1:100 'Typhoon' Submarine Building Thread - Page 2

Mankster · 28-07-2006

Access in this kit is the big problem. The opening in the main pressure hull, that hold all the equipment, is just too small. Everything goes in alright, but only in a particular order and if you need to get a component out again, you will need to take a load of stuff out to get to it.

I have decided to make the opening larger and fit a new lid. In my previous Typhoon, I fitted a clear lid instead of the Aluminium one but kept the standard opening.

Well I have marked it out, just got to pick up a diamond cutting disc for the Dremel at the weekend, as I think the cut would be too thick with chewed up fibreglass if I used a jigsaw. There are some rather thick metal inserts around the original opening, to allow you to cut a treads into for the bolts that hold the lid down, which I’ll need to cut through in 4 places.

ajg141 · 28-07-2006

Now that's more like it! Much more practical. I wish I'd had the confidence to make that modification. Life would have been much easier now! I'll be interested to hear how easy it is to cut through those glassed in steel inserts though!

Andrew

magpie · 29-07-2006

Mind blowing kit there Mankster!
The scribing looks good alright. You displayed it very well too. I'm looking forward to following it's development and I agree it will be a long and rewarding build.
Jason

Mankster · 29-07-2006

Quote:

Originally Posted by magpie

Mind blowing kit there Mankster!
The scribing looks good alright. You displayed it very well too. I'm looking forward to following it's development and I agree it will be a long and rewarding build.
Jason

Thanks Jason.

**Bunkerbarge** · 29-07-2006

I would just offer a word of caution. Engles are verey highly regarded in all thier engineering aspects of thier models and I am certain that they will have tried and tested all possibilities when designing the kits.

All things such as this opening are a compromise between practicalities and strength and I would expect them to have decided that the hole they designed was the best compromise. I am sure that you will be sacrificing strength to remove as much as you are suggesting which could then manifest itself later as a flexible hull which could leak.

Mankster · 29-07-2006

Quote:

Originally Posted by Bunkerbarge

I would just offer a word of caution. Engles are verey highly regarded in all thier engineering aspects of thier models and I am certain that they will have tried and tested all possibilities when designing the kits.

All things such as this opening are a compromise between practicalities and strength and I would expect them to have decided that the hole they designed was the best compromise. I am sure that you will be sacrificing strength to remove as much as you are suggesting which could then manifest itself later as a flexible hull which could leak.

Good points Richard. Naturally I wouldn't be attempting anything this drastic without prior thought and previous experience building this type of sealing system in other hulls. The strength is confered mainly by the 2 bulkhead. The actual hull sides that form part of the pressure hull will be the weakest and most flexible components (and I am not touching these). Once the lid is on and locked down there will be no over all change in rigidity. Considering that my new lid is actually less flexible than the Engel item and I will lock it down with 36 rather than 14 nuts and bolts, I think it will be stronger than the original once sealed. Still time will tell, but I am confident this will will be more secure than the the Engel original.

Mankster · 30-07-2006

Here’s my new larger opening. It turned out a lot neater than I feared just using a hand tool. I used a diamond cutting disc on the fibreglass part. Knife through butter and very neat cut as you can see. I changed over to the standard cut-off wheel attachment to cut through the metal bars as the diamond disc was getting very hot. I went through 3 cut off wheels to cut through the 4 metal bars. It took about an hour in total, most of it on the metal bit. There is no apparent loss of rigidity in the structure. But it does now weight 1.5kg (3 1/2lb)_less having removed most of the metal! I’ll just be glassing my new bolts in place as normal rather than tapping a thread for them so I won’t be installing new metal bars. This will lower the centre of gravity of the completed sub as all as all that weight was at the top of the pressure hull. This will mean a more stable, easier to trim boat.!
I did all the work from the out side surface, so if you built your boat the original way and want later change to a bigger opening, it should prove no problem. Just take out all the components first as fibreglass dust is fine and goes everywhere.

Here you can see the polycarbonate lids I have made up, 3 are 6mm thick and 1is 8mm thick. I think the 6mm one will suffice (seem stronger than the original Engel lid see picture). I made a few extra incase I messed up with the drilling. Its worthwhile using polycarbonate rather than acrylic (which is far more commonly used in other subs I have seen in the UK). Firstly polycarbonate is much stronger (they make safety visors and bullet proof shield from this), does not crack and craze during drilling if your not careful and most importantly won’t crack under pressure should the worst happen. Down sides of polycarbonate is that it can yellow under prolonged exposure to sunlight and it cost rather a lot more that acrylic. In the UK suppliers seem hell bent on selling it only in rather large sheets at but if you get off cuts like I did then its much more reasonable

ajg141 · 30-07-2006

Neat work Ramesh. Hope you enjoy drilling all those holes and keeping the bolts vertical as you glass them in. Then it'll be on to drilling and filing the 200+ square holes in the hull I suppose. That drove me mad - and I itched for weeks!

Andrew

**Bunkerbarge** · 30-07-2006

I have to say Jason, that's a pretty neat job. Those small cutters are superb tools but not the easiest to keep in a straight line for such a distance.

You have obviously made youself a much easier access which, if you sent a couple of pictures off to Engles, may even cause a bit of a rethink on thier part!!

Mankster · 31-07-2006

Thanks Richard, I clamped a steel rule to the marked line and butted up the flat surface of the diamond disc against it as I cut.
Engel have been using this type of lid since their original USS Patrick Henry. I guess if it works don't fix it. If they had a larger lid, then the meatal bars would have to be longer and hence even heavier. If they didn't use metal bars then they risk some of thier customers not securing the bolts properly so it loosens if they over tighten the nut, or stripping a thread off a bolt and not being able to replace it because it is bonded in. Also a larger lid will need many more bolts, and this might put off a lot of customers if it took them 20 min to get their lid on and off everytime. In the manual Engel (are oblidged??) make a point of saying for safety reason the main battery must always be removed from the sub for charging, and if you install any external charging jack or switches the warrenty is immediatley invlidated. So I guess they need to make it easy for customers to take it one and off. I will be installing a quick access/ ventilation hatch so hopefully once I screw the lid down at home I won't need to take it off at pond side at all. I am sure Engel are aware of the limitation of their lid design but the alternative may cause them more problems. Their latest 2 subs now use the bayonet locking system but hence are now devoid of other features like operateable /retractable front planes and working periscopes.