table saw fence question

[tsbrewers]

Hey people, I have a question about the fence on my table saw. I have the ridgid 3650 TS and ever since I bought it the tape has been off. It is gets closer the closer to the blade it is. For example, at 10" the fence is right on, at 30" the fence is probably off 1/4" (30 1/4" from blade)

I replaced the stock fence with the beis 30" fence in the last Lowes beis orgy. The new fence is the same, so I am wondering if it is setup error, or if I just got two bad tapes on the fences? the blade is parallel to the miter slots and the fence itself is also parallel to the blade/miter slot, so I am not sure where to look.

Brew

[LCHIEN]

offhand it seems like it could only be one of two things.
Either the tape you are checking with is off or the tape on the rails is off.

I assume when you replaced the fence you also replaced the rail... which means you replaced the scale on the rail, too...

So if two scales are seemingly off the same way then the most likely is the tape you check them with. Have you checked that tape? It happens...

[Knottscott]

If you referenced both tapes with the same measuring device, it could the measuring device that's off.

It's possible that both tapes are off, but a bit unlikely. Be sure the front rail is level with the top.

[Knottscott]

Looks like you need to get up pretty early in the morning to beat Loring to the punch! You're to be commended on a great answer too!

[tsbrewers]

yup both fences are the same way. It possibly could be the tape I am using to measure, but I have literally 20 tape measures in my garage, (stanley fat max'es, I buy when they are on sale), and I have used them all over the last few years with the saw and I haven't noticed some being "on" and some being wrong, or anything like that.

I will really try to check it well when I get the wixey gauge mounted up and see if I can figure it out. Thanks for the tips

Brew

[RodKirby]

NOTHING beats measuring with a steel rule from a blade tooth to the fence - assuming of course, your original measurement was with the steel rule.

[agent511]

i don't know what the problem is, but it would be quite extraordinary, to say the least, for a scale from any manufacturer (even HF!) to be so inaccurate as to lose or gain 1/4" in 20 inches. And here is someone who has the same error with a scale from Ridgid and seperately from Biesemeyer. They don't stretch, you know. So it would be illogical to even consider it is the scale on the rails. Likewise I don't think the scale on the measuring device is off either. I would pose that the most logical reason is some type of human error, and am curious to hear back as to the answer to this riddle.

[LCHIEN]

i don't know what the problem is, but it would be quite extraordinary, to say the least, for a scale from any manufacturer (even HF!) to be so inaccurate as to lose or gain 1/4" in 20 inches. And here is someone who has the same error with a scale from Ridgid and seperately from Biesemeyer. They don't stretch, you know. So it would be illogical to even consider it is the scale on the rails. Likewise I don't think the scale on the measuring device is off either. I would pose that the most logical reason is some type of human error, and am curious to hear back as to the answer to this riddle.

I sort of agree, at this point the OP has to figure out which device is off if any, and if not, then there has to be a consistent measurment technique error.

[tsbrewers]

i don't know what the problem is, but it would be quite extraordinary, to say the least, for a scale from any manufacturer (even HF!) to be so inaccurate as to lose or gain 1/4" in 20 inches. And here is someone who has the same error with a scale from Ridgid and seperately from Biesemeyer. They don't stretch, you know. So it would be illogical to even consider it is the scale on the rails. Likewise I don't think the scale on the measuring device is off either. I would pose that the most logical reason is some type of human error, and am curious to hear back as to the answer to this riddle.

Well, couple things, the 1/4" was an example, I think it is less than an 1/8" in actuality. I do believe the original tape, was exactly that, tape, and flexible. I recall when I got the saw it was a common problem (from reading the Ridgid forums) and most people just put a new tape on from Ridgid. Since I have been in the habit of using a tape measure to double check my measurement, I didn't worry about it. Well, when I put the beis on, and it is the same way, that got me wondering.

Now, it is entirely possible that it is me, BUT, I have been a professional carpenter for 20 years and have had this saw for probably 4 years, so it is not a one time mis-calculation or anything. unfortunately the error is quite repeatable. I will install the wixey this weekend and see if that helps, or if that is off too, there definitely is something going on.

Brew

[eezlock]

tablesaw fence questions...

Brew, I think that your tape that you are checking with could be causing the problem. Get yourself a good quality steel ruler with etched markings and use that as a refrence point to check with. Most tape measures whether they
are expensive or not, have some measure of inaccuracy in them when they are manufactured...this is allowable even to gov't specs. A Starret or other quality steel ruler is more accurate and reliable and can be trusted for years
to come. A lot of the time ( most times) I use my 12" combination square
to measure with...I have checked it against tape measures of different lengths and most of them are off by a small amount as is usually the case.
Eezlock

[cabinetman]

Measured distance is measured distance. The Bies comes with a flat metal tape that you stick down once you are very close to a perfect measured distance, with the "viewer indicator" in it's middle position for the measured distance of the fence to the blade you're using. Then use a tape measure or any other measure device to get a perfect measure of any distance from the blade to the fence (it could be 6" or 8" or 12", it doesn't matter). Then check the fence for the indicator to be set for the exact dimension.

NOW, IF THAT DOESN'T WORK THIS IS THE REAL PROBLEM.
.

[LarryG]

I think your problem probably stems from using different measuring devices. Whether it's a steel tape, a wooden yardstick, a high-zoot stainless steel rule, or the adhesive-backed scale on a table saw fence -- they're all subject to errors. All of these can expand or contract to some extent; most of them can stretch; all of them can have the markings printed or etched wrong.

Brand name is not necessarily an indicator of accuracy. The fence scale on my PM2000 drifts off by a 16th or so out around 36" (IIRC) when I check it against other tapes that compare okay against each other. The scale is a sticky-backed steel ribbon, with printed markings, manufactured by Starrett. That's arguably the most respected name in the measuring business, but still the scale on my saw is wrong.

I can believe your assortment of FatMax tapes are consistent -- they're all from the same source, manufactured on the same equipment. Compare them to nearest Lufkin or Kobalt or whatever, however, and you will likely find disagreement.

As a pro carpenter you, more than anyone else in this thread, will be familiar with the concept of story sticks. What many people fail to realize is that any measuring device is really just another kind of story stick. Back when I worked as a carpenter, there was one grizzled old vet who would take a measurement and mumble something like, "Two feet, five inches, and six of them little marks." It was always said tongue-in-cheek, but the fact is that he neither knew nor cared whether his measurement of 2'-5 3/8" was accurate in the absolute sense. All that mattered was that the piece of trim he was about to cut would fit. He ensured that by making sure he used the same measuring device at all times and placed his cut mark precisely at two feet five inches and six little marks.

The point of all this is that it rarely matters whether a measuring device is absolutely accurate, because most of the time all we need is relative accuracy. We get that by using the same device for all measurements. Set your fence away from the blade using your FatMax, make your cut, and then measure the keeper piece with the same tape. I'll bet you'll find the two measurements agree.