Ripping long board at 45 degrees

[Gerry S. Wojtowicz]

I recently tried to rip a 48 inch piece of Poplar with my table saw blade tilted at 45 degrees. I was using a Freud combination blade. I would get about 1/4 the length of the board and the table saw bound up, popped a breaker and stopped. I tried a couple of more times and got the same result.

The only reasons I can think of as to why this was happening was (a) my saw blade needs sharpening, (b) I need to use a dedicated rip blade, or (c) my fence is not parallel to the blade.

I will check all of these, but I was wondering if anyone can offer any suggestions as to why this is happening or solutions to stop it from happening again?

Thanks

Gerry

[Ken Fitzgerald]

Gerry,

Obviously something is causng the blade to bind.

I'd check that the fence is parallel to the miter gauge slot.

Check that the blade is aligned with the miter gauge slot.

Check that the fence is straight....not cupped in the middle.

Are you using a splitter of some kind or a riving knife? That would prevent the wood from coming back together at the rear of the blade.

Then I'd consider a ripping blade but my experience ripping poplar with a combination blade has been good.

Good luck!

[Greg Hines, MD]

I would guess that a splitter or riving knife would fix your problem. Check for parallelism, but I would guess binding from the back of the board behind the blade.

Doc

[Tony Bilello]

Keep in mind also that you are cutting about 50% more thickness.
What saw are you using and how much HP?

[Joe Chritz]

Welcome aboard.

Once those problems are checked you could also rip it a bit long and then make a finish pass. I have had to do this with plywood a couple times when trying to get good miters. It isn't always an option but helps when it can be used.

My money is on blade and fence not parallel.

Joe

[Anthony Whitesell]

Gerry,

Obviously something is causng the blade to bind.

I'd check that the fence is parallel to the miter gauge slot.

Check that the blade is aligned with the miter gauge slot.

Check that the fence is straight....not cupped in the middle.

Are you using a splitter of some kind or a riving knife? That would prevent the wood from coming back together at the rear of the blade.

Then I'd consider a ripping blade but my experience ripping poplar with a combination blade has been good.

Good luck!

Better yet...check to see that the blade is parallel to the miter slot at 90 and 45 degrees. Due to the design of the trunions, parallel at one does not mean parallel at the other.

To adjust parallel at 90 degrees, just nudge the trunion in the appropriate direction. To adjust the trunion at 45 degrees, shim the front or rear of the trunion down. Shimming the rear down shifts the blade left, shimming the front shifts the blade right...I think.

[Duncan Horner]

Just curious, but upon which side of the blade are you ripping this stock?

Always wondered whether there might be an increased possibility of binding when the stock is pinned between the blade and the fence, which might exacerbate any alignment issues.

[John Thompson]

Fence and blade not parallel is my guess also.. but as mentioned you hae around 2" thickness you are cutting there and a 50 T blade is not the way to do that if you want efficiency. I just got through doing 64 45* angled cuts for strips used for a quadlinear glue up of QSWO. A 20 T Amana got the call and it came out beautifully.

But.. the set-up was well secured.. the fence aligned properly and I used a blade that could clear the waste of that rip quickly to avoid problems.

Good luck...

Sarge..

[Frank Drew]

John's photo shows that he's using a hold-down, a hold-in, and a push stick, all of which contribute to good results when ripping at an angle (which involves somewhat different forces than ripping at 90 degrees).

[Doug Shepard]

Better yet...check to see that the blade is parallel to the miter slot at 90 and 45 degrees. Due to the design of the trunions, parallel at one does not mean parallel at the other.
...


That's my guess. I had a CMan saw that was impossible to get aligned parallel at both angles and would get all sorts of burning and near stalls for miter cuts of any significant length.

[Jose Kilpatrick]

John's photo shows that he's using a hold-down, a hold-in, and a push stick, all of which contribute to good results when ripping at an angle (which involves somewhat different forces than ripping at 90 degrees).

Ripping at a 45 has more of a tendencey to bind the stock between the blade and the fence depending on where your fence is positioned in relation to the rotation of the blade.

[Mike Goetzke]

There are many more experienced than I but my guess, like suggested above, is you are pinching the piece between the fence/blade. If you have a left tilt saw the rip fence should be on the right and vise versa. Plus you are lucky the saw stalled - sounds like you came close to a possible kick back. Remember, it's been said many times before here, if something doesn't seem right it usually isn't.


