Page 1 of 1

Speed Control Knob Set Screw slipping on allen Wrench solved

Posted: Mon Feb 20, 2017 2:14 am
by allsas
I was reassembling and setting the speed indicator ring. The original speed control knob set screw socket started to allow the allen wrench to turn in the socket, not loosening the setscrew. I replaced the set screw and continued. This set screw was tightened with a T handle wrench after taking the knob off several times in the process to correct the indicator ring. About the third time, the T handle allen wrench started to slip in the socket.

I tried shimming the allen wrench to allow the set screw to be loosened . Shimming did not work. Gluing the allen wrench in the socket with epoxy didn't work. I didn't have any cyanoacrylate to glue the T handle allen wrench in the socket. I remembered that I have a L shaped 3/32 allen wrench used previously for the Speed control setscrew.

The L shaped Set screw loosened the setscrew using a pliers on the short end of the wrench.

The T handle wrench tightens the set screw too tight and can alter the socket and allow the wrench to slip. The L shaped 3/32 doesn't allow the set screw to be tightened as much and may be a better quality wrench. The L shaped wrench fit the socket tighter and allowed it to be loosened with the aid of a pliers. The T handled tightened the set screw too easily and was smaller and allowed two set screws to slip when loosening and tightening.

The L shaped allen wrench means we are not trying to find a way to remove an overtightened set screw

Re: Speed Control Knob Set Screw slipping on allen Wrench solved

Posted: Mon Feb 20, 2017 3:27 am
by dusty
Before you screw up the screw beyond recovery: get that set screw out, get a new set screw, dress the end of the "t"-shaped allen wrench (or get a new "t"-shaped 3/32" allen wrench.

By dress the wrench, I mean grind about 1/8" off the end. Your problem is caused by the fact that tip of the allen wrench is becoming round.

Good self discipline will help also. I find myself NOT ALWAYS getting a seat with the wrench into the socket. Bottom the wrench in the socket. I find some that I have to pick the saw dust out of to get a good solid seat.

Re: Speed Control Knob Set Screw slipping on allen Wrench solved

Posted: Mon Feb 20, 2017 11:06 am
by JPG
Also there are allen wrenches with good steel and then there are others and some are not very accurate dimension wise(both recent phenomenons since off shore sourcing).

Just for curiosity measure the two wrenches across the flats and across opposite points.

Re: Speed Control Knob Set Screw - Another Solution

Posted: Mon Feb 20, 2017 12:22 pm
by br549
I replaced the small, hard to see allen head set screw with a home-made set screw with a slot for regular screw driver. Easier to see, easier to turn with screw driver instead of an allen wrench where you get maybe half a turn before you need to reposition (unless you have a very long allen wrench)

Re: Speed Control Knob Set Screw slipping on allen Wrench solved

Posted: Tue Feb 21, 2017 4:35 pm
by allsas
Thanks for your answers.

I bought a couple of new set screws.

I was pleasantly surprised when the L shaped allen Wrench gripped. I was tightening the set screw 4 -5 times tighter than the L shaped allows. The pop when it loosened with the L shaped allen wrench was the confirmation of how much I had tightened it and why it wasn't a problem until I started using the T handled wrench.

BR49: Good picture. I had a Speed Control Knob with a slotted head in place of the set screw. Of course, I poked around with a allen wrench for more than a half an hour until I saw the slotted head. May be a tip some where that the PO used. I thought that he improvised with a slotted head screw after loosing the set screw.