I am having a heck of a time getting two bits set up correctly.
1. A 45 degree locking miter bit – I simply cannot get the bit to cut both sides evenly. The joint simply will not match at the corner – when I lock the two pieces together the closest I can get is a variance of about 1/16.
2. Locking glue joint bit – similar problem – I cannot get the two pieces to match flush.
Trying to learn to set up these two bits has just about used all my scrap pieces of wood!
Replies
I had the same problem with my 45* miter locking bit and gave up on it. I think that the problem is that both the material and the machine setup have to be absolutely perfect (flat, straight, and square) or the joint will be "off". I also found that my joint quality got worse with larger workpieces.
MLCS sells a setup block which I may buy someday, but it isn't a high priority.
Gentlemen,
I appreciate all the advice and tips that you have given and went to my shop to try some of them out. I just spent about 2 hours trying some but alas, I think I have found a problem that will make setting up any bit difficult and I would like a little advice - thanks in advance!
I have a Porter-Cable 891 router mounted on a bench dog table (the type that mounts to your table saw) and I use the PC above table adjustment handle to raise and lower. Problem: when I have the clamp closed the raising and lowering is very tight. If I open the clamp to adjust the height the router literally drops what appears to be an 1/8 in or so - consequently I cannot accurately adjust. I have loosened the clamp adjusting screw and it helps for a little but after raising 2-3 times it starts binding up again.
I took the motor out and lightly sanded the inside of the base, used 0000 steel wool and auto wax on motor housing and still no go.
Does anyone have any ideas?
Edited 12/15/2006 9:17 pm ET by kre8ted
I have had similar problems, and I found that time and patients were the only answer for me. I did get them to match, but it took a long time. If you have a 1/16 difference, it is a 1/32 adjustment, and it just gets finer. Good luck.
It is frustrating, but this helped me.
http://www.woodshopdemos.com/cmt-lm10.htm
K,
They are rascals to set up, are they not? :-)
The link you were given above will hopefully help.
Two other considerations for you:
1 Remember that the cutter is a 45 degree affair. To adjust the cut you need to move the cutter both up (or down) above the table and out of (or in to) the fence. If you just adjust one of these parameters, you are much less likely to zero in on the right position for the cutter viz a viz your workpiece thickness.
2 If and when you do get the right setting for your lockmitre cutter, keep a lump with the fully cut profile in it, as it will provide a shortcut to resetting the cutter for any subsequent pieces of the same thickness. I have 5 myself, for work between 1/2 inch (the thinnest the small LM cutter will work on ) to 1 inch, with 5/8, 3/4 qnd 7/8 inch pieces in between.
Incientally, having a template as in 2 above also helps to set the cutter for other thicknesses, as you use the template nearest your current workpiece thickness as the starting point and make very small (and equal) in/out - up/down adjustments from there.
If you perservere, you will enjoy the benefits of a lock mitre, which include a very strong glue joint, a strong mechanical joint (in one plane at least) and strong carcases with sharp, clean corners.
Lataxe
PS In the interests of router table safety :-) I should mention that the lock mitre is a nasty beast if messed with, so:
* take many passes and small cuts, with the cutter at the right speed (usually slower than the router's max).
* closely shroud the bit in a false fence and (if possible) the table insert- no hole or ledge for the workpiece to catch against.
* the lock mitre cutter does not like to cut against the grain or into hard or loose knots.
* use vertical and horizontal hold downs; the LM cutter will mince the work if given a chance - especially on the last cut when it is projecting the most from the fence.
* use some form of large pusher that is big enough to stop your hand going into the cutter, should there be a slip.
* the stock, table and fence do need to be flat & square.
Edited 12/9/2006 1:24 pm ET by Lataxe
Thank you for taking the time to provide the details and advice - I appreciate it. I was stumped on the fine tuning and I think you have given me some insights that will help - I will let you know how it works. This is my fisrt post and am very pleased with how every one responded to my question.
Thanks
K,
The article in FWW about the technique of gluing up mitre joints like Hal recommened is in the April 98 issue and is by Steve Latta.
You might be able to find the article on this Taunton site, as a PDF, if you've paid for the extended Taunton Web service. It's also on Taunton's latest DVD of back articles, along with thousands of others.
