Replies

1. 
   Rob_Sp | May 15, 2012 05:14pm | #13

   Check your fence

   to see if it is straight. By the way, what's with the Rube Goldberg featherboard assembly? It's just ripping for God's sake, be a man dammit, and push it through by hand......... :-)  

1. 
   wericha | May 15, 2012 05:23pm | #14

   Amen!!!

   They don't call ole Rob "4 Fingers" for nuthin'

   ;-)

2. 
   PhillipB | May 15, 2012 07:57pm | #17

   Rube Goldberg??

   robscaffe wrote:... what's with the Rube Goldberg featherboard assembly? It's just ripping for God's sake, be a man dammit, and push it through by hand......... :-)  

    Hey, watchit there buddy.  I have a Patent on that baby.  Patent Number - 208uoj0u0h2432u08-234y626h7-007, to be exact.

   These jems are being sold exclusively by Tiffany's and Cartier.  We just got a Request-To-Carry (RTC)  from BVLGARI, the famous Italian jeweler.  

   And just to be clear, instead of ordinary sandpaper glued to the bottom of the pine board, we are using diamond dust.  Much nicer for sure, but the downside is that the diamond dust will scratch the furniture.

   Not too shabby for a po' boy from Oak Park, wouldn't you say?

1. 
   roc | May 15, 2012 10:05pm | #18

   Not much of a table saw guy am I but

   i have been following along here.  Because I am not much into table saws , because I don't make stacks of identical parts or work with sheet stock every day, I was reluctant to say anything.

   When I started getting serious about LEARNING woodworking I was all about a nice table saw.  I wanted a cabinet saw but didn't find anything I thought was worth the seven hundred dollars or so I had to spend (only contractor saws in that price range then ) so I bought a most basic new Delta cheepy with a broken hand wheel (so discounted floor model ) and went through the whole thing and made it accurate to use.

   Once I learned the hand tool woodworking that I was interested in I was glad I hadn't spent thousands on a cabinet saw and found the bandsaw was the best way to go FOR ME AND WHAT I DO.  I am not trying to talk you out of a nice cabinet saw.  You know what you need better than I do.

   I have more back ground in metal machining tools than the wood tools so have the tools and skills I needed to get some serious accuracy out of my cheepy.

   For instance I filed the square steel tube beam fence straight and true.

   SO MY QUESTION IS

   is your fence face flat ?  That is if you put an accurate straight edge along it's length do you have any gap(s) ?  Using winding sticks or dial guage and your jointer table etc. is there any wind in it ?

   AND A SECOND THOUGHT . . .

   I have had in my mind since this thread started . . . is your stock bowing from released stress in the wood ?

   As far as accuracy off the blade I agree with both sides of the argument . .

   for instance :

   1.  There are "glue line blades" for cutting a nice enough surface so the edges can be glued up for a good joint right off the blade (I am sure the Forests are quite good enough for that; I sure like my Forest blades ).

   Sam Maloof made a habit of this when he made his chair seats.  Part of the key is he was using thick stock that was well stored and dried and he was cutting short stock lengths.

   2.  I too was thinking "Best to joint the edge after ripping to make it as accurate as possible" . . . for long stock or for thin stock.

   Thanks for listening.  What do you think about all that ?

1. 
   PhillipB | May 17, 2012 11:50am | #22

   Thanks for your thoughtful comments

   Sorry for the late reply but I have my Notifications turned Off.

   Your comments prompted into a deeper analysis of this issue.  Here are my results.

   While I had previously done a quick bow/concavity check of the rip fence (blade side), I did so using a machine edge laying on the fence surface.  Today I repeated this process but did so with the same surface laying on my jointer outfeed table.  I discovered that I had a 0.014" (0.36 mm) gap beginning 3" from the front of the fence to approx. 18" from the front.  This was much more accurate because the machined rule was too easy to knock over while running the feeler gauge between it and the fence surface.  With the mass of the fence against the jointer table I did not have this issue.  This resulted in much more meaningful data.

   Based on this I marked the fence and re-enacted the rip process and took several photos to illustrate what I believe the reason for the board concavity.

   Photo 1 - Set Up

   This white tape represents where the gap begins (3") and where it ends (18") along the fence.  It also shows where I had my finger board positioned.

   Photo 2 - Starting Rip

   This illustrates the start of the rip and also shows where the board gap begins.  This is depicted by the position of the blue pencil.

