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Ridgid Table Saw (R4520) Riving Knife Issues

2483 Views 28 Replies 9 Participants Last post by  Steve Neul
Hope everyone had a good weekend! Over the weekend, I was trying to cut some hard maple with my table saw and was continually having issues where the maple would get stuck between the riving knife / fence. The stock was cutting fairly well for the first part of the cut (so does not appear to be a blade issue), but seems to get stuck only in the later half of the cut.

To fix this, I raised the blade as high as it would go and then attempted to re-calibrate the riving knife by adjusting the horizontal adjustment screws slightly and monkeying with the vertical alignment screws. After re-tightening everything, I lowered the blade and attempted to cut, but still stuck! The issue seems to be that even though the riving knife seems to be fairly aligned when fully raised (I was able to make some cuts, although with some difficulty, when the blade was fully raised), when lowering the blade, the riving knife changes positions and goes out of alignment.

I remember seeing this noted as an issue with these saws a while ago, but couldn't find a solution. I have had the table saw for about ~8 months now and have noticed the issue, but haven't had a problem (likely because I haven't been using wood as hard as hard maple and the riving knife has a little bit of give).

Has anyone else had this issue on these Ridgid table saws (or other table saws) and how did you fix it? Thanks for the help!
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Align the riving knife with a straight edge coming off the plane of the blade, checking for equal space on either side.
Use a feeler gauge if you want it perfect. It must be parallel to the plane of the blade.
If your work gets "jammed" half way through the cut, flip it end for end and complete the cut.
If it's pinching closed on the riving knife, slip a small wedge in the kerf spreading it open enough to complete the pass.
I keep one handy right on top of my fence head for easy access.
does the same blade cut other wood with no riving knife issues? Sometimes wood is under internal compression and will pinch down on knife or blade if you don't have knife. Can you shut saw of and remove wood? try turning it around and fee the other direction. I have had wood pinch blade on cabinet saw and stop blade. I have added tapered ship in out feed and spread wood apart and continue. I had to remove the knife and guard from my Grizzley because narrow kerf blades were same size as knife, no problem on fill kerf.
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The issue seems to be that even though the riving knife seems to be fairly aligned when fully raised (I was able to make some cuts, although with some difficulty, when the blade was fully raised), when lowering the blade, the riving knife changes positions and goes out of alignment.
I don't have a Rigid saw. From what you are saying the knife isn't in the same plane as the blade, to work well it has to be. I didn't find in the online manual where it talks about adjusting the knife.

To fix this, I raised the blade as high as it would go and then attempted to re-calibrate the riving knife by adjusting the horizontal adjustment screws slightly
Are there upper and lower horizontal adjustment screws? If so you can change the angle there.

The knife is a little thinner than the blade, the knife should be in the center of the kerf regardless of the blade height.
Also, verify your fence is parallel to the blade. If the rear of the fence is slightly closer to the line of cut than the front of the fence it will also cause pinching the wood against the riving knife.

The riving knife should not go out of alignment once set. Check to make sure there isn't any wood chips in the riving knife's mounting area that can throw off the alignment.
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Thanks everyone for the quick / very helpful replies! I think you all were exactly right that the riving knife was just out of plane with the blade. The adjustment system for the Ridgid table saws is a little frustrating; when you get the knife lined up, even if you're holding the knife firmly, tightening the screws moves the knife, so you have to start off holding the knife out of line.

I need to fiddle a little more, but think that I should be able to get it lined up. Will post back once I have a chance to give it a test in the next couple of days. Thanks again!

Ryan
Is there a way to to make a block with a notch for the kerf and clamp it to the plate of the blade, then cclamp the riving knife while tightening?

Could a misaligned fence throw the riving knife out of alignment?

Sounds like you’ve got it solved, but have you ever done a full alignment check on the saw?

Don‘t assume it’s right out of the box.

For some brands I think a periodic alignment check is probably a good idea.
Thanks everyone for the quick / very helpful replies! I think you all were exactly right that the riving knife was just out of plane with the blade. The adjustment system for the Ridgid table saws is a little frustrating; when you get the knife lined up, even if you're holding the knife firmly, tightening the screws moves the knife, so you have to start off holding the knife out of line.

I need to fiddle a little more, but think that I should be able to get it lined up. Will post back once I have a chance to give it a test in the next couple of days. Thanks again!

