Ouch...
SP G250 jam nut
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halocline
Contributor
Is the only problem with the SP jam nut that it requires the SP wrench? Don't you guys own a pair of pliers? With a little padding that works fine.
I bought the SP multi tool years ago and it's very useful, well worth the price, I just don't see what problem you're trying to solve here.
With a little padding that works fine. I bought the SP multi tool years ago and it's very useful, well worth the price, I just don't see what problem you're trying to solve here.
OP
&
Hi AMS, the problem with all of those pieces of hardware is that the outside dimensions are too large. Note the 7/8" wrench size. Those jam nuts will not screw all the way down to the case because the exhaust tee interferes with it.
Is the only problem with the SP jam nut that it requires the SP wrench? Don't you guys own a pair of pliers?
I tend to agree with Matt here. However, if we (that means Bryan doing all the work and taking all the chances) can get these made for a few bucks, ($7 or less in my book) I would certainly order a couple.
So let's start a poll:
How many would you guys be purchasing if he can get them made for a reasonable price?
I could be in for some....
If Bryan is going to make some custom SP jam nuts then the opportunity exists to make some design changes!
Apart from the proprietary SP spline, what else bugs you about the standard production part?
Is 316 stainless the best material choice vs OEM plated marine brass due to dissimilar metal galvanic corrosion in an electrolyte (salt water) or crevice corrosion? Article: Principles and prevention of crevice corrosion
Instead of a plain hex (with or without a cylindrical part to fit under the exhaust T) it could be a cylinder with a hex at one end or simple flats in the middle (easy with external profile broaching External Profile Broaching)
Will a design that is optimal for a G250 also fit the myriad of other SP second stages?
Apart from the proprietary SP spline, what else bugs you about the standard production part?
Is 316 stainless the best material choice vs OEM plated marine brass due to dissimilar metal galvanic corrosion in an electrolyte (salt water) or crevice corrosion? Article: Principles and prevention of crevice corrosion
Instead of a plain hex (with or without a cylindrical part to fit under the exhaust T) it could be a cylinder with a hex at one end or simple flats in the middle (easy with external profile broaching External Profile Broaching)
Will a design that is optimal for a G250 also fit the myriad of other SP second stages?
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I'd be good for a bunch.
As for shape, what are your comments on the $14-21 Atomic jam nut shape?
Jam nut, brass, 02-0037-00, Buy Atomic Aquatics at DIVESEEKERS.com 888-SCUBA-47
Plain hex works for me, if we're going to see if Bryan can have it made. Or whatever shape he tells us will be less expensive. Chrome/brass, yah.
As for shape, what are your comments on the $14-21 Atomic jam nut shape?
Jam nut, brass, 02-0037-00, Buy Atomic Aquatics at DIVESEEKERS.com 888-SCUBA-47
Plain hex works for me, if we're going to see if Bryan can have it made. Or whatever shape he tells us will be less expensive. Chrome/brass, yah.
Here's the current crop of jam nuts:
From left to right,
Atomic 0.439" high
SP G250 0.375" high
SP R-series 0.393" high
SP G250V 0.500" high
SP G260 0.470" high
From left to right,
Atomic 0.439" high
SP G250 0.375" high
SP R-series 0.393" high
SP G250V 0.500" high
SP G260 0.470" high
Height seems to be a non-issue between the G250 and R,S series. Both barrel spindles are same length for something in the .380" range.
The G250V and G260 have a longer shaft, like the Atomic, hence the 0.44-0.50" nuts.
But even a taller Atomic nut on a G250 seems to leave enough threads for a good hose attachment.
As far as using it on a G260 goes, I think you could just add a flat washer to mimic what SP did with the R-series:
So, I'd vote for a thin walled 9/16"-18 chromed brass hex, about 0.400" high.
Thoughts?
The G250V and G260 have a longer shaft, like the Atomic, hence the 0.44-0.50" nuts.
But even a taller Atomic nut on a G250 seems to leave enough threads for a good hose attachment.
As far as using it on a G260 goes, I think you could just add a flat washer to mimic what SP did with the R-series:
So, I'd vote for a thin walled 9/16"-18 chromed brass hex, about 0.400" high.
Thoughts?
If I'm doing it....It will be in one size/style and chrome plated brass.
OP
Rob, that's quite a selection you have. I'm limited to only one jam nut type. Could you try the shortest jam nut on the longest air barrel; then attach a standard and Superflow hose to ensure the hose 'B' nut will torque down against the jam nut and still swivel please?
Thanks.
Thanks.
