I am not having much success making perfect miter joints for the frame of a door for a clock I am making. I can get 3 perfect joints, but not 4. My current method is to make the cut on my table saw, then fine tune with a stationary disc sander.
Is this purely operator error, or is there a better technique? Would a miter trimmer, or the “Professional Miter Box” from Lee Valley help?
I appreciate any suggestions.
Thanks,
Randy.
Replies
When you say you can get three but not four, do you mean that you can get a perfect 45° angle 75% of the time (on average), or do you mean that all of the angles are slightly off (presumably by the same amount), and you can't get that last joint to close?
If it's the former, then, well, I guess "practice makes perfect" is the only thing I can suggest.
If it's the latter, then the best approach is to diagnose why you're getting the error. What are you using to hold the pieces in position when you crosscut them? Hint: The stock miter gauge is not likely to be good enough. You need a precision miter gauge (better) or a sliding crosscut sled (best).
-Steve
It's the latter.......can't get the last joint to close. I am using the stock miter guage.
Okay, so you need a better means of holding the stock properly. A good sled will go a long way to that end. If you'd prefer to buy rather than build, one of the fancy miter gauges (Incra, Jess-Em, etc.) will likely work as well. They have the advantage of easier tweaking, but aren't quite as solid overall.
-Steve
In addition to the other advice, if the opposite sides (or top/bottom) are not exactly the same length it will affect the closing, even if the miters are spot on.
Check the lengths. Carefully. This is where pretty exact measurements are important.
Take care, Mike
Edited 10/15/2007 3:42 pm by mwenz
It's possible that one or more sides of the frame have a little twist in them.
Lay each one down on the flattest surface in your shop to make sure.
I've had more than one Nobex (long story), both were almost dead on with each joint only needing a whisker, and I mean a whisker, taken off the inside of any given miter. One pass with a very finely set block plane resulted in perfection.
If you need a disk sander to true up the joint then you need a new method of cutting the joint in the first place. If you remove a little too much with the disk sander (frightfully easy to do) then you have to chase the difference all the way around the frame.
Wouldn't a chuting board set for an accurate 45 and a good plane be a faster, more faster and more accurate way to trim them to fit?
rshelly,
The single thing that improved the quality of my miters was making a dedicated miter guage for the tablesaw. Simply a piece of plywood, with a factory (good 90*) corner oriented at 45* to the blade with a strip underneath for the miterslot in the sawtable. Use it by attaching (glue and screws) a fence to each of the sides, so you can clamp (to eliminate creep) the stock. Use first one side, then the other, as a reference to cut the miters, if you are off a tiny bit in fixing the strip for the slot, the two cuts will still add up to 90*
As mentioned, exact length in the pieces is necessary, as is trueness in the sawblade (must be vertical).
Ray
I use an aftermarket miter gauge(Incra 1000) and a stop block to insure exact lengths and exact 45's. Everybody can get 3 corners to fit, but it's the elusive 4th corner that's the kicker. Exact 45's and exact lengths are what make that elusive 4th corner possible.
By the way, what clock are you building?
Work Safe, Count to 10 when your done for the day !!
Bruce S.
Thanks for the suggestions.
I am building a Massachusetts shelf clock. I was fortunate enough to get to measure a Simon Willard clock that I am patterning this one from.
I agree with the shooting board suggestion.First, make sure that your stock is milled 4 square. You can make a shooting board/bench hook out of ply or mdf and a bit of hardwood for a few dollars. If you need to, you can use the shooting board with a shim to make fraction of a degree corrections so that your miters fit perfectly.I made one a few years ago, and don't know how I got along without it. I use it with a low angle plane to shave off thin wisps of end grain when fitting miters on joinery, picture frames, etc. It is very versatile, and for less money you will have a fixture that is more useful than an Incra jig or a miter guillotine (both of which I own). Pics on request.Glaucon
If you don't think too good, then don't think too much...
Just wondering what clock you were doing. I did the Clock on the October cover of the Eagle America catalog and http://www.eagleamerica.com site.
Work Safe, Count to 10 when your done for the day !!
Bruce S.
Edited 10/15/2007 8:16 pm ET by BruceS
No expert on anything.. However, if the 'sticks' you are cutting are relatively small size I would cut by hand. I make a hardwood block with one end cut to the angle I want. I rout a groove into the block that holds the stick with a 'slip fit'. The stick will be fully enclosed in this slot and the top of the stick approximately 1/4 to 1/2 inch below the surface of the cutting block.
OK laugh but I use one of them XACTO razor saws or a jewelers saw.
Here is a link I found to show the tool which you can find at most hobby shops. The link is just the first one that popped up and I have nothing to do with them.