Ryan
I've never had to do this, but why not clamp two straight 1" x 2's to either side of the blade and include the riving knife as well. This will keep everything in the same plane as the blade and centered on the blade while you "gradually" tighten the screws.

Check the blade's parallelism to the miter slot first, as this is the "standard reference" for all other adjustments!
Thanks! The only issue with clamping on either sides of the blade / riving knife is that it will likely limit access to the screws that you need to tighten. I'm going to think about something along these lines though - surely can make something work!
Thanks! The only issue with clamping on either sides of the blade / riving knife is that it will likely limit access to the screws that you need to tighten. I'm going to think about something along these lines though - surely can make something work!
At least for this online manual the knife adjustment is on page 25.
Kind of confusing not being hands-on with the saw. Seems the adjusting is done with the knife locked in place, I don't see how it can be done with boards clamping the blade and knife, or that it should be tried. The way I read it it is the vertical adjustment you need to make to change the angle of the knife relative to the blade.

On YouTube search for: Ridgid r4520 riving knife
There are multiple related videos, I don't have the bandwidth to watch them.
Thanks! The only issue with clamping on either sides of the blade / riving knife is that it will likely limit access to the screws that you need to tighten. I'm going to think about something along these lines though - surely can make something work!
Well, it was a suggestion not having "hands on" the saw! I came up with another idea that is more simplified.
Make a kerf in a straight 1 X 3" about 12" long, centered, no riving knife. Then attach the knife just loosely and slip the kerfed piece of wood down over top of the blade and knife which will center it and make the knife parallel to the blade. IF you can access the screws, tighten them up and that should do it. You may need to slip a business card on either side of the kerf to center the knife?
Thanks everyone for the great suggestions! I ended up being able to get it much better aligned with a little trial-and-error work. I was able to get my maple ripped fairly easily (think saw HP ended up being the ultimate bottlekneck but not an issue).

I'm not sure why I thought the uneven raising knife was a known Ridgid table saw issue - I must have seen it in a review, but very exciting to have it raising / lowering evenly!

Thanks for all of the thoughts / help.
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Hope everyone had a good weekend! Over the weekend, I was trying to cut some hard maple with my table saw and was continually having issues where the maple would get stuck between the riving knife / fence. The stock was cutting fairly well for the first part of the cut (so does not appear to be a blade issue), but seems to get stuck only in the later half of the cut.

To fix this, I raised the blade as high as it would go and then attempted to re-calibrate the riving knife by adjusting the horizontal adjustment screws slightly and monkeying with the vertical alignment screws. After re-tightening everything, I lowered the blade and attempted to cut, but still stuck! The issue seems to be that even though the riving knife seems to be fairly aligned when fully raised (I was able to make some cuts, although with some difficulty, when the blade was fully raised), when lowering the blade, the riving knife changes positions and goes out of alignment.

I remember seeing this noted as an issue with these saws a while ago, but couldn't find a solution. I have had the table saw for about ~8 months now and have noticed the issue, but haven't had a problem (likely because I haven't been using wood as hard as hard maple and the riving knife has a little bit of give).

Has anyone else had this issue on these Ridgid table saws (or other table saws) and how did you fix it? Thanks for the help!
As of right now unless you have someone that can fabricate parts they're is no fix.i have had three of these saws and cannot get any resolution. I am currently trying to get them to replace the saw or refund my money. I also left a message on the better business bureau forum
Hope everyone had a good weekend! Over the weekend, I was trying to cut some hard maple with my table saw and was continually having issues where the maple would get stuck between the riving knife / fence. The stock was cutting fairly well for the first part of the cut (so does not appear to be a blade issue), but seems to get stuck only in the later half of the cut.

To fix this, I raised the blade as high as it would go and then attempted to re-calibrate the riving knife by adjusting the horizontal adjustment screws slightly and monkeying with the vertical alignment screws. After re-tightening everything, I lowered the blade and attempted to cut, but still stuck! The issue seems to be that even though the riving knife seems to be fairly aligned when fully raised (I was able to make some cuts, although with some difficulty, when the blade was fully raised), when lowering the blade, the riving knife changes positions and goes out of alignment.

I remember seeing this noted as an issue with these saws a while ago, but couldn't find a solution. I have had the table saw for about ~8 months now and have noticed the issue, but haven't had a problem (likely because I haven't been using wood as hard as hard maple and the riving knife has a little bit of give).



