Bronco Type XXIII build

[Monahan Steam Models]

This type of submarine build has been on my bucket list since I first discovered Simon’s offerings from his company 32nd Parallel in the late 80’s.

In place of the dream I had in the late 80’s, presently I’ve managed to secure a Bronco type XXIII kit. A 2.5” MSD and most of the bits and pieces of an original David Meriman fittings kit designed for this build thanks to Bob Martin.

I plan to keep this build straight forward and keep to a build that David, Tom and Bob have successfully built and shown. The only additional features may eventually include a pair of working G7E electric torpedoes.

The plan is to make this a snort system boat with a AD2 pitch control on the stern planes and depth controller on the forward planes. An emergency gas back up will be used also.

Im looking forward to this build. It’s been a long time coming. Also I need a break away form the type VIIC build

Nick

[tifosi12]

Good luck!

This was my previous build and I gave up on it after numerous unsuccessful attempts to cut the hull in a straight horizontal line. That's the hardest part on this build and it never was pretty and solid enough to have worked. The rest of the build is straight forward.

If you run out of Bronco XXIII parts (except for the hulls) I have plenty of them left over.

[Monahan Steam Models]

Good luck!

This was my previous build and I gave up on it after numerous unsuccessful attempts to cut the hull in a straight horizontal line. That's the hardest part on this build and it never was pretty and solid enough to have worked. The rest of the build is straight forward.

If you run out of Bronco XXIII parts (except for the hulls) I have plenty of them left over.

I’ve been putting off this build due to the horizontal cut you mentioned. I think I’m finally ready to attempt it.

I would be interested in purchasing the Type XXIII parts you have. I’ll send you a PM.

[tifosi12]

I’ve been putting off this build due to the horizontal cut you mentioned. I think I’m finally ready to attempt it.

I would be interested in purchasing the Type XXIII parts you have. I’ll send you a PM.

The horizontal cut is a nightmare: I built an elaborate jig for my Dremel drill press to guide the plastic body half by and cut it in the process but that didn't work: The plastic wall is so thin that it will warp and bend under the pressure of the Dremel cutter and you end up with a non straight line. In addition you would really need to water cool it as the plastic warms up and creates a much wider gap than what your Dremel wheel is. And finally once you have the cut, it is hard to properly align the "roof" to it because the wall is so thin, it will fall off. In the fittings kit you have Dave included some plastic shins that are supposed to hold these two parts together and align them. Problem is, those shins would never stay on. My best advice would be to add a new lip to both sections on which they can touch and rest instead.

You mentioned type VII. I started out with that as well. What a different world where you can just open/remove the deck. So much easier. That's also why I want to do the Lindberg I-53 next as it has a similar deck.

My failure with XXIII taught me never ever to try that hull cutting approach again. Either the model comes that way already or I can control it with a 3D file. But no more abismal Dremel experience.

As for my leftovers, I'll let you know what I have. Happy to pass that on.

[Monahan Steam Models]

The original plan to split the hull was going to be carried out with the same method David and Tom used in their original builds as I already have all the tools and materials to attempt this method. My hesitation going ahead with that method is mainly what you have described with the heat build up and also the parts moving or flexing during the cutting. I’ve used my dremel to make cuts in plastic models in the past with good results but the heat and vibration is a real problem.

What I plan to attempt to make the cut now is to first carefully scribe a line horizontally down the side of the hull using a flexible metal straight edge as a guide. I’m thinking I will bond the forward and rear hull sections of each side together first and make the cut to each hull half while it is laying flat and secured down to a build board. If successful in creating a single straight scribed line, I may then decide to finish the long cut carefully with a razor saw.

Well that’s the plan currently. Now let’s see how bad I actually screw it up!

[tifosi12]

The original plan to split the hull was going to be carried out with the same method David and Tom used in their original builds as I already have all the tools and materials to attempt this method. My hesitation going ahead with that method is mainly what you have described with the heat build up and also the parts moving or flexing during the cutting. I’ve used my dremel to make cuts in plastic models in the past with good results but the heat and vibration is a real problem.

What I plan to attempt to make the cut now is to first carefully scribe a line horizontally down the side of the hull using a flexible metal straight edge as a guide. I’m thinking I will bond the forward and rear hull sections of each side together first and make the cut to each hull half while it is laying flat and secured down to a build board. If successful in creating a single straight scribed line, I may then decide to finish the long cut carefully with a razor saw.

Well that’s the plan currently. Now let’s see how bad I actually screw it up!

Again, good luck.

I glued the front and rear sections together as well. Your approach with it lying down is probably better than mine where the Dremel was in the drill press and I moved the hull along (kinda like cutting lumber). And a razor saw also sounds better. I hope you succeed.

[tifosi12]

You might also check online for some extra decals. They do exist for this type of sub and its scale. The ones that come with it are somewhat limited and not the easiest to make stick to it. This is all that remains from my project:

[redboat219]

If I recall correctly from David's Revell Gato RC conversion DVD when he made the longitudinal cut to the hull using a Dremel he didn't do it in one continous running cut from bow to stern instead he made intermittent cuts along the hull like a set of dashes --- --- --leaving small sections of plastic supports that connected the top and bottom sections to prevent the hull buckling. Once the required length of cut to the hull was achieved he then went back and cut those columns.

[He Who Shall Not Be Named]

If I recall correctly from David's Revell Gato RC conversion DVD when he made the longitudinal cut to the hull using a Dremel he didn't do it in one continous running cut from bow to stern instead he made intermittent cuts along the hull like a set of dashes --- --- --leaving small sections of plastic supports that connected the top and bottom sections to prevent the hull buckling. Once the required length of cut to the hull was achieved he then went back and cut those columns.

... And it was not one continuous feed of the cut-off wheel into the work. The parting of the hull halves was accomplished through short, quick stabbing strokes, stopping when the plastic got gummy from excess heat. And the magic trick, that assured a perfect cut and minimal material loss to kerf: a rock steady moto-tool holding fixture that fixed the blade in height. And a rock-solid mounting of the hull to the work surface so it does not scoot around as you make the equatorial cut.


David

[redboat219]

David can you discuss the technique for making the cut surfaces match and level to minimize the visible seam.

[He Who Shall Not Be Named]

David can you discuss the technique for making the cut surfaces match and level to minimize the visible seam.

You build up material lost to kerf by either gluing on a cap-strip of comparable thickness.



Or you apply a filler (traditional Bondo type or CA-baking soda grout) between masking tape dams that you later block sand down to the appropriate height.



David

[tifosi12]

Here are my left over Bronco kit pieces. Some are still in their plastic wrapper. What's missing are the hulls, which I tried to cut time and again and failed at it time and again.

[redboat219]

Wow! I see atleast 3 sets of torpedo tubes.
Maybe you can still salvage one or two hulls using the technique David just described.

[Monahan Steam Models]

Wow! I see atleast 3 sets of torpedo tubes.
Maybe you can still salvage one or two hulls using the technique David just described.

I believe what Tifosi12 is saying is those boats are on forever patrol

[tifosi12]

Wow! I see atleast 3 sets of torpedo tubes.
Maybe you can still salvage one or two hulls using the technique David just described.

Yeah, those hulls now live in a landfill somewhere.