GEN Tube on JF 16610 - Questions

[wne]

Hey guys,

 

Domi and me installed today the GEN Tube+GEN Crown on a JF 16610LN.
We got some problems, since we need to modify the case to accept the GEN Tube.

 

It went all without problems, but the Crown has now a little Gap between Case and Crown..
On the Rep Tube you dont have this Gap since the  crown is very very close to the case. You know what I mean?

Now I'm unsure which looks more "GEN-Like".. with GEN Tube or with Rep Tube:

 

GEN Tube + GEN Crown:
Imgur: Gen Tube+Gen Crown

 

Rep Tube + Rep Crown:
Imgur: Rep Tube+Rep Crown

 

What do you think?

[TickleShoes]

Have him remove this lip on the lathe. The tube will sit flat and doesn’t change the case. Easy

[mymanmatt]

I usually taper the hole for the case tube. Most of the cases don’t have a taper, they are just flat. That will keep your tube original. 

[automatico]

If the case is not machined for a gasket between the case tube and case, cutting the shoulder off the case tube is a good fix. 

Might want to check WR if you plan to take it in water.

 

I have had to cut a few cases to allow for the gasket but it is not much fun.  You have to mount the case in a table vise, line up the case tube hole with the cutter, and cut the gasket seat with a milling bit in a milling machine.  Imho a drill press might not be very precise for this.  The set-up takes longer than the cutting.  I looked for the cutter but I 'straightened up' my shop and can not find it...iirc it is 4.0mm as the shoulder on an oem spec case tube is about 3.85mm. 

Some gaskets are rubber and some are hard plastic and you turn the case tube down until it seats against the case.  Theoretically...I had a batch of 'oem spec' case tubes that broke off under much pressure at all.  I do not know where I got them but the row of threads where they screw into the case were about 2/3 as long as oem.

 

Something else...I have seen replica 7.0mm triplock crowns with O rings in the cap where the crown bottoms out to compress the O ring against the end of the case tube and the crown (and coronet) stay in the same position as time goes by.  I have also seen crowns with flat round gaskets in the crown cap and the gasket flattens out over time and the crown gets closer to the case after a while.