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bosch 4000 table saw problem

cawfy's picture

Does anyone here have the bosch 4000 table saw?If so have you had any problems w/the blade lifting mechanism?Mine had just recently started to have trouble lifting(it's approx. 2 y/o),not bad but definately not like the ease of it's usual operation.I keep it pretty clean underneath but blew it out anyway.It seemed to work fine for a while but the trouble came back and after trying to see what it might be I noticed some play between the gear on the threaded rod and the cast bracket on which it sits.

The threaded rod goes through the gear and the diameter is reduced and it goes through the bracket where it passes through a s/s washer and it's last bit of lengh is threded w/2 nuts one used I imagine as a keeper.

The nuts where loose so I tried tightening them but it did not help the situation.Then I backed the nuts off a bit and tried again,no good.I tried pushing up on the motor while raising the blade and it went up,no problem.Couldn't quite figure out why it had the play in the mechanism but left the blade up so I could finish cuting some 2x material.

Just then a friend happened by and after catching up a bit told him my tale of woe and decided to do what I was telling myself not to do..show him whats happening w/the t/s.Sooo,I go over everything and we have the saw on it's side trying to figure whats what,trying this,that and the other thing and presto change-o.That sucker(gear on threaded rod)is now stuck fast,will not budge a bit.Niether w/ brute strength or blunt instruments.The saw is now farquat of course because it is stuck in the lowered positioin.At least the blade is safe for a while.

Any help from a bosch t/s owner or someone w/ a similar blade lift mechanism is much appreciated.Other than that trouble I really like this saw but I think there may be a design mistake in that mechanism or that another s/s washer should've but was not installed between the gear and the bracket itself.(the gear is some type of plastic or composit and it sits directly on the bracket).

Thanks for any help you may offer.

regards,George

(post #123115, reply #1 of 15)

I believe what your experiencing is a known problem with the slides. They corrode slightly and cause the mechanism to bind if not kept lubricated. Perhaps in cleaning you got them too squeaky clean. I think they recommend Lubriplate or similar but now that its bound up something that will get into the mechanism would likely be a better choice. At least until you get things moving.

I would give simple WD-40 a shot and try to free the mechanism by working it gently but firmly from both ends. Both the crank and pushing it up from underneath.

When I get a chance I will try to find my manual, dig up that section and post back. You might also try Bosch technical support. I'm pretty sure they have a 1-800 number. From what I hear they are pretty helpful.

They might also have a web site and have the manuals available for download as a PDF file.

(post #123115, reply #2 of 15)

Mine is 2 years old and a scaffold fell on it once but works like a champ.  So other than the slightly crushed look it is none the worse for wear.  DanT

(post #123115, reply #4 of 15)

Hey Dan,can you post a pic of that champ w/the battle scars?What got crushed,the saw body or the stand?Who was responsible for the crushing?You must've imediately been bummed out.Ouch!

Glad it's still workin for you!

George C.

(post #123115, reply #5 of 15)

Ive been holding out and havent picked a portable yet. 


The only problem I have heard in my research is that the vibration of that saw loosens all the bolts, so I guess as a regular maintenance measure you may want to occasionally check them.


-zen

(post #123115, reply #7 of 15)

Ummm, well........I.......ummmm...........guess I was the one responsible.  Thanks for asking lol. 


We have 12' Spartan box trucks for work.  Inside they have a step like deal and thats where we carry the table saws.  I needed 3 sections of scaffold for a high living room we were painting so I went to my buddy's shop and loaded it all.  While rounding a curve at about 60 the 6 pieces of scaffold switched sides and landed directly on top of the right front corner of the saw.  Bent it down some, broke the plastic off the fence and did so with enough impact to break the plastic base in that corner. 


Since it was only 6 months old we straitened up the the fence and the table doesn't affect anything.  The base still had enough left to hold itself up so we still use it.  It does work better on its own stand than it does on a table top though.  DanT

(post #123115, reply #10 of 15)

DO NOT USE WD-40 ON THAT SAW!!!!



Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!!   What a Ride!


