When you mentioned the valve on the DeepWorker being actuated from a lever inside, it made me wonder about sealing a moving shaft at depth. I know you're not using one on the diesel/electric but how do you pressure-seal a shaft that still has to move, either rotationally or longitudinally (axially) on a DIY project ?
I am using a rotating shaft on the diesel sub with two o-ring seals. The part is air tested prior to installing. Also before the sub hits the water I do a vacuum test for 24 hr. I suck the air out of the sub with a pump to create the vacuum. That test ensures the seals are good.
@@HankPronk Gotcha - I assumed the hydraulic motor would be mounted outside, avoiding the need to seal the shaft. O-ring and lip seals are common on outboards and stern drives, but they don't see any depth. Good to know, thx !
You do not use a negative tank? We always used the variable as a trim tank. Set the trim depending on load and fill the negative tank. Empty the main ballasts and dive. When under a few feet empty the negative tank. The variable can be pumped out as the sub compressed.
Every sub movie has the line Blow negative to the mark at 10 meters or so depth. First your sub is floated at a known starting point usually on a clear tube with a in and out valve in a vertical fashion. You pump in to the negative. That gives you negative ballast when the end ballast are flooded. In a large sub you may also put a trim tank at each end or some use a movable keel weigh to save plumbing and eliminate dive planes. Professor Gary Boucher had a great sub like that. Once the ballasts are flooded you start down and remove pat or all of the negative ballast. You may then use a gear type pump to trim the sub if you go deep enough to compress the hull. This way you do not use your precious air just to fiddle with the trim. Many P subs stick with the Kitteridge design for savings and simplification to avoid the extra steps and plumbing. If you read the Gato class operation manual there is a section about trim. Great read by the way.
You need motors or dive planes all the way down, unless you add water to the variable ballast tank. If you add water to that tank, then you need to pump it out to stop descending.
Hank actually I’ve been thinking of building a submersible just like the Dr Pepper sub and with a modern twist like the mantis deep worker . I think that it’s a great submersible the Dr Pepper one , say modern batteries and ballest tanks around the top of the pressure hull to get me up above the surface . I wonder if they did plans for that submersible .
You are having WAY too much fun… Keep up the awesomesauce!!
Thanks! Will do!
Outstanding Hank .
Thank you
Hi Hank, can you tell us if you have plans for a Drop Weight?
Yes there will be a drop weight towards the front.
When you mentioned the valve on the DeepWorker being actuated from a lever inside, it made me wonder about sealing a moving shaft at depth. I know you're not using one on the diesel/electric but how do you pressure-seal a shaft that still has to move, either rotationally or longitudinally (axially) on a DIY project ?
I am using a rotating shaft on the diesel sub with two o-ring seals. The part is air tested prior to installing. Also before the sub hits the water I do a vacuum test for 24 hr. I suck the air out of the sub with a pump to create the vacuum. That test ensures the seals are good.
@@HankPronk
Gotcha - I assumed the hydraulic motor would be mounted outside, avoiding the need to seal the shaft.
O-ring and lip seals are common on outboards and stern drives, but they don't see any depth.
Good to know, thx !
Is the balance also to be kept with the thrusters? I believe ypu mentioned passengers, so that would offset the balance a bit I assume.
The balance of the sub (trim) is adjusted with a sliding weight. The trusters are only for travel up down or forward reverse.
You do not use a negative tank?
We always used the variable as a trim tank.
Set the trim depending on load and fill the negative tank. Empty the main ballasts and dive. When under a few feet empty the negative tank. The variable can be pumped out as the sub compressed.
The way I do it, you are all done as soon as the hatch window is under. I have never heard of a negative tank? Interesting.
Every sub movie has the line Blow negative to the mark at 10 meters or so depth.
First your sub is floated at a known starting point usually on a clear tube with a in and out valve in a vertical fashion.
You pump in to the negative. That gives you negative ballast when the end ballast are flooded. In a large sub you may also put a trim tank at each end or some use a movable keel weigh to save plumbing and eliminate dive planes. Professor Gary Boucher had a great sub like that.
Once the ballasts are flooded you start down and remove pat or all of the negative ballast.
You may then use a gear type pump to trim the sub if you go deep enough to compress the hull.
This way you do not use your precious air just to fiddle with the trim.
Many P subs stick with the Kitteridge design for savings and simplification to avoid the extra steps and plumbing.
If you read the Gato class operation manual there is a section about trim. Great read by the way.
Does the diesel sub accelerate as you go down as well? You mentioned to start descent you need motors, is there a point when it’s negatively buoyant?
You need motors or dive planes all the way down, unless you add water to the variable ballast tank. If you add water to that tank, then you need to pump it out to stop descending.
Hank actually I’ve been thinking of building a submersible just like the Dr Pepper sub and with a modern twist like the mantis deep worker . I think that it’s a great submersible the Dr Pepper one , say modern batteries and ballest tanks around the top of the pressure hull to get me up above the surface . I wonder if they did plans for that submersible .
I am not familiar with that sub?
Thought that chain was a bolt ring to assemble the sub. Would have been horrible for travel speeds, LOL
Yes, it sure would lol
Thought the same thing! XD
Makes sense 😎👍 good job
Thanks
That is a totally safe way to submerge your sub with the variable ballest tank .
Yes, very good control.
And it is very safe way to always know that you will get back to the surface.
How deep do you think your sub is going down to?
The sub is being built to dive 100 feet and will be tested un-manned to 150 feet. Anything deeper I can use my small sub.