Thread: Accurate Mitre Joints

Have you achieved a perfect 90 degrees between the fence and blade? Have you checked the 45 degree angle each way with a known 45 degree reference? Are you using 45 degrees in both directions or just one and flipping one piece?

Matt

Yes to all your questions.I reset the fence and the crosscut was right on target even after several trail cuts.I had a bit of an incident several months ago and I think I may have warped the blade abit. Yesterday I spoke to a guy that makes the blades and he asked me to try and cut a 45 on the right and left and check each cut with and under the light I could see a bit of wavering in each angle.Today I took the saw to a local tool repair shop and the guy there told me he had had several Makitas in with the same problem

Originally Posted by mat

Have you achieved a perfect 90 degrees between the fence and blade? Have you checked the 45 degree angle each way with a known 45 degree reference? Are you using 45 degrees in both directions or just one and flipping one piece?

Yes to all your questions. I finally took the saw to a local tool reapir shop for him to have a look at it. I think the blade may be warped

Wayne

Perhaps you can tell us about your incident so we can try not to do the same.

Have the same saw and same problem .
If your stock is symetrical cut one 45 then turn over to cut its mate ie if both cut on the same side of saw blade must be 90 deg
Or this may help I built a simple jig the strip of timber at the bottom fits tightly in gap in saw table, run the saw accross with depth stop set to just cut into base and using an accurate square set the two stops at 45 to the blade cut & 90 to each other.

You might not find this all that helpful but I have been working wood for quite a few years now and avoid your problem by never ever using mitres!

Works for me


Ross

Ross

Good luck to you if you can steer clear of mitres I try to steer clear also but when you have to make 40 picture frames in a short time its the only way to go






Don't take life too seriously; No one gets out alive.

Mat
I was making a feather board out of some scrap oak. I cut 5ml cuts to creatE the feather then put the material on Makita SCMS to cut the 45 when the blade touched the material the whole saw actually jumped off the table. I was lucky thatI had clamped the materila down otherwise I might be missing some items from my hand. At this point I have taken the saw to the doctor for check up. I may have warped the blade if so they can fix that quite easily.

Ashore
Thanks for your reply. I think I understand your technique. How do you anchor the jig to the base of the saw. Are you 45 accurate once you do this.
Thanks for your help
Wayne

Wayne
Make sure the kerf strips are parallel and tight , cut a piece of timbet just a little wider then sand till a tight fit , I used a belt sander for this. Screw to a flat base sheet and fit ontable into the gap between the kerf strips. If you don't replace the kerf strips or adjust them the jig will always sit in exactly the same position. Mark the base with a saw cut "do not forget depth stop or you will make mark 2 as I did " Then the stops at 45 to the cut or set one stop and set the other with an accurate 90 degree square . then if even 1/2 a degree off 45 the two mitre joints will always match perfectly always 90 degrees. But takilg extra time setting the first 45 pays off hope the extra pics help



Rgds Russell



Don't take life too seriously; No one gets out alive

I think making lovely tight fitting mitres (and thats the only time they look good ....unless your comfortable with fillers and paint) is really only possible by hand....they have to be very accurate or you'll see gaps....unless your willing to purchase some futuristic machine that only professional framers buy.

What I find works are shooting hand planes.....I have a cheap compound saw but I only use it for the initial ruff mitre cut outside the line. then I take it to my mitre shooting table with a razor sharp blade (thick blade to handle tough end grain in a plane with a stable bearing when on its side.....I just welded a wide flatterned plate to one side of an old stanley no.4)....
Only got like a millimetre or two to get right on a squeeky fit....If all set up right it should shave the timber like shaving ham,,,,each pass leaving a bueatiful finish spot on 45 degrees far superior to what you get initially off the saw
You just shave once , check for fit, shave again etc until your spot on your knife line..........the point is you approach a perfect mitre with confidence everytime ...you develop a feel ...far better than that hit and miss approach that seems to come with power tools........

So if I was you I wouldn't worry too much about it and just use it for ruff cutoffs...and set up shooting boards ........Well I reakon anyway....

Russell
Last nite I toyed with your idea and it works really well. How did you anchor the narrow strip to the bottom of the jig did you glue or use screws.Did you use the inside our outside of the 45 to make the cut.I also cut several 45's amd glue them together without any clamps and I couldn't beleive it but it also worked well.Did you use any type of clamp to hold the work piece in postion to keep it from moving.
Thanks for your help.
Wayne

Wayne

The strip on the bottom I glued and used 12mm brads from nail gun as it is too narrow to screw
I use the inside of the 45 as the cutting action of the blade pushes the wood hard up against the guide
I dont use any clamps as i usually make final minute adjustments by hand the
one other tip make your 45 s higher than i did and cut the two opposite sides of picture frames together if the profile allows

I do use either a strip glamp or a specilized clamp i made for gluing and often put in a feather for added strength


Rgds Russell



Don't take life too seriously; No one gets out alive.

If you interested in learning more about shooting boards and fine tuning mitres there is a good DVD available from Lie Nielsen that covers it pretty well.

I bought a copy on DVD (it was about $49 delivered) and recieved it in about 6 days.

It covers shootingboards, choices of handplanes and techniques for shooting mitres, 90 degree cuts and veneers.

Heres the link http://www.lie-nielsen.com/library.h...6&sku=DVD-DC-3


Joe