ajg141

I'm sorry to hear about the 'O' ring failure Paul - but pleased that you got the boat out before too much damagr was done. The thought of what could have happened to all the electronics inside that wtc is something I am very worried about too. How the blazes do you extract them anyway - particularly the dive tanks with their alloy mounting brackets with the screws hidden beneath them? I'm interested that you are going to make neoprene gaskets - this is something I think I should do too before tank testing always assuming I can find a large enough tank! Where have you ordered yours from?
It's also interesting that you mention the prop shaft bearings - are you referring to the brass tubes through the wtc that seal againsy the propshaft with silicon tubing? Mine are araldited in - but if you do this try an densure that the shafts are very accurately aligned as I hav efound mine binding to the extent that the motor will sometimes stall. Mine seem OK now - but it has taken a while.

Andrew

Mankster

You may have to add some extra bolts if your going with neoprene sheet, and it will be more critical that all the bolts are tightened the same amount. You may want to retain the Engel plasticard sheet on the lid that restricts how much you tighten the bolts.

Screw Loose

Hi Andrew, my optimistic thought was shattered tonight a little, as when I tested the electroncis later on the tanks chucked it. To such an extent that the board wouldnt even power up.

I have removed the TAE board, and have dried it out and used a non oil based de-watering solution we use for PCB's at work. The tanks seem to be working ok, I never used the origional brakets supplied, I made a slider for the rear bracket, the one thats impossible to reach, and an "L" bracket for the frount which can be slid upwards to be removed, and just a cable tie to secure it in place, a belt and braces approach.

I left it on the fire surround tonight and its working again thank god ! But I am still going to be doing a lot of repeated bench tests before it goes near the water again I know that.

On the subject of the bearings for the motors, you are right its the brass tubes that gave way. I also used twin pack, Devcon I think. But it turns out after a little digging on here tonight that these twin packs can be prone to loosening with vibration. Something I didnt know previous.

I have solved it I hope, by using a run of Milliput round the bearings, and sealed it with resin, just to incase it. Hopefully that will seal it.

and thanks Mankster for the advice on the bolts. I think I will add a few anyway, but if the tension of the bolts is that crucial, I may use my torque wrench and see what setting they have to be to make a seal. especially if I am going to use a Neoprene sheet.

I know one thing, any exuberance or impatience to get it in the water has gone, that was he last chance I am going to take with it !

Funny, I would have never thought in a million years a bearing like that would come loose, never mind 2 within 20 minutes !

Paul

subzero

Hi paul, sorry to hear the news..but it looks like you have reserected the circuit board with some quick thinking.

Unfortunately it is a popular misconception that these two pack type glues will adhere to fibre glass...they don't, they only form a hard blob on the surface and as you have unfortunately found out and they will come loose in a hard blob too as they do not bind to the fibre glass, only one thing does and thats fibre glass resin, everything i build into a fibreglass hull is resined in.

Don't loose heart over it though..the end is nigh

...errr sorry in sight

Screw Loose

I like the choice of words Sub !!! Sunday afternoon I was thinking the end had came to it !!!

I wouldnt care, I know i shouldnt take notice of the instructions. I dont honestly know why I used twin pack to begin with. Never again i know that !

Today the bearings, and I mean all bearings have been resined in, and on high load ones like the prop shafts I have reinforced them with Milliput.

And nervousley I connected the tanks back up again, and they work fine !
Talk about dodging a bullet on that one!!! Still having a few issues with the lid warping slightley. I have had to remove a little of the materiel around the forward planes, as they were catching. So I think in the near future I am going to reinforce the lid with additional fibreglass and resin. just bands of it maybe ,to keep the weight down.

fingers crossed for Thursday morning!

I will take a couple of pictures, so long as it doesnt sink this time !!!

Paul

Screw Loose

Hopefully the boat is ready for the water again !

