Anyone use helicoils...? Much sadness.

[secret_squirrel]

Have you tried re-tapping at m3? Sounds like not much to lose.

 

[My_Teenage_Self]

I think the hole is already too big to get a decent 3.5mm thread in there TBH. 2.9mm tap drill, and the 3mm grub screw is already waaaay loose.

It's already an M3 thread in there - the threads are essentially gone.

 

[02gf74]

Find a piece of aluminium alloy and drill 3.0 mm hole. Tap it for m3.5 and see how strong it is. Will leave 0.8 mm each side.

BTW some callipers have tiny o-ring over the tapered end so require less force to seal.

 

[just jacques]

I've used Helicoil, Recoil & time sert. For a quick low precision, low torque repairs I use The former. For anything that requires precision &/or high torque I use the latter.
Time serts are more complicated to install & expensive, but its also a very expensive fail if you do it wrong.

 

[integerspin]

In an emergency I have blocked bleed ports with a bolt and a ball bearing.
Helicoil are usually better for hand installs.
I have a box of small Helicoil taps, I will see if there is a 3mm in
there[if I remember].

 

[The Bear]

Re:

Why all the obsession with metric threads? If you're replacing the screw try the various imperial options for something equivalent to the diameter you need.

 

[02gf74]

Obvious question is why not send it back for replacement or refund? If you stripped the thread then SHAME ON YOU.

Helicoil is out due to lack of surrounding metal.

Options are
1. Try M3.5 grub
2. Plug end and drill and tap outlet on side, M3
3. Fill with lumiweld, drill and retap.
4. Use as paperweight.

 

[My_Teenage_Self]

Obvious question is why not send it back for replacement or refund? If you stripped the thread then SHAME ON YOU.

Helicoil is out due to lack of surrounding metal.

Options are
1. Try M3.5 grub
2. Plug end and drill and tap outlet on side, M3
3. Fill with lumiweld, drill and retap.
4. Use as paperweight.

Cos I bought them aaaaaages ago, and have only just got round to fitting them the grub nut undone with a crack - I think it had galvanic corroded (Alloy body, stainless grub screw).

I'm setting it to one side until I can decide on the best course of action :facepalm:

 

[02gf74]

The bit that stickds out, is it round and enough of it to put a thread on, then screw on a specially made cap that has thread for the bleed screw?

 

[wadsy]

Re:

Time-sert superior to helicoils, but same issue with enough material around to drill out.

If the item can be dis-assembled, could you maybe get the original hole welded up and re-drill/tap?