The Metcalf P Class Re-Build

[jeep4grog]

Since the Subdriver is on it’s way. I guess it’s time to start the build thread…

I started this last year just before my stroke and wasn’t all that successful in building the do it yourself WTC as I wished. So, after listening to some sound advice from a friend in the Cleveland Boat Club, I ordered Dave’s masterpiece Sub-Driver.

I looked into the Gato kit for the bow plane riser, but the Brits do it different (see Pic). I want to try an match that look and function.

I have some damaged wash needles from a Bosch Ampoule washer from work. I think they look a lot like the original snorkel mast on the p class boats. It is hollow and 316L-SS so should last a long time. I will use the pump I already have. It’s a Gast, 10DC diaphragm pump and should work well for the snort. Pics here too.

I have a Robbe F-14 Navy controller so I think I have enough channels to do all I want…

[jeep4grog]

My Subdriver has arrived, thank you Mr Merriman!!!

Now the work begins...

[Deep Diver]

Since the Subdriver is on it’s way. I guess it’s time to start the build thread…

I started this last year just before my stroke and wasn’t all that successful in building the do it yourself WTC as I wished. So, after listening to some sound advice from a friend in the Cleveland Boat Club, I ordered Dave’s masterpiece Sub-Driver.

I looked into the Gato kit for the bow plane riser, but the Brits do it different (see Pic). I want to try an match that look and function.

I have some damaged wash needles from a Bosch Ampoule washer from work. I think they look a lot like the original snorkel mast on the p class boats. It is hollow and 316L-SS so should last a long time. I will use the pump I already have. It’s a Gast, 10DC diaphragm pump and should work well for the snort. Pics here too.

I have a Robbe F-14 Navy controller so I think I have enough channels to do all I want…

Good Day
There is a good diaogarm in a book on the "A" class I do think it is called "The Alliance" on the workings of the bow planes, the Sub museum in Gosport U.K may have a copy, or if you e-mail them they may just send you the detail that you require.:)

[jeep4grog]

I am trying to see if I can fit 2 ESC's, 3 additional servos, an 8 channel receiver, and a SubTech SES-3 switch in the Subdriver. It looks like it will all fit, but it will be tight. I am planning on having independent control of the motors. Once it is all laid out and the wiring figured out, I will take pictures.

I am also working on the shaft struts. I have to pick up some 5/16” brass tubing today to start assembling them. I will solder brass struts to the tube, put oil impregnated brass bushings in the tube to support the shafts and they should look and work like the real thing.

Pictures will added be as soon as all the parts are assembled and the real build begins…

[jeep4grog]

I am building the shaft struts so while waiting for the epoxy to dry, I was beginning the install of the ESC's and stuff in the Subdriver.

I noticed that there are no capacitors on the motors. Do I need to add them or are they installed in the motors?

Thanks!

[junglelord]

I believe that surpressor capacitors are always needed on motors.
I will let Mr Merriman correct me if thats wrong.
I was told that anyway.

[He Who Shall Not Be Named]

I believe that surpressor capacitors are always needed on motors.
I will let Mr Merriman correct me if thats wrong.
I was told that anyway.

Indeed they should. If the gent whe has a SubDriver without them would give me his address I'll get two sets of cap's off to him. Sorry about that.

David,

[jeep4grog]

It's OK Dave I have caps I can install. I just wanted to check first. Some of the newer motors have them installed internally now and I didn’t want to double up.

I finished the shaft struts yesterday. It was a real interesting project...

I tried to solder these together, but couldn't get the solder to stay or flow. That K&S brass wouldn’t let it stick? Acid cleaning and/or sanding the parts didn’t help either. I tried brazing, but that was too hot for the thin brass and it kept collapsing and changing shape, next was some aluminum welding rod, that was a mess too. It wouldn't flow well, so I gave up and used JB Weld and that worked. Leanred a few thrings....

Good thing this stuff comes in 12" lengths. Gave me lots of material to practice with.

These are straight and the shaft rotates freely in it. All I need to do is give them a little grinding to finish them off. I think they will look pretty much like the originals once installed and painted.

[toppack]

Yes they look very much like the originals,
Lookin' Good! :)

[Kazzer]

When I did my S Class, I just used 1/8" brass rod as the strut, ran a 4BA thread on it (hey it's a British boat) and then drilled a hole into the bearing and tapped that out. No glue, no soldering - tight as a drum!

