Okay now, please take a patience pill. I’m a wanna be woodworker but gettin’ better at it and I have a problem. I have been given an old 9 inch Rockwell tablesaw. It runs good and the blade seems to run straight up and down BUT it runs at an angle when you look at it from front to back. I’ve looked underneith but can’t tell what adjustment to make. Can anybody help?
Thanks!
Life may be short but it can be very wide!
Replies
An angle as far as out of parallel with the miter slots, right?
If so, you need to loosen teh trunnion bolts and nudge the trunion brackets until the blade is parallel. A long F-clamp can help give leverage. Also be prepared to try a few times before getting it just right as the act of tightening the bolts can push it back out of alignment.
........heh, heh, heh! Thats the problem.....What and where are those trunnion bolts located? Do I have to stand on my head to get to them? Do I have to lay the saw on it's side to get to them or what?
Thanks Samson.Life may be short but it can be very wide!
If your Delta is old enough and has the motor hanging off of the back, you may be able to go in through the motor mounting location to make adjustments. You can remove the motor and remove the back panel from the base to gain better access.
"I cut this piece four times and it's still too short."
You are so right, as would be the case for most/many such saws. However, the front end trunnion most likely has some case metal in the way, and will probably require contortions and cussin' in accessing the trunnion bolts. Does Delta cut bolt access slots in its sheet panels?Mine's an old Craftsman, and I can get to the rear bolts with no problem at all per your description, but the fronts are unpleasant, bearish, pain-filled, agonizing, frustrating, danged difficult and ... and ... (he sobbed.)---John
========================================="What you leave behind is not what is engraved in stone monuments, but what is woven into the lives of others."
---Pericles
Befor you try to deal with the trunions, check to see if the tabletop is bolted to the frame. Adjusting the blade to be parallel with the miter slot can be done by adjusting the table.
The only time I adjust my trunions on my G1023 is to ensure that the blade, when tilted, is still parallel to the slots. In this adjustment, the trunion height is usually adjusted.
But each table saw is different. Find a manualn for your saw, it should help you.
I'm not familiar with the Rockwell 9" saw, but I'm assuming it is similar to most any other contractor or cabinet style saw. If it is not, this stuff may be well off base.
Look under your saw table top. The blade is on a carriage that allows the blade to be raised or tilted wiht the hand wheels on the outside fo the cabinet. The trunnions are the brackets (for lack of a better word) that this carriage rides on. They are bolted to the table top from underneath - and yes they can be a b*tch to reach and work on.
Hi -
First things first - rough check of alignments:
Eyeballing may tell you something useful sometime in your lifetime, but will lead you far astray in machine adjustments. The key for blade parallelism lies in measuring from the miter gauge slot. Adjust the trunnions to achieve "absolute" parallelism between blade and slot.
Always adjust the fence to exactly match the plane of the blade. Even if the blade isn't square to the table, it will rip well against a parallel fence.
In other words, if you're eyballing in reference to the fence, then the blade could actually be perfect but the fence misadjusted. In truth, it would be a far stretch to imagine trunnions so far from home that the misalignment could be easily eyeballed - they just don't have that much range of movement. I suspect that your fence got a whack and just needs to be put back into alignment. For initial evaluation, perform a few easy alignment adjustments before getting into the tough stuff.
You may need to purchase a good engineer's square to adjust the blade for perpendicular. Once you think it's perpendicular to the tabletop, cut a piece of flat 2x4 into two equal lengths using the miter gauge. Turn one of them over so that the two cut ends are facing one another but with one upside down, and touch them together. If there's a gap at top or bottom in the vertical cut, that gap is equal to exactly twice the misadjustment from vertical at 1-1/2" from the tabletop. Oncew you ahve achieved 90 degrees, be sure to lock the adjustment so it can't drift out of tune. (Obvously, this will work without a square ... eyeball to vertical, then fine-tune with successive trial cuts. Same for miter gauge setting below.)
