Hi,
Finally managed to buy the materials for the 2 pine bookcases I’m about to build.
The side of the bookcase is 73″ tall Material is 3/4″ thick X 11 1/4″ wide. Would it be best to use the table saw to cut the long dados down the sides of the bookcase? Is that a safe way to do it? or would I be better off routering the dadoes?
The bookcase has adjustable shelving so I have to cut a dado the length (72″) of the board… 1″ in from the edge so I can recess the metal standards. Then I have to cut a 1/4″ deep dado X 3/8″ wide on the back edge to fit the back for the bookcase.
I’ve used the dado blades on my Contractor saw to dado and rabbit small 24″ length pieces for cabinets but I have never dadoed a long board 6′ X 11 1/4″. Any tips you could offer me would be greatly appreciated.
Wanda
Replies
Hi Wanda,
First, a minor terminology thing: dadoes go across the grain; grooves go with the grain. It sounds like you want to create a groove, rather than a dado.
It seems to me that a router would be a safer and more effective way to go, because you can stabilise the board and control the cut better. A router will also probably give you a better quality groove bottom and easier/better depth control than will moving the board over a dado blade.
It also seems to me that doing the rebate on the back would also be easier and safer with the router.
[You could also get really ambitious and do this with hand tools..... ;-) ]
Good luck on this project; I hope that you'll post some pics when you get done.
.
Tschüß!
James
"I'm sorry, Dave, I'm afraid I can't do that...."
-- A.C. Clarke
Guten Abend,
It's all a matter of semantics. Believe me I do know the difference between a dado and groove. You could classify them as both gooves. Distinction being one runs the length of a board the other runs across the width. (against the grain as you described).
?.... would a router table with a fence set up do an adequate job of cutting the groove down the length of the 6'board? Providing of course I set up an outfeed table. Would the router table give me a clean even dado with a uniform depth? or do you still think a fixed router would be the safest and best way to proceed?
Problem is I don't have an edge clamp on my router and I don't have one of those clamp'n guides either. However, I could use one of the 6' pine boards I purchased for the shelves as a guide. Measure in 1" from each end and line up the 6'board (guide) with those lines. Clamp the pieces to my workbench with a couple of C clamps and away I go.
I'm a bit nervous View Image about beginning this project because one mistake would cost me dearly $$$$$$$$$$$ The wood cost me $188 If I screw up a dado on one board I'm out $27.00 OUCH!!!! NO room for errors. The pressure is on.
I suppose a good edge guide connected to my router plus an auxillary wooden fence connected to it would come in handy. But maybe the "rebate"/ rabbit could be done using the router table....
Wanda
Grüße Auf Newfundland
Übung macht den Meister!
View Image
Hi Wanda ,
How dare you try and make a groove with a dado set or a dado with a groove set .
I do it all on the TS , the accuracy of the width and depth of the cut will be more then adequate . Typically we set the standards a bit proud of the side .
Just the thin edge of the standard hits the slot or groove so the type of cut here is not critical , the TS does a fine job .
The router table can also produce great results depending on if you have a matching bit size or a dado set could give a closer fit possibly ?
regards dusty
Grüß Gott Wanda!
A router table will certainly work, but I think you run into the same problems/challenges as with the TS: trying to simultaneously keep a 6 foot long board tight against the fence for a straight cut and keep it flat against the table to control groove depth, all while also trying to avoid kickback. Using a router table or a TS is certainly doable, but it seems to me that using a router "freehand" with a fence/edge guide is easier, more controllable, and safer; that's all.
One of your shelf boards would work fine as a fence (as long as the edge is straight).
No need to be too terribly nervous: just double check all of your measurements, layout, and tool settings before you make any saw dust. That should preclude any preventable mistakes. I'm sure your bookcases will turn out just fine.
.<!----><!----><!---->
Tschüß!<!----><!---->
<!----><!---->James<!----><!---->
<!----> <!---->
"I'm sorry, Dave, I'm afraid I can't do that...."
-- A.C. Clarke
Hi,
I'd prefer to build a bookcase using fixed shelving but that's not an option. In my opinion it would hold up much better. Less chance or racking. But anyways I must choose which method I'm going to use to cut the grooves. However, I could chicken out and instead just drill holes 2" apart down the length of the case side for shelf pins.
Just wondering... are shelf pins just as supportive as shelf standards? I'm thinking it's easier to just drill holes in the sides than grooves.. If standards are better I will cut the grooves using a router with a straight edge. Kickback is always a concern when using the table saw. I enjoy working with the router.