[He Who Shall Not Be Named]

It's OK Dave I have caps I can install. I just wanted to check first. Some of the newer motors have them installed internally now and I didn’t want to double up.

I finished the shaft struts yesterday. It was a real interesting project...

I tried to solder these together, but couldn't get the solder to stay or flow. That K&S brass wouldn’t let it stick? Acid cleaning and/or sanding the parts didn’t help either. I tried brazing, but that was too hot for the thin brass and it kept collapsing and changing shape, next was some aluminum welding rod, that was a mess too. It wouldn't flow well, so I gave up and used JB Weld and that worked. Leanred a few thrings....

Good thing this stuff comes in 12" lengths. Gave me lots of material to practice with.

These are straight and the shaft rotates freely in it. All I need to do is give them a little grinding to finish them off. I think they will look pretty much like the originals once installed and painted.

Brass and other copper bearing alloys are the easiest to solder. Did you attempt to solder with those Olite bearings in the bearing tube? If so, the oil expanded with the heat and leached out and migrated onto the outside of the tube and contaminated the joint between tube and struts, spoiling the wetting action of the molten solder.

David,

[jeep4grog]

No Mr. Merriman,

I have been working in maintenance long enought to know that!
The bearings were not in the tubes when I tried the solder. I think it's whatever that K&S brass was made of. I have some brass shim stock from another project and it can be soldered. Any brass I have from McMaster works fine.

Since I thought I was losing my mind (there isn't much left anyway...) I tried a few other pieces. No problem. I cant get anything to stick to that brass flat stock except the epoxy!?!?

Putting the Subdriver together today. Caps are in, adding the 2 ESC's and wiring.

[He Who Shall Not Be Named]

No Mr. Merriman,

I have been working in maintenance long enought to know that!
The bearings were not in the tubes when I tried the solder. I think it's whatever that K&S brass was made of. I have some brass shim stock from another project and it can be soldered. Any brass I have from McMaster works fine.

Since I thought I was losing my mind (there isn't much left anyway...) I tried a few other pieces. No problem. I cant get anything to stick to that brass flat stock except the epoxy!?!?

Putting the Subdriver together today. Caps are in, adding the 2 ESC's and wiring.

Sometimes I find myself dealing with idiots. I now have some appreciation for your skill level. That won't happen again.

K&S typically uses 'cartridge brass', I don't know the alloy for sure, but I think the copper and zinc has a bit of manganese in there -- anyway, it solders good. But maybe they sent you some stuff packaged incorrectly?

David,

[jeep4grog]

I may never know the answer. I purchased the brass at my local hobby store... and it sheds solder like a duck sheds water!

On to the next subject:
I have two sets of props. One the Raboesch (The #157 right and left) and a set from Harbor Models (their model # 1717 right and left). I have pics. The harbor model props are a bit larger and have a more pronounced pitch. Any suggestions on what set to use? It seems the Harbor Model props will give me more push with less speed.

As a side note, the Subdriver is getting busy too...

[He Who Shall Not Be Named]

I may never know the answer. I purchased the brass at my local hobby store... and it sheds solder like a duck sheds water!

On to the next subject:
I have two sets of props. One the Raboesch (The #157 right and left) and a set from Harbor Models (their model # 1717 right and left). I have pics. The harbor model props are a bit larger and have a more pronounced pitch. Any suggestions on what set to use? It seems the Harbor Model props will give me more push with less speed.

As a side note, the Subdriver is getting busy too...


Hell ... I don't know.

Sea-trials will tell the tale as to which set works best.

David,

[toppack]

Jeep4grog,
I see that you are using 2 speed-controls???
Are you trying to use motors for steering instead of rudder, or both?
Do you know that you can connect the motors in parallel on a single Speed-Control?
I have that type SC and it will handle the current of 2 of those motors with no problem.
Man, there's a lot of wires to connect up with 2 SCs! :D

[jeep4grog]

I have a Robbe Navy F-14 Radio (6 channels installed) with the dual throttles installed, so... Why not? I should get better control at slow and reverse speeds.

It's a static diver, with a snorkel and gas, why not finish it have dual trhottle control? I started life as an electrician... I like wires and stuff like that!

If it was easy, anyone could do it and it wouldn't be special.

[toppack]

I have a Robbe Navy F-14 Radio (6 channels installed) with the dual throttles installed, so... Why not? I should get better control at slow and reverse speeds.

