New SN2's Seem A Bit Too Tight (easy fix)

[Gil Jones]

Contacting Tim Geist at 304-295-8166 is the logical way to solve the problem with a new (and likely thinner) cir-clip.

The one I recently bought from Woodcraft ($119) was a bit hard to turn the T-handle and there was a wee bit of roughness.
I popped off the cir-clip and the problem was gone, so I checked the cir-clip thickness (.0750"), and compared it to the cir-clips on my other two SN2's which were both .0685".
The extra .0065" of steel in the cir-clip was forcing the base of the plastic backing plate into the scroll plate with enough pressure to cause stiff operation (my thought anyway).
Removing .0065 of cir-clip steel is not fun, so I removed .0065 of plastic from the base of the backing plate where it contacts the scroll ring (with my belt-sander).
Problem gone, smooth operation restored.
Probably the latest shipment of cir-clips are a bit too thick, and nobody noticed, or checked.
And no, I am not recommending that you modify your plastic OEM backing plate as I did, but it is a quick fix.
Still, we should not have to repair 'new' products.
Gil

 

[Joe Greiner]

The thicknesses you measured correspond to metric dimensions of 1.9mm and 1.75mm.

My 24th edition of Machinery's handbook lists only metric retaining rings. Those dimensions don't appear in a single series; rather, one is for external, and the other is for internal. Possibly, the wrong type of ring was installed, and a proper replacement should be available. Are the shapes similar in other respects?

Aside from that, sheet metal gauges were once based on weight per square foot, with thickness dependent. Now such material is usually specified by thickness itself.

The nice thing about standards, is that there are so many to choose from. (From an old computer journal).

 

[Gil Jones]

Hey, Joe,
The old and new cir-clips are visually identical, and the only difference I noticed was the new ones being .0065" thicker. Whether they are metric or SAE means zip to me. The new ones are simply too thick. I was not interested in waiting for, or searching for, the "dimensionally correct" part, or sanding the steel to fit. Hence, I just removed the .0065" of plastic to get the same result.
Gil

 

[Joe Greiner]

Hi, Gil.

Like you said in your first message, you don't recommend it for others.

Aren't they made downunder? Likely to metric standards. It could be the plastic plate was simply made to accommodate the wrong groove, hence the mis-fit. And your fix is probably the right answer anyway.

Just guessing, of course; but working on puzzles like this makes quality control so much fun.

Joe

 

[MichaelMouse]

Curiosity. Isn't the clip in a groove? Can't go beyond the groove into the plastic unless it's bent, so dishing and/or reversing the clip would seem to take care of things?

 

[Gil Jones]

Yep, the cir-clip is in a groove.
Let us know how your idea works.
Gil

 

[Rich L.]

Sn2

Hey Guys, What does SN2 stand for?

 

[Donna Banfield]

Super Nova 2

 

[Carole Valentine]

Curiosity. Isn't the clip in a groove? Can't go beyond the groove into the plastic unless it's bent, so dishing and/or reversing the clip would seem to take care of things?

I believe it lies under a lip not in an actual groove - the bottom of the c-clip rests on the backplate. May be wrong but I'm not going to go take mine out again to check. At any rate, it contacts the backplate. Mine measured 1.83mm (the one that came with the chuck) and 1.69mm for the one that was sent to replace it. Tim will ship replacements out to anyone who has one that is not right.

 

[MichaelMouse]

I believe it lies under a lip not in an actual groove - the bottom of the c-clip rests on the backplate.

That means my suggestion won't work. Thanks. I was puzzled as to why others would not have done it, now I know.

 

[Gil Jones]

The cir-clip sits in a groove.

 

[Joe Greiner]

Can you bring it to next Tuesday's meeting?

(My e-mail has been mis-behaving lately.)

 

[Gil Jones]

Sure, I'll even bring a snap-ring pliers.

 

[Chuck Jones]

The c-clips don't really change much!

I received the two c-clips Tom Geist sent as replacements for my latest SN2 chucks and I replaced the one on the chuck I bought in March. I cannot tell one bit of difference. The gears still feel very rough. As far as the tightness is concerned that was already getting better with use. Both of the two stamped “PRC†are noticeably rougher than the NZ version I bought in July 2007. I can sit it on the table and spin the hex tool with ease with one finger and thumb; smooth as silk. That’s certainly not the case with either of the two newer ones. We may as well face facts. The Chinese versions are poorer quality.

As a practical matter all three chucks seem to work fine. The difference is not enough for me to incur the frustration of pursuing the issue further or returning the chucks. It’s just that now I will view the SN2 as a cheap, reasonably workable Chinese-made commodity tool; not a slightly more expensive high quality tool like the earlier SN2’s. There is no longer a reason to favor the SN2 over other cheaper products. This will of course affect my attitude about any Technatool product.

 

[Carole Valentine]

If you simply popped the c-clip out and replaced it but did not bump the backer plate up it may still sitting too low from the pressure of the old clip. Mine operates every bit as smoothly now as my 3 NZ made ones...maybe even a tad smoother. Actually I took one of each completely apart and laid the parts side by side and could tell no difference at all.

 

[Bill Blasic]

Carol,
I would expect that there would be very little difference as the machine that made them in NZ is now making them in China. I think about half the Nova chucks I have have been made in China and I see, feel no difference between them. The important thing is that they stand behind their products.
Bill