Calling all Morso experts - help pls!

[Madwolfie]

Hi
I am a newbie to this forum, but have been framing for a few years. I need to answer a few vexing problems, please bear with me, I have searched but could not find answers to these. I use a Morso and a Cassese underpinner, I have never been to a framing class.

1. When I come to make the last corner of a frame there is a gap of about 3-4mm - which requires some effort to push together in order to underpin correctly - is this normal and if not how do I correct it ? The mitres seem to fit perfectly otherwise.

2. Sometimes my corners have a small gap on the back of the frame, (also visible at the corners edge) but are perfect when viewed from the front - Lion suggested the blades may be at fault, but I have two sets (one new) and they have both been re-sharpened to no avail.

3. I have heard a lot of talk about which underpin to put in first - I usually put the one nearest the inside of the frame then work towards the outer edge - is this correct ?

Your help would be much appreciated as quality of finish is something I pride myself on and I don't like throwing stuff away, if it is not up to scratch ) I have previously used other professional framers to supply finished frames to me, but now I have the luxury of my own workshop and can do the frames on demand with no waiting time.

Thanks in advance
C

[prospero]

Hi and Welcome Madwolfie.

Sounds like you need your left fence on the Morso tweaking. But first, the underpinner....

The gap at the back of the frame is a classic not-enough-pressure symptom. Usually you get this on hard woods such as Oak and Ash. What could be happening is the wedge is lifting and forcing apart the two ends of the moulding before it penetrates. As it bites it will pull the faces together, but the gap at the back will remain. Could also be the shape of the moulding where the pressure pad is pushing on a high point offset from the insertion point. There are various ways to cure this. Depends on the individual moulding.

If your Morso is set correctly, there should be a slight gap between the faces on the last join. The springyness of the wedges does this. It doesn't mean the angles are wrong. When you push the last two faces together they should mate perfectly.
This is why you should insert the wedges from the outside edge in. I always go all the way round on the outside, then switch wedge position and do the inner ones. the principle behind this is that when you join the last corner, the inside faces of the other corners are squeezed together because the outside wedges provide a fulcrum point. If you do the inner ones first, the outer edges of the frame will tend to be levered open.

* I know some machines are equipped to pin two wedge positions at once. Mine isn't. In any case I prefer to do it this way. Others will no doubt disagree. To my way of thinking, if you only had the choice of one wedge position per corner, it would be near the outside. The inner wedge serves mainly to equalise the hight where the inner faces meet. On a perfectly straight piece of timber you wouldn't get any misalignments. But most lengths will have a slight twist somewhere. Before the advent of underpinners all frames were clamped in a vice and nailed and you can only really put nails in toward the outside edge. Think of this: Make a frame and pin it on the inside only (no glue). The stand it on end and try to push it sideways. It will move and you can force the corners open easily. Do the same with one pinned on the outside only. It will be absolutely rigid.


To set the left fence of the Morso for perfect joins, you can use a few bits of scrap timber - wider the better as this will amplify any errors. Cut four pieces the same length and dry-fit them together. There should be no gaps. Most likely, if 3 corners are pushed tight together there will be a gap on the inside of the fourth one. Slacken the left fence and move it toward you a tiny amount. This adjustment is multipled x4 in the actual frame. Try another test frame. If there are no gaps then you have the correct setting. If there is still a gap, but not so bad, then tweak the fence a tad more in the same direction. If you start to get a gap on the outside, then you have overcooked it so move it in the other direction. It's largely a question of trial and error. You may need to tweak again as the blades lose their edge. Wood being a natural material has a certain 'give' so setting the machine to a perfect 45deg will not necessarily result in a 45deg cut.

Hope that is reasonably understandable.

[mikeysaling]

prospero - you never cease to amaze me - very well explained . with my hansen i cannot do the left fence thing and need 'sharp' blades all the time - no question - morso is the best when you know the beast.

[Madwolfie]

WOW !
Thanks prospero - simples ! Very clearly explained, thanks for your time.

I take it that by pressure you mean - on the underpinner - which will mean adjusting the head acutely for each moulding height. I tend to leave it on the same setting. You learn by your mistakes !

I am a little loathe to move the fence on the Morso as the mitres look great at the moment, but will try a very small adjustment to see if it helps. There are adjustments on the angle of the mitre with the underpinner side guides, but guess that is best just to keep the moulding in line whilst the pinner does its job.

I have to say that with very little help I have managed to achieve results better than most of the 'professional' framers I have used in the past. But the Keencut Gold caused me the most agro - whilst I was searching I noticed a post from another newbie with the same gripe. Mine was definitely NOT set up square when I got it - it took me ages to work it all out - and it still goes out every now and again.

I agree with mikeysaling too, blades are best when VERY sharp ALL the time - applies to all knives really.
Thanks once again (restore my faith in Forums
C