EX-21 help needed - Urgent

[Bill WIlson]

OK, I'm in the middle of Christmas projects and all of the sudden my EX-21 developed a loud knocking sound, at all speeds.  I bought this saw from Seyco, the year before manufacturing went to China.  I've never had any problems with it.  This problem did not come on gradually.  I was cutting puzzles and it was running smooth, then all of the sudden it wasn't.

I called Seyco, but Ray isn't in until Monday and the fellow I talked to suggested a couple basic things, but couldn't go much farther.

The knocking seems to be coming from the front, but I can't say for certain.

No obvious loose hardware anyplace.

No apparent damage, excessive play or loose hardware in the upper & lower front rockers.

Blade tensions normally.

Top arm is parallel to the table.

Bottom clamp thumbscrew is not hitting the table.

Took the cover plate off and checked the rear rocker arm & cam.  No apparent damage and nothing seems loose.

I admit, I'm stumped and not sure where to start.  I hate to start tearing stuff apart, at least until I have some idea what I'm looking for.  If anyone has any suggestions, fire away.

Thanks

 

[kmmcrafts]

In both top and bottom arm tubes there is a bellows but only one is for the air blower, the other is to be a cushion to prevent the link rods from hammering on the tube or saw body. I call them tubes as it’s just square tubing. I’m thinking that might be the issue. 

Edited November 22, 2023 by kmmcrafts

[Bill WIlson]

That could be.  I know the top & bottom arms are held in with 4 screws, but to get them out, do I have to also disconnect them from the drive links?

[kmmcrafts]

Weird, I replied an hour ago on my phone but it didn't go through, LOL.. Probably show up after I re-type it all out again..

Yeah, you will have to remove just the one screw that holds the link arm that goes into the tube.. The one that goes back to the motor.. The other short links that go to the front blade chucks etc can stay on I think you just need to remove the one so you can pull out the end cap with the four screws on the tube itself.. That should allow you to pull that out and see back in there better. 

If your air blower is still working fine it's likely the one on the bottom arm.. but I would run the saw and try to determine if the noise is in the top or bottom arm. You might be able to shine a small pen light or similar in there and be able to see if the bellows has come apart or not..  

[kmmcrafts]

The bellows are pushed onto a little nub that is on the rocker arms.. I've even seen where they just popped off.. likely from the rubber becoming deteriorated over the years.. You might be able to use some tape.. probably electrical tape would work as it's a bit more flexible.. to sort of doctor it up until you can get a new one mailed in to you. Also might be able to match something up at a auto parts store. CV boots for a small car or ATV and cut it down might also work.. 

Here is what it should look like when pulling the end caps off.. https://seyco.com/product/ex21-c27c-top-and-bottom-front-rocker-arm-assemblies/

[Bill WIlson]

Great stuff Kevin.  I hope that this turns out to be my issue.  The fact that it happened so suddenly, without any warning and that nothing seems loose, broken or out of alignment, it would make sense.

I can't seem to isolate the noise precisely, but If I were to guess, I'd say it is coming from the bottom arm.  My first thought was that the lower thumbscrew was hitting the underside of the table, but that wasn't the case.  I'm getting air out of my blower nozzle, which would seem to lend credence to it being the bottom arm.

Thanks again Kevin.  It may be a few days before I get back to this, but I'll post an update on what I find.

 

[kmmcrafts]

Let me tell you, those bellows can be a bit of a pain to get back in the tube without knocking them off the rocker arm or getting them twisted up.. I told myself the next time I do it I'm putting some soapy water or something a little slick to help them slide into the tube better.. they seemed to want to catch on something and pull them off the little nub or get all cockeyed in there.. so maybe a tip to save some frustration maybe coat the rubber where it would want to touch the inside of the tube with a little soap or something.. Let me know if that helps, LOL.. maybe just my saw that I struggled with but anyway.. just a heads up that it might be tricky to put back in.. 

[Bill WIlson]

Thanks for the tip Kevin.  I'll keep that in mind.

[Bill WIlson]

First off, Happy Thanksgiving to everyone!

Got up early this morning and began disassembly of my scroll saw.  Kevin, you were right!  I removed the bottom rocker arm and when I pulled out, the bellows was in pieces.  Now all I have to do is get a replacement and I should be back in business.  I'm tempted to try and attach a small piece of thin rubber sheet inside the tube to supplement the cushioning but not sure how or if that will help.  I've been cutting stand up puzzles out of 7/8" thick IDKWII wood and running the saw at full speed, which I rarely ever do.  That may have contributed to the self-destruction of the bottom bellows, but I feel better at least knowing what happened.

Again, thanks so much Kevin.  You are the man!  Have a great holiday!

[dgman]

46 minutes ago, Bill WIlson said:

First off, Happy Thanksgiving to everyone!

