this post was submitted on 11 Sep 2024
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22
Stripped inner thread on 2020 x axis profile for an Ender 3v2 (lemm.ee)
submitted 1 month ago* (last edited 1 month ago) by [email protected] to c/[email protected]
18 comments fedilink hide all child comments
 

So I was attempting to install kevinakasam's belt mod and I'm fairly sure I stripped the thread that holds the M4 screw in the outer right side of the X axis profile (the side without the extruder attached to the tensioner). How screwed am I? Could I get away with trying Loctite red?

Pics for reference!

Edit: Thanks a ton everyone, I'll keep you all up to date when I try to finish the project this weekend!

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[–] [email protected] 4 points 1 month ago (2 children)

So the thread in the aluminum was stripped?

There’s a few options that might work. Threadlocker isn’t really epoxy or glue. I’d the thread is merely loose, it’ll keep it from coming out with vibration.

Another option is straight up epoxy- but this would be hard to undo.

Possibly, the best option would be to re-tap the thread. You might be able to get an m4 tap and clean it up with that.

If that doesn’t work, or it’s already that far gone, you could probably go up to an m5, though that would weaken the extrusion more than intended.

If you do want to try re-tapping, avoid the trap of buying tap and die sets. Just get the individual pieces you need (the chuck/holder thing and a the m4 or m5 tap.) a cheap set will still be more expensive than high-quality taps in the 2-3 sizes you actually wind up using.

(Also, general note 1/8” smooth rod is in every hardware store, and a die is much cheaper than 1/8” thread and usually looks neater, unless you need it fully threaded.)

[–] [email protected] 4 points 1 month ago (1 children)

If it's stripped, I doubt chasing the threads with a m4 tap will accomplish much. Tapping it for the next size up (m5) seems like a good choice.

What would you consider a high quality tap or die? I have a cheap(er) set that I got at home cheapo. With how little use it gets, its biggest issue is surface rust from sitting in my garage 24/7.

[–] [email protected] 3 points 1 month ago (1 children)

So, the biggest difference in quality is the steel and hardness.

For 2020 aluminum, it’s not that big of a deal. Even less so for “occasional” use. For harder metals, the cheapos will wear out faster and that maybe leads to frustration.

Guess my point was… we almost never use more than 2-3 in a set, so, it’s better to get the 2-3 and better quality at the same - but totally get the cheapie if you don’t want to spend that much.

At least I only use m3,5 and 1/8” sets.

Also, for the record, you can absolutely tap plastic for a reasonably strong thread. Just add a couple extra perimeters.

[–] [email protected] 1 points 1 month ago (1 children)

So, the biggest difference in quality is the steel and hardness.

My question was rooted in how you would know the quality/hardness of the steel at time of purchase - especially as a (fairly) layperson.

I think my set is dewalt. It included taps, dies, and drill bits for M3-M7. I don't think I've ever used the drills, and the have gotten a lot more use than the dies, but I think I've used almost everything in the kit more than once. Before kids, it was cars. Post kids, it's mostly cheap Chinese furniture my wife buys that I have to chase threads in to get it to assembly well.

Also, for the record, you can absolutely tap plastic for a reasonably strong thread

I've had pretty good success sizing 3D printed holes to be interference fit. That's how I designed/printed the bed leveling thumb wheels for my i3 clone. They backed off far less frequently than the stock metal once.

[–] [email protected] 2 points 1 month ago

Mostly by the cost? As for sets, they’re going to be 200+ easy.

Theres also some difference in tolerances, but to be honest, a super tight tolerance is a double edged sword. Bulk-produced bolts won’t be as tight anyhow.

For casual/infrequent uses, it’s totally fine to get the inexpensive ones. (I’d recommend going to a local hardware store, they tend to have not totally-shitty sets and most sizes/threads individually.)

Also, for printed parts, you can absolutely just cut in with the bolt, unless your printer is somewhat inconsistent, a with a well-calibrated printer, all you really need to know is how much your holes tend to shrink (the thermal contraction as the plastic causes the final diameter to be smaller. This is why we invented test prints….. well. Not me. Somebody’s smarter than me.)

