The Framers Forum

It may be me being thick but, I have a problem that someone on this forum may be able to point me in the right direction of a solution.

Recently all my joints have started opening, let me explaine, I offer the two sticks to be joined to the underpinner - they look tight, I then pin and when you hold the joint up to the light you can see a consistent gap from top to bottom (the joint is open) it is as if the wedges spring the mitre open instead of closing the joint tight.

This happens both with my Cassese CS88 and my Pro Tuner so I don't think it's the underpinner.

I keep checking my Morso but that appears square and I have a brand new set of Morso blades.

Any help or suggestions appreciated.

Thanks

Mark

Im sure others will be able to provide a good explanation for this one. the only time I have suffered from this was when some glue ( just a small blob) got on the underpinner plate. It forced the joint open when under pressure from the top clamp.

First question: Have you got the v-nails in the pinner sharp side up?

If the answer is "yes, of course I have"......

Are you using the correct type of v-nail? Softwood/Hardwood for the wood?

Could be as Alan said a blob of glue on the pinner bed lifting the join in the wrong place.

Could be not enough top pressure. Especialy important on oak/ash. If the two bits are allowed to lift slightly as the nail starts to bite, the join will lift and seperate. (As we used to say at Playtex. )

Thanks for the quick response, I do not think it is a blob of glue as it is the same on both underpinners.

I use genuine Cassese wedges in the CS88 so they are the right way up.
I load the Pro Turner so I could get this wrong, but I am correct in this case.

It happens with hard and soft wood + plastic, it is worse as the moulding gets wider, ie 15mm not so bad but 35mm far worse.

On the CS88, how far above have you got the pressure pad set?

Thanks Prospero, I think the top presser on the CS88 is fairly high, so I can see clearly. I am not aware that this is any different to how I have always had it set. The same will be the case on the Pro Turner.

I probably can’t really help with this but, it sounds like from what you’re said, that you are experiencing a new problem that has not happened before, so it must be something that has changed recently? New blades on the Morso?

Also, have you tried adjusting the CS88’s back fence angles and maybe not using the rebate clamp? By back fence angles I mean the vertical angles (see photo). I know you've said it happens on the other underpinner as well, but worth a try?

I'm not exactly au fait with the CS88, although I do have one that I am fostering and I do give it some exercise now and then.
I think the setting range for the pad hight is quite wide, but I like it about 10mm above the moulding for no good reason other than it feels right.
Whatever you have it set at, try it lower and see if that makes a difference.

Seems strange that both your machines produce a gap though. I can't think how iffy cutting would do this as you describe.

Thanks David and Prospero, I will try lowering the top pressor later. I will also change the Morso blades, as I said they are new from Morso and look spot on, it is driving me mad. If anyone wants joints with a uniform gap, I am your man!

Have your Morso blades ever been sharpened? Non hollow-ground blades can cause these types of problems

You could send 4 cut pieces to a framer on here, they could then pin them on their underpinner to help you identify where the problem lie

I had this problem recently, after investing in new blades. It turned out that Morso did actually have a batch of faulty blades, so they were replaced by Mainline, who I had bought them off.
I do think that blades are often the problem, I have about 6 sets now and only 3 make perfect joints.

Thanks all, I have now changed the NEW Morso blades for a newley sharpened set and the problem has imptovrd 90%, however it is still not perfect. I have stripped and cleaned everything and now at a loss as to what to do next.

Just an update if anyone is interested, I have stripped the underpinner twice! cleaned and lubricated everything.

Now the joints are acceptable, are they perfect? Well they are as good as they were.

Interestingly, the new Morso blades were from Mainline 2009, I have kept them as spares, I should have tested them straight away - we live and learn!

I am a newby. I know this may be a basic thing but did you check the angle of the 45 degree is right? I had a similar issue and found the pieces fit together better once the angle has been adjusted on my guillotine.

Amrit

MarkScrivens wrote:Just an update if anyone is interested, I have stripped the underpinner twice! cleaned and lubricated everything.

Now the joints are acceptable, are they perfect? Well they are as good as they were.

Interestingly, the new Morso blades were from Mainline 2009, I have kept them as spares, I should have tested them straight away - we live and learn!

Amrit wrote:I am a newby. I know this may be a basic thing but did you check the angle of the 45 degree is right? I had a similar issue and found the pieces fit together better once the angle has been adjusted on my guillotine.

Amrit

Sounds like you have solved your own problem.
But basically, the angle is right when you can cut a frame with no gaps. It's all in the left fence adjustment. The right fence should line up with the measuring scale and never be moved once it's set. In practice, swinging the left fence toward you will compensate for slightly dull or not-quite-ground-perfectly blades. It's trial and error. Move it a tiny amount and cut a test frame using some wide, flat timber. There is and engraved line on the fence - near the locking knob - that lines up with a line on the bed on the Morso. You can use this to gauge the deflection. Or, use a long stick of moulding tight against the fence at one end and displace the other end about an inch. The adjustments need to be very fine as they will be x4 in a complete frame. It makes the left hand cut slightly greater than 45deg, which seems silly but wood is funny stuff.