Got up early this morning and began disassembly of my scroll saw.  Kevin, you were right!  I removed the bottom rocker arm and when I pulled out, the bellows was in pieces.  Now all I have to do is get a replacement and I should be back in business.  I'm tempted to try and attach a small piece of thin rubber sheet inside the tube to supplement the cushioning but not sure how or if that will help.  I've been cutting stand up puzzles out of 7/8" thick IDKWII wood and running the saw at full speed, which I rarely ever do.  That may have contributed to the self-destruction of the bottom bellows, but I feel better at least knowing what happened.

Again, thanks so much Kevin.  You are the man!  Have a great holiday!

Bill, now that you have figured out what your problem was, it’s time to think about a spare saw. If you’re like everyone else, you don’t have room for a second saw, but if you had a spare saw, you wouldn’t be in such a panic like you are now. When I purchased my current saw, I decided to keep my old saw just in case of such an event. 

[rafairchild2]

25 minutes ago, dgman said:

...it’s time to think about a spare saw. ...

So true.  I know it is difficult for people space and $$$ wise to have a backup.  This applies to anything, but if you are a business, always remember...

"Two is One... One is None..."

[TAIrving]

And Advanced Machinery has a special on right now for a Hegner.  

[kmmcrafts]

Happy Thanksgiving to you all as well. 

 

I’m glad that was all  the issue was. I’m not sure what you could use for a band aid for a few days until the correct part can placed in there. I know some ATV’s have CV boots that are close to the same thing but you would have to cut it down to size. Auto parts stores may have something. 
 

 

[OCtoolguy]

How about a piece of high density foam rubber instead of a bellows that really just serves as a bumper?

[BadBob]

A second saw is an excellent idea if you are depending on it. If I have trouble with my saw, it always happens at the worst time.

I don't have a lower bellows in my EX-21. I've had the whole thing apart, and there isn't one in there. Do I need one?

[kmmcrafts]

1 hour ago, BadBob said:

A second saw is an excellent idea if you are depending on it. If I have trouble with my saw, it always happens at the worst time.

I don't have a lower bellows in my EX-21. I've had the whole thing apart, and there isn't one in there. Do I need one?

Probably not, I  believe some of the saws have a different link arm system and they don’t use the second bellows.

If it’s not banging loud when running it doesn’t use the second bellows I assume.

[OCtoolguy]

3 hours ago, BadBob said:

A second saw is an excellent idea if you are depending on it. If I have trouble with my saw, it always happens at the worst time.

I don't have a lower bellows in my EX-21. I've had the whole thing apart, and there isn't one in there. Do I need one?

If you're not having issues I don't see why. 

[Bill WIlson]

The idea of a 2nd saw was one I seriously considered back when I bought the EX-21.  I was replacing a DeWalt that had never given me any problems, but I had used for a number of years and when the opportunity to get an EX came around, it seemed expendable.  I really had no good reason to sell the DeWalt, other than I had no space for a 2nd saw.  Even still, I almost kept it, even if I would have had to break it down and tuck it away someplace.

As it turns out a friend was interested in a back-up saw.  He makes stuff to sell and had a couple sons who he thought might have some interest in scrolling, so I sold it to him.  Funny thing, one of the first thoughts that crossed my mind, when I didn't know what was wrong with my EX or when I could get it running again, was to call my friend up and ask him if he still had the DeWalt and offer to buy it back from him.  I still don't have anyplace to put a 2nd saw, but this isn't the first time this has happened to me.  Many years ago, my first scroll saw, a Craftsman, broke down under similar circumstances.  I borrowed my BIL's Delta Q3 to finish up my Christmas projects.  I eventually replaced the Craftsman with the DeWalt.  Since I don't make stuff to sell, I never really felt that a back-up saw was anything more than a luxury.  Might have to reconsider. 

[Phantom Scroller]

 I could wrong but I had a knocking noise on the front of my ex21 only to find it was the arm that holds the hold down hitting the machine. Worth a check unless you removed the arm of course.Roly

[Bill WIlson]

The hold down arm is but a distant memory. 

But thanks for the response. 

[OCtoolguy]

1 hour ago, Bill WIlson said:

The hold down arm is but a distant memory. 

But thanks for the response. 

As most are.

[BadBob]

3 hours ago, Bill WIlson said:

The hold down arm is but a distant memory. 

I have one. It's in a box.

[kmmcrafts]

Found a great use for my hold down.. I welded a old cam / timing gear on it and then welded some 1/4" bolts to it and it makes a great handle for holding the cam timing gears while trying to re-install a timing chain on a 3.7L or 4.7L Dodge or Jeep.. Made a nice handle and you can stick a screwdriver through the slot where the blade normally is to hold everything while you go down underneath to make sure everything is timed correct before tightening all the bolts.. I'm sure you all could find something to do with yours if you have a need for a tool or something to make with it. LOL 

[OCtoolguy]

@Bill WIlson, did you fix your saw? I've been waiting to hear.

[rjweb]

We want pictures, RJ