[–] [email protected] 2 points 1 month ago (2 children)

Okay, I have no clue what I'm doing but I did look up a little bit on tapping and think I might be able to try that. Of all the threads to strip I think I may have gotten lucky. The screw doesn't seem to do much other than keep the metal plate from sliding up and down (though I may be wrong) so I'm not too worried about strength I think.

What do you mean about the rod? Is this to buy a rod, cut it to size, use a die to thread it, and screw that in?

Is this a "good enough" tap? Looks like I'd need to get a wrench for it too?

[–] [email protected] 2 points 1 month ago (1 children)

Imo for a single job, I'd prioritize getting some tap magic over worrying about tap quality. For aluminum, tap magic makes a big difference.

[–] [email protected] 1 points 1 month ago (1 children)

I'm starting from no knowledge here, so all advice is great! Do you mean this stuff? Or should I get the aluminum version?

[–] [email protected] 1 points 1 month ago

The aluminum version would be preferred, but what you linked will do just fine. I can't find a small tin of the aluminum version on Amazon, so don't bother overspending on a large container.

If you are going up a thread size, make sure you get the appropriate drill bit. You need to drill out the hole before tapping. M5 usually calls for a 4.2mm predrill.

[–] [email protected] 2 points 1 month ago (1 children)

So the stuff about the 1/8” rod is… just a general fabrication tip.

If you’re ever reading a bill of materials and they call for threaded rod- which is unfortunately common for a lot of printer groups- you can almost always use the same size smooth rod if you cut thread on the ends with a die.

It saves money (threaded rod is smooth rod with threads cut the full length,) and it looks neater. (A drill and some sand paper and a bit of scrapped t-shirt cloth doped with green buffing compound will make it shiny, even.)

What the other person is saying about tap magic, is just to use lubricants while cutting. 3-in-1’s og is my go to. Tap magic is a similar brand. You can get by with wd-40 if you have to.

all it’s doing is helping with temperature, and making cleaner cuts since it lubes every thing (the cutting edge still bites, but it doesn’t bind as much with the chips.)

The other thing to remember is that every turn or half turn, you should break off the chips (the metal coming off,) by backing off a quarter turn. This helps keep the cutting head free making a neater thread.

Other than that there’s no reason to be intimidated by any of this. For this, you can probably just cut the m5 thread, but you’ll want to predrill what ever bolt’s standard bore size is, and be sure to keep that square and straight as you do.

The uxcell is a “cheap” brand, for a one-time thing it’s fine but if you find you use it more and it’s getting frustrating to use… it’s lost its edge and is dull.

[–] [email protected] 1 points 1 month ago

Thank you!!! I have a fear that this is the start of the dark dark path of having a full workshop.

[–] [email protected] 2 points 1 month ago (1 children)

Can you upload a picture of your stripped screw?

[–] [email protected] 1 points 1 month ago

Just uploaded it, thanks!

[–] [email protected] 2 points 1 month ago

Do you have enough margin to drill it out and retap to an m5 thread?

[–] [email protected] 2 points 1 month ago (1 children)

If I recall correctly that hole goes all the way through the extrusion.

Worst case you can use a bolt and nut.

[–] [email protected] 2 points 1 month ago (1 children)

In the V2, the other side is occupied by a screw holding the tensioner in, but I was told I could use a T-nut and that would save me a lot of headache

[–] [email protected] 1 points 1 month ago

Tnut should do the trick. If not you could use the same bolt all the way through for the tensioner but that might be a pain to line up right.

[–] [email protected] 2 points 1 month ago

Don't forget cutting oil for tapping. In a pinch any oil or thin grease will work. I think that screw position was pretty short depth, but if you seize and snap a tap in the extrusion it will be a shit time even got a shallow home. I wanted to put the picture of a tap snapped flush with one of the end holes but I guess it was on my old phone. I got it out with a screw extractor but it was really hard to drill the pilot hole, and didn't seem like it would work at first.