Good Luck,

Mike

[Don Bullock]

OK Sarge, you peaked my curiosity with your picture and the post with your QSWO legs in another thread. Is there some place where I can see more details of how you set up for the 45 degree cuts. Your hold-down, a hold-in, and a push stick technique looks like something I'm going to need. Thanks.

[John Thompson]

Evening Don.. I'm taking an early withdrawal from the shop to-night as I usually work till around mid-night. But... tomorrow I will get a few pictures to give you a better idea of how what you see is and works. You are catching portions of some of the components in that picture.

Before I post them.. basically I use a short fence on my stock long fence to create a free zone once the stock has been severed in lieu of having the already cut stock touching the fence beyond the cut.

I use a scrap block Quik-Clamped to the fence to hold the stock down. I use my home-made.. fold down when not in use on end of saw spring-board left to stop left in this picture. But tommorrow you will get to see another spring-board of a bit different configuration that will actually encloe the blade teeth for the most part while still supporting forward of the stock that has not entered the blade yet.

I have come up with different ways to skin a cat over the last 37 years due to necessity of what I had at the time opposed to what that has evolved too now. But.. if it works is always the bottom line with an attempt to be safe as possible in a given method.

Anyhoo.. film at 11 AM or there-abouts tomorrow if the creeks don't rise over-night.

Regards...

Sarge..

[Tom Veatch]

...Shimming the rear down shifts the blade left, shimming the front shifts the blade right...I think.

It depends on the direction of tilt. Shimming the front of the table higher, shifts the front of the blade in the direction of tilt. Shimming the back of the table higher shifts the back of the blade in the direction of tilt.

[Anthony Whitesell]

It depends on the direction of tilt. Shimming the front of the table higher, shifts the front of the blade in the direction of tilt. Shimming the back of the table higher shifts the back of the blade in the direction of tilt.

At first I was going to say that you had it backwards, then I though about it further. It will actually depends on how the trunions are mounted. If the trunions are mounted to the base (as you described) and you shim the table you are correct. In my case the trunions are mounted to the table, so everything is reversed because you are shimming the trunnions down and not the table up.

[Chip Lindley]

Better results @45 deg. might be had if you rip the board to width first @90 deg! THEN trim the edge to 45! Wasteful? maybe! Better results? YES!

[Don Bullock]

...
Anyhoo.. film at 11 AM or there-abouts tomorrow if the creeks don't rise over-night.

Regards...

Sarge..

Thank you Sarge. I realize that there are many ways to skin a cat (make any cut), but it's hard to beat a method that is successful for an experienced woodworker like you. From what I saw in the picture of the QSWO legs I can tell that you have perfected one of the ways to rip 45 degree cuts. I greatly appreciate your willingness to share and am looking forward to the pictures of your set up.

[John Thompson]

Better results @45 deg. might be had if you rip the board to width first @90 deg! THEN trim the edge to 45! Wasteful? maybe! Better results? YES!

Basically Chip.. that is what I do. I veneered 3/8" QSWO to poplar stock then rip to width as you mention for the individual pieces to be run through at 45*. But.. I don't rip to precise width.. I leave the piece approximately 1/16" to 1/8" proud. When you rip to precisely the width you have to have the blade set up on the opposing side to exactly catch the pure outer edge or you will end up short of precise. And the slightly proud helps prevent a ragged edge from possible tear out on that second side IMO.

This kind of cut is IMO a tricky affair as one slip in the wrong direction with a push stick.. mis-directed pressure on the fence.. etc. will move the stock just enough to gap the edge. I prefer supporting right with fence. left with either my spring-board or a feather of some nature and using a flat push stick to guide it through keeping the hands clear when I get to the final 8".

I did 64 45* rips as Don saw and they came out about as well as I am going to get them. I did have 4 pieces of back-up veneered just in case but.. not forturnately not needed in this case.

I suspect it was just "beginners luck". :)

Here's a picture of one of them as they all are the same as the picture of all eight glued that Don saw in the thread.. Creekers visit with John Thompson. Judge for yourself..

Sarge..

[Prashun Patel]

You didn't mention how thick the stock is, and the power of yr saw. I had the same problem on an underpowered saw trying to rip 2x4's on a bevel.

I was able to compensate by running multiple passes. Of course, this means you'd have to remove the splitter for the initial non-throughcut passes. Ironically, this FEELS safer to me than a single rip with the guard on bkz the stock will stay straight and the blade and you don't work so hard through the initial passes.

