Bosch 4100 users- question about the fence (lots of wander toward the rear)

[Kirill Kaminsky]

Hey guys, I recently purchased a bosch 4100 table saw, and I am quite upset that the fence wanders the amount that it does. Specifically, it is not stable toward the rear. If you hold the front of the fence, the fence wanders about 1/4 of an inch (toward the rear). It is impossible to move the fence and know whether the fence is parallel to the blade or not. Is there anyway to make the fence wander less? Anyway to make it so that when I move the fence left and right, it remains straight and parallel?

Thanks!

[Bret Duffin]

I'm not familiar with that particular model of saw but the situation you are describing is totally unacceptable. Once properly adjusted when you lock your fence lever down it should self align to the blade and be solid front to back. Some of the cheaper fence systems have a tension rod that travels through the fence to a locking device at the back. Check to see if you have one like that and that it is adjusted properly.

[Stephen Shapinsky]

I have that saw. In my opinion it's a decent saw for what it is (small and portable). The fence is nothing to write home about. All that said, what you describe is totally unacceptable.

1. I assume you've tried adjusting that screw at the rear of the fence. This should allow the rear "tooth" to fit into the rear groove snugly when the fence is secured. My fence has no play I can detect. p. 38 in the manuel explains this process. Perhaps the screw is over-tightened?
2. If you've tried #1 call Bosch. A fence that moves is unusable and unsafe.

[Chris Tsutsui]

I have a 4100.

To see if the fence is parallel to the miter slot you can do a quick test by aligning the fence with the miter slot, clamp it down, and feel with your finger if there's uneveness along the fence and miterslot.

Then you can make a simple jig that slides in the miter slot with a brass screw that feels the blade. Slide the jig along the miter groove and see if it binds or separates where the screw head projects out and makes contact with the blade. You can also use a combo square to do this.

The fence in the rear won't wander if you've tightened the adjustment knob properly and locked the fence down.

If the fence movement is sticky or inhibited by grime, etc... Clean both the fence and rails very well and spray a silicone type of dry lubricant, wipe it down and make sure everything moves smoothly. I use a paint brush to dust off the rails periodically.

I also use dry lub on the fence and table top to make sure wood glides easily. If the rough aluminum gets dirty, your wood will be very difficult to slide on the surfaces and then you have to push with force which can be dangerous.

The saw is really a top notch jobsite saw and I've really made a lot of work on it since it's my primary home table saw. If you cut a lot of hardwoods, then this saw benefits by the thin kerf rip or combo blades like that of Freud.

If you put on a full kerf saw blade and work with thicker hardwoods you will notice that it doesn't exactly cut as easily as a cabinet saw. :(

[Neil Brooks]

I have a 4100.

Me, too.


The fence in the rear won't wander if you've tightened the adjustment knob properly and locked the fence down.Bingo!

The manual can guide you through this. I'm perfectly happy with the saw, the fence, and the work I'm able to do with it....

I second everything Chris said.

I use an Incra 1000SE on mine, and a pretty good Ridgid blade (that will, at some point, be replaced by a Forrest WWII).

I've set mine up "properly," keep the internals fairly clean, and put a couple of coats of Johnson's Paste Wax on the top (and the miter slots) every other month or so.

Please close the loop with us, by letting us know your progress!

[Kirill Kaminsky]

Thank you for the responses. I think a few of you guys misunderstood the problem, sorry I didn't make it clear. Once the fence is locked down, there is no movement. It is solid. My problem is prior to locking the fence down, there is no way to know whether the fence is parallel because there is so much movement. The fence is supposed to be "self alligning" once you lock it down, but this does not happen. Unless I manually verify the fence is parallel to the blade (which is a huge inconvenience), i have no way to tell that it is straight when locked down. I think its unacceptable that I have to do this to get a straight cut everytime- the fence should remain parallel to the blade when it is moved left or right. The ridgid 4510 portable table saw does this- the fence is solid. When you move the fence left or right, it remains parallel to the blade. I was definitely expecting this to be the case with the bosch....

By the way, I did get into contact with bosch. There response was basically for me to take the saw to an authorized service center. I don't have the time or the space in my car to do so anytime soon :(

[Mike Reinholtz]

I've had the exact problem you are going through as well, it only got worse as time went on. My solution was to keep a 24" square resting where the fence storage is on the side of the saw. EVERY time I moved the fence, I would rest the square on the table and hold the fence up against it so I would know the fence was straight. I had horrible luck with pieces rarely coming out straight until I realized this was the problem. No matter how much I adjusted on the knob on the back of the fence, the problem remained. It's tedious, but it worked for me until I could afford something else. I eventually sold the saw. As far as the portable machines go, I think it's one of the best out there.

I could be totally out of line in saying this, but I don't think the portable saws are really made for "fine woodworking". A lot of times in construction people aren't looking for anywhere near the tolerances we strive for, which is what I would guess the portable saws are move geared towards.

[Daniel Nilsson]

I have a GTS10 which I think is the european version of the 4000. If the fences of the GTS10/4000 and 4100 are of the same construction, I have two tips:

1) when sliding the fence sideways, keep some forward pressure on it, it might help or not to not open the locking handle fully but only a little

2) if it doesn't lock down completely parallell to the miter slots when using mentioned forward pressure, you may open the screws on top closest to the locking handle a little and adjust the fence. Just make sure that with forward pressure, without locking, you're parallell, since locking doesn't move anything.

My 4000 had a fence that was slightly out of parallell, slightly turned to the left when using forward pressure, so it pinched stuff between the blade and the fence. For months I always applied a clockwise twisting motion just before locking down to force it a more correct position, before I finally took the eleven seconds to adjust the fence by loosening the mentioned screws.

[Daniel Nilsson]

Actually, maybe it was just one screw. Don't have the saw in front of me right now..

[Mikail Khan]

Had a bosch 4000 for about 5 years. No problems with the fence whatsoever.

Examine the slide pads on the fence to see if they are worn. Part #182. The slide pads should keep the fence perpendicular to the fence rail when the fence is not locked down. It is listed as a commonly replaced part and cost $4.

http://www.toolpartsdirect.com/cgi-bin/schematic.cgi/bosch/4000.139


MK

[Daniel Nilsson]

Good picture! What I was talking about was making sure #178 and #188 are perfectly perpendicular, which they weren't for me. You can ofcourse adjust for parallellism with the miter slots and blade in a number of ways, but when #178/#188 perpendicularity (is that a word?) is off, which apparently it can be in some cases, that's easy to fix. I guess you could adjust for uneven slide pad wearing this way too.

[Tom Esh]

...Once the fence is locked down, there is no movement. It is solid. My problem is prior to locking the fence down, there is no way to know whether the fence is parallel because there is so much movement. The fence is supposed to be "self alligning" once you lock it down...
Really sounds like the rear adjustment screw (which controls the clamping of the rear of the fence). Too tight and it will defeat the self-alignment. Too loose and the rear will move under pressure or not lock at all. The "sweet spot" is somewhere between. That's the way it's supposed to work. If not I'd suspect a defective part.