Back of rip fence not locking

[rlb1961]

Well, here is another thread on this problem. I read through a few other threads to see what other people had done, but could't seem to get the back of my fence to lock down. I made sure the lip was in the channel, tightened the adjustment screw, etc. Nothing helped. When I pushed stock tight against the fence, it would deflect as much as 1/4" at the back.

I discovered two things right away. When I engaged the locking handle, the lip on the back of the fence barely moved, maybe a couple thousandths of an inch at the most. And even when the adjustment screw was tightened all the way down, it would not engage the back rail.

The first thing I did was go down to my local hardware store and get a longer screw (it is just a 10-24 pan head screw - I got 2" screws to replace the original). That allowed me to adjust the screw far enough to make the lip engage the rail. The only problem now is that I have to adjust it so close to the rail to get it to engage when I tighten the handle that the fence will not slide smoothly when the handle is lifted.

After taking apart the fence and inspecting it, I think I know what the problem is, but I am not sure what the fix will be. If you look inside the front part of the fence, you will see that the handle operates an eccentric cam. In addition to locking the front of the fence to the front rail, the cam raises a small lever against the rod that runs through the fence. This pressure against the rod is what is supposed to engage the lip on the rear of the fence against the rear rail. The problem is that the surface against which the lever rides has worn down, and so instead of pushing toward the back of the fence, it rides almost straight up and down. This limits the "throw" of the rod to a few thousandths of an inch.

In order to correct this, I am sure I need to shim the surface in some way so that the lever pushes the rod toward the rear of the fence again. I only need to gain about 1/32" throw. Any suggestions? I tried glueing plastic shims in, but they didn't slope toward the back of the fence, so the lever continued moving straight up and down, just a little further out.

I thought about cutting a very small wedge-shaped piece of hardwood and using that as the bearing surface, but I don't know how I would attach it to the aluminum surface.

Does any of this make sense?

[RayintheUK]

Skip,

Most of it does, yes. Have you looked at an exploded diagram of the parts? There's one on my site, the link is:

http://www.raygirling.com/ryobi/ryobi.htm#figure61

N.B: The site will take a little while to load because it's so graphics-intensive, but when it's settled down, hit "Refresh" and you'll be straight to the picture. There's a parts list underneath. Maybe a new part is your answer?

HTH

Ray.

[Brian G]

Skip, after reading your paragraph:

quote:After taking apart the fence and inspecting it, I think I know what the problem is, but I am not sure what the fix will be. If you look inside the front part of the fence, you will see that the handle operates an eccentric cam. In addition to locking the front of the fence to the front rail, the cam raises a small lever against the rod that runs through the fence.

I have an idea that you might try, although my poor ability to 'splain what to do might be confusing. The first time I took apart the fence and reassembled it, the eccentric roller (Part 19 on page 47 of the manual) wouldn't engaging the locking lever. What happened was that, during reassembly, I didn't have the locking handle "high enough" (i.e., in the full upright, and unlocked position). That caused the "fat part" of the eccentric roller to be in contact with the front locking plate (Part 25 on page 47), and didn't give enough "distance" to move the rod far enough to engage the rear locking mechanism.

Try this (or something like it):

Disassemble the fence (i.e., the two adjustment screws on top), and loosen the screw on the rear locking mechanism (the one you replaced) to almost the full distance it can be loosened without falling out. I found reassembly easier if I sat in a chair and held the fence vertical (locking handle topside). That way, the rod that connects to the rear locking mechanism won't slip out of it's hole. When you reassemble, make sure the locking handle is 7/8-ish to full up (i.e., unlocked) position. You may have to hold it in place with your thumb. Now, with your other three hands ( put the front assembly back on the rip fence (all the while keeping the locking handle in full unlocked position), making sure that the rod finds the hole it slides in. Screw in the adjustment screws (the ones on top). Don't worry about fine tuning for square, yet. You may have to do the disassemble/reassemble a few times.

Now that it's back together, set the fence on the rails, and engage the locking handle slightly. It probably won't engage the rear locking mechanism fully; tighten the screw a few turns until it does. It's a trial and error thing at this point. It's possible to have the locking handle too far to vertical during reassembly, so that it locks "too soon" and the handle ends up being in the way of infeed. Disassemble, go through the process again, but this time hold the locking handle at about 3/4-ish full vertical.

Long and confusing. . . .probably. I can clarify.

[Black wallnut]

Skip, this is a shop day for me so I may not get back to you as fast as sometimes but try removing your eccentric roller and turning it 180°. It is possible that it is installed incorrectly, it has happened before. How old is your saw? Which model? Something just is not adding up to me. I've had mine for 5+ years and have not worn out the part you are talking about, nor have I heard of anyone else wearing this part out. Methinks, IMHO, that this is not your problem but I've been wrong before.......once. Let me know.

[RodKirby]

MarK - ditto on my BT3000 - 10 years old!

[rlb1961]

quote:Originally posted by Black wallnut

Skip, this is a shop day for me so I may not get back to you as fast as sometimes but try removing your eccentric roller and turning it 180°. It is possible that it is installed incorrectly, it has happened before. How old is your saw? Which model? Something just is not adding up to me. I've had mine for 5+ years and have not worn out the part you are talking about, nor have I heard of anyone else wearing this part out. Methinks, IMHO, that this is not your problem but I've been wrong before.......once. Let me know.

