SP G250 jam nut

[rsingler]

Deleted.
Doing more tests

 

[Rusty Shackleford]

One more thread hijack:

Coated Bolt Carrier Group The Silver in the middle could replace chrome from the looks.

What they call Mystic Silver. If it could be applied to brass, it could plate second stages.

 

[rsingler]

I just checked on a real second stage (BA) and it takes almost two full turns of the hose B-nut before a seal is made. Total turns before final torque was 4 1/2. That brings us to the question of what would be the maximum length of the jam nut that will allow at least 4 turns of the B-nut before hitting the jam nut?

@couv , I was able to replicate your findings. I found a hose that required 1 3/4 turns to seal. Most did better, but I think 2 turns is a good worst case scenario. And 2 turns more at 18 thread pitch will certainly bury the oring in the barrel. The variance seemed to be related to how close to the end of the hose they placed the oring.

With my WORST hose/B-nut (most recessed):
for a G250 with a total barrel spindle length of 0.787", 4 turns are reached at a jam nut height of 0.420";
However, for an R295 with a total barrel spindle length of 0.759", 4 turns are reached at a jam nut height of 0.363". Problem is, the R295 o-ring land is covered up at 4 turns. This barrel has a shallower chamfer, and when the B-nut is unscrewed to the position where the o-ring rests (around 3 turns), that jam nut height would be 0.424". So I tested the point at which the hose broke seal with the R295, and it required less than 1.turn to seal! Two more turns to 3 turns, to bury the oring should have been adequate for that particular reg.

So there is the conundrum. If we specify 0.424", then the R295 will only have three turns. If we specify 0.363", the R295 and S600 and G250V will have that oring land covered. And at 0.363, the G260 hose goes on over 5 turns (and covers that land).

There may be a hose/regulator combination that might leak with a nut height of 0.424", because of only three turns on the nut, but I think it would be a rare hose.
All those S600's will have to omit that sealing oring if our requirement is four turns.

No simple answer, but 0.424" seems fine.
We still have to decide whether we can help the G250V and G260 owners with a washer, but if they can afford those fancy newfangled regs, then maybe they can afford that spliny wrench. You can only do so much.

 

[ams511]

We still have to decide whether we can help the G250V and G260 owners with a washer, but if they can afford those fancy newfangled regs, then maybe they can afford that spliny wrench. You can only do so much.

It was never about the money, as we probably all own the tool anyway. Simon has one forged on Mount Fuji from a meteorite that landed a millennia ago . The Fellowship of Spline was about freeing us from the evil of the proprietary nut.

I don't remember if it was mentioned in this or the other thread but the Halcyon-branded G-250V supposedly uses a regular nut.

 

[rsingler]

It was never about the money, as we probably all own the tool anyway. Simon has one forged on Mount Fuji from a meteorite that landed a millennia ago . The Fellowship of Spline was about freeing us from the evil of the proprietary nut.

I don't remember if it was mentioned in this or the other thread but the Halcyon-branded G-250V supposedly uses a regular nut.

Just teasing, mate. We all indeed own the tool, and it is indeed about that darned spline. Will have to check out the Halcyon. Thanks!

 

[Couv]

I found a hose that required 1 3/4 turns to seal.

.....yeah I rounded up toward the safe side.

No simple answer, but 0.424" seems fine.
We still have to decide whether we can help the G250V and G260 owners with a washer, but if they can afford those fancy newfangled regs, then maybe they can afford that spliny wrench. You can only do so much.

I think that is the simple answer. 0.424" fits our needs, and washers should be easy to come by for oddball people who probably won't be purchasing this nut anyway.

Thanks for all the work Dr. Rob.

@OWIC647 OK Bryan, get to work.

 

[lexvil]

I would be in for 3

 

[rsingler]

Here's a Halcyon G250V/260 clone, next to an S550 clone. One broad-based hex nut (instead of a washer), and one hex nut just like we need. Sorry, image quality not too good.

 

[ams511]

The Aura is not a S550 clone but more of a R380/390/395 clone, according to Halcyon it uses a classic downstream design. The S550 was essentially an S600 without the adjustment knob. I think the closest regulator in the more recent SP line is the S360.

 

[rsingler]

Thanks! Was trying to guess from the faceplate. In any case, I think the hex nut is close to what we're trying to do.
If you have access to one, would love measurements.