popping blades

[hatcherca]

I have a DeWalt 788 scrollsaw and suddenly it's begun to pop blades. They don't break. They just pop out of the screwy thing that holds them. I took it to toolserve and they said they tightend the jaws. This seemed to help for about a week. Now it's doing it again. Anyone have any suggestions?

Carol

[JTTHECLOCKMAN]

Carol

LONG ANSWER: First let me say whoever told you they tightened jaws just gave you a line because there is no jaws to tighten. Now a couple things have to be answered. Have you noticed the amount of blade between the clamps shrinking??? In other words when you go to insert the blade is there still enough blade to catch the clamps?? This has not changed???? Have you changed brands of blades since this started happening???

Now not sure if these are things you are already doing but we will go over them and all of them could lead to the problems you describe. First take a look at the clamps themselves the setscrew on one side should be sticking into the clamp about half way and this should be the same for both top and bottom. I am or I like to set mine up just a tad different but it still the same principle. I like my setscrew to just be even with the edge of the clamp on both the top and bottom. This way when the thumbscrew is pushed against the blade the blade is resting against alot of metal and not just the setscrew. Matter of choice no big deal. Now the thumbscrew, take this out and look at the flat edge. It should be perfectly flat. In fact the end should spin within the piece that has the threads. If this does not pull it out and add a drop of oil. If working fine make sure the end is not shiny and to do this hit it with a touch of sandpaper. Now to the blades themselves. They are all manufatured and shipped out with traces of oil on them so when going to use them it is a good idea to clean the ends both top and bottom and to do this you can use some denatured alcohol or sandpaper which is what I like to use. Do both sides of both ends. Not doing this can cause the blades to slip. Now hopefully the threads are not stripped on the thumbscrew so when you go to tighten there is resistance. One other thing that may cause your problem is there is a crack in the clamp itself from overtightening. If the above fixes do not cure the problem then you have to look for the cracks and this can be found by shining a light behind and all around the clamp as you look at the clamp with the blade locked in place. You should not be able to see any traces of light where there should be none. Hope this helps and if you answered yes to the very first part of my post then you have a different problem. We will go into that at a latter time. Good luck.

One other thing, the setscrews that I mentioned, hit them with a bit of sandpaper also in case they loaded up with oil from the blades. To do this just fold a pice of sandpaper in half and run it between the clamps. For my mind where are the blades letting go??? Top or bottom???

[hatcherca]

Thanks a lot, John. I will try your suggestions right away.

Carol

[JTTHECLOCKMAN]

Carol,

You answered quickly and am not sure if you saw my edited part on the bottom.

[hatcherca]

Wow! The alcohol seeems to have worked like a charm. Is this something new - the oil on the blades? I haven't had trouble with slipping blades until the past six months.

Thanks a lot for the info.

carol

[JTTHECLOCKMAN]

Carol

No this is not new. All blades when manufactured because of the way they are cut use an oil to keep cool so there are traces left behind from this process and even though they get wiped down before packaging there still is some left behind. If this is your fix then I highly suggest wiping down the setscrew and thumbscrew. You can do this by either swiping a wet cloth between the clamps or a piece of sandpaper. The reason this my not have effected you as quickly as some others may depend on your use and also with the dewalt they have that rotating pin on the bottom of the thumbscrew. What that does is prevent the thumscrew from turning against the metal of the blade thus making it shiny and slippery. But after a period of time it catches up to even the Dewalt saw. Hopefully that is the remedy but if still having problems do not hesitate to ask. Good luck and Happy Scrolling. :)