Author Topic: Thumb screw fix?  (Read 2239 times)

Offline jscott2

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Thumb screw fix?
« on: December 03, 2017, 10:24:46 am »
The thumb screws on my Delta 40-690, the DW-788 clone, need some help.  The rotating part (anvil?) that contacts the blade doesn't rotate as easily as it should.  Can it be fixed?

Can I remove the anvil? How?  It it comes off, do I clean it and then lube it with a tiny drop of sewing machine oil or . . .?

Is ti enough to squirt some WD-40 into the gap between the screw and the anvil and work the anvil around?

I will appreciate any suggestions.

Thanks,
Jim
Using a Delta 40-690 in the Montreal, Quebec (Canada) area

Offline scrollgirl

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Re: Thumb screw fix?
« Reply #1 on: December 03, 2017, 10:34:50 am »
Hi, Jim:

I think it would be best to replace the part. Any lubricant or oil or WD-40 that you apply will in all likelihood contaminate the face of the screw and the blade will slip when cutting. This area needs to be as clean and dry as possible and even the motion of the arms of the saw moving will be enough to redistribute the oil to this area. I wouldn't want to chance it. The piece is very cheap and in my opinion, needs to be replaced.

Sheila

I also want to add that the housing that is threaded (the part you screw the 'anvil' into) is made of aluminum, not steel. The steel screw that goes through it and holds the blade will cause the aluminum to fail over time. The fact that it is hard to turn may indicate that the aluminum threads may indeed already be crumbling and are getting ready to fail. This piece can be replaced fairly inexpensively, as I mentioned above. It probably just had its time.
« Last Edit: December 03, 2017, 10:38:44 am by scrollgirl »
Sheila A. Bergner-Landry
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Owner, Sheila Landry Designs
www.sheilalandrydesigns.com
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Offline jscott2

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Re: Thumb screw fix?
« Reply #2 on: December 03, 2017, 12:34:26 pm »
Sheila, thanks for you comments.  I will probably have to replace the thumbscrew one day but am trying to postpone the day. 

I found that Seyco has a replacement anvil for the thumbscrew so I screwed up my courage, got out the needle nose pliers, and with a gentle pull of the anvil separated from the body of the thumbscrew.   :D  It seems to be held in by the friction of a tiny O-ring on the shaft of the anvil.

I'm going to try cleaning it with a damp cloth and see how it goes.  I will put spare replacement chucks, thumbscrews, and set screws on my to-do list but now can continue with my Christmas scrolling.

Thanks,
Jim
Using a Delta 40-690 in the Montreal, Quebec (Canada) area

Offline scrollgirl

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Re: Thumb screw fix?
« Reply #3 on: December 03, 2017, 12:55:27 pm »
I am not sure I understood the exact piece you were referring to. Yes - the little 'pad' just pushes in. Still - be careful about getting any oil on it or near it. It will cause your blades to slip.

Happy Christmas Scrolling!
Sheila A. Bergner-Landry
Designer, Artist, Teacher
Owner, Sheila Landry Designs
www.sheilalandrydesigns.com
Knowledge Is Power

Offline jscott2

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Re: Thumb screw fix?
« Reply #4 on: December 03, 2017, 01:52:17 pm »
Sheila, my description probably doesn't use the correct term.  When I say "anvil" - it is circled in red in the attached photo - I assume your reference to the "little pad" is to the same part. 

I cleaned the shaft of the "little pad" and the hole it goes into with a damp Kleenex and have let it dry out completely.  It is turning much more freely in the thumbscrew body now.  No oil.

Thanks again,
Jim
Using a Delta 40-690 in the Montreal, Quebec (Canada) area

Offline scrollgirl

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Re: Thumb screw fix?
« Reply #5 on: December 03, 2017, 01:55:57 pm »
That is good. Yes. From the first post I misunderstood. I hope it gets you through your holiday scrolling. :)

Sheila
Sheila A. Bergner-Landry
Designer, Artist, Teacher
Owner, Sheila Landry Designs
www.sheilalandrydesigns.com
Knowledge Is Power

Offline justlarry

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Re: Thumb screw fix?
« Reply #6 on: December 03, 2017, 05:49:57 pm »
I also have the 40-690.  I pull the swivel tip off and wipe it with a clean cloth or paper towel.  I have read that putting a drop of machine oil on the o-ring will help.  I would put a drop of oil on a paper towel and wipe the o-ring with that.  I think too much oil will be trouble.  Maybe a drop a year?  Thumb screw is steel and the pad is aluminum and the steel threads will destroy the aluminum threads.  When this starts to happen the thumb screw gets harder and harder to tighten and loosen.  To solve this I use a very small amount of anti seize compound.  I use a tooth pick to put a very small drop of anti seize on the threads, and wipe this into the threads with a paper towel. I found a little bit of anti seize goes a long way.  So much in fact that after I had put on the anti seize from the tube the clamps would actually vibrate loose while I was sawing.  I used anti seize many times when rebuilding auto engines when steel bolts would screw into aluminum blocks.  It is available at auto parts stores.  After using the anti seize very little pressure is needed to tighter or loosen the thumb screws.  JUST REMEMBER, oil and anti seize is an enemy to wood when scrolling, so only a very little bit is needed.

Larry

 

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