[John Thompson]

Thank you Sarge. I realize that there are many ways to skin a cat (make any cut), but it's hard to beat a method that is successful for an experienced woodworker like you. From what I saw in the picture of the QSWO legs I can tell that you have perfected one of the ways to rip 45 degree cuts. I greatly appreciate your willingness to share and am looking forward to the pictures of your set up.

I have included picture of using my standard spring-board I used in the "test" cut you saw the picture of Don. That one is normally used on all rip cuts but will work on 45* but leaved the blade a bit open and will not support left farther than the front of blade.

On the "real deal" when I cut the QSWO strips using a special spring-board I set up just for miter cuts. It has a 2" tall face fence and works off a sliding bar in the left miter slot. You put the stock to be cut to the fence and then slide the face up to it... move the spring-board forward with the saw on. When you get to the depth of the face you want you turn off the saw and lock the spring-board in the miter track.

By doing so.. you have support left throughout the cut until the stock is severed... and you hide the blade teeth making it more difficult for a boo-boo with your finger. I find it to work very well in usage and gives about as much protection as you can get when the shield can't be used on this cut with my saw.

The first two are set ups with the standard board... the remaining two are the set-up with what I actually use in a live and real deal cut..

Hope that helps...

Sarge..

[Don Bullock]

Thanks for the pictures. They are very helpful along with your explanation. From your results your method works very well. Is there a plan available for either or both of your spring-boards?

[John Thompson]

Thanks for the pictures. They are very helpful along with your explanation. From your results your method works very well. Is there a plan available for either or both of your spring-boards?

As far a a plan Don.. when I recieved my engineering degree from the Georgia Institute of Shade-treeology, they did not teach using plans when you designed and built something. You just visioned it.. then built it as you visioned. So.. I have never drawn up a formal plan on jigs or furniture for that matter other than scribbling some notes and dimentions on a note-pad. I can't draw a straight line in reality.

But... if you look carefully at either board.. it is almost self evident how it was done. If you need a straight over-head picture it will probably reveal more. A basic main-board from a piece of scrap ply.. two thin strips of wood glued to the front ends.. a thin long strip to those two tabs now attached.. the another short strip glued center with a final long strip rounded at both ends to avoid catching stock entering and exiting glued with that piece being the forward fence or "rider" as I call it.

Again.. if you need an over-head shot I will get one. BTW.. don't let my ripping spring-board fool you with the sliding latch and extra re-enforcements.. and gap between the head and body. I use it so much that I designed it to slide full left of table.. un-latch.. and the main body folds down the left side of saw. Only about 4" of the front face is still on the surface. That gets it out of the way on the occasion I don't use it but avoids having to take it completely off the table as it gets used much at my joint.

So.. picture the main body full without gap and folding parafanalia.

Sarge..

[Don Bullock]

As far a a plan Don.. when I recieved my engineering degree from the Georgia Institute of Shade-treeology, they did not teach using plans when you designed and built something. You just visioned it.. then built it as you visioned. So.. I have never drawn up a formal plan on jigs or furniture for that matter other than scribbling some notes and dimentions on a note-pad. I can't draw a straight line in reality.
...
Sarge..

Thanks. I learned design from the same school. Maybe we were classmates.;):D

[Nissim Avrahami]

Thanks. I learned design from the same school. Maybe we were classmates.;):D
Hi Don

Here are another two designs from the same school that Sarge and you visited... :)

Regards
niki
110640110641110642110643

[John Thompson]

Hi Don

Here are another two designs from the same school that Sarge and you visited... :)

Regards
niki
110640110641110642110643

Hey Niki.. haven't seen you around lately so glad to see you pop up. Don probably has an American style saw without slider but.. with a little shade tree engineering something like your on that slider might work.

If you see this Don.. Niki is another who lives and breathes safety and jig set-ups to perform given task so.. pay attention when he post. If you want to visit his shop though.. you'll have to get a Visa and call your travel agent to make arrangement to go to Poland.

As always.. regards from across the pond and keep those sausage boys there employed as I need my fix... :)

Sarge..

[Don Bullock]

Niki, Thanks for the pictures if your jig designs. I like your solutions, but they would be difficult to use on my left tilt SawStop and Incra fence. Like Sarge said, a little tinkering and I might be able to use one or both of your ideas.