If you do a lot of this work and you have money to burn get one of them miniature table saws. I do not have now but I had one long ago when I was into model building. They are GREAT but expensive. I do not remember the brand but it was more like a little machine shop. Sorry I got rid of it but I needed money to feed the wife and children then.
EDIT: LOL I forgot the link
http://www.a2zhobbies.com/Xacto/Saws/
Edited 10/15/2007 7:46 pm by WillGeorge
Another thought. Using a powered saw followed by the sander may be mixing two variables which can compound any error.
You ought to be able to just use the table saw *if* the blade can produce a clean enough cut.
The only ways I have been able to produce usable miters off the table saw has been:
Using grip tape on the fence to help eliminate creep of the work piece.
Knife the lines accurately.
Cut a blade's width away from the knifed line.
Trim to the knifed line via a second cut.
The last one has helped me to ensure that the work piece does not shift--depending on the angle of the fence, the piece will want to ever so slightly creep into the blade or away from it. Still, I usually shoot the miters instead of trying to control a table saw.
As long as the pieces are dimensioned the same in width/thickness, the blade is cutting true 45 deg. miters *and* 90 degrees to the surface, and the pieces on the opposite sides are the same length, they will go together fresh off the saw. However, if the pieces sit, especially if they are stacked flat on something else, they will most likely twist, bow or warp a little. If that happens it is essentially like they were not cut correctly (even if they were).
You've picked an awesome family from which to draw inspiration from for your clock.
Take care, Mike
Perhaps your door frame is not exactly square. Try scribing the outline of your trim around the door frame in pencil. Where the horizontal and verticle sections cross use your sliding bevel to bisect the angle (suppose to be 45 deg). Use this angle to set your miter saw and cut both pieces. This works for me, I renovate old homes.
Regards,
Wonga.
Hi Randy,
As the others have said, the disc sander is a wee bit agricultural for fine work.
In addition to the mitre sleds, if you cut the joints as you have, and then clamp them in correct position onto a scrap board, cut through the joint with a fine handsaw (I use a japanese saw), they'll fit perfectly. The kerf matches perfectly and the gap's pretty well invisible - any wander in one side will be matched by wander on the other.
The technique has a name, but I can't remember it for the life of me at the moment.
Cheers,
eddie
Making "perfect" miters can be one of the most challenging jobs in the shop. The theory is simple - cut your rails (and stiles) the same length, miter the ends, and you're good to go. The devil, however, is in the details.
When you say that the first three are perfect, but the fourth isn't, I would guess that:
A mitered door frame involves making eight cuts. All eight miters must be exactly 45* and four of the miter cuts must exactly match the lengths of the opposite rail and stile.
If your miter is off by even 0.1*, that joint won't be 90* - it could be 89.8* or 90.2*. Each joint will look fine, but as you work your way around the frame, the errors add up and the fourth joint won't be closed.
Even if your miters are perfect 45's, if the lengths of the rails (or stiles) differ slightly, the errors add up and the last joint will be off.
Before you spend a lot of money on a high precision jig, review your technique and eliminate as much error as you can. One lesson I learned was to clamp my boards for the miter cuts. On angled cuts, the saw blade exerts a lateral (sideways) force on the board. If the board moves by even a couple of thousandths of an inch, the angle will be off.
All valid points.
Others have suggested precision miter gauges.....in reviewing these products online, one of the most important features over my stock miter gauge seems to be the ability to adjust the width of the runner that fits into the slot on the table. With the amount of slop I've now noticed in my current miter gauge I am surprised that I am able to get the joint as close as I have.
I am currently leaning towards purchasing one of these miter gauges and giving it another try.
Thanks.
I have the incra 1000se and its been really good! It's dead on, and fine adjustment. It was recommended here, and I do not regret it one bit. It was around $100 when I got it.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 have most of the Incra fences and other stuff. Hard to beat but I do not use it all the time. To me my Incra 1000se is the best tool I have in the shop. Well, except for my routers...And the 1000s on my Incra Miter Express? is wonderful.. However, I found that my saw blade made a big difference. I usually use a FREUD
thin kerf and I found that putting blade stabilizers on it helps ALOT!I use a RIDIGID table saw which some think is junk but I like it.. OK, I could do better but NOT the saw's fault. I have it 'dead on' as far as cuttin' straight.And as others have posted.. Try some 'sticky backed' sandpaper on the miter gauge to hold things where you placed them!Cutting miters is like playing LOTTO.. Sometimes you win but.. Loose often...
Yeah, a "stock" miter gauge probably won't give you enough precision to get "perfect" miters. I'm not even sure where my "stock" miter gauge is anymore. - lol
My little dissertation was intended to point out some the more common problems with getting "perfect" miters - and "perfect" mitered doors. As others have mentioned, your saw also need to be dialed in to a knats whisker and you gotta have a good blade.