   Photo 3 - Leading Edge Out of Concavity

   This shows the leading edge of the board beginning to to leave the concave section of the fence.  This, in effect, is now forcing the board against the blade, thus beginning the resultant board convavity which agrees with the pencil position.

   Photo 4 - Trailing Edge Going into Concavity

   This photo depicts the trailing edge of the board going into the concave section of the fence.  At this moment, the narrow (concave) section of the board is passing over the section of the fence that is not concave, but this does not affect the trailing edge because it is now narrower than the trailing edge and thus has no affect on the trailing edge of the board.

   I am satisfied that this is the culprit and demonstrates my need for a more accurate table saw. I would also add that the position of the deformity (bow or concavity) in the fence will determine where the board is affected.

   I hope this detailed analysis with help others disect a similar rip fence issue should it arise.  

   
2. 
   Rob_Sp | May 16, 2012 10:38am | #19

   Paint it a bright color

   and put a laser on it and you will sell a million of them, Phillip. In fact I'll be first in line for the IPO.

   As for me, I'm working on a penetrating oil finish that actually breast feeds the wood. Look for it on the cover of Time Magazine soon.

   Best of Luck with your saw

   Rob

1. 
   PhillipB | May 16, 2012 11:02am | #20

   Great sense of humor!

   robscaffe wrote:I'm working on a penetrating oil finish that actually breast feeds the wood. Look for it on the cover of Time Magazine soon.

   Rob

   If you'd quit with the funnies I might be able to get off the floor and get back to work :-)

1. 
   VAM | May 16, 2012 08:24pm | #21

   To See If

   there is any possibility the fence is flexing you could put a dial indicator on a mount against the off side of the fence and see whether it moves as you rip a piece of wood.

3. 
   roc | May 17, 2012 02:15pm | #23

   Demonstrates my need for a more accurate table saw

    Well Done !

   AND if you have a SWHTPS (she who holds the purse strings ) you now have  an irrefutable, empirical, argument for said new saw !  Not that that will necessarily help the negotiations (any thing can happen when dealing with "The Department of Finance and Allocations " ) but we can dream can't we ?

   Let us know which saw you get.

   Being the awful sod that I am I would check the new saw/fence with at least as fine a test as you demonstrated here.  Just to keep 'em honest you understand.

   It just shows; a wood worker has to fettle everything from his blue pencil to his table saw.  Can't trust the blighters to do it for ya.

   Keep up the good work and interesting posts.

1. 
   PhillipB | May 17, 2012 06:06pm | #24

   SWHTPS?

   Ah, that would me my Financial Advisor.  Yes, indeedy, she does keep a keen eye on me especially when she sees me toting my billfold over to the computer.

   "Sweety.  What are you doing? ... "

   Don't be fooled by the  term of endearment, cuz there is absolutely more bite than there is bark to my babe.  I can attest to that for as long as you like.  

   In truth, she has already give me a thumbs-up on the Unisaw.  However, when that happens I usually jump back on the fence just to take another look around before I really take the plunge.

   On another front - I have a dial indicator coming in the mail as I write.  It was purchased to retune my DJ-20 jointer, but it will serve admirably to tune the new TS fence and whatever else needs tuning.

   Thanks for the great feedback.

1. 
   baumgrenze | Feb 09, 2013 08:16pm | #31

   Fighting the Same Problem

   Phillip

   Did you ever get a decent answer to this question? I'm fighting the same problem.

   I've been an amateur woodworker for over 50 years. I got my current table saw over 40 years ago when I moved to Palo Alto, CA. It is not fancy but what I could afford at the time, a Sears 113 29940 10". Years ago I beefed up the support for the arbor tilting bearing. It was originally supported near the center of a 16 gage sheet steel panel reinforced by two 3/8" 16 gage angles spot welded vertically 3-1/2" apart on either side of the bearing. I filled the space between the angles with 1/4'" aluminum plate. The side panel no longer 'breathes' in and out when the saw is running. I can appreciate that this was inducing a slight harmonic tilting of the arbor.

   The OEM rip fence is nothing to brag about, but I have a Ripstrate mounted on it on a piece of KD birch, 2-1/2 x 1-1/8 running the length of the fence. I routinely set the fence using a Starrett combination square to measure that the fence is parallel to the miter grooves in the table top. The blade is square with them.

