you can just as easily attach a block with a spring clamp or Quick-Grip.

I position the stop block as far to the rear of the fence as it will go.

[Tom Miller]

Another option that allows plenty of clearance for the clamp, is to drill a hole in the stop block big enough for one end of the clamp to get into. Or, cut a rabbet, etc.

Re: species of wood -- I use whatever's closest to the surface of my cutoff bin.

Regards,
Tom

[MilDoc]

I made a U-shaped box just wide enough to fit over the fence with a tight friction fit, with a piece of UMW tape on the blade side. About 3" long and mounted on the fence just ahead of the blade, it doesn't move even after repetitive cuts, but I can push it back to allow cut measurement, then pull it forward for the cuts.

[JimD]

I like to have a wooden face on my rip fence. It's about 4 inches tall, a little longer than the rip fence, and has a t-slot at the top. It is held in place by filed down 1/4 nuts in the slot of the rip fence. My stop block is a scrap piece of 1/2 inch thick oak held to the t-slot of the wooden face of the rip fence by a toilet bolt and wing nut. Easy to put on and off.

Jim

[mackmack]

Dimensions are about 3" long x 2" wide, by exactly 1" thick.

Just so I have this correctly. The stop block adds 2 inches to the fence in this case?

It's alright to have the fence that close to the blade(I suppose the actual fence would be like 3 inches or so away from the blade) when crosscutting?

That's really the main thing I am concerned about and want to get correct, I have gotten kick back once and I am very very careful about how I cut wood now.

So 2 inch Stop block against the fence is safe and enough room?

[RayintheUK]

Dimensions are about 3" long x 2" wide, by exactly 1" thick.

The "exactly 1" thick" shows that this is the horizontal dimension, so that Larry knows that the block adds exactly 1" to the fence position relative to the rule on the rail/the blade. The width is not important, as all measurements are taken from the inside (blade side) of the block anyway, but having a known exact dimension helps greatly if using the rule.

I've got my block drilled and countersunk to accept a couple of machine screws which fit into nuts that are slid into the T-nut slot in the fence. That does away with the need to clamp and - if of a known exact width - makes measuring easier.

The block must always be at the handle end of the fence and far enough back from the leading edge of the blade that the stock will not be in contact with the block, miter guage and blade all at the same time.

My block looks something like this:



HTH

Ray.

[LarryG]

Ray is correct: the 1" dimension is the horizontal dimension, i.e. the one parellel to the saw's rails. Using a simple increment like this makes positioning the fence easier whether you use the scale on the rail, or a rule/tape between the blade and the rip fence. Either way, you have to allow for the thickness of the stop block when positioning the fence, and being able to add one full inch makes it less likely you'll make a mistake with the arithmetic.

That said, some people think that 1" is not enough, and that a thicker stop block will further reduce the chances a small offcut will cock sideways and get into the blade and be kicked back. Although I've not had a problem using a 1" block, I cannot argue with their logic. So you might want to make your block 2" thick, or even 3" ... any even-inch increment will still simplify the arithmetic when positioning the fence.

[scorrpio]

Mine is about 2" thick with a 1" notch where the clamp goes. Really, the idea behind the stop block is that minute discrepancy between blade and fence does not result in a pinched offcut. If the fence is out of parallel by just 1/64", it can be enough to produce kickback. But really, a 1" thick stop block is more than plenty. If your offcut skews by more than that, your cut is gonna be crooked to the point of unusable. I use a 2" thick block only because I need the clamp notch and still have enough thickness for it to stay rigid.

[mschrank]

The block must always be at the handle end of the fence and far enough back from the leading edge of the blade that the stock will not be in contact with the block, miter guage and blade all at the same time.

MM, I just want to make sure you read this from Ray's post. I'm not sure you are really picturing it correctly. Your stock only touches the stop block initially...once you start moving your stock forward, it should slide past the end of the stop block before touching the blade.

This is an important safety item, so be sure to keep asking questions if you're still unsure

For me, the thickness isn't a big deal. I tend to grab whatever scrap is handy. Usually it's 3/4" thick, but might be undersize plywood as well. To get my measurement, I temporarily clamp the block in line with the blade and measure from block to blade. Then lock down the fence and re-clamp the block near the fence handle.

[LarryG]

But really, a 1" thick stop block is more than plenty. If your offcut skews by more than that, your cut is gonna be crooked to the point of unusable.

I don't understand how the offcut skewing means the cut is necessarily crooked. The offcut can and will rotate even with a dead straight cut.

The proponents of thicker blocks argue that these provide more "elbow room" when the offcut rotates and effectively becomes longer because it must now be measured along its diagonal. That's why I cannot fault their logic: obviously having (say) 2" of free play between the blade and fence allows the offcut to rotate a lot more than with only half as much free play.

(I recall someone reporting a tendency for offcuts of a certain length and width to cause problems with a narrow stop block, but at the moment I'm unable to find the relevant thread.)

[RayintheUK]

I recall someone reporting a tendency for offcuts of a certain length and width to cause problems with a narrow stop block, but at the moment I'm unable to find the relevant thread.

Was it this one. Larry?

Ray.