Wanda
Grüß Gott Wanda,
Pins in holes work ok, but Veritas (I think) makes brass "hole liners" for the pins, that keep the relatively small surface area of the pins from digging into and mis-shaping the pin holes when under load. Might be something you could use if you go with the pins rather than standards method.
http://www.leevalley.com/hardware/page.aspx?c=1&p=40183&cat=3,43648,43649&ap=1.
<!----><!----><!---->
Tschüß!<!----><!---->
<!----><!---->James<!----><!---->
<!----> <!---->
"I'm sorry, Dave, I'm afraid I can't do that...."
-- A.C. Clarke
Edited 4/26/2007 5:23 pm by pzgren
Hi,
The hockey game is about to begin soon so I'll be brief.
I know exactly what you're talking about without having to go to the LeeValley site. I have their catalog Memorized. LOL
My brother -in- law purchased a set of cheap bookcases last year that came with plastic pins. After awhile the area around the pins started to enlarge due to the weight of the books on the shelf.. the pins began to dip until eventually the shelves slipped off the plastic pins.
Needless to say those bookcases are history now. They were only constructed from pressboard and a flimsy 1/8" thick cardboard backing. You get what you pay for I guess.
IMHO He would be much better off with a fixed shelf bookcase! Although I've known adjustable shelf bookcases made from plywood to hold up quite well over time.
Wanda
Wanda, <<I know exactly what you're talking about without having to go to the LeeValley site. I have their catalog Memorized. LOL >> WOW!! I'm impressed.... ;-) I have the LN catalogue memorised, but it's a LOT smaller than any of the LV catalogues....
.<!----><!----><!---->
Tschüß!<!----><!---->
<!----><!---->James<!----><!---->
<!----> <!---->
"I'm sorry, Dave, I'm afraid I can't do that...."
-- A.C. Clarke
Hi guys,
I've made up my mind. I am going to go ahead and set up my dado blades on the TS and cut the grooves. I will use my router to cut the dadoes across the boards. Luckily I have a good jig for that. (T-Square made from 3/4" plywood.)
I"m worn out now after spending time in the tool room. I've got to buy myself one of those anti fatigue mats. My legs are tired!
Finally got the grooves cut for the shop cupboards. I'm in the middle of attempting to build frame and panel doors. so far so good. So when the time comes to assemble the frames for the bookcases I'll be well practiced. :)
The bandsaw and router table are getting a good workout. Great for cutting tenons and grooves. (I don't have to worry about kickback) I couldn't imagine life without my router!
I have a ? not concerning bookcases but rather router bits. While cutting the grooves today on the router table I noticed that the router bit left a ridge on the inside of the groove.... after closer inspection of the 1/4" straight bit I discovered that it wasn't even across the top. (one side of the bit was slightly higher than the other)As far as I know shouldn't a straight bit be level across the top? I'm going to have to replace that bit with a good quality freud bit.
Wanda
Hi,
Would it make much difference if I went with 12" wide sides and 11 3/4" shelves? Would the wider shelves offer more support? Any need to attach 3/4" thick by 1inch wide edging to these wider shelves?.
I've got to stop procrastinating and get those bookcases built.
Wanda
Wanda,
<<Would it make much difference if I went with 12" wide sides and 11 3/4" shelves?>>
More than anything else, that seems to be a design/aesthetic question. At approx 12", I don't see that ¼" of shelf depth is going to make any substantial/practical difference in strength.
For sag control over the length of the shelves, you may have to reinforce them. There are several ways to do this; probably the simplest is to groove in a 1" or 2" wide x ¾" (or whatever thickness your shelves are) thick board perpendicular to the bottom surface of the shelf; this will give your shelves approx 2 -3 times the weight capacity without sagging.
This link has a calculator for determining the amount of sag on a board with user input on some of the specifics on the wood being used. You might find it useful.
http://www.woodbin.com/calcs/sagulator.htm
Googling "sagulator" will return numerous hits with lots of useful info.
.<!----><!----><!---->
Tschüß!<!----><!---->
<!----><!---->James<!----><!---->
<!----> <!---->
"I'm sorry, Dave, I'm afraid I can't do that...."
-- A.C. Clarke
Morgen!
Just checked out the sagulator. (deflection according to the sagulator= 0.02) for Lodgpole pine
Length of shelves (27") case sides (12") depth of shelves ( 12") I decided to go with those dimensions because it means less ripping on the table saw.
Unfortunately, the shelves are fixed. So I can't attach any cleats to the back of the bookcase to strengthen the shevles. However I could attach a cleat underneath the bottom shelf because that shelf is fixed and you won't see the cleat because the bottom trim covers it.