Lataxe
Do an advanced search,45 degree lock miter. There are some good instructions there. Forget the set up blocks, they are only a ball-park locator and you will always need to tweak the height to get it right on. Eyeballing the center is good enough, test cut and tweak. Set up the bit by using the exact same thickness material as finished project lumber. Run two pieces horizontally and put them together as you would a regular glue joint, tweak height adjustment by 1/2 the difference till they come together flush. Yes there is a learning curve with this bit, be patient, you'll get it.
Work Safe, Count to 10 when your done for the day !!
Bruce S.
Edited 12/9/2006 6:57 pm ET by BruceS
Thanks for the help - I have had great responses and reading the other posts has been helpful - I will be trying again and will let you know how it works
Thanks
Edited 12/12/2006 5:55 am ET by kre8ted
My question is "Why do you need this joint?"
Why not just make a real good miter joint and glue them together?
It is actually quick and pretty easy to make perfect ones every time
Hal
http://www.rivercitywoodworks.com
Why this joint ? The greatest feature of this joint is it's ease of gluing. It is self aligning and does not slip under clamp pressure. And you only have to clamp on the sides that pull the lock together.Work Safe, Count to 10 when your done for the day !!
Bruce S.
Bruce,
I am not trying to be a smart Alec here, but your argument about it being self aligning can't be true, just based on what you have said earlier on this thread. How can it be self aligning if you can't get it to align at all?
As I ask this, I hope you know that I don't really need a reply or answer. I have seen woodworkers struggling with these bits before, spending lots of time and many test cuts, only to eventually give up. I understand that in theory this bit should work well. It is just too much actual work.
I do know that in order for it to work, you have to have your material perfectly thicknessed, and your setup must be perfect. Really, it takes more time than it will ever be worth.
Here is how you can make perfect miters that really do self align.
1. Cut your 45 degree miter cuts. Check to make sure they are at the correct angle. Don't trust the saw. On lengthwise miters (going with the grain), I usually overcut the angle by just a bit so that the outside is tighter than the inside. On end cuts, I cut them perfectly. Make the cuts, then put them together and check them with a good square that is actually square.
2. Place the boards with the long sides up and the points of the miters touching.
3. Tape the joint together with 1" masking tape, slightly stretching the tape. Don't tape the length of the joint, but tape across it. I guess you can also use strapping tape, but I've never tried it. After you have taped it across the joint, finish by running a length of tape the length of the joint just to keep the glue in the miter.
4. Carefully flip the whole thing over and apply a bead of glue into the miter, near the outside of the joint (with the boards upside down, this will be in the bottom of the trough). Don't coat the entire joint with glue. If you do, the wood near the inside will swell, forcing the outside apart. It doesn't take as much glue as you would think.
5. Fold the miter into it's final position, and Ta Daa...you've got your miter. You only need to fold one side up. I have some perfectly square pieces on hand to clamp the whole thing to while the glue dries.
This will even work with plywood panels if you need to miter them, or if you have a plywood side panel on a face framed cabinet. The beauty of this method is that the materials don't need to be the same thickness.
There is also a way to clamp the joint with clamps at a 45 degree angle, but it is more work and really not necessary.
Hal
http://www.rivercitywoodworks.com
Hal,
You say, "I do know that in order for it to work, you have to have your material perfectly thicknessed, and your setup must be perfect. Really, it takes more time than it will ever be worth".
Is it not good practice to have material perfectly thicknessed then? I thickness mine properly (to 0.1mm, the limit of the thickneser's accuracy) as a matter of course, as this makes subsequent construction much easier than it is with lumpy bits of wood.
"Perfect" setup is not really needed with the LM bit, just a reasonable degree of accuracy - the sort most woodworkers looking for precision will achieve as a matter of course. Bruce can do it by eye; I use templates to help. In either case, it's no more difficult than any other set up of a precision machine.
Your method of taping plain mitres sounds intruiging and I will give it a go on the next carcase I make. I remember an article (but not the issue or author) in FWW about doing just that, in which the author said that such a joint can be very strong, even if the mitre is cut on end grain (which was a surprise).
The closest I came to your technique involved mitre jointing four large ash frame & panel sides into a carcase for a plan chest. I was too nervous to rely just on the strapclamps I used, so stuck a few biscuits into the mitres, which ensured they lined up easily. As it also involved gluing in the drawer dividers (into rabbets) at the same time, the whole operation was fraught!
