Hoffritz mod for Willgoy

[MarkPinTx]

Makes sense on the Swinden keys. Ever done an Ulster scout? Hope this isn't a threadjack, but perhaps it will contribute to the overall store of knife construction and repair knowledge.

Perhaps more on point, I can visualize exactly what you are referring to on the cast bolsters. I wonder though, what is the normal method of making them? Stamped? Or maybe just cast in such a way that the back is flat or flattened?

And it seems it would be a heck of a trick to pin scales on an assembled knife? Dont the pins on the liner side have to be peened pretty good and ground off? And the center pin, as noted, is usually loaded by the spring (or is it?).

Geez, our beloved slipjoints are so simple in principle, but there is so much "trigger work" in getting them together (design too I believe for the same reasons, tolerances on the things must be a black art).

Final semi-on-topic question: what is that pearl handled knife in the background?

 

[glennbad]

I believe most bolsters are cut/stamped from a solid piece of whatever, and then shaped appropriately. It seems the German/European ones of a certain age were "cast", maybe to save on material costs, not sure. This picture, although not of the bolsters on Will's knife, shows what they look like.





The center pin is loaded by the spring. Some mechanics will install that last when assembling a knife. I like to have it in place, and usually pin the blade pivot pins last. To each his own, I guess. But yes, pinning the covers on an assembled knife, the pins would have to be pretty well finished and mostly flat to do that right.

As far as that pearl knife, I would have to look at it again. I picked it up at a flea market, and it looked like it had been in prison with a gassing-out cell knife. Been meaning to try and recover it.

I have done a few Scout knives. If you would like to discuss that further, please VM or email me so we don't clutter this thread up anymore.

Thanks,
Glenn

 

[MarkPinTx]

Oh wow, thanks for the picture. I was thinking just a bit of concave not that shape with the pin boss. Interesting. Are the more conventional bolsters just flat slabs from the back as I imagine?

Wonder why they did that casting? Nickel silver isn't that hard to work or expensive. Maybe just someone overthinking like Swinden!

 

[glennbad]

Most bolsters are flat-backed, and pinned or soldered to the liners. The ones in that picture are brass, so they did it with both brass and nickel silver that I have seen.

As for why, it probably made the manufacturing process easier. With the Swinden system, it reduced the pinning process on a knife to just one pin.

 

[Brian.Evans]

Dont the pins on the liner side have to be peened pretty good and ground off? And the center pin, as noted, is usually loaded by the spring (or is it?).

Geez, our beloved slipjoints are so simple in principle, but there is so much "trigger work" in getting them together (design too I believe for the same reasons, tolerances on the things must be a black art).

Not to jump on Glenn's thread, hope he doesn't mind.

I'd be interested to hear/see how you pin the cover pins. I know a lot of the old guys used the thin part of their steady rests (stiddy) to slide between the liners to hold the pins on place and have something hammer against. Maybe that doesn't make sense, I have a shoulder injury and I've taken a considerable amount of pain medicine.

I'll show you what I mean later, but here's a picture to get the idea.

The notch in the center is to work around the center pin.


Also, the principle behind slipjoints is simple. But to get no gaps between liners and spring, springs flush in three positions, seamless welded or soldered bolsters, properly ground, blade centered, and everything else like we like it....well......it's difficult. Getting everything exactly right will drive a man to drink. And then the accuracy really goes out the window. Lol.

 

[glennbad]

This video by Kaleb shows the process much better than I could explain it...I would think it would take more peening to produce a head on the liner side, but his work is top notch, so I trust his technique.


[video=youtube;s43vAbvSSGQ]http://www.youtube.com/watch?feature=player_detailpage&v=s43vAbvSSGQ[/video]

 

[MarkPinTx]

Ahh ok. Well I would have thought it would have taken peening from the liner side as well.

 

[screened porch]

I can't drill holes in the right place on a cover unless I have the knife apart to use the liners as templates. Hence all my epoxy fixes.

 

[glennbad]

I can't drill holes in the right place on a cover unless I have the knife apart to use the liners as templates. Hence all my epoxy fixes.

You could always make a template and poke through where the holes are. If you can't poke the holes through, then use a pencil to shade the template. The holes should show through.