1/72 OTW Trenchant with 3.5" Subdriver

[He Who Shall Not Be Named]

holes are the only way sometimes. I have had to make non scale holes just to get my boats to drive right. It came down to, is it gonna look super pretty in its stand or is it gonna work how I want in the water.

Kevin's right -- sometimes you gotta bite the bullet and punch those holes into the deck. Here are some hard-and-fast rules to insure you get those bubbles out:

1. Make the vent holes at least 1/8" in diameter (too small and surface tension between the bubble and water will be strong enough to prevent escape of the air)

2. Bevel under the hole to minimize the thickness of the holes bore

3. And grease the underside of the deck to keep bubbles from clinging to the underside of the deck (the grease reduces the air-bubbles ability to 'stick' to the underside of the deck).

David,

[Slats]

Kevin, David, thanks guys,

my holes were trying to keep with scale fidelity and I did notice the bubble seemed to span the hole diameter I had. I'll add some 1/8" ones and make the minimum size that size. I'll then re-test / trim her.

Re the grease would vaseline be ok?

Best

John

[Nuke Power]

Vasoline... what ever you like sailor :)

[toppack]

I don't know what Sailors prefer :D
but I like Silicone-grease.

[Nuke Power]

yes i prefer silicone aswell. KY is soluable and will dissolve once you submerge.

[He Who Shall Not Be Named]

Kevin, David, thanks guys,

my holes were trying to keep with scale fidelity and I did notice the bubble seemed to span the hole diameter I had. I'll add some 1/8" ones and make the minimum size that size. I'll then re-test / trim her.

Re the grease would vaseline be ok?

Best

John

Yup, the Vaseline will work just fine.

David,

[He Who Shall Not Be Named]

yes i prefer silicone aswell. KY is soluable and will dissolve once you submerge.

... don't make me stop this car!

David,

[Slats]

Ok more tank testing and some photos too.

Here you can see Trenchant in the wet stuff. I drilled the upper deck with some more openings and still needed to add a tad more weight. I do run my boats slightly positive as I run in a lake where visibility in some areas is patch at best.

That said she is too positive still.

The subdriver photos show here that I use a 3.5" single screw subdriver and have connected forward of the ballast tank a 3" enclosure for the 7.2 v battery.

David / Mike, what would it cost to have a connecting end cap like the two I have connected between the battery compartment 3" and the BT 3.5"?
I used some threaded brass rod to join the end caps and glued them together. I added a battery tray to the 3" battery compartment.

This is a very nice boat and I do like the colour scheme - it will be good for 4 eyes here to see it too in this pattern. I have added some weathering - scum line and removed some tiles too.

All up I like it.

Best

John

[Slats]

sorry helps if I add the photos....

[Slats]

here is some more photos

[He Who Shall Not Be Named]

Ok more tank testing and some photos too.

Here you can see Trenchant in the wet stuff. I drilled the upper deck with some more openings and still needed to add a tad more weight. I do run my boats slightly positive as I run in a lake where visibility in some areas is patch at best.

That said she is too positive still.

The subdriver photos show here that I use a 3.5" single screw subdriver and have connected forward of the ballast tank a 3" enclosure for the 7.2 v battery.

David / Mike, what would it cost to have a connecting end cap like the two I have connected between the battery compartment 3" and the BT 3.5"?
I used some threaded brass rod to join the end caps and glued them together. I added a battery tray to the 3" battery compartment.

This is a very nice boat and I do like the colour scheme - it will be good for 4 eyes here to see it too in this pattern. I have added some weathering - scum line and removed some tiles too.

All up I like it.

Best

John

Let me get this straight, John: you're looking for a 3.5/3 union coupler? If so, we don't make 'em yet, but a good idea. I could develop that for you: make the masters, tools, and parts. But, only if we (Caswell/D&E) can be assured sales of additional units to other customers; is there a market for this interface piece.

Mike: might be a worthwhile product. Want me to do it, or do we just sell John the two separate bulkheads and let him do the grunt work of attaching them?

David,

[Nuke Power]

They can be usefull for people making your fav rcab system. Also good since you never add a space to put a sport pack battery. Laot of people would like the battery and everything in ne whole unit without having to use lipo.

[Slats]

David,
I'd like one, as I feel a moulding would be so much better than the way I affixed mine together. That said they way I have it ain't broke - it works just fine.

If not commercially viable - don't worry about - I complete understand and I am sure others will too. We live in the real world.

The 3.5" Subdriver could easily be coupled to an SLA in the wet area. I choose a NimH pack as I have a 7.2 V motor in the 3.5" SD I have, and like the idea of using the 7.2V bat pack over going wet (and I must say heavier), with the SLA.

Having the battery pack section join the ballast tank, just makes IMO the whole SD look neat and tidy as one whole package. Indeed that's what I love about the original 3" D&E Subdriver is that its so neat and tidy. Of course that SD has the electricals inside, here in mine they are external.

Best
John

[toppack]

I like being able to remove battery without disconnecting the complete sub driver. That's one thing I like about the 3.5 design, over the other SDs. :)
Also gives more options in weight positioning.
(I realize it needs to be all in one assembly for the very Small versions, tho.)

[Slats]

I like being able to remove battery without disconnecting the complete sub driver. That's one thing I like about the 3.5 design, over the other SDs......

Yes very good point, my on / off switch is the simple removal of a positive plug (which is waterproofed) off its pickup on the external battery compartment end cap.

That said if the SD with all internal pwr hooks up etc is inside the SD, depending on how much access you have I find its not that difficult to take off the forward batt end cap (with the boat on the stand of course) and change batteries that way. I have to say though I am pretty anal about checking my gear, so if I need a new battery I have typically ran the sub for quite a while, and like a high performance piece of gear I retreat to the pits to make sure its all OK and take her out for some rest and inspection.

I'll show you how I do the waterproofing of the external hookups with some more photos later. Its very simple and it works!

Best
John