It's a static diver, with a snorkel and gas, why not finish it have dual trhottle control? I started life as an electrician... I like wires and stuff like that!

If it was easy, anyone could do it and it wouldn't be special.

Okay, Great, :)
I thought you knew what you were doing but Just thought I should check.
Those are Good sealed speed-controls. I'll drink to THAT!

[jeep4grog]

I NEVER claimed that I knew what I was doing... :):)

[He Who Shall Not Be Named]

I NEVER claimed that I knew what I was doing... :):)

Then you'll fit in just fine here.

Speak with AUTHORITY, and they'll believe anything.

David,

[Albion]

At the risk of opening old wounds, that may already be healed. Very suprised about the K&S tube, been soldering the stuff for years , never a problem, maybe a duff batch?

I assume you were using , a BIG enough soldering iron, or using a torch so as to get the heat in there?

When racing slot cars, which often had oilites soldered into them, i would place the bearing on a heat resistant surface with a paper towel underneath the bearing. Place hot iron onto the bearing, and the towel would draw the lubricant out of the bearing (not the graphite of course). The bearing would then solder more easily. Afterwards you could add lubricant back into the bearing. Typically these bearings have a low quality lubricant in them, and doing this would not only help solder the bearing but improve life and performance of the bearing

[He Who Shall Not Be Named]

At the risk of opening old wounds, that may already be healed. Very suprised about the K&S tube, been soldering the stuff for years , never a problem, maybe a duff batch?

I assume you were using , a BIG enough soldering iron, or using a torch so as to get the heat in there?

When racing slot cars, which often had oilites soldered into them, i would place the bearing on a heat resistant surface with a paper towel underneath the bearing. Place hot iron onto the bearing, and the towel would draw the lubricant out of the bearing (not the graphite of course). The bearing would then solder more easily. Afterwards you could add lubricant back into the bearing. Typically these bearings have a low quality lubricant in them, and doing this would not only help solder the bearing but improve life and performance of the bearing


A variation on this is: After you've cooked or vacuumed the oil out of the sintered bearing (an open cell structure to the metal is the mechanism that holds and distributes the lubricant to the moving shaft within the bore of the bearing), you refresh the bearing with the new oil by dunking the dry bearing into a small container of the oil, and subjecting that to a 28-inch vacuum. Wait for the foam to fall, break the vacuum, and you have a completely saturated bearing.

David,

[Albion]

OK neat....

[jeep4grog]

Well heck yes I did use enough heat. I started with a soldering gun, went to a MAPP torch and ended up with an Oxy Acetylene torch to braze the parts… It way too thin and wouldn’t stay in shape. I think it was the flat stock. The solder would stick to the tube, but just ran off the flat stock. The bearings are not soldered in. I cut a small groove into them and pressed the tube into the grove. They lined up well and the shaft rotates freely.

Another way to “recharge” the oillight bearing is to put a cup of light oil into a tall can and heat it by placing it into a pot of boiling water. Put the bearings into the hot oil for about 15 min and it will soak in. Not as good a David’s method, but if you don’t have a vacuum pump it will do in a pinch.

[jeep4grog]

Getting cold in Ohio again so it's back to finishing the sub!!

We spent the summer working on the new house and building a second garage on the property to have a place for the '40 Packard re-build my wife and I want to start.

In late Feb the sub hull had an major accident and was knocked off the workbench in the garage. It split the hull and damaged all the planes on the port side as well as destroying the rudder. I had to re-glass the hull and make all new planes and a rudder. It all came out pretty well.

The Sub Driver is almost complete and the shaft struts, planes and rudder are installed. Now it's time to fit the SubDriver in the hull and hook everything up. It will have functioning forward planes too!!

I also finished off a section of the basement and added a project room for the wife and a place for me to build.

My next project is on the way from LA. I found a Robbe U47 with "blown" electronics for $250. It’s built but needs some work and TLC. Does The Magician Dave have a recommended Sub Driver for this one? I would like to make it a static diver too...

[jeep4grog]

Here are a shot of the Robbe U-47 that is coming.

A Red lead bottom? What was he thinking???!!

[He Who Shall Not Be Named]

Unfortunately, if I remember right, the cylinder of that kit is a vital structural element, the armature in fact, off of which all the hull frames and other foundation pieces are glued. Sorry, pal, you're stuck with that tube as your water tight space.

