I am not sure what I am doing wrong – I am cutting tenons from 3/8″ by 1 and 3/8 wide slats so I have a 1/4 by 1 and 1/4 tenons. attached is a photo of the setup – blade raised 3/16 – there is space between the spacer block and the start of the dado blae so I can get a 3/4″ depth of cut – so I make two passes one at full depth and then I back the board away from spacer block to make second pass or vice versa.
My problem is sometimes the shoulders are not square to each other – I can only think that somehow when the board leaves the spacer block that there is some small amount of slippage – maybe as the board passes over the blade – maybe it is pulling the board out of alignment – that is all I can guess – due to the fact I am taking such a small amount (3/16) I do not see another method working. I can’t imagine using a tenoning jig.
The only other alternative I can see possibly working is housing a larger dado blade – maybe 13/16 or 7/8 in a sacrificial board so I just make one pass and I cannot go deeper than 3/4 – is this is better idea than using my miter guide to pass the slats, after registering them against the spacer block, over the 1/2 inch dado blade? The shoulders are not always out of square – just about half and I do not think I can fix it by chiseling out the shoulders to bring them square – the way to fix it is to pull the slat close to the balde, adjust and run it over the blade again – I am just wondering if I am using the best setup for dealing with really thin stock, taking 3/8 inch thick boards to create 1/4 inch tenon cheeks – thanks, Tom
Replies
I have no idea.. HOWEVER that stop/reference block should be well behind the blade!
My opinion only. I clamp my stock down to my 'whatever' I used to move the 'stick' into the blade..
And then again I NEVER had good luch using a table saw for cuting tenons.. I use me router!
Edited 5/13/2008 1:25 am by WillGeorge
I'm not TS expert. But cutting tenons on TS is not a challenge.
For cutting tenons and dado, I usually use simple tablesaw sled. Set-up is pretty fast and I control the work-piece with confident. Most importantly, I feel safe.
Since your TS is equipped wit dado blades, cut tenons & dado horizontally.
Note : Simple TS cross-cut sled needs only one runner. Use either side of your miter t-track channel.
Good luck
Tom,
I cut my tenons the same way (but without a dado blade usually). Have you checked the squareness of your stock? Also check if the miter gauge face is square to the table.
Chris @ www.flairwoodwork.spaces.live.com
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
Tom,
If I am cutting tenons horizontally on the TS, at the very least, I would screw a sacrificial backer to the miter gauge. Attach a stop block to this backer, not the TS rip fence. You can then clamp your stock to the backer fence if you need to. I sometimes glue a strip of sandpaper to the face of the backerboard to reduce any movement of the stock.
Having said that, I now find myself more frequently cutting tenons on the router table. Don't know why. Perhaps I tired of the TS after doing 79,695,462,036 tenons....
Best!
-nazard
Ditto what WillGeorge said about the stop block. The way you show it is inviting a kickback. When using the miter guage, the end of the wood should never touch the blade and the fence (or stop) at the same time -- the piece should move beyond the stop prior to engaging the blade so it doesn't get wedged. Also ditto the advice about clamping the stock to the guage.
That said, I only use the horizontal method (either on the TS or the RAS) when I'm doing rough work. For the good stuff, I prefer to cut tenons on a tenon jig using the two outer blades in the dado set, separated by a spacer of the proper thickness for the desired tenon. For me, this yields more consistent results. YMMV.
If you want to use the horizontal method, consider making a crosscut sled. That should eliminate your problem with wacky shoulders.
Mike Hennessy
Pittsburgh, PA
Mike.. RAS and PUSHED it through the stick many times .. I guess I was lucky!
Your work will slip on a bare metal miter gauge. Either glue some sandpaper to it or add a wood fence. It helps to add sandpaper to that also. If the end of your stock is not square in both directions, width and thickness, as you remove waste in the first pass, the next pass will go a bit deeper. The same can happen if the stop block is not square to the table. You may want to lift it off the table a little so sawdust won't accumulate and cause a difference in registration. That clamp on the block could make the block tip a little.
The depth can be effected if the throat plate isn't flush with the table. Blades can run when cutting against wood on one side and nothing on the other. I would make the shoulder cut all around first, then remove the waste on the end, rather than starting on the end and working toward the shoulder. This will keep the registration end intact for the important cuts.
On larger tenons and on tenon machines, the stop registers on the tenon shoulder, not the end of the stock. Another way is to use a long fence on the miter gauge and attach the stop block to the opposite end of that fence, away from the blade. In this case, the saw fence gets moved out of the way. You don't want both ends of a work piece to be captured.