I managed to find the shelf standards and the shelf pins at Home Hardware so I will go ahead now and cut the dadoes in the case sides for the 2 bookcases. I have my fingers crossed that all goes according to plan. I'll be sure to do a test cut first to make sure the saw is cutting accurately.
Wanda
I think you'll be happy with the results, Wanda.
Again, I emphasize two things.
Run them through with some hold downs as that will improve the accuracy.
Run them through a second time. A dado blade pushes a lot of wood and I often find especially on long pieces that I didn't get that last 1/16" off with the first pass.
Good morning Wanda,In regards to your question about router bits, the answer is no. A straight cutting bit doesn't have to be level across the top. The end of the bit will always be the same distance from the base of the router, therefore it will be capable of cutting a flat-bottomed groove(or dado, as the situation may demand). This does not mean, however, that it will. When using a bit with an uneven end feed rate becomes a concern as the bit can rise up in the cut (push the base off the wood a bit) if you don't allow the bit time to complete it's cut.A question for you; where in the groove (or dado) is the bit leaving the ridge? Nat
hi,
Would be better if I took a picture of the grooved stile wouldn't it.. kind of hard to explain in words. A visual is needed. :)
The 1/4" bit is leaving a (ridge/raised line the length of the groove) on the upper inside edge of the groove. depth of the groove= 3/8ths The groove is smooth on the bottom. The first pass looked good. Never noticed this "ridge/raised line till I passed the stile through a 2nd time over the router table. I'm using a variable speed self starting 1 3/4 hp Porter cable router. I am only removing small amounts of material on each pass with the router bit. Good thing I'm only working with 3/4" pine.
If the above description doesn't help diagnose the problem then I'll have to post a picture.
Wanda
Wanda,If you're doing multiple passes with a bit, the ridge is probably caused by a slight mis-alignment between passes; A speck of dust between the stock can cause this as can a fixed-base router. The rotational centre on a fixed-base router isn't always dead centre of the router body which can cause the bit to move when the body is rotated in the base during a height adjustment. A problem I've encountered with 1/4" bits is they like to deflect when removing more material than they want to in one go. There are probably some here who would disagree with me on this point, but a router/table combo really isn't the right tool for plowing long grooves unless you have a million feather boards and hold-downs and the patience of a saint (an overly aggresive feed rate is virtually guaranteed to deflect a 1/4" bit). The table saw with a dado head is a much better choice. You only need one or two feather boards and you can feed the stock as fast as the saw's motor can handle. Lastly, with a dado head, you can do it all in one pass, thus saving on set-up time, checking depth, adjusting, checking depth, running first pass, adjusting, checking depth, adjusting, checking depth, adjusting, getting sick of checking depth and just running the stock, realising you weren't deep enough on that last pass, adjusting, checking depth............Nat
Hi BigNat,
I went out to Home Depot and purchased a Freud 1/4" straight bit. Now after reading your post I'm not so sure that was a wise decision. Perhaps I should be using a slot cutting bit instead. Oh my!
After making the tenons on the table using the dado blades. I discovered that my tenons don't fit down into the groove.. It's that little ridge that is holding them "up"! The width of the tenons are perfect. I'm going to run all the pieces I have grooved through the saw tomorrow and see what happens.
Maybe I should return the 1/4" bit and put the money towards the slot cutting bit instead. ($23.00) For now I'll just set up the dado blades on the Table saw and see what happens.
ShopNotes had an excellent article on how to cut stub tenons on the router table using a simple jig made from plywood and hardboard. Issue #89. They used a slot cutting router bit.
So many ways to tackle a task.
Wanda
Hi,
I have a ? concerning the Adjustable pine bookcases. I managed to get one carcass put together today only to notice that the shelf I cut was a bit warped. depth of shelf (12") laminated lodgpole pine) Would I be better off buying pine veneered plywood for the shelves instead of the the laminated pine shelving.
Probably Wouldn't be so problematic if the shelving was dadoed into the sides of the carcass but I'm building an ajustable shelf bookcase.
Wanda
I know it is counterintuitive, but pine plywood is expensive and not easy to come by. Since you have started with solid lumber, I would stay with it. Needless to say, you should take care in picking pieces that are as straight as possible.********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
Wanda, you've got it backwards, IMHO. Although pins will be plenty strong, it's a lot easier (and quicker) to cut straight grooves than to align four rows of pin holes without a pretty accurate jig. With pins, unless your holes are exactly aligned on all four corners, your shelves will rock, and there's no easy fix withoug bunging up at least one set of holes. Stick with the grooves. It's easy to fix a misaligned standard -- just unscrew and reposition. 6' is not that long. Don't let it scare you -- just make sure you're set up properly before beginning the cut and take it slow and careful.
