Help - stripped Jesus bolt

[bmclaurin]

I think I have overtightened the Jesus bolt (M4x 18 shaft screw 0136), and it appears to be stripped inside the the M4 nut 0136a. But for the life of me, I cannot figure out how to remove it. The bolt simply spins inside the nut when I try to back it out. It doesn't spin freely, as it takes a bit of force to turn the hex driver. Any ideas about how to get it out? My TDR is grounded until I can figure this out. Thanks.

[RJ]

I would probably isolate the nut by putting the heli inside a plastic garbage bag, cut a small hole for the nut and tape around it, then use a Dremel with carbide cutter to cut the nut off, grinding from the center of the bolt outward so as not to damage the rotor hub.

[bmclaurin]

Thanks for the suggestion. I'll give that a go and see what happens. Next time I'm not using a 90-degree allen wrench to tighten this bolt down.

[bmclaurin]

Well, it was ugly, but that did the trick. My Dremel slipped once and marred the surface of the center hub a bit, but just cosmetic. Now I have to wait for a replacement bolt to arrive from Germany.

Regarding the bolt itself, I recall when I built my kit, that it included an updated M4x18 bolt (part #0414a) to use in place of the standard M4x18 bolt (part #0136). Both of these bolts were supplied with my kit, and I used the updated one when I built it (which is the one I overtightened and stripped). I still have the original, standard 0136 bolt. I'm wondering if I could use the 0136 bolt as a temporary solution until the 0414a arrives from Germany. It might be a few weeks, as it looks like Jan is on vacation for the next couple weeks (attending IRCHA, I guess).

Anyone see any problem with trying that? If it matters, my TDR is not an aggressive setup (12S, Pyro 700-56, ~1750-1800 rpm, etc.).

Thanks again.

[mkovalcson]

It should be no problem. BTW I got 100 bolts from McMaster Car for the head bolt. You could have your part and plenty of spares if you went that route.

[Mercuriell]

Jesus bolts are usually 10.8 steel which bends rather than snaps like a twig which the higher tensile 12.9 metal is prone to. You can tell by looking at the bolt head, 12.9 has striations on the cap whereas the 10.8 is smooth.

[bmclaurin]

Thanks, guys. That's interesting on the tensile strength of the bolts. Strange, also, because both the standard and updated bolts that Jan supplied in my kit have smooth caps with no striations.

[DT75]

The bolt(s) should be marked :

[Mercuriell]

Originally Posted by bmclaurin

Thanks, guys. That's interesting on the tensile strength of the bolts. Strange, also, because both the standard and updated bolts that Jan supplied in my kit have smooth caps with no striations.

That's because it's better for them to bend rather than breakn same goes for blade grip bolts !

[bmclaurin]

Originally Posted by DT75

The bolt(s) should be marked :

Awesome...thanks! That's what mine look like, so I'm good to go.

Originally Posted by Mercuriell

That's because it's better for them to bend rather than breakn same goes for blade grip bolts !

Oh, I see...I had it backward.