   Today I decided to clean up some pieces of birch, 2' long, 7/8" x 2-3/4". I don't have a jointer. I mounted a Sears sanding disk and carefully squared it to the table. I was careful to remove less than 1/64" per pass as I sanded. I used the Ripstrate fence. The pieces are beautifully square, they are just ~1/64" narrower 12" from each end than they are at the ends. I checked them with a dial caliper. I checked the narrowing against a steel engine block straight edge using feeler gages. The error is uniform across the 7/8" face and starts about 5" from each end. The error on each face is about 0.008-0.009". I saw the same behavior when I first ripped the wood using a Freud 10" ripping blade.

   I, too, was curious why I am getting an 'hourglass' shaped plank.

   Thanks,

   baumgrenze

1. 
   roc | Feb 10, 2013 12:06am | #32

   Hi

   There  is a chance he may not reply because he has his message notification off so he doesn't get tons of duplicate notifications.

   Please note that at the bottom right of this thread there is a page turn button with "1 and  2 ".  You may be just seeing page two's comments.  If you go to page one you will see that we hashed this out pretty well and his solutions to the problem.

   Hope that helps.  Better than my retyping or cutting and pasting it all over  again.

   PS: I will send Phillip a privet message so maybe he will know to come talk with you.

4. 
   CharlieL | May 29, 2012 12:53pm | #25

   Deleted

1. 
   PhillipB | May 14, 2012 02:03pm | #1

   While I wish for that to be the case, it is not.  

   Both edges of the board were fresh off a finely tuned jointer which resulted in flat surfaces to both edges.  

   I just double-checked: With the board edge that rides against the rip fence laying on the infeed table of my DJ-20, I was barely able to slide a 0.003" feeler gauge between board and table.  

   That's flat enough for most purposes.

1. 
   PhillipB | May 14, 2012 02:06pm | #2

   Why All the Notices?????????

   Off topic, but why, why, why must I receive 12-16 notices everytime someone posts a comment to a thread that I participate in??

   This is maddening!!!!!

1. 
   CharlieL | May 29, 2012 12:54pm | #26

   Deleted

1. 
   PhillipB | May 14, 2012 02:24pm | #4

   You are not bothering me.  

   What I meant to say was:

    Off topic, but why, why, why must I receive 12-16 IDENTICAL notices everytime someone posts a SINGLE comment to a thread that I participate in??

   ==

   IOWs, everytime someone makes a comment to a thread that I am subscribed to, this website notifies me 12-16 times that the post was made.  One notification would be sufficient.

2. 
   wericha | May 14, 2012 02:25pm | #5

   What kind of blade are you using?  Also, is there any burning of the cut on either side of the blade?

1. 
   PhillipB | May 14, 2012 04:38pm | #6

   I'm using a Forrest blade that is still very sharp.  Here are a few photos which may help.

   The first photo shows my ripping setup.  The second shows the ripped board surface (board edge is at top in photo).  From this you can see that there is no blade buring whatsoever.

   
1. 
   wericha | May 14, 2012 08:57pm | #7

   Is this something "new" or

   Is this something "new" or has it always been an issue?

   In other words, when is the first ime you noticed this?

2. 
   PhillipB | May 15, 2012 11:01am | #9

   Great question

   I just noticed this yesterday and this is why.  

   I've known for years that my TS was not intended for the fine work that I try to do.  I have compensated for that shortcoming by building precise cross-cut sleds, using Forrest blades, and tuning this TS as accurately as I have been able to do over the years.  This attention to detail has paid off quite nicely for me.

   Having said that, I have always shied away from using the rip fence because I knew it was not designed to be a precise accessory on this contractor saw.  I have found alternative ways to make up for this deficiency.  However, because of a new project I need to tackle, I was forced to use the rip fence to get started on this project.

   I used my digital caliper to tune the fence to a single tooth of my Forrest blade and matched it (front to back) to within 0.003 inch as I recall.  I figured that that was parallel enough.  But, after making a few passes on a test board, I soon discovered the 'bowed' result.  Thus this thread.

   To be clear, I have tuned the trunnion to insure that the blade ran parallel to my left miter gauge slot.  I did this only to verify that this basic tuning was at least in the 'ball park' for this inexpensive TS.  Bottom line here is that when cross-cutting stock on my sled, I do get very precise 90-degree cuts.

   This has been a great learning process for me, but the bottom line is that it time to upgrade to a better TS.  Yesterday, my uncle agreed to take this old saw ( He is currently using a TS that uses 9" blades.  Can you imagine that?  I was shocked to learn that a few weeks back when I was in Santa Fe.)  Anyway, his sons have always wanted him to ditch the 9-incher, so they will do that to make space for my TS.  This means I will have to purchase a new TS and I really like the Unisaw.