Tom, Good day to ya! I see your problem, man. That stop block should be set way back where your work piece will disengage it before it ever reaches the blade. What's happening is that there is just enough bind between the stop block and the work piece that it is pulling it slightly out of alignment, thus, the out of square tenons. Set your stop block up way back at the very beginning of your fence, register your work piece against it, hold on tight to prevent movement, then run your work piece through the dado blade. Am I making sense? Go for it and above all be safe.
Harry
Following the path of least resistance makes rivers and men crooked.
Tom,
I agree with the poster who suggested attaching a wood fence to the face of the miter guage. Make it long enough to support the stock behind the dado cutters, even a few inches beyond. Make a pass across the cutters, and, using the dado you cut in the fence as reference to measure from, clamp a block to the fence to butt the slats' ends against. As another poster said, it's near impossible to keep them from sliding as the cut is being made, without a positive stop to put them against.
If you are confident that the slats are all the same length, you can clamp this block at the dado cutter, referencing from the end of the slat that is being cut. If there is a chance that there is a bit of variation in length, or that the ends are out of square, clamp the block away from the dado cutter, referencing from the opposite end of the slat, for the first tenon. Then for the second end, raise the clamp block up on the fence, and closer to the cutter, so that it references off the shoulder you cut with the first set. This will keep the distance between tenons exactly the same, and move any variations in length to the tenon itself, where it won't matter--it'll be hidden in the mortise.
Ray
Thanks for the comments - I'll try adding a sacrifical fence to the miter gauge.I overlooked what the photo is showing. I moved the stop block up to the dado to take measurements from so I can get the block set at the right depth but what the photo does not show is after I set the fence I move the block down so the tenon does not ride along the block while cutting to prevent kickback, binding, as referenced in earlier posts. Thanks again for the commments - Tom.
Using your method.. stop block and fence must be parallel to blade.. then the face of the miter must be 90* to the blade and fence. And because a miter indicator says it is.. it isn't necessarily. My cheap Delta miter gauge is off a hair that I have to shim the face-plate to compensate.
I cut mortises with a 750 lb. industrial mortise machine... but to save the fiddling with tenons about a year ago I went back to a method I used years ago when I was working with a circular saw under a piece of ply as a dedicated TS. The name of the tools used slips my mind....
Oh yeah... hand-saw.. file and rasp. That's it! ha.. ha... ha..ha..ha..
Sarge..
Edited 5/13/2008 11:33 am ET by SARGEgrinder47
None of those problems with routed tenons.
Tom,
In addition to what others have said about increase friction on the miter gauge face plate/ or adding a wood fence, holding the work tight, plus clearing the stop-block fully before blade contact.
I would check the obvious - throat plate height. If the leading edge is even a micron above, which you may not notice if it has radial edges, it could catch the work ever so slightly and make the work twist, changing the attack angle destroying the angle needed.
Saw dust can accumulate under the throat bedding and raise it without operator realizing it. Also stock throat plates are notorious for not being flat - in any direction.
Also , is your miter gauge bar tuned so it is traveling true to the miter slot. A variation here would cause a change in your cut.
The plate problem is a ticket for an accident.
Work safe
BB
Tom,
Thanks for this discussion.
I'll be making tenons across the side panels for a QA piece that are to be inserted into mortises in the post blocks so this discussion is of partiicular interest to me, especially getting them square to the ends.
As these panels will be ~ 22" wide, keeping the shoulder cuts square will be paramount. From the posts so far I'm leaning towards a sled arrangement on the T/S with dado blade; the RAS probably won't work due to the length of the cut. Even with a router table the sled arrangement makes a lot of sense too.
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Tom, make sure your miter guage is dead on 90 to the blade. If it's off just half a degree, your shoulders won't match.
Switch to floating tenons. A lot less hassle.
If it moves, tax it. If it keeps moving, regulate it.
And if it stops moving, subsidize it.
The problem is with the shoulders so I can't see how loose tenons will help. Am I missing something?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Are you saying you can't cut a piece square with the saw? If that's the case then you have bigger problems. My suggestion assumes you can cut two pieces square and perpendicular to one another. The reason I suggested floating tenons, is that if you have two square pieces use a router or bench mortice to cut the mortice & cut your tenon material then you are done. IMO floating tenons are just as strong and simple. That's just my opinion. Government's view of the economy could be summed up in a few short phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it.
Are you saying you can't cut a piece square with the saw?