[[ I am assuming that your Rockwell does have a tilting arbor, and that you can adjust the blade's tilt angle ... ??? If that's not the case, then I'm not so sure you would want to attempt much woodworking with the tool. On the other hand, if it's not adjustable, then you just have to get into the fixed mounts and shim as needed to achieve alignment. Arrrrgh. ]]
Perform a similar adjustment for the miter gauge. Set it at 90 degrees to the blade using a good 6" square. Be sure that the square contacts only the blade body and no teeth ... and lightly with VERY light pressure. Again cut through a flat 2x4, and turn one piece over so that the cut ends are facing one another and touching firmly. A straightedge will tell you if the pieces' edges are on the same line. If the edges don't come to the same line, correct the gauge setting. Loosen gauge lock only slightly, tap gauge to rotate in corrective direction, and check again with another test block. It won't take long to seesaw the adjustment to perfection. Use a scratchawl to mark that alignment point on the gauge's head and bar. Again, "tap" does NOT mean "whack it with a hammer."
If the workpiece is held tightly to the miter gauge fence and binds partway through a crosscut, then the trunnions are certainly badly misaligned. Conversely, a free cut is NOT a positive indicator, as misalignment could exist in the other direction without binding a cut. Check the piece held firmly in the miter gauge to see if its visual clearance to the blade teeth is equal at both start and end of cut. If equal at both ends of stroke, then it's not too far off, and dial indicator checking is the next step.
CAVEAT:
If your miter gauge bar is loose in the table slot, then the bar can wiggle and your dial indicator will tell you all kinds of numbers, only one of which is true. You'll need to true the bar by center-punching and filing the sides until it fits as nearly perfectly as possible over its entire length.
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Trunnions and adjustment:
Trunnions are roughly semicircular machined castings just beneath the saw's tabletop. The blade arbor/tilt mechanism is slung in the trunnions - one on each end. Their purpose is to allow the arbor to be adjusted in a true arc from horizontal to 45 degrees. (Horizontal arbor = vertical blade.)
Your 9" sounds as though it's a contractor saw, but:
Contractor's saw trunnions are bolted to the table top, because the saw's sides are likely to be a bit too flimsy to mount them there, whereas the reinforced (steel or cast iron) top is heavy enough to support the load without deforming. A cabinet saw will have very stout sides with the trunnions mounted there - much easier to adjust parallelism by moving only the table top. I fear you're not so lucky.
Contractor Saw:
Leave the saw upright. Remove throat plate and blade.
Look up from the underside, and you'll see a trunnion at the front and back (infeed and outfeed ends), with the arbor mounting plate slung between them. Bolting arrangements vary, but there are likely to be at least 2 and perhaps 3 bolts holding each trunnion to the top. If there are 3, the obvious "oddball" is there as a pivot. If there are 2 each, loosen all 4 then snug only one to be just over finger-tight so as to act as a pivot. "Loosen" and "tighten" are easily said but usually the devil to accomplish. A ratchet socket wrench, extension(s), and universal joint will help in retention of sanity. Be sure to blow, brush, vacuum and conjure all the dust from the underside areas, or you'll get an unpleasant facefull.
Reinstall the blade. The trunnions (at least one) must be moved left and right so as to swing the plane of the blade until it's dead parallel to the top's miter groove. Use a mallet and a wood stick to tap the target trunnion left or right until parallelism is achieved. DO NOT use a hammer and screwdriver !
If moving one end isn't sufficient, then move that one end in the helpful direction, snug one of its bolts lightly, and move the other trunnion. A very little experience will soon show you how much to snug the bolts to keep things from unwanted shifting yet allow you to persuade a little movement.
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ASIDE:
Lockwashers, if present, can be confounding because they'll hang and then release quickly - eithre no movement or a bunch at once. Most often, you'll be able to adjust bolt tightness around that problem so long as you're aware of it. If worse comes to worst, then remove one bolt at a time and reassemble with no lockwashers. Perform adjustments and lock all bolts tight without lockwashers. Remove one bolt, add lockwasher, and tighten firmly - the other bolts will maintain alignment. Continue, one bolt at a time, until all lockwashers are in place.
There's always a way ... if I could just find my flashlight ...
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ADJUST:
There are a zillion homemade methods, but I prefer to gauge with a dial indicator (you can rent or borrow if you haven't one.)
Install a good blade on the arbor. It will have some wobble just because blades have runout. You'll select a single tooth and always measure only near that one tooth so as to take wobble out of the equation. (If your arbor is bent, you're a dead duck. Remove it and have a new one machined.) Affix the indicator securely to your miter gauge, and gage horizontally to the BODY of the blade near one tooth at the feed end of the table. Mark that tooth with a marker. If it helps, mark a dot at the point where the indicator contacts the body. Measure low on the blade, as near to the table top as possible, so as to maximize the distance between front and rear readings.
