I need some help with my Excalibur!!!

[rafairchild2]

I was hoping Someone could point me in the right direction.

All of a sudden today my Excalibur is not cutting right.  See image 1.png and you can see how I cannot stay on the line in a simple curve.  And look at the out-cut and how crooked it is. My cuts are not 90 degrees. This is walnut and I tried a #7 and #5 FD UR blade. This started after cutting 3 other toys with no problem.

  Now.  I checked the blade being 90 degrees to the table and it is on 4 sides. (L, R, F, B)  (2.png)

I noticed that the rocker arm under the table from the pegas chuck had some slop in it, so I tightened the 3 bolts. (3.png )  I think I over-tightened as that slowed the blade strokes way down so I loosened them back a little, there is very little play on the bottom bar when there is no tension.  When I tension it is rock solid. 

During the cut, I threw the angle on it, (4.png )and the top of the piece to the top of the chuck is a perfect 90.  So I am thinking something is off below.  But you can see by the piece how off it is.  What's weird is, the first 3 pieces I cut today were fine, then the next thing I knew I could not stay on the line and weird stuff was happening. 

I just swapped out the upper and lower thumbscrews to my 'new' backups.  I also checked the set screw that it was not worn and scuffed it.  It is almost as if the blade is twisting on the bottom.  Not sure though.

  Any suggestions on where else to look, and how tight/ loose should that bottom rocker arm be?

Edited March 1 by rafairchild2

[JTTHECLOCKMAN]

I do not have that saw and no little about it. But you need to look at the action itself. Manually push the arm up and down with the square next to the blade and if the blade moves straight up and down then it is not the saw and it is your pushing technique. At times we get to pushing too hard and you are putting pressure where there should not be. As you are cutting let off from pushing and if your piece walks back to a certain position it tells you that you were doing too much side pressure. It happens to all of us. May have to change the speed of the saw one way or other. Certain woods just cut slower than others. Other than that I can not help.

[Scrappile]

My guess is that you are pushing too hard especially for that thick of wood.  Cutting thick is a slow process, have to let the blade to the work.  It gets boring some times.

Edited March 1 by Scrappile

[rafairchild2]

30 minutes ago, Scrappile said:

My guess is that you are pushing too hard especially for that thick of wood.  Cutting thick is a slow process, have let the blade to the work.  It gets boring some times.

Not the problem.  I have been cutting for a long time, I am known for splitting lines, and had cut 3 toys just before things went sideways.  I made sure I was not pushing hard as well.  Sped up the blade, slowed it down, stopped pushing, and watched the blade... did all sorts of technique things.  Nope, this is mechanical/ adjustment.

Edited March 1 by rafairchild2

[JTTHECLOCKMAN]

If that being the case can you push on the arms and do they move. Maybe a bearing has worn out but again as the saws moves it should show signs of vibration. I know on the Dewalts the table use to rock. You would see this when you put your weight on one side of the table to the other when shifting your cuts. Maybe look at that. We are all just spitballing here. 

[kmmcrafts]

Take a piece of thicker stock scrap and cut into it a short straight line, then spin the piece to the back of the blade.. should slide right into the slot you just cut if the blade is square to the table. Might be a dumb remark here but squares can throw you off sometimes as table tops get worn.. especially those painted table tops like the EX saws have..  could be worn and giving you a false reading.

 

Edit to add: You table doesn't look too worn.. I have seen the dust port holes also give you false readings though.. 

There are only a handful of things it can be.. I've even had a bad "twisted" blade that was making weird things like this happen.. don't know how it got like that because it was brand new blade.. so if you haven't tried another blade maybe check that. I know you're not new to scrolling so..

Another thing is the actual wood itself. I've also had a piece of cherry wood that gave me fits.. turned out the wood was under some sort of weird tension and moved after being cut.. any other wood I cut was fine.. so it had something to do with the wood itself. 

Edited March 1 by kmmcrafts

[Bill WIlson]

Yea, I'd be tempted to blame it on the blade.  I've had brand new ones that would barely cut or would track wildly.  If you've already tried multiple blades, then I got nuthin'. 

