Cassese stacked wedges going in at a slant

[Danielle]

First of all Hello to everyone, this is my first post!

So I have a casses 486xl, which I'm still getting used to, it seems so far to be extremely temperamental!

I had no problem before stacking 4 genuine cassese pins into an obeche moulding until tonight.
On the last corner the last corner the wedges stacked at a slant and came through the side.
Anyone, any idea why this would happen?

[pramsay13]

Sometimes on the softer mouldings the wedges start to veer off course. If I'm stacking more than 3 I will start them nearer the middle and maybe put less in the outer edge than in the inside.
Did you take it apart again to see what happened?

[easypopsgcf]

Too close to the back, the wedges are V shaped and open up as they are stacked, avoid being too close to the back edge and put less there than at the front

[Steve N]

I would say that trying to stack 4 wedges is asking a lot, they are bond to veer off course, 2 is the maximum I stack, try using deeper wedges, instead of using 4x 7mm use 2x15mm or 2x12mm as an example

[Jamesnkr]

Wood being a natural material and non-uniform, you probably hit a knot or other imperfection which sent the wedge off track.

[Whitewater Gallery]

If I am stacking 3 15 or 12's I will usually only stack one at the back. Some mouldings are worse than others and it can vary form stick to stick, sometimes in harder woods I find that they follow the grain. I have never found it to be a problem just having one at the back.

[Graysalchemy]

They will always twist due to the resistance of the wood, the harder the wood the more they will bend, or if the hit a knot or anything like that. Sometimes with really hard wood they will split.

It is always better to use one large wedge than two smaller ones.

[prospero]

I agree that a four-stack if pushing it a bit. I also concur with the one in the back and more on the inside method, especially on mouldings that are taller than they are wide.

Pine is the worst for deflecting wedges. If you get a coarse-grained section with the rays going diagonally, you can find wedges doing a 90º turn and coming straight out the back.


btw. Welcome to the Forum Danielle. Hope you don't mind if I move your topic to the Help section. This bit is more for posting examples of interesting frames you have made or terrible frames you have seen.

[Not your average framer]

While it is true that many of the better quality underpinners will often succeed in stacking as many as four wedges, it is worth considering the amount of force required to push that forth wedge and the three wedges in front of it into the moulding.

As an ex-design engineer, I am only too well aware that all the extra force is also acting upon any parts within the underpinner and accelerating the wear of some of these parts. Not only that, but in many cases if the underpinner is pneumatically operated, then the higher level of air pressure required to accomplish this feat gives the pneumatic components in the system a pretty good hammering as well.

Be nice to your underpinner and it will last longer than if you hamer it just because you can.

While we are discussing this subject, I remembered a not very good picture i posted in another thread showing ten wedges double stacked in five positions with the aid of a laser printed paper rule stuck in place on the top plate of my CS-88. in many cases a spread of double stacked wedges will keep the corner joints strong and tight without resorting to stacking more wedges further into the moulding. Here is a link to the thread:

http://theframersforum.com/viewtopic.ph ... ges#p80427