Anyway, the LM cutter and its joint is very strong - mechanically (in one plane) as well as in terms of the extra glue surface. I use it a lot to form "flush" draw bottoms that cannot drop out and drawer fronts that cannot pull off - typically in 1/2 or 3/8 ins birch plywood.
So, why dismiss a technique that is useful (in my experience and that of others) in favour of another? Both techniques are useful and the more of them you have the better (unless some form of woodworking religion gets hold of one's mind of course). :-)
Lataxe
Edited 12/11/2006 1:22 pm ET by Lataxe
You misread me, Yes there is precision needed in the set up, but it's not to difficult when you finally get the nack. The self aligning part comes into play after the cuts have been made and your doing the glue up, the "tongue/grove" align the joint perfectly with no slippage of the joint while clamping.Work Safe, Count to 10 when your done for the day !!
Bruce S.
Hey Bruce,
I thought you were the original poster. Sorry, my comments should have been directed to Kre8.
Hal
Edited 12/11/2006 1:51 pm ET by Hal J
Edited 12/11/2006 1:52 pm ET by Hal J
I think your dead on with this comment, with a good glue up setup you can due this quite well There has been some good articles in this magazine for this very thing. I like the method that uses fiber reinforced packing tape. Troy
Troy,
I just use 1" masking tape and it works every time.
Hal
As far as the glue joint goes , typically whatever gets glued up with this joint will get surfaced or sanded to final spec . Closer than 1/32nd or so may be pointless .
get them close then run it through a thickness sander or the equivalent .
good luck dusty
Kre8ted,
Hey, I just discovered a guy demonstrating how to use this bit from another post.
You can see it at http://www.woodshopdemos.com
Hal
Edited 12/11/2006 12:04 am ET by Hal J
Thanks Hal - I just checked it out and it looks good - I received some great tips on here from others also - this is my first time trying the website out and I appreciate the great response and help from so many people. and h
Just wanted to let you know that I glued some miters today that I cut on my table saw with a crosscut sled, and in gluing them using the tape method, they really turned out well. I doubled the tape to make it stronger because these were large solid wood panels. I was gluing wide, end grain miters.
You should try it on some scraps, just to try it.
When doing it with the grain, I would suggest jointing the edges you are going to glue if you have a right tilt table saw that you cut them on.
Hal
http://www.rivercitywoodworks.com
Thanks Hal - I have never tried the tape metheod but will try it out.
You said that "When doing it with the grain, I would suggest jointing the edges" what do you mean by "joint the edges"?
Keith
Oh, I just lay the fence on my jointer over to 45 degrees and run the cut edge over it, taking off 1/32".
This makes a really nice glue surface for the miter.
Hal
http://www.rivercitywoodworks.com
I walked into my shop and saw my jointer there and realized that was what you must have meant! Thanks for the help.
If your blades are sharp and you planned ahead in regard to grain direction, jointing really helps to make a perfect miter.
Hal
What guidelines do you recommend on grain direction?
Kre8ted,
Hmmm...well, usually the grain on the edge of a board goes one way or the other. In deciding which board to use for a piece that will be mitered, or even which face of the board, you will need to think ahead so that after you have cut the 45 degree angle on the board, it will have the grain going in the correct direction over the jointer when you joint the saw cut.
I joint with the face of the board up, which means that the fence is tilted over 45 degrees to the right on my jointer. This also means that the grain needs to run out toward the lower edge of the board as it runs across the jointer. Otherwise, it is possible to have tearout on the sharp edge of the board that will show.
If you are using a hand plane to do this jointing, the grain could go either way. Be careful though that you don't accidentally slide your plane off the board and cut your hand on the edge of the miter.
Hal
http://www.rivercitywoodworks.com
Hal,
I am making a toy box out of cherry and hickory(I'm a new grandpa) - I designed it using the cherry for corner posts and doing a mortise and tenon joint for the sides and ends so I wouldn't have to do the 45s.
I have had trouble doing 45s in the past (fit and strength) which is why I went to the lock miter and the mortise and tenon design keeps me away from them. I will try them again on a couple of sample pieces using some of your tips.
I have been doing woodworking sporadically over the years but in the past two years I have acquired new equipment and been doing more pieces and improving my skills - I appreciate your tips.
Merry Christmas!
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