[JTTHECLOCKMAN]

Over the years I had blades that did wonky stuff too. But you notice right away and just change blades. To have a saw just all of a sudden do something weird just hard to find. You should get a warning of a sound or an occasional bad cut. I gave you all I have too. 

[Scrappile]

One more thing from me.  Try different blades.  I have found that the blade that worked for me in the past does not work as good on a current project.  Different wood different blades.  I have quite a library of blames and I do not hesitate to switch around.  In all my years of scrolling, I have never had a "favorite blade". I go through many different types, many different configurations of teeth. 

[rafairchild2]

So here's my scrap wood test.  I cut into a 3/4" Walnut and as you can see, the cut is 90 to the table.  I did also back it in as well.  A little sticky though.

But here's the bug-a-boo.  I cut the same wood in a circle, and this is how far it will drop before getting stuck.  It seems the bottom of the blade is moving or something on turns.  I went really slow and made sure I did not put pressure the wrong way.  Again, everything is square to the table, I did a little fine tweaking of the set screws, and may try and see what happens if I move the bottom over more.

I did a 1/2" piece round cut and it dropped right though.

At least I was able to stay on the line during the turn, so I gained some blade control back.  This is a FD #3 UR.  So I have also tried 5, 7, and Pegas #10 on a straight cut.

I replaced the thumb screws, I made sure the set screw was flat, and I scuffed.  I tightened the rocker arms back just a little bit more.

For those with an Excalibur, how much play do you have in the rocker arms when there is no tension?  Same with the pagas chuck, is there any play when there is no tension?

Edited March 1 by rafairchild2

[kmmcrafts]

There is quite a lot of play in both upper and lower clamps and rocker arms in my saws.. There has to be some looseness otherwise it'll put a strain on the motor. Once the tension is on the blade everything should be pretty tight though. 

[rafairchild2]

7 minutes ago, kmmcrafts said:

There is quite a lot of play in both upper and lower clamps and rocker arms in my saws.. There has to be some looseness otherwise it'll put a strain on the motor. Once the tension is on the blade everything should be pretty tight though. 

Okay, that is how mine are.  I just wanted to double-check that the play was normal.  I noticed when I tightened them the motor slowed down, and figured that was not good!

[kmmcrafts]

Maybe we need to start at the beginning of the tune process.. Maybe something has moved out of alignment.. First check the upper arm is parallel to the table top by measuring it ( I like to cut a block of scrap that just fits under the arm and I slide it from the front to the back. ) I think my block is 3 1/4? that just fits, your saw may be different.. 

One thing that messes with tension on these saws is the threaded rod and or the threaded block that the rod screws into at the back knob on the saw.. The threads wear from the banging they recieve when you lower the upper arm down each time that puts pressure onto those threads and they will wear out over time... the harder you drop the arm down and let it slam to the lower position the harder it is on those threads.. When the threads get worn your saw will lose it's tension just the same way that a slipping blade will do.. you will cuss at the clamps and everything but what the actual problem is, LOL  

[rafairchild2]

1 hour ago, kmmcrafts said:

Maybe we need to start at the beginning of the tune process..

Darn, that was the one thing I did not do, and usually check it every few weeks if I am running hard.  Just tweaked it. So here is how close I am front and back, while under tension.  Pretty close to parallel. 1.5mm diff.

I am going to set my blade back where it was, as that seemed to make things worse. I was back to having trouble staying on the lines, and it is so far off 90 on the cut, it is not funny. The blade just was not responsive. Really drifty. 

I am pretty gentle raising and lowering the arm.  Only a couple of times it came down and slammed, I tightened it up to prevent that.  Is there a replacement part for the knob?  This machine is just over a year old.  I am not hard on it, and do not use it for major production.  I also do not run it full speed either.

[kmmcrafts]

The rear tension assembly is probably not the issue then, usually a good way to know is the saw starts lowering or raising the upper arm on its own and you have to keep adjusting the back knob to keep the upper arm parallel.. Seyco does sell the parts but around $55.. Mine was bad but i just took it apart and added blue loc-tite threadlocker and I haven't had any issues since then. 