Keep track of yer big mitts. You don't want to be smacking and shifting the indicator. The indicator must not move at all on the miter gauge, so that its zero position always remains the same.
Now rotate that one tooth backwards until it just clears the top at the outfeed end, and gauge to the blade body at that same dot point. If it gauges at exactly the same horizontal distance, then the blade is parallel to the miter slot. If not, you'll see that it needs to move either right or left to "get right." If you get repetition within 0.003" (equivalent to about 0.005"/foot), call it a job well done and go butcher some wood. (Confession - I can't leave mine alone until repetition differential is less than a thousandth, perhaps about 5/10ths. Some say 0.007" is plenty good, I say gooder is gooder. I did have a new arbor machined 'cause that tolerance isn't usually attainable with factory hardware.)
With your trunnion bolts still slightly snug, use the mallet and persuader to move one of them just a tad. Measure again. Repeat until Sunday dinner or until you've achieved parallelism. You're not done.
On old saws and certainly on those with lockwashers, the trunnion is quite likely to wiggle as the bolts are tightened. Arrgh. Now you gain experience in the difference between loose enough to adjust and too loose. Slowly snug the bolts until they're nearly tight, and re-check parallelism. Keep at it until all bolts are tight and the blade is parallel.
The job shouldn't have to be done often, and is well worth the exercise to get the saw humming along properly and safely.
Whew.
Regards,
---John
==========================================
---Pericles
Back again ... just a bit more ... sometimes forget just how much a newbie might need to become proficient ... sorry
You might back up just a bit and look at how the various adjustments interact for basic setup. There are angles that can be set as you approach different projects, but we'll just look here at what's in play when a saw is perfectly adjusted to make a cut that's perfectly square in 3 planes.
1) The blade must stand at exactly 90 degrees to table top.
(Easy. Frequent)
2) The blade's plane must parallel the line of the top's miter slot.
(Hard - trunnion adjustment. Infrequent.)
3) The miter gauge head must be 90 degrees to the line of its slot.
(Easy. Frequent. But quite subtle....)
That 3rd element is the last adjusted. You can't easily measure (by cut results) whether the head is at 90 to the slot - if the blade's misaligned, then perfect 90 will still cut at an angle. Therefore you first align the blade (trunnions) perfectly ... it's worth losing sleep over ... and then trust the accuracy of that alignment to adjust angle of the miter gauge head by adjusting to actual as-cut results.
4) The fence must be parallel to the blade.
(Easy. Frequent....)
However, if #2 is out, then the miter gauge cannot be adjusted to move parallel to the fence. Reliably adjust fence for parallelism AFTER step #2.
---Pericles
PJohn: How'd ya know I was a "Whack-it-with-a-hammer" type? Thanks for the warning and the help. I'm amazed at the unselfish sharing and willingness to help that shows up on this site. I've been foolin' 'round with an old lathe for the past few years but have been kinda oozin' over into hand tools and their use. ((It's tough finding a golf course that is open here in MN at this time of year)).
Thanks again for your help. I'll be back. Peace!
Life may be short but it can be very wide
I made no such assumption. However, the nature of your question suggested that you weren't familiar with machine tool assembly techniques, and it's my experience that you may also not have been instructed on the finer points of delicate hammer technique, so I threw it in just in case. Har.---John=======================================================
"What you leave behind is not what is engraved in stone
monuments, but what is woven into the lives of others."
---Pericles
John, In searching the archives, I came across your answer to another woodworker.
"4) The fence must be parallel to the blade. (Easy. Frequent....)However, if #2 is out, then the miter gauge cannot be adjusted to move parallel to the fence. Reliably adjust fence for parallelism AFTER step #2."
Okay. Step 2 is in alignment -- miter slots to blade. My problem is that the fence is not in alignment with the blade. I have a Rockwell Contractor's tablesaw -- how do you adjust the fence to the blade. Also do you know if this type of adjustment is covered in the manual? Are manuals available online for 20-year-old saws?