I bought a sheet of neoprene today, and ripped off that stupid O ring that comes with the kit. I dont know if its something I have been doing wrong, but I have never had a lot of luck or faith in it!

I cut out a rough sheet thats about the same size as the lid, and got the metal lid and marked out the holes for the screws to fit through.

I used a piece of 4mm ( M4 screws used ) brass pipe and a hammer as a punch. I was amazed I managed to measure it first time to be honest. I fitted it on the WTC, put the bolts in and it wasnt rucked up or had any bulges


It was then cut inside, to fit around the spacer on the inside of the lid, and put on the boat. So nervousley I pressurised it and its tight!

It kept its internal pressure for about an hour, and quite a high pressure, so hopefully thats that prob sorted. And a new set of fibre washers on the screws helped as well.

So its back to the lake tommorrow morning. With any luck it wont sink this time!

One thing about subs, they get a lot of attention, so when it goes wrong its hard to get away with it !

Paul

Screw Loose

Well it didnt sink today!!! !!

I must admit I pressure tested it, and left it for ages just to make sure!

I put it in, adjusted the ballast again and off it went. The only snags I had were the prop shaft couplings coming loose. So I will dril a small indentation on the shaft for the grub screw to fit into, and the lid is bending pretty severley.

As you can see the lake isnt the best this time of year, the council have "forgot" to dredge it yet, so its pretty murkey.



I think I read on Manksters thread that his did similar. The trouble was its pretty warm today, and the lid was basically just a different shape about 30 mins into it.

I am thinking of how to strengthen the lid now. I am thinking of small lightweight box section along the length of the lid, or wodden dowels or something. Maybe like a brace of glass fibre down the length of the lid. In bands like I said before. The lid bends so much, that the forward planes dont come out! Its that bad.



The ballast needs tweaking, its still sitting to low in the water, but thats a job for another day. But you can see the neoprene seal, just needs trimming.

But on the whole, it was pretty successfull. No major complaints.

Paul

ajg141

I'm glad all went well Paul. Looks great in the water. Pity about the flexing lid though. I hadn't thought about that preventing the fromt planes from deploying though. I wonder if mine will do the same?
The resoldering the diodes and resistors on the front plane control board was done for me last night by someone whom you might know (Anthony) as my eyesight has deteriorated agaoin after the op (a nuisance but apparently fixable). Now I'm re-connecting the board. Pressure testing is getting closer! I just hope I don't have the same problems you've experienced.

Andrew

Screw Loose

Hi Andrew, sorry to hear about the op not going to plan. I hope it is sorted out soon. Makes working on these things a little easyer ! Is it going to be laser surgery ?

I would imagine yours may be similar to mine in the flexing. Just guessing though, I mean I may have cocked something up in the past. But going to fix it somehow. I cant operate the forward planes till I do.

I have even been thinking of adding a litte bit of the Styrofoam behind the lid, so it sits on the WTC. But will play it by ear. Totaly guessing to be honest !

But one way or another it needs fixing. Same as the prop shafts. Unless the grub screws have something to grip onto, the couplings come loose every time its put into reverse! Just little things really.

But makes it more interesting trying to do it with one hand !

Paul

Screw Loose

I have finished the strengthening on the lid today. I chocked it apart last night with a few bits of wood, and left it overnight. I measured the distance it has to sit in, on the lower hull and made the chocks 10mm wider at both sides.

I have used cable grip, that is used for mounting cables onto walls etc, the idea is it has holes in it , to keep the weight down, but is strong enough not to bend under pressure. In theory

I have only put 3 bands in, and it has strengthened it considerably. The downside is with all the extra fibreglass etc, and the cable tie, the lid weighs more than it did.



I have added some extra foam inside the lid, to help with the balance, the last thing I wasnt is it to be top heavy and wallow about. And I have put a little foam in the lower hull to raise the bow up a little. I may get rid of that and take some of the lead out. I will see what its like in the water.

So back down to the lake Tuesday, if all goes to plan !