Forget the primal scream,  just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #123115, reply #11 of 15)

Ok, didn't say I did.  But always good to see someone who feels strongly about his point.  DanT

(post #123115, reply #12 of 15)

I'll reiterate the WD-40 point.  I ruined several bottom brackets on bicycles when I was younger using said product as a "lubricant."  Live and learn!


Dustin

(post #123115, reply #13 of 15)

WD-40 is not an issue in this case it is being used to free a stuck mechanism. You would think I advocated using the blood of unbaptized babies.

Actually in this application, slides it works OK, not great but I have used and seen it used in similar cases for decades, as long as it is allowed to dry for a bit and wiped mostly dry. Certainly better than nothing as long as the sawdust is kept from caking on the mechanism.

These slides are not high velocity wear surfaces like bearings or motor driven gears. I use an industrial wax compound but wax, and the dry lubricants suggested are lousy penetrants and are unlikely to help free a stuck mechanism. Once he gets everything free he can remove the ever so offensive WD-40 and replace it with the blood of unbaptized babies or something similarly uncontroversial.

As I remember, been several years, it Bosch recommended Lubriplate, or was it a moly grease, but I haven't been able to find the manual. Wax works for me.

Went to the Bosch site and looked up the manual. Lo and behold they recommend "SAE 20 or 30 oil or WD-40" for "elevation support rods and gears", "sliding rails and supports" and "table locking cams'. Go figure.

From:
http://66.77.255.87/Images/BOSCHPDF/4000_pdf/PDF_MANUAL/2610998763%207-00%204000.pdf

Page: 54 under: Lubrication.

Even if not used for actual lubrication WD-40 is useful for removing pitch, sap and tar from the saw and especially the mechanisms. It occurs, reading the manual refreshed my memory, to me there was a notice that came with my saw that removal of these deposits is necessary to keep the elevation mechanism operating smoothly. Mineral spirits or turpentine would also work but WD-40 is handy.

Perhaps sap buildup caused the gentleman's problems. Liberal use of WD-40 might get it unstuck. Of course he can wipe away and lubricate with anyhting he wishes.

(post #123115, reply #14 of 15)

I'm not ragging on ya, just trying to say be careful around any greased areas that you want to remain greased.


Dustin

(post #123115, reply #3 of 15)

Hi 4Lorn1,thanks for the quick reply and the tips.Though the slides appeard to be pretty clean I didn't think to chk for any corrosion.I will chk it out.As far as lubing it though,I can do that,it's the "working it back and fourth" thats the problem.I will call Bosch and see what they may be able to do to help me out.I'll also be chk'n thier web site out.

Thanks for your time and effort 4Lorn1,much appreciated!

George C.

(post #123115, reply #9 of 15)

clean the slides with wet aluminum foil... dry... and use a dry lube...


Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!!   What a Ride!


Forget the primal scream,  just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #123115, reply #8 of 15)

DO NOT USE WD-40 ON THYAT SAW!!!!


yur asking for more problems....


dry lube ONLY....



Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!!   What a Ride!


Forget the primal scream,  just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #123115, reply #6 of 15)

You should definitely call Bosch Tech support.

I had a similar problem with mine, and the problem was due to sawdust clogging the two plastic gears you're talking about (that raise/lower the blade).

I mentioned this to a Bosch rep, and he told me about cleaning the gears regularly (like everyday if the saw is used heavily) with some sort of brush. I keep a 1/2" acid brush with the saw, and I cut off a bit of the bristles so the brush is stiffer.

If you are keeping these gears clean, then you have some other problem.

The Bosch guy gave me a free chit to have the saw "fixed" (even though it was out of warranty). I thought the repair service would mount some sort of shroud to keep dust out of the gears. Turns out they just mounted some kind of additional support bracket on the raising mechanism, since apparently, if you force the crank (when the gears are clogged with sawdust) there is an aluminum housing that can crack. According to the repair guy, it would cost about $200 to replace that housing.

He said the only real solution is to clean the gears regularly -- daily, if you are cutting resinous wood such as framing stock.

This is clearly a design flaw on an otherwise good machine.

******************************************************** "It is what we learn after we think we know it all, that counts." John Wooden 1910-2010

bosch 4000 blade rising problem (post #123115, reply #15 of 15)

2 quick spritzes with WD40 did the trick.  Thanks 4lorn1.  My baby is now baptized.