Problems cutting long mount apertures

[Framegirl]

I have a Keencut Ultimate Gold Mount Cutter which is generally great. However, sometimes when I am cutting long mount apertures, the blade does not cut all the way through the board. I have put a new blade in and I know it is fine because it cuts the short sides of the aperture perfectly, so I think it must be because it is a long side (e.g. 75cm). I have just cut the same thing 3 times and it has not worked on any of them so am tearing my hair out. Does anyone know why this is happening and how to prevent it?

[silvercleave]

Hi framegirl

First make sure that the bench you are using is PERFECTLY Flat, and that the base of the cutter is supported on all the length, secondly hold the bar down firmly in the middle, it might not be quite down.

It only needs to be up by a millimetre to skip cut

All the best and I hope it works

Ian

[IFGL]

Do not put any weight on the big black bar, do not even rest your hand on it whilst cutting, if you do it will lift the cutting head and cause the kind of problem you are having, this can happen on long cuts as you lean over the cutter, as the last post suggests make sure everything is flat.

[Roboframer]

Of course make sure your machine is on a sturdy flat surface and that it is actually laying flat on it etc etc. Also look at the underside of the cutter bar, there's a rubber gripper cord in a channel, make sure it's even and un-twisted and while you're at it, make sure there's nothing stuck there that shouldn't be.

Make sure the slip mat is in good condition too, the blade can switch to previous grooves/scores or run across them, or it could be that in the centre of long cuts there are no scores in the slip mat, but at the end of the cut, there are - lots! Also make sure your slip mat is wider, much wider, than the distance between your mat guide and cutter bar.

Once you're sure all is as it should be then concentrate on your physical cutting style - on long cuts you may have to bend your upper body, even raise your heels, but as you straighten as the cutting head gets closer to your body, make sure the applied pressures and angles stay constant. Your forearm, hand and wrist should stay the same while the rest of you does what it has to to ensure that.

Practice by taking 2" strips off a load of skinny offcuts.

[Framegirl]

Thanks for the advice - much appreciated - will try these.