Mike HennessyPittsburgh, PA
There's nothing wrong with using a board clamped to the surface with C clamps and if you have/can make a feather board for the other side, the piece you need to plough the groove in won't move and damage anything. Just make sure there's adequate support for the stock on the outfeed end and use a push stick or block to keep your hands away from the bit. Remember, a mistake is just an opportunity for innovation, and many other catchy sayings, as well."It's all a matter of semantics"What do you mean? ;P
"I cut this piece four times and it's still too short."
Good afternoon,
My saw is all tuned and ready to go. I double checked to make sure the blade is parallel to the miter slots and 90 degrees to the table. Then checked the fence to make sure it was 90 degrees to the table on both sides and parallel to the miter slots. I find sometimes with my fence that the board I'm ripping tends to get away from the fence when I'm pushing the last bit of wood through the blade. (heeling I guess you'd call it) and I end up having to put too much force against the board to hold it tight to the fence.
I have the stacked dado blade set up. Now it's only a matter of setting up a proper outfeed support. I'll use the 2 feather boards I made the other day as hold downs.
No more excuses... It's time to make some wood chips!
Wanda
Wanda, ain't it grand when you have a variety of choices to do something, all of which could be considered "right"? That means, you can choose whichever solution happens to float yer boat at that moment. Either the TS or router will work fine for this, although it's likely to be easier to do on the TS with a dado blade. Still, the router will work as well. One way to do this with a router that's just about as easy as setting up the TS is to use an edge guide. Once you have one, these cuts are a snap.
Get a piece of 1/4" ply or hardboard about 6" wide. Tack a straight piece of scrap along one edge, say 3/4" square, the whole length of the guide. (I like to make my guides a full 8' long and run the straight edge guide a bit longer on each end -- this lets me use the guide with full 8' stock.) The width between the straight edge and the far edge of the ply should be about the same as the width from the edge of your router to almost the center of a 1/2" bit chucked in the router. Then, use the router to trim the guide to exact width by running it along the straight edge guide. You now have a custom-made fence that is simple to use. Just line the edge up with one edge of where you want your dado/groove, and have at it. Then, flip the guide to the other dado/groove edge and finish it off.
I have several of these guides that I use frequently -- one for a circular saw and a couple for different size router bits. Once you make 'em, you'll use 'em all the time. way easier than trying to figure where to clamp a simple board straight edge. With these, you just line up the edge of the guide with the edge of the cut. Helps prevent tear-out as an added bonus.
Mike Hennessy
Pittsburgh, PA
I've done that several ways. If you use the table saw, just be sure you have holddowns pressing both downward and against the board. And me, I'd run them through twice.
I have bookcases upstairs made exactly as Wanda describes. I used a router for the grooves, and used the next bookcase upright as a guide. It worked fine. There's a good deal of wood to be removed, so getting dust extraction to work on the router is helpful. I used the home vacuum cleaner and lots of duct tape, and that worked fine too.
This is definately one of those things that comes down to preference and experience. I prefer a dado, dust collection is better and there is less of a chance to make a mistake. Many who don't use dado sets frequently are intimidated by the set up, or they just think it takes too long. All the experienced profesionals I know (myself inceluded) find the Dado a lot faster, more accurate and safer. This opinion is based soley on ones experience and comfort. Not to mention the type of table saw. I have a large cabinet saw.
Go with which ever method you feel most comfortable with now, but stay open minded about alternative techniques.
Don't forget to post your pics...
Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
I use the saw with the grain with long boards. I use a wood insert I made only for dados. The insert is very slightly humped at the center .Maybe 1/16" ,tapered each way from front to back. The reason for this is, rarely is a long board completely flat.The hump ensures the dado is the same height all thru the dado.The hump is gradual so pushing stock thru is not a problem.If you have a disk sander this only takes a few seconds to do.
mike
The table saw would be a good choice. However, if you are a novice, I would suggest using multiple passes with a single saw blade rather than a dado head. Dado heads can be very dangerous when used on table saws if you are not very careful. I have seen some terrible kickbacks with dados on a table saw. As for the rabbet for the back, I might use a router. A very experienced person could get along fine using a dado head for both cuts.