Nope, not at all. The issue was keeping the shoulders square and I'm assuming on the length of the cut as well as square to the tenons and mating member.
I think it's a matter of personal preference, tool availability and skillset not the technique. I was/am curious as to how loose tenons would offer any advantage to solving the issue of square shoulders.
In my situation I'm mating side panels to post blocks. I'm planning on making them much the same way one would make tenons for a breadboard. With my present setup cutting mortises on the ends of the panels could be problematic for me, that's all.
Thanks,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Seems to me it's either got to be the blade not at 90, or the miter slide not at 90.
Not intending to offend and it is preferences, but I'm having a hard time picturing your situation. You say your shoulders are not square then how can you be cutting square pieces? Your blade has to be off square to the table. The reason I said floating is that if the two pieces to be joined are square and the mortises are cut perpendicular to the pieces then they have to go together square. I guess I'm not writing well what I'm trying to say for that I'm sorry. From your description if the shoulders are not square I just can see how the blade is at 90 to the table. It has to be off. Government's view of the economy could be summed up in a few short phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it.
OK, we're both on the wrong wavelength, methinks.
I've been following this discussion for inputs as I'm about ready to make tenons for the ends of a QA case piece that I'm making. I want to avoid any problems relative to square shoulders that the OP was/is experiencing. I just did the glue ups recently, cleaned up the joints and all is square and true.
Next step is making the tenons on each end so this discussion is of particular interest to me for obvious reasons. I will be making the case using the same construction techniques as did Randall O'Donnell for the lower case on his Curly Cherry Highboy in FWW #117. I'm also using cherry.
Sorry for any confusion.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
If you want it perfect, don't rely on machines for the crucial shoulder edges and placement. Hog off most with the machines if you like, but take the last bits with a chisel after marking with a sharp knife. Best yet, mark with the knife while the piece is clamped in position on the pieces it will join. Also, using a chisel allows you to undercut the endgran on the shoulder slightly to ensure a no gap fit at the visible edge.
Thanks man,
That's what I was planning on, maybe a different choice of tools but same end result. I use machines to do the hogging/brute work and fine tune joints etc. with hand tools all the time.
Even joining boards for panels on the jointer I find that if I'm not careful little gaps are left cause of uneven pressure - sloppy technique. Clamp 'em to the bench and a few light passes with a jack and Bob's your uncle as they say.
I tried an experiment with my #78 last night and it worked real good for squaring up the shoulders on some test pieces. As Uncle Normy says, this aint rocket science.
:-)
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 5/13/2008 4:33 pm ET by KiddervilleAcres
I see said the blind man!Government's view of the economy could be summed up in a few short phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it.
It's all good man.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Just a thought to consider but I swear by T/S sleds, especially for squaring panels. I feel it's the same concept as a sliding table, which I can't afford. You can tweak the cut to whatever precision you require and they afford clamping to hold the workpiece steady and eliminate any slipping during the cut.
With jigs you can place the workpiece at an anglr if ya want to.
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 5/13/2008 4:46 pm ET by KiddervilleAcres
I should apologize for not being clear - I hope these pictures show what seems to be the problem. Notice how one shoulder is lower than the other. I am simply registering this slat against the stop block, then dragging it with my miter gauge to the dado blade (yes, the piece clears the stop block before touching the blade). and then I take the piece again, pulled away from the stop block to cut the other part of the cheek.(I am not worried about the irregularities in the cheeks - the magnification overstates it ) Then I turn the slat on the other face repeat the process and then turn the slat on its sides, repeat the process so that 3/16 is removed from all sides. The only thing I can think is that the blade is dragging the slat into it even though I am firmly gripping the slat as I push with the miter guide. I made sure I started with square stock because I knew the pieces needed to touch squarely on the stop block.I hope this helps explain my predicament - this does not happen on all slats, some are worse (like this pic) than others. I think the difference in height has to be less than 1/32 - but just enough so when the piece sits in its mortise you see some space under one of the shoulders while on the other side the other shoulder is resting on the mortised piece. Let me know if you need any more details and if this changes your advice - thanks, Tom.
I believe you have a jig/mitre issue or the stock is not perfect. Do you have a set of calipers? Check the stock width and thickness to see how well you did preparing the stock. If you have a "true" straight edge (you know a machinst quality one) I would check along the length too. To make tenons rotating the stock as you are requires perfect stock and a perfect jig or mitre fence unless you dont mind cleaning up the final with a shoulder plane. A shoulder plane is a dream to fix this problem. I now use the shaper with a fancy cutter to make perfect tenons in a single pass. You might want to nibble the next ones with a square tooth blade to save yourself hours of paring. Been there, done that. If you can add a clamp to hold the stock rigid during the cuts that also reduces the amount of paring.