Has anyone else had this issue on these Ridgid table saws (or other table saws) and how did you fix it? Thanks for the help!
I have had three of these saws and all had the same issue especially with the raising and lowering of the blade amongst the fence pinching the stock causing kickback. This saw has been discontinued for a reason but can't seem to get any resolution. Unless you have someone that can fabricate parts That are a better quality than what they put in it,it's just not worth it. It has became a safety issue and I am trying to currently get them to either replace it or give me a refund. There are too many issues with this saw if I were you I would stop using it immediately
Hope everyone had a good weekend! Over the weekend, I was trying to cut some hard maple with my table saw and was continually having issues where the maple would get stuck between the riving knife / fence. The stock was cutting fairly well for the first part of the cut (so does not appear to be a blade issue), but seems to get stuck only in the later half of the cut.

To fix this, I raised the blade as high as it would go and then attempted to re-calibrate the riving knife by adjusting the horizontal adjustment screws slightly and monkeying with the vertical alignment screws. After re-tightening everything, I lowered the blade and attempted to cut, but still stuck! The issue seems to be that even though the riving knife seems to be fairly aligned when fully raised (I was able to make some cuts, although with some difficulty, when the blade was fully raised), when lowering the blade, the riving knife changes positions and goes out of alignment.

I remember seeing this noted as an issue with these saws a while ago, but couldn't find a solution. I have had the table saw for about ~8 months now and have noticed the issue, but haven't had a problem (likely because I haven't been using wood as hard as hard maple and the riving knife has a little bit of give).

Has anyone else had this issue on these Ridgid table saws (or other table saws) and how did you fix it? Thanks for the help!
Sounds like the riving knife needs to be adjusted slightly left. Myself I quit using a riving knife because pine was inclined to close up behind the cut and pinch on the riving knife.
Sounds like the riving knife needs to be adjusted slightly left. Myself I quit using a riving knife because pine was inclined to close up behind the cut and pinch on the riving knife.
I've stopped using the saw. Too many safety issues. That's why it has been discontinued. They need to replace the saw or refund the money
2230034, member: 23311"]
Sounds like the riving knife needs to be adjusted slightly left. Myself I quit using a riving knife because pine was inclined to close up behind the cut and pinch on the riving knife.
[/QUOTE]
I've stopped using the saw. Too many safety issues. That's why it has been discontinued. They need to replace the saw or refund the money
2230034, member: 23311"]
Sounds like the riving knife needs to be adjusted slightly left. Myself I quit using a riving knife because pine was inclined to close up behind the cut and pinch on the riving knife.
[/QUOTE]Personally I think the most dangerous parts of any machinery is the safety devices.
Sounds like the riving knife needs to be adjusted slightly left. Myself I quit using a riving knife because pine was inclined to close up behind the cut and pinch on the riving knife.
That's exactly what is supposed to happen!
When you are working with reaction wood like Pine, keep a small wedge immediately available on the fence of the saw to insert into the kerf right behind the splitter.
This will keep the kerf open until you finish the pass.
The riving knife or splitter also maintains registration of the work against the fence to prevent oit from coming away, rrotating up and over the blade, a "kickback".
I haven't had a single kickback since I reinstalled the splitters on my old Craftsman table saws.
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As of right now unless you have someone that can fabricate parts they're is no fix.i have had three of these saws and cannot get any resolution. I am currently trying to get them to replace the saw or refund my money. I also left a message on the better business bureau forum
If you do not have a replacement, and while you wait for your refund. Could you remove the riving knife, and create or buy a zero clearance throat plate with a splitter?
That's exactly what is supposed to happen!
When you are working with reaction wood like Pine, keep a small wedge immediately available on the fence of the saw to insert into the kerf right behind the splitter.
This will keep the kerf open until you finish the pass.
The riving knife or splitter also maintains registration of the work against the fence to prevent oit from coming away, rrotating up and over the blade, a "kickback".
I haven't had a single kickback since I reinstalled the splitters on my old Craftsman table saws.
I don't like it or anything else clamping itself to the riving knife or anything else. It can pinch the riving knife where you have to turn the saw off and drive a wedge in the saw cut to complete the cut. Actually the first time I got hurt on a saw is when a board pinched the riving knife and I didn't have the time to deal with that problem so I tried to force it loose and got a kickback.
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