My suggestion is similar:I use a table saw. I would clamp down a feather board or a piece of scrap to hold that rascal against the fence nice and tight.I would use another feather board or another piece of scrap along the fence to hold that rascal against the table nice and tight. Bear in mind that the board may be slightly cupped which will make that dado shallow in those areas, right?I do multiple passes on dado's--at least two passes--depending on the depth of the dado.Use scrap of the same thickness to set the dado to depth and distance from the fence and run a test piece through just to make sure.Regards, Scooter"I may be drunk, but you're crazy, and I'll be sober tomorrow." WC Fields, "Its a Gift" 1934
Hi guys,
I had no problems running the 6ft boards over the dado blades. I used an assistant. Made sure I held the board down firmly on the table and against the fence as I passed it over the dado blades. Worked like a charm. Had no problem cutting the 1/4" rabbit on the inside face of the case sides. Could have used the router but the table saw is so much faster. Less set up.
Is it true that dado blades are illegal in the UK? I have never run into any problems using my dado blades. If you keep the board tight against the fence and pressed down against the table how can kickback accur? Maybe I've just been lucky all this time who knows. I clean my dado blades regularly making sure they cut properly. I can see using a dull blade might cause problems.
wanda
If you keep the board tight against the fence and pressed down against the table how can kickback accur?
Accidents happen. Usually when the user is least expecting it (i.e. not paying 100% attention). If everybody did everything right there would be no accidents...
"If you keep the board tight against the fence and pressed down against the table how can kickback accur?"
Oh that's as simple as abc, Wanda. No overhead guard, hold-down or featherboard on top of the work-- a common approach in US style woodworking I regularly observed when I lived and worked there. A knot, or stress in the wood relieved as the blade cuts the channel. The wood pinches on the dado blade due to the stress release, and,...... wham., resulting in a smack in the puss, guts, shoulder, upper body, or, if it misses all those, a projectile sailing across the workshop.
Especially nasty end results of dado blade use can include fingers/hands dropping onto the spinning blade as the piece rears up and kicks back towards the operator. I've even seen workers pass their hands, whilst holding down the wood, right over the top of the blade as it cuts the groove or channel perhaps 12 mm below their hand. Another smart trick I've seen (sic) more often than I care to remember is ending the cut with the heel of the hand on the rear upper corner of the plank as it passes over the blade-- always scared the heck out of me when I saw it.
Now I know that many of you will say dado blades are always used with hold downs that prevents such accidents happening, and I know that's untrue because I watched many full-time US workers do exactly as I described with no guards, hold-downs or anything. Set the fence, set the blade depth and away to go. It was far too much effort as far as they were concerned to set up guards for just one or two cuts.
And so far I've only described rip cuts. I haven't described any of the acts of rank stupidity I've seen on housing type cuts, or dado cuts in US parlance, but here's one. A narrow bookcase end, perhaps 6' or 8' long by about 12" wide, where the end is held against the long rip fence and the housing taken across the middle of the board. Yes, idiotic approach to cutting the joint as it may be, I saw it done far too many times to remember how often I witnessed it.
"Is it true that dado blades are illegal in the UK?"
No, but the legislation is so tight regarding their use on table saws that they might as well be. The arbors on European configured saws are too short to accept a dado head, therefore we can't use them. We can buy dado blades, but about the only machines they'll fit on are radial arm saws. Slainte.Richard Jones Furniture
acts of rank stupidity ..............
idiotic approach to cutting ................
Wow, this guy must be hiding out in my shop!
"Wow, this guy must be hiding out in my shop!"
So long as you're not there when he's working there blewcrowe, you should be alright, ha, ha. Slainte.Richard Jones Furniture
BTW, I haven't said so but I've been to your site and your product is beautiful.
And yes, I know, many of us here in the U.S. are not safety prone, so pardon my joking around: it's my nature.
For each of us in this world, our strengths are our weaknesses.
Hi,
OMG! I better get my house in order! I'm going to have to make some featherboards asap. Better yet I might just invest in a good pair of magnetic "featherboards .. TiteGrip.
I do agree that cutting a dado on the short ends of long pieces is dangerous. The board tends to "creep" away from the fence. A router with an edge guide would be the ideal machine to tackle that job. I am always aware of where the blade is as I'm passing a piece of wood over the table saw. I keep my fingers well away from the path of the blade.
From now on I will use featherboards when cutting dadoes. I have seen first hand what happens when a board gets kicked back. Happens so fast you have no time to react.
Talking about bad habits.. how many times Have I witnessed people pushing wood freehand across the table saw without the use of a miter gauge or cross cut sled .
Wanda
This forum post is now archived. Commenting has been disabled