There appears to be a screw missing in your first picture of the last post..  if the others are loose that could be your issue.. those square aluminum pieces insert into the arm tubes need to be good and tight as those keep your rocker arms in alignment..  

Edited March 2 by kmmcrafts

[OCtoolguy]

You say the saw is only a year old? Is it a Chinese made Excalibur? If so that opens a whole different can of worms. Please check the i.d. plate to see where the saw was made.

[rafairchild2]

Yes, this is the Chinese-made Excalibur.   I had a WEN 16, and was just working my way up.  At the time I thought it was made in Taiwan.  When I learned otherwise  I knew that it would have a limited life, thus why I kept it at slower speeds.  I was hoping for 2 to 3 years out of it.  Still, I have saved money and most likely will go Pegas or Seyco 30" if I am forced into it.

I am hoping right now whatever is causing this issue can be fixed.

Below are what I had cut before issues cropped up.  Look at the circles and the heart.  The pieces dropped right out and I stayed right on the lines.  Now, it's as if I have no control on the turns.

Edited March 2 by rafairchild2

[rafairchild2]

9 hours ago, kmmcrafts said:

There appears to be a screw missing in your first picture of the last post..  if the others are loose that could be your issue.. those square aluminum pieces insert into the arm tubes need to be good and tight as those keep your rocker arms in alignment..  

Yes, I just removed them before this photo.  That held the plate for the wood hold down.  So in this case, it does not affect things.  I wanted to get my angle as close to the blade for the parallel adjustment. That being said, I reinstalled the plate.

So far,

1. I have checked the upper and lower rocker arm bolts, just tight enough to not come off, and have minimal slop when not tensioned.  I made sure I did not over-tighten as to slow down the motor.
2. Checked the parallel of the arm to the table front to back.  Within 1.5 mm front to back.
3. Checked the level of the table and the level of the arm horizontally, left to right. Spot on.
4. Made sure my blade chuck holds the blade dead center top and bottom chuck
5. Made sure the blade when tensioned is dead 90 degrees to the table

I am going through checking other nuts and bolts, making sure that when the arm is up, it stays up.  I use two hands to raise and gently lower into place.

 

 

Edited March 2 by rafairchild2

[dgman]

Any chance the blade is slipping in the blade clamps after tensioning? Looking at the circle you cut, it looks like there is not enough tension on the blade to stay on the line with the thickness of wood you are cutting. Try this….tension the blade, cut a circle, then release the tension. Push down on the top arm. If there is a large bow in the blade, it means the blade slipped  in the blade clamps. If not, I don’t know what the problem is.

[rafairchild2]

1 hour ago, dgman said:

Any chance the blade is slipping in the blade clamps after tensioning? Looking at the circle you cut, it looks like there is not enough tension on the blade to stay on the line with the thickness of wood you are cutting. Try this….tension the blade, cut a circle, then release the tension. Push down on the top arm. If there is a large bow in the blade, it means the blade slipped  in the blade clamps. If not, I don’t know what the problem is.

Generally, I make sure that the blade is well-tensioned.  I scuff the sides of it as well.  I recently changed out the thumb screws thinking they might be worn.  It just seems odd this started all of a sudden.  I am very consistent in how I do my setup and tensioning. 

That being said, I am taking all suggestions and giving them a try. See my post below in a few minutes.

I just ordered a Pegas Chuck Head renewal kit, just in case that is an issue.

Edited March 2 by rafairchild2

[rafairchild2]

If you take a look at the image you can see the issue I am having.  The only way to describe this is the blade just not tracking as it used to. I did 3 pieces and all was fine, then boom 4th piece things went nuts. I find the blade is not 'responsive' on the turns, I can see it twist, but not respond back for quite some time, I am even pulling back to reduce any blade pressure from front to rear.

Note, I cut with the waste wood to the right However, all of a sudden the blade will 'snap' back of course over compensating when turning back.  I am making sure I am light in the hand, light pressure/push.

