Thumb screws for arms loosening themselves

[Jamey Howard]

Hey all. So I’ve done about five knives now on my new WE system and I love it, but I have noticed that the thumb screws that hold the arms at the chosen angle have a tendency to loosen themselves on my unit.

I’m not sure if it’s my technique, or whether I’m doing something wrong perhaps. I have noticed it happens a lot more on the left side than the right side (about three times more often on the left), but I’ve swapped the arms over and that still holds true so it’s not the arm itself, I don’t think.

I tighten the thumb screws as hard as I can after I’ve chosen my angle with the cube, and they hold for the first 5-10 minutes then start to loosen, and after that point even though I tighten back up again they seem to loosen every minute or so.

I’ve taken to using a pair of pliers to get them tighter than I can manage by hand but that’s not an ideal solution and I’m worried I might damage something doing that as it’s obviously not designed for forces greater than can be achieved by hand.

Can anyone offer me some advice please? It’s very frustrating, especially if I forget to check and notice the arm has slipped, then have to go back down a grit or two. I was already contemplating buying the upgraded arms but I want to make sure it’s not something I’m doing wrong first.

[Bill Wood]

Hi Jamey. I just recently received my WEPS and had a similar problem. That you used a pair of pliers to tighten the thumb screws I don’t know if my answer will help. I noticed my thumb screws were also loosening up and what I found helpful was as I tightend the screws I grabbed the bracket the thumbscrew goes into and wiggled it back and forth and this seemed to let the screw seat tighter. Anyways this helped me.

[Mark]

Lots of people have had this problem. Some of the solutions were to use a drop of purple (low strength) loctite on the screws or to wrap them with teflon tape. I just make it a part of my routine to check them after 20-30 strokes.

[Leo James Mitchell]

Lots of people have had this problem. Some of the solutions were to use a drop of purple (low strength) loctite on the screws or to wrap them with teflon tape. I just make it a part of my routine to check them after 20-30 strokes.

This is very good advice…the purple loctite helps a lot and like you I check the screws repeatedly as I sharpen. It is second nature to me now.

Leo

[Jamey Howard]

Ok, I’ll see if I can track down purple loctite and in the meantime carry on with pliers but be careful about it.

Does the same problem exist on the upgraded arms too?

[cbwx34]

Just to make sure… do the screws you have taper on the end (almost to a point?)

[Cris Scott]

I haven’t had any problem with the screws coming loose on the new arms. Additionally, the new arms have an allen wrench inserts. I just hand tighten and give an additional “very slight” turn with the allen wrench.

[Jamey Howard]

Just to make sure… do the screws you have taper on the end (almost to a point?)

They do taper, yes. Looking at the both I can see one of them is slightly flatter on the end than the other one, but I already tried swapping my arms around so I don’t think that’s much of an issue, and it’s only a tiny bit flatter, not by much.

I haven’t had any problem with the screws coming loose on the new arms. Additionally, the new arms have an allen wrench inserts. I just hand tighten and give an additional “very slight” turn with the allen wrench.

So the upgraded arms have hex recesses in the heads? Interesting. In this photo (below) on the product page they don’t have any:

Is that photo out of date? Are upgraded arms now coming with screws that accept a hex key for extra tightening?

[blacksheep25]

I have both the regular and upgrade arms; have sharpened lots of knives with the regular setup and once in a while it would loosen up, upgrade arms don’t seem to have that problem (but I’ve only sharpened maybe 20 knives with them).

One thing to check is if the adjustment screw tip has a sharp point or is more rounded. One would think the sharper point might be better but consider this: a rounded point might allow more contact between the screw and base rod. Here is something you should check, remove the screw from the clamp and see how it fits into the base rod locking holes. I checked both my upgrade and regular arms and they both fit well, specifically the contact area is at the wider part of the tapered tip. If only the tip is touching, you’d probably want to file a really small amount off the very point so that it makes more contact.

The upgrade arms are also threaded all the way through, so you can use another set of screws on the opposite side, however since that side would be clamping against the flat part of the base bar, you’d probably want to use screws with a flat (vice pointed tip) end.

[cbwx34]

Interesting. In this photo (below) on the product page they don’t have any:

Is that photo out of date? Are upgraded arms now coming with screws that accept a hex key for extra tightening?

I’ve never needed to use the hex for “extra tightening”, but yes, that is an old photo.

[Craig Davis]

I’ve got the upgraded arms that will take a hex key. Tonight I sharpened four knives and had one arm loosen up once (for the first time).

I will say this, with my limited experience with this system, there is a way to tighten these screws. You must “find” the detent while turning the screw. I mean “find” the detent by moving the arm slightly while turning the screw. If the screw is not centered on the detent it will loosen up.

[cbwx34]

If only the tip is touching, you’d probably want to file a really small amount off the very point so that it makes more contact.

I wonder if this might also rough up the end a bit, resulting in a more secure grip?

I will say this, with my limited experience with this system, there is a way to tighten these screws. You must “find” the detent while turning the screw. I mean “find” the detent by moving the arm slightly while turning the screw. If the screw is not centered on the detent it will loosen up.

Good tip!

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