Many thanks for your help. GrandpaH
Hi - I don't know the Rockwells. Usually, there's a pair of bolt heads visible on the fence frame that will allow alignment adjustments. How about sending both top and underside views of the fence - maybe we can sort it out. My Email is [email protected] Worst that could happen is that you'd need to purchase a better aftermarket fence.No idea re manual without doing some searching - the mfgrs all vary. Google would be a good place for you to start, as well as at mfgr web site.ADDED:
Just found this for sale on CraigsList. Does yours look like this? This one has the expected 2 bolts atop the fence frame for dajustment. If your's looks like that, we're in business - let me know.
http://boise.craigslist.org/tls/254224177.htmlBest - - JohnEdited 1/21/2007 10:58 pm by PJohn
Edited 1/21/2007 10:58 pm by PJohn
John, Thank you very much. In a stroke of luck, I found my manual amongst a stack of project sketches. Yes the two bolts on the top of the fence are the adjustment points for the fence. Problem solved. GrandpaH.
Caution - you're going to find that the bolts may move things just a tad as they're tightened. Best approach is to loosen only enough to allow adjustment, and then alternate tightening very gingerly. A few thousandths (no more than 0.010") open on the trailing edge of the blade is acceptable (I keep mine parallel.) If you're tight on trailing and open at entry, it's going to sail wood back at you immediately - dangerous. Be sure it's either parallel or opening ever so slightly from leading to trailing edge of blade. Adjust and check repeatedly until you're sure it's right. Check very carefully after bolts are tight. It's trying, but you'll get it.Raise blade fully. Loosen fence alignment bolts, unlock fence on rail, and move entire fence assembly to (gentle) contact - don't distort the blade, which is VERY susceptible to bending - keep yer eyes open. Slowly tighten the fence on its rail, being careful to check that it doesn't bind the blade. Loosen/tighten, etc., until the fence is locked lightly and the blade is barely free to rotate. Although teh alignment bolts are still loose, the fence can't move, and all of its internals should now be lined up. Gently tighten the alignment bolts, then secure them.Free the fence lock, move fence away a fraction of an inch, then return and check alignment. It will be out, but better. Repeat as needed. Practice will have you getting it right in one or two tries.Got it? Loosey-goosey assembly moved to blade, then fence lock engaged. Fence alignment bolts are loose, but fence cannot move with lock engaged. Gently lock alignment bolts, then tighten securely. Unlock and move the fence, return it, and measure/observe for parallel. Fix it. Do it all again. A few tries should do it.You will need to whack the near end of the fence with your palm to ensure that the entire guide length (width?) is touching the rail - every time you even think about moving it. That is, with the position lock disengaged, the entire fence will wiggle a bit so it's out of aligment first right, then left, etc. A whack toward the rear of the saw will get it aligned against the front rail where it's supposed to be, and have things lined up before you lock it in place. That's habit not only for aligning, but for time it's moved and re-locked.CHEK CHECK CHECK - Be SURE the danged thing isn't tight on the exit end!Let me know if this all seems to have turned to mud.Best - - John
Edited 1/23/2007 3:59 am by PJohn
Just so we can all be on the same page, does your saw look like this one more or less:
http://www.owwm.com/PhotoIndex/detail.asp?id=3424
That's be a "contractors" table saw (as opposed to a "bench top" portable type or a large "cabinet" type).
Samson: Checked the photo index and did not see my machine in there. It appears to be a more recent machine than the one in the photo you sent........My motor is under the table in inside the base. Number on the base are: Series # 34-570 and Serial # FW9559. I've been lookin' for Rockwell and Delta info but can't find any info on how to find out anything about the machine I have. I don't know how old it is but it can't be too old. Maybe 25 years old. The blade is adjustable (up and down, and to 4 degrees) and I need a new fence too along with getting the blade straight.....I have a lot of good information from all you guys so I'm gonna get to it........ Later.
J MLife may be short but it can be very wide!
This might be to late, but I do have an answer.
To align the blade to the miter gauge groove on a Rockwell RK7241S table saw:
1. Unplug the saw.
2. Remove dust bag and guard to allow access to the saw from underneath.
3. Look up from underneath an find the "U shaped" bracket that the motor is attached to with 4 bolts.
4. On the side opposite blade you will find one bolt that can be loosened with a 10 mm socket and a screw with a phillips head. Loosen both of those and move or pry the blade back in alignment. I was able to use the bracket where the rip fence attaches.
5. Measure from the miter gauge groove to the blade to check alignment.
6. Re-tighten and reassemble.
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