Mark, when you talk about turining the eccentric roller 180 degrees, I assume you are talking about along the horizontal axis (parallel to the pin), and not the weritcal axis...

[rlb1961]

quote:
Mark, when you talk about turining the eccentric roller 180 degrees, I assume you are talking about along the horizontal axis (parallel to the pin), and not the weritcal axis...

Make that "turning" and "vertical"... (where did my Spell Check go?)

[Black wallnut]

I think so......my spell check does not always work either.....there is only two ways that it can go on..one right / one wrong...pretty easy to check.

[rlb1961]

Like everyone else in the USA, most of my day yesterday was spent with friends and family, so I did not have a chance to get back to this. I am going to take the fence apart again today and see if anything is put in backward, etc.

Just for those who may be having a similar problem, I did find an effective, if cumbersome, workaround until I can get the problem fixed permanently. As I said in my first post, after I added the longer adjustment screw to the back, I could tighten the screw enough for the lip to engage when the locking handle was lowered, but it would bind on the rail if I tried to move the fence with the locking handle up. My solution for the day (I was in the middle of building a CMS station) was this: I would keep the adjustment screw loosened by 1-2 turns when moving the fence. Once I had the fence exactly where I wanted, I would engage the locking handle, then tighten the adjustment screw snug with the end of the rod. I would then lift the handle, tighten the screw another 1/4 turn, and re-engage the locking handle. The fence was rock-solid at both the front and the back!

It is a hassle to keep adjusting the screw for each fence setting, but better than getting sloppy cuts from the fence deflecting.

[rlb1961]

Fixed it! I took the time to take the entire fence apart today, and really looked at how everything worked together. I discovered I had the right idea, but the wrong solution...

As I said earlier, the problem was the length of the "throw" of the pushrod. When the locking handle was lowered, the pushrod was not travelling to the rear of the fence enough to lock the rear of the fence to the rear rail.

In looking carefully at the front of the fence, I found that what I was calling the lever (but the parts manual calls the clamper) had about 1/2" section without a shoulder - just flat metal. I also noticed that this section on mine was slightly bent toward the front of the fence. This slight angle on the bearing surface of the clamper was what was causing it to rise and fall almost vertically. Once I took a pair of vise grips and a pair of channel locks and straightened the angle, it caused the clamper to move more from front to back as it rose, creating the movement in the pushrod that was needed.

After re-assembling the fence and adjusting the screw correctly on the back of the fence, it now slides smoothly when unlocked, and clamps down securing at both ends when locked!

Thanks for your help everyone! I hope this helps anyone else having the same problem!

[greglwood]

In looking carefully at the front of the fence, I found that what I was calling the lever (but the parts manual calls the clamper) had about 1/2" section without a shoulder - just flat metal. I also noticed that this section on mine was slightly bent toward the front of the fence. This slight angle on the bearing surface of the clamper was what was causing it to rise and fall almost vertically. Once I took a pair of vise grips and a pair of channel locks and straightened the angle, it caused the clamper to move more from front to back as it rose, creating the movement in the pushrod that was needed.

After re-assembling the fence and adjusting the screw correctly on the back of the fence, it now slides smoothly when unlocked, and clamps down securing at both ends when locked!

Thanks for your help everyone! I hope this helps anyone else having the same problem!

Ok, so I am reviving an old thread. This explains my problem to a tee. I have check everything and all is well. Cam is positioned correct. No worn or broken parts ,etc. However my clamper is also angled as explained earlier on this thread. Now my question is, is it suppose to be straight? This is no small soft piece of metal. This would take considerable force to bend, which make me think it came from the factory this way and if so then it is propably suppose to be that way.Hard to believe they would have such a manufacturing defect.



Anyway my problem is exactly as he described; with the fence disassembled and the cam in place, if I operate the handle the rod does extend, but you would have to measure it with a micrometer. Less than an 1/8 of an inch, maybe not even a 1/16th.


Thanks
Greg

[Black wallnut]

Welcome to the forum Greg! Great catch!!! Yes your problem is that your clamper is bent. It should be straight not bent. It is possible that it was bent the very first time it was placed on the rails. When the fence is correctly assembled you should not have to lower the locking handle very far past parallel to the floor.

[greglwood]

Is there suppose to be any curve at all or should it be perfectly straight?

[Black wallnut]

Straight top to bottom. Side to side I'm not positive about.

[greglwood]

Straight top to bottom. Side to side I'm not positive about.

Well that did it. I bent it straight and reinstalled. Works perfectly now for the first time ever. I see now why/how. As you pull the lever down and the cam rotate, it forces the top of the clamper to push on the slanted part of the front block, which in turn causes the top of the clamper to push back toward the roller holder (back of the fence). When it was bent it would not rise. The bottom of the clamper would push toward the roller holder, but since the top did not rise on the slant, its distance to the roller holder did not really change. It must rise on the slant in order for the distance to shorten.

I still have no idea how it got bent in the first place.

Greg