FWIW, I use the Incra 3000 miter gauge on my table saw and I also have the Makita LS1013 compound miter saw. Both saws have been "tweaked" to as close to perfect as I can get them and I still manage to blow a door once in a while. - lol
Dave45 pretty much echos my recommendations.I always chuckled when a certain machinery demonstrator always did a compound miter joint and held up one corner to show how tight it was. Any fool can make one corner look good. As you have found, getting the last of four is the proof.
".......getting the last of four is the proof."
Yeah, and when you get pretty good at making four good miter joints, you decide that making six, or eight, or whatever can't be all that tough and you get to make another journey down the Humble Road. - lol
Jim Cummins (RIP) did a Taunton video on small shop projects and he showed a great way to cut odd miter angles. Using trig for setup. I replicated his technique and made a 31-sided coopered cylinder without any appreciable gaps. Worked great.
31 sides??!! You're funning me, right? - lol
Actually, I've found a way to get perfect miters every time - if you're working with flat stock. Cut the first miter and then - without moving the saw - flip the stock for the second cut. Even if the first cut is a little "off", the second cut will make the same error but in the opposite direction. When the joint is assembled, the errors offset one another and you'll get a perfect 90*.
Call me a cheater, but I've finally found a way to make octagonal columns without a lot of aggravation. I've always done them with splines and getting the pieces to align just right was a real hassle. I have a job coming in that will have a 10" diameter octagonal column approximately 32" long. The customer will probably want the piece in Walnut which I consider to be a high "pucker factor" wood. Since I don't want to make any more mistakes than necessary, I bit the bullet and got a 22.5* lock miter bit set from MLCS.
The set came in Saturday's mail and within about two hours I had made this test column - including the setup blocks. Bring it on, dude. I think I'm ready. - lol
To all that 'knock' a lockmiter bit.. Wonderful bit once it is setup correctly!
Randy,
You've gotten a lot of good advice about how to use a jig on the table saw to get good miters but you need to tune the saw itself. If the miter slot isn't exactly parallel to the blade no amount of tweaking the miter gauge or the jig will give you a good cut. A good blade on the saw helps also.
John White
Yestermorrow School, Waitsfield, Vermont
Author of "Care and Repair of Shop Machines"
All lengths are right on, stock is square, shoot it. It's the best way.
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 10/16/2007 9:28 pm ET by KiddervilleAcres
Bob,At the risk of carrying Adam's water, I'd agree. I don't know when shooting boards were developed but they sure are handy. If ever there was an application where you'd want to shave off micron by micron to ensure a perfect fit, mitering must be it.Glaucon
If you don't think too good, then don't think too much...
Glaucon,
It just seems to me that folks spend all this money to buy these fancy jigs. I'd rather spend money on some really nice stock.
Besides, making that shooting board to get them there mitres square is all part of the adventure! Not to mention the fun making the mitre sled to get you there!
Adam gets my heart pumping, which isn't a bad thing for an auld fart like me!
Geesh maybe I'm having too much fun, is there such a thing?
Cheers Man,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Randy,
I'd be happy if I would get one perfect. So far I've been doing various test cuts, don't own a table saw and I don't believe it would help much anyhow. Shooting board does not seem to be of much use either at least for the 'male' part of the miter cut.
What seems to be working ok is to 'kerf in' the joint. Probably the joints will get tighter after wedging the tenons. Some better wood might help, too.
Based on my very limited experience my guess it is neither the equipment nor the technique but mostly practice.
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Atlanta, GA
Galoot-Tools
Thanks to all of the feedback I received here, I have done it!
I purchased the Incra 1000 miter gauge and a good blade. I placed some adhesive backed sandpaper on the fence.
The very first attempt produced 4 absolutely perfect joints. Straight from the saw to glue up!
Thanks to everyone who replied.
Randy.
What's that expression, "Any problem that can be resolved with money is not a problem."...assuming you have the money :-) Otherwise, you have what's known as a "bootstrapping problem."
If you have a mitersaw, adjust the swing to 45 1/4°,may all eight cuts.The miters will pull together.From your posts I'm assuming you only have a tablesaw. Do the same thing as noted above,either with the miter gauge or panel jig.If your case is square or extemely close and the legs are the same length you will have perfect miter joints.
This is an old carpenters trick for outside corners,base crown,shoe molding etc.The case may check out to be absolutely square by eye with the finest starret square money can buy. And the moldings still are off, try my way
mike
Mike -
That trick often works, but I've had failures when I've used it on mitered doors. If you force a joint to close up, you introduce stresses that will relieve - sooner or later.
Since doors often get slammed, that can shock them enough to cause the joint to fail when the stress relieves.
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