   Off Topic.  I have been forced to dissable all notifications because I receive anywhere from 4 to 16 notifications for a single new post.  Today I received 4 notifications on a post made yesterday in another of my threads that was marked as NEW this morning.  Whomever is running this website has absolutely no clue what they're doing.  So, I will check back in later today for new comments.

3. 
   RalphBarker | May 15, 2012 11:41am | #10

   Don't tell, OK?

   [whisper on] Don't tell anyone, Phillip, but I've been using a 9" Delta contractor saw since the early '70s. [whisper off]  ;-)

   A few years ago, I tricked it out with a Delta T-square fence. And, I use Forrest blades, as well. It still cuts OK for what I do. And, if I need to crosscut big stuff, it goes on the 12" Delta RAS, or gets cut . . . wait for it . . . by hand.  ;-)

4. 
   PhillipB | May 15, 2012 07:14pm | #15

   Don't worry ...

   I won't tell a soul, but still ... 9 inch table saw blade?!  I could think of a lot to say on this, but I'll let it pass. It was what it was back then.  In all seriousness, I've been on the planet a few years and I've never heard of a 9" table saw blade.  Live and learn, I suppose.  

   Next thing I know you're gonna tell me that Forrest still makes 9 inch saw blades.  I just checked.  You're right.  They do. More stuff I never knew about.  It's amazing what a guy can learn in these forums.  :-)

5. 
   RalphBarker | May 15, 2012 11:56am | #11

   Back to the original question

   Pending delivery and installation of your new Unisaw, a couple of thoughts come to mind.

   The first thought I had was the possibility of run-out on your blade, and the possibility it it flexing during the cut. If that were the case, I'd usually expect to see some burning on the board edge, though, which you aren't experiencing. That might still be the case, though, particularly if it is a thin-kerf blade without a "stiffener" plate.

   The next thought was about the fence. Might it be flexing during the cut? Or, does it have lock-downs at both the front and the back of the fence? Also, is the face of the fence dead flat when it is locked down?

6. 
   wericha | May 15, 2012 12:14pm | #12

   Oh Ralph, and here I thought you were one of "us"...........

   A 9" contractor saw.............

   The shame of it all...............

   Even most cabinet saws in the '70s had pretty inadequate fences.  I had the same fence as Phillip and I can tell you it was very difficult to deal with.  Most likely the featherboard is causing the fence face to flex.  I'm really surprised the waste piece doesn't show some burn.  In any case, there will be significant blade marks to deal with.

   I upgraded mine to a Vega fence and was very pleased.  It has a micro-adjust feature that I really came to enjoy, especially when switching between thin and full kerf blades. 

7. 
   PhillipB | May 15, 2012 07:41pm | #16

   Great questions

   RalphBarker wrote:The next thought was about the fence. Might it be flexing during the cut? Or, does it have lock-downs at both the front and the back of the fence?

   The feather board is set slightly snug against the stock, so I don't think it would in any way cause the fence to flex.

    RalphBarker wrote:... does it have lock-downs at both the front and the back of the fence?

   The back end of the rip fence is not "locked down" per se, but when the front lever is pulled down into lock position, it does provide sufficient tension on the rear of the fence to hold it in place.  It is not the 'free floating' type of rip fence.

    RalphBarker wrote: Also, is the face of the fence dead flat when it is locked down?

   As I mentioned earlier, there is a variance of about 0.003 difference from the front of the blade to the read of blade with regard to the fence.  That is probably as good as it will ever get.

   Off topic - getting quotes to work correctly in these forums is frustrating.  I'm being polite here.

8. 
   CharlieL | May 29, 2012 12:55pm | #28

   Deleted

3. 
   CharlieL | May 29, 2012 12:54pm | #27

   Deleted

1. 
   PhillipB | May 14, 2012 02:19pm | #3

   All of my TS blades are Forrests.  This particular blade is about a year old and still very sharp.

   I never force any stock into a blade, be it router, band saw or table saw.  

   Having said that, you are correct when you note that forcing stock into a dull blade is definitely a recipe for a bad outcome.

2. 
   wericha | May 14, 2012 09:01pm | #8

   Never use a cut edge as a final edge.  Either use a jointer or, better yet, a hand plane.  Using the edge from a table saw is just plain sloppy.

5. 
   CharlieL | May 29, 2012 12:57pm | #29

   Deleted

6. 
   CharlieL | May 29, 2012 12:58pm | #30

   Deleted