Good luck
Brad
What are you using for a dado set? That's a very rough cut. Are you sure the dado is set up square to the table? It looks like your throat plate is low and you are tipping down and cutting deeper on the second pass. Are you backing up after the forward cut, don't do that. Go slow and deliberate on the cut. Your tenons should look more like these.Beat it to fit / Paint it to match
Hi Hammer1 - I am using a Freud dado set - I think this received an award for best value from another magazine. I am probably going too fast over the blade. I think my throat plate needs adjusting - I like that setup you have. Just to add a followup - tonight I switched my miter gauge and I was careful to hold the slat better against the miter gauge and I got near perfect tenons. I think what is happening is with my other gauge I was not able to hold on to the slat as well and I think the blade dragged the tenon away from me, causing it to cut deeper than the stop block allowed. I think that was causing the problem. Maybe I should have set up a stop block on the other end to help hold the slat in place - I did not think to do that because the slat was much longer than my sled.
Tom,
I wish I could show you but alas I'm not in the woodshop.
I'm envisioning you trying to hold the stick square to the fence on the mitre guage, dealing with imperfections of a throat plate on the T/S, and whatever else might be going on and I'm thinking sled, sled, sled - ditch the mitre guage.
If you could construct a sled, very similar to a crosscut sled but used with a dado blade. Dead flat surface and square fence for registration of the workpiece, nuts on 90° to the blade, clamps to hold everythang in place, zero clearance for tearout reduction/elimination, stop block precision and repeatability - the list goes on.
Maybe it's my inner dysfunctionallity talking to me (NOT being sarcastic here),
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Wouldn't hurt to put a piece of self-adhesive sand-paper on the face of the mitre face to help avoid "creep".
BTW.. hammer nailed it on the roughness of the cut. The last time I saw one that rough was by an Egyptian carpenter working on one of those pyramids while I was passing through selling snake oil. ha.. ha...
Good to see you get a handle on it...
Sarge..
IMHO, cutting shoulders on all four sides like that, and expecting them to line up perfectly, is a hit-and-miss thing. I think Tage Frid even mentions such in his classic book ("Tage Frid Teaches Woodworking"). As you've found, you can see gaps of even 1/64" and less when you assemble the joint. Some hand work with a shoulder plane and/or chisels is needed.
I just cut the shoulders on the two long sides with the table saw, and then "connect" them across the two short sides with a hand saw and chisels. That way all the corners always line up.
BTW, you may want to try a tenonning jig to cut the tenons themselves sometimes, once you've established the shoulders. Once you fabricate a spacer equal in thickness ot the desired tenon thickness plus the blade kerf, you can easily turn out tenons of consistant, "piston fit" thickness, even if the stock thickness varies a little. Lots easier than using a dado blade, where the tenon thickness depends sensitively on both stock thickness, and blade height - a very fussy thing, considering the "perfect" fit of a tenon has a tolerance of only a few thousandths of an inch.
I see said the blind man! That said to his lame wife to climb the tree and call somebody.. I forgot who!
Bones, I haven't tried to follow this discussion closely, but it is possible for problems like this occur, even with a perfect blade, and that's when the throat insert isn't perfectly level with the saw's table. I've had it happen, and I think BG once ran into mysterious problems with some tenons and found the same culprit.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
"Bones, I haven't tried to follow this discussion closely, but it is possible for problems like this occur, even with a perfect blade, and that's when the throat insert isn't perfectly level with the saw's table. I've had it happen, and I think BG once ran into mysterious problems with some tenons and found the same culprit."
I hear you. It goes back to the basics square stock & blade perpandicular to the table and the miter slot. Any of those things out, errors magnify, but I did not mention technique wich even with the first two can cause issues. The picture posted said a thousand words. Government's view of the economy could be summed up in a few short phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it.
I'm pretty simple at times. In this picture which segment is not 90 to the other isegment that is in question. i.e is BC not 90 or is it ED?
View ImageGovernment's view of the economy could be summed up in a few short phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it.
tom it looks as if your stop is to far foward causing slight kick back.if some of your cuts are good it's probably not the tool but the technique,try sliding your stop block further back so as to not create a kickback situation.I think this will solve your problem . Jeff
This forum post is now archived. Commenting has been disabled