The Framers Forum

I am sure this has been covered many times. I have Morso F with two set of sharpened blades and using a Minigraf 44 underpinner, my joints are not quite perfect I am getting a small gap on the inside and slightly springy when pinning, is their a video or any literature on getting the right setup.

Thanks in advance

Lex

Try slackening the left-hand fence and moving it toward you a gnat's eyebrow. Lock it tight again and make a square test frame from scraps - wider moulding the better. A piece of flat timber is just as good. It the gap is gone, bingo. If it is less then repeat another gnat's.

If you start getting gaps on the outside then you have over-gnatted it.

The thing is with cutting wood is that it's a natural material and setting the chopper angles 45deg dead doesn't always produce a 45deg cut.

Thanks for the advise

prospero wrote: make a square test frame from scraps - wider moulding the better. A piece of flat timber is just as good.

I'd say it's even better (or a wide flat moulding cut face down) as it takes the rebate supports out of the equation.

Robo & Prospero you guy's are legends I always watch your post's with interest. Well I have it pretty dam good now thanks a million, simple when you know how

Lex

I found that if I cut two strips of mdf the same width and about 500mm in length I can square the morso. Lay one strip flat on the right/ measuring arm and cut a mitre then turn it upside down and test how far it is out by laying it against the left hand blade. You can then adjust the fence accordingly.

iamzero wrote:I found that if I cut two strips of mdf the same width and about 500mm in length I can square the morso. Lay one strip flat on the right/ measuring arm and cut a mitre then turn it upside down and test how far it is out by laying it against the left hand blade. You can then adjust the fence accordingly.

That's a perfectly sound method of setting the fence to 45deg, but the whole point of moving the left fence is to move it away from there. It may seem illogical, but just because the blades are set to 45deg it doesn't mean you will get a frame total internal angles 360deg.
Wood is an organic material. The only way to keep a tight frame is to make minute adjustments to account for the way it cuts.

How can you possible adjust the fence for every length of moulding you cut? I have to tweak the fence every time I change blades or as the wear but constant tweaking surely isn't the norm is it?

I never have to do constant adjustments. Once you find to magic spot.
I find that the ideal is when the last two corners are just slightly apart before you join them. If they want to overlap then the left fence needs a tiny move toward you. Remember that if the actual angle of the miter cut is even a few seconds of arc under 45deg the fault is multiplied x4. The wider the moulding the more the divergence is apparent.