My gut is telling me that the lower chuck or the lower rocker is moving laterally while I am cutting the turns. Even though it is tensioned properly.  I just don't know where else to tighten.

Even though my blade is 90 degree's, to the table/piece, I adjusted the top chuck set screw to move the top of the blade to the left more to compensate for this issue, there is a lot you can move the screw before it is out of 90 when throwing the engineering angle on it.

The below image shows the issue after cutting.  The top of the piece is on the left side.  If you notice, there is almost a curve in the cut, again pointing to something mechanical.

PS: You can see I check everything to engineering grade angles and such. I am really anal about setup.

Edited March 2 by rafairchild2

[JTTHECLOCKMAN]

If you are pulling blades from the same batch, try switching to either different brand blades or a different group of blades. 

[jamieline]

Put a new blade in the saw and throw the tension lever. Turn on the saw, then turn off. Releasee the tension. Is there more flex in the blade than when you first put it in?

Try the same but this time cut a piece of scrap wood. Again if there is more flex in the blade I would say it is slipping in the holders.

I found this out when I was cutting some 1 1/2 stock. I also waxed the blade for every cut in the thick material.

[kmmcrafts]

Just my 2 cents from all that has been tried and done.. 

If it were mechanical you'd hear something different in the sound of the machine.. If the bearings was worn that bad you'd definitely hear something or see it with the square. Since everything is spot on yet doing this I believe you are losing tension.. I know you mentioned you changed the screws etc.. but if you have been tightening the blade too tight the chucks could have spread apart and not holding  the blade like it should.. yeah Pegas chucks can do that too even though they are made better. 

If you have your original chucks still... maybe swap them out and see if that rules out anything..  

Before changing out the chucks.. I know you mentioned you lower the upper arm down easy. What is your process for tightening the blade.. Do you lower it down and clamp the blade and apply tension and done? I have always found that on my Excalibur that I get slack in my blade if I don't tighten it twice.. What I do is clamp the blade tension it then release tension undo the thumb screw and then re-clamp the blade and apply the tension. I find that first time I tension sort of "pulls down on the upper arm" into its true resting place.. If you have the arm adjusted pretty snug maybe you're creating too much friction on that ball.. and it's not lowering the arm all the way into position easily. Behind that upper arm deal that you adjust is a spring loaded ball that sort of drags onto the upper arm for holding it up.. That ball actually should have some lube of some sort on it and it should be able to spin freely.. IF you have that too tightly adjusted it'll wear out the upper arm tube.. I've seen someone in the past showing a photo of how that ball seized up and wore a groove right through the steel upper arm tube. You don't want that so tight it's hard to move.. Should move freely yet have just enough friction to hold up the arm. 

 

Edited March 3 by kmmcrafts

[rafairchild2]

21 hours ago, kmmcrafts said:

What is your process for tightening the blade.. Do you lower it down and clamp the blade and apply tension and done? 

 

I am leaning towards slippage too.  i only replaced the thumb screws as i could not find my spare set screw.  I ordered a refresh kit from Pegas.

As to my process, to change/tighten the new blade. I first scuff my blade top and bottom with a sharpening stone.

1. I lower the arm into place. 
2. Without a blade in, I flip the lever to the TENSIONED position, as this allows me to see inside the chuck better.
3. I thread the lower part of the blade through the blade hole, then line the top of my new blade with the top part inside the chuck (hard to describe, but it is the same point every time). 
4. Next, I tighten the top thumb screw finger tight, and UN-tension the lever.
5. Reach under the table and tighten the bottom thumb screw.
6. From there, I UN-Tension the lever, loosen the top thumb screw, pull UP on the blade getting rid of any potential slack, and tighten the thumb screw.
7. After re-tensioning, I run the saw for a few seconds.
8. I repeat step 6.
9. After resetting the blade (if needed) I will check for any lateral movement and also 'pluck' the blade listening for that high 'C' note.
10. Rock and Roll.

Here's a video of my process.