bladesslipping out of clamps

[ike]

Yesterday I had a problem of the blade sleeping out of the top clamp.I tried all the  remedies, sanding blade cleaning the blade end with no luck. i slowed down the speed and watched the blade, it just slid out of the clamp sideways. I went to my back up saw , also a Dewalt and traded the clamping screw and it worked fine, I have about 3000 hours on the saw tomarrow I go to the repair shop and buy  a new clamp knob at a cost of $10

 

IKE 

Edited June 5, 2016 by ike

[OLD WORMY]

Ike, I sometimes have to remove the blade clamp screws and file the ends flat to remove the glaze that sometimes makes the blades slip.

[NC Scroller]

Ike it could be the holder and not the screw. Over tightening will bend or strip out the holder which is just aluminum. The screw is steel. That is what I would look at.

[dgman]

Hey Ike, I have a great tip for you. Go over to Works in Progress & Tutorials, page 3, bottom of page named: "Simple jig for blade slippage". This will help you keep your thumb screw in tip top shape!

[Lucky2]

Ike, I don't own a Dewalt saw, I own an EX21 they both have similar blade clamping abilities. About every three months or so, I take a small piece of sandpaper,and sand in between the clamp screw and the opposite side of the clamp. Doing this seems to be working, cause I've never had a blade slip out of the clamp.

Len

[amazingkevin]

Yesterday I had a problem of the blade sleeping out of the top clamp.I tried all the  remedies, sanding blade cleaning the blade end with no luck. i slowed down the speed and watched the blade, it just slid out of the clamp sideways. I went to my back up saw , also a Dewalt and traded the clamping screw and it worked fine, I have about 3000 hours on the saw tomorrow I go to the repair shop and buy  a new clamp knob at a cost of $10

 

IKE 

There's all the usual reasons for blades slippage ,and i've tried them all.One that's been over looked and never talked about is the screw where the blade rests opposite the thumb screw.On the Dewalt you'll need an allen wrench to turn it half a turn to change the grooves wore in it to not slip but grab for you.biggest help was changing the top and bottom thumb screws by putting the top in the bottom and the bottom one in the top holder.

[WayneMahler]

I run an EX-21. But have found if I clean the blade holders it helps a lot. I clean my blades before installing but I have cleaned machining oil from the holders and clamps. Maybe try this ?

[ike]

Thanks for all the tips I will give them a try before I buy a new screw.

 

IKE

[CharleyL]

If you discover that the threads of the blade clamp screw holes in the aluminum arm are worn out, you can replace the arm, but you can also replace the threads with stainless steel threads and they will last forever. You will need to buy a special kit from a company called "Heli Coil", which contains a larger tap, a special Heli Coil installing tool, and about a dozen Heli Coil "spring like" threads. You follow the instructions to thread the hole larger with the included tap. Then place one of the Heli Coil threaded pieces on the installer tool, and thread it into the newly threaded hole. A metal tang is then broken off the end of this thread like spring, which locks it into the hole, preventing it from backing out while in use. The end result is new stainless steel threads that will fit your present blade clamp wing bolt and they won't wear out like the original aluminum threads did. You can buy Heli Coil kits from automotive parts stores and from Grainger, MSC, McMaster, etc. Just make certain that you are getting Heli Coils, and not threaded inserts. Threaded inserts are solid metal bushing type pieces with threads on both the inside and outside. They require a larger hole to install them, and they frequently do not stay in place. The locking feature of the Heli Coil brand works very well to make them stay in place forever, but they can be removed and replaced easily if they should somehow ever wear out or get damaged.

 

Charley  

Edited June 6, 2016 by CharleyL

[Scrappile]

That's great info, Charley.  Have you done this to your saw?

[CharleyL]

No, but I've used Heli Coil products for years and wouldn't hesitate if my saw needed it.. I'm a retired automation engineer (EE) and spent most of my working career working very closely with mechanical engineers and tool makers, designing and building new specialized high speed manufacturing machinery, sometimes only one or two of a kind. Most of what I did was design the electrical controls for these machines, but I worked very closely with the mechanical guys when changes or repairs were needed and they needed extra help. Machine shops use Heli Coils quite a bit when making something that will need to be frequently assembled and dis-assembled, even if made from steel. They will install them in any piece of steel, cast iron, or aluminum machinery when the original bolt hole gets worn or stripped out. It's a very common fix.

 

Charley

Edited June 7, 2016 by CharleyL

[ike]

I just got my new thumb screw and cut out the word air-force tightened the screw with hand on.y and it didn't slip at all. Problem solved.