David,

[jeep4grog]

Bummer,

Guess it's an Engle tank or I will see if I can figure out a modified snort/gas/balast tank type of system. If all else fails, it stays a dynamic diver

[He Who Shall Not Be Named]

The kit supplied direct-drive motors were awful. Go with two geared 380-400's. Use about 3000mAh of Lithium-polymer battery and you'll have plenty of room for an inside hard tank so you can make it a static diver.

David,

[jeep4grog]

This might be a question for Kazzer?

I see you sell the same size P Class hull that I am resurrecting (and as we all know, necromancy is a sin and I am sure I will pay for this).

I did pick this up used and in need of a complete rebuild. I have no instructions and I was wondering if you could give me a "quesstimate" of how much lead weight I should start with in the hull.

I have the 3.5” Sub driver that Mr. Merriman made me last year.

[Kazzer]

This might be a question for Kazzer?

I see you sell the same size P Class hull that I am resurrecting (and as we all know, necromancy is a sin and I am sure I will pay for this).

I did pick this up used and in need of a complete rebuild. I have no instructions and I was wondering if you could give me a "quesstimate" of how much lead weight I should start with in the hull.

I have the 3.5” Sub driver that Mr. Merriman made me last year.


No idea, sorry. I haven't even thought of doing that boat. Don't we have some documentation on doing this - somewhere?

[Subculture]

Now I don't know if your 3.5" SD has a variable ballast tank or not (some of the eariler ones had a screw jack didn't they?). The standard way of going about this sort of thing as outlined by Skip Asay is thus-

Build your boat, then place it in a test tank.

Hopefully it's significantly buoyant.

Ballast your boat down with lead until it is as close as you can get to neutrally buoyant.

Now add foam blocks (make sure these are fairly accurate and uniform) below the waterline until your boat reaches the required waterline. You may need to make a cradle to hold the foam, or use some sort of lash-up of string and zip ties etc.

Once that's achieved remove the foam, measure it, and calculate the volume of the blocks. That's the size of ballast tank you need.

Having got that, any additional weight needed to get the boat down to the require waterline is placed in the keel of the boat, as low as you can get it.

If you don't have much reserve buoyancy, you can add foam either side of the SD. This should be placed as high as you can get it, but below the waterline.

Note that although the boats may come from the same moulds, there can be significant differences in displacement from boat to boat. Some are laid up thicker or thinner, so it's difficult to say use 'x' amount of lead. Injection moulded models have a higher tolerence in this respect, so it's a lot easier to predict the weight needed.

[Kazzer]

Ballast your boat down with lead until it is as close as you can get to neutrally buoyant.


Can you just clarify exactly what this means please. I imagine it is that the boat is floating, but all parts of it are underwater, just below the surface?

[Subculture]

Yep you got it. In reality neutral buoyancy is very tricky to achieve, and your boat is always a bit positive or a bit negative, but the hydrovanes can usually take care of a few grams either way.

[jeep4grog]

I have an older Metcalf glass hull that I had to reglass a bit.... so who knows the actual weight. I know the procedure but I was hoping that there might be a starting weight to add to the model in the instructions. Since I dont have the instructions for this one (even after several emails and two letters to Metcalf), I hoped that this info might exist here since Caswell sells a very similar hull.
I see ads here for lead weight sold for several other models and was hoping that a build had been completed and that info was avaiable.
I don't mind trial and error a bit, but maybe a rough starting point would keep the wife from getting too excited if I could reduce the ammount of bath tub testing time! It is about 14 deg (F) here today and everybody has thier pools emptied for the season...
Turns out the wife and some friends are going shopping Sunday so I guess that is the day to test.

[Kazzer]

Metcalfe got out of the business a while ago and doesn't seem to answer emails. Now the Darnell molds belong to Andy Grigg, and his workmanship is far superior. These are the models we sell.

Unfortunately, there are no instructions for these boats other than one set I have of the S Class, originally drawn up by Darnell. The drawings don't have any mention of the amount of lead, so it's suck it and see. However, threads like this will be a great asset in the future, so please post your findings.

[jeep4grog]

I shall do so...

[Subculture]

I don't think Dave Metcalf has any interest in model submarines, it was just an extension to his moulding business. He is a member of a club I used to belong to NLSME, and is heavily involved with O-gauge/Garden railways.

I few years ago I organised a sub day at the NLSME pond at Colney Heath, and although he was a member, I never saw him bring anything along.

Simply put, there is no rule of thumb for this kind of thing, you have to use empirical methods to figure it out.