Broken bolt or tap erosion near Minneapolis

[olsonm3915]

Does anyone here have experience with having broken bolts/screws/taps burned/welded/eroded out of bike parts?

I just bought a 1984 Honda Interceptor 500, and while taking off the front fender, broke off two of the 6mm bolts that attach the fender to the fork sliders. Because removing the fork tubes is a major pain on these particular forks (does "backup ring" ring a bell for anyone) I can't drill straight into the remains of the broken bolts, and would prefer to have someone use spark erosion, plasma, etc. to burn the bolts out.

If anyone knows of a place near Minneapolis MN that can do this sort of thing I would love to hear about it.

 

[Joe2Lmaker]

Try: Accu-Prompt, Inc.

Ask them about EDM drill a.k.a. hole popping

<Link>

 

[olsonm3915]

Try: Accu-Prompt, Inc.
Ask them about EDM drill a.k.a. hole popping

<Link>

Excellent! I've just been in touch with a guy in my company's model shop and he showed me their "hole popper" but it has clearance issues.

It turns out I have about a half dozen designers and engineers working the problem now..



Thanks, I'll let the group know how it turns out.

 

[08FJR4ME]

Try: Accu-Prompt, Inc.
Ask them about EDM drill a.k.a. hole popping

<Link>

Excellent! I've just been in touch with a guy in my company's model shop and he showed me their "hole popper" but it has clearance issues.

It turns out I have about a half dozen designers and engineers working the problem now..



Thanks, I'll let the group know how it turns out.

Just a hint on old bolts: Let soak overnight with some kind of penatrating oil and when your ready the next day if you can use a propane torch to heat things up a little without damaging anything it usually works great.

Good luck on your project.

 

[olsonm3915]

It turned out that unlike the similar-looking forks that I had so much trouble with a few years ago on a 1981 Gold Wing, the 1984 VF500F forks come apart in the conventional way. So it was easy to get the fork tubes out, which gave me good access for a medium long (6 inch?) 1/8" drill bit to go through the stuck M6 screws. I bought a square section tapered fluted extractor and successfully removed one of the screws intact, but it took a lot of heat applied from a propane torch to get the screw to turn. As soon as I would remove the torch the screw would seize up again. The 2nd screw turned out OK too, I managed to ruin the temper on the extractor by overheating it, but I just chucked in a 13/64" drill bit and drilled out the screw (more or less on center) and re-tapped the hole. Not as perfect as the first but plenty strong enough, and I always have the option of using a longer bolt with a nut below boss on the fork slider since the hole is drilled and tapped all the way through.

The lesson for me here is to be very cautious about attempting to remove potentially seized fasteners, especially the little ones that can be so easily twisted off. Extended pre-soaking with Aero Kroil is going to be SOP on this old bike.