John Drain's Model PT-Boat Site

20mm Oerlikon Cannon

The pictures above show the Oerlikon cannon fitted with shoulder cups and sights, this was usual on British MTB's and seems to also be the case on some of the earlier US PT-Boats (maybe where they were retrofitted to the boats by the crew).

Sometimes there was a bag fitted below the cannon cradle to catch used shell casings and there also seems to have been a strap for the operator.

Later US PT's used the leaning brace shown on the model cannon below and they didn't seem to bother with sights. The leaning brace would have given much better control over the guns elevation for shooting at aircraft.

A very good documentary from World of Warships, Naval Weapons, on the 20mm Oerlikon on Youtube: https://www.youtube.com/watch?v=W7qExnBNWJk

Or this one from Forgotten Weapons.com - 4 fun facts about the 20mm Oerlikon Cannon - https://www.youtube.com/watch?v=6yCxITYzW-0

John's Idea for the 20mm Oerikon Cannon - John Drain's Model PT-Boat Site

The objective is a (possibly operational) 1/20th scale 20mm Canon.

Excuse the base on the photo above, this is actually the base for the 37mm Canon and if you look at the photo for that canon it shows the correct base for the 20mm.

Picture of the first pass of the brass tubing of John's version of the 20mm Oerikon Cannon - John Drain's Model PT-Boat SiteBasic barrel made from brass tubing, in order to make the cooling spline I used gold plated wire wrap pins cut off an IC socket, 16 fit perfectly around the tube, pull eight forwards, hold them in place with silicon tubing and solder in place, then remove the other eight, perfect and simple to do!

Picture of the first pass of the brass tubing with drilling of John's version of the 20mm Oerikon Cannon - John Drain's Model PT-Boat SiteAnother bit of tubing drilled and filed with needle files.

Assembly starts

Picture of an example of the slicon tubing sleeve used in John's version of the 20mm Oerikon Cannon - John Drain's Model PT-Boat Site Leave the silicon tubing on until it's all soldered.

Voila!

Make some side bits, a bottom thingy and a back bit

This shows the sides, bottom, back and a couple of top thingy's in place and the folded leaning brace.

Picture of the Leaning Brace from John's version of the 20mm Oerikon Cannon - John Drain's Model PT-Boat Site Leaning Brace soldered in place

Looks quite the part so-far

The ammunition Magazine folded out of sheet with wires soldered on. Cut around the front and back (not soldered on yet) with scissors and then file to shape.

Picture of the first pass of the cradle from John's version of the 20mm Oerikon Cannon - John Drain's Model PT-Boat SiteThe cradle Picture of the second pass of the cradle from John's version of the 20mm Oerikon Cannon - John Drain's Model PT-Boat Site

Picture of the Cradle with Tripod Mount from John's version of the 20mm Oerikon Cannon - John Drain's Model PT-Boat SiteThe cradle and tripod mount.

Picture of the Tripod Mount soildered in from John's version of the 20mm Oerikon Cannon - John Drain's Model PT-Boat SiteThe tripod legs soldered in place

The base cut out with a hole saw. A countersunk screw in the middle will hold it in place.

Solder legs to base

Brass nut soldered at the top.

I use the stand drill a lot at low speeds with a range of files to trim up things that are supposed to be round, like the base and the nut.

I am not sure what to do with the finish yet!

1/35th scale Oerlikon Canon (May 2016)

For the 1/35th scale Elco or the 1/35th scale S Boot I decided to buy a resin kit and make that up:

Picture of 1/35th Resin Kit for the 20mm Oerikon Cannon from CMK (1) - John Drain's Model PT-Boat Site

Picture of 1/35th Resin Kit for the 20mm Oerikon Cannon from CMK (2) - John Drain's Model PT-Boat Site

Picture of 1/35th Resin Kit for the 20mm Oerikon Cannon from CMK (3) - John Drain's Model PT-Boat Site

Picture of 1/35th Resin Kit for the 20mm Oerikon Cannon from CMK (4) - John Drain's Model PT-Boat Site

This is a resin and photo-etch model kit from CMK.

Czech Master Kits, more commonly known as CMK, has been one of the Czech Republic's contributions to modeling since the mid-1990s. Originally it focused on production of resin cast kits but later production expanded and a range of resin detail accessories, detail sets, white metal accessories together with modelers' tools and aids was introduced. In addition, CMK also publishes monograph books focusing on interesting subjects which contain detailed scale drawings as well as original photographs and color profiles.

CMK company is well known to most modelers as producers of very high quality resin kits and etched brass conversion and detail sets for vehicles and aircraft in all scales. They have been a very early contributor to the small scale armor community and known as one of the best companies out there.

This is US version with the USN carriage and front metal shield.

Picture of the CMK version of the USN Carriage and Front Shield - John Drain's Nodel PT-Boat Site

I had a few issues with this kit as the parts are quite small and I'm not, I broke a few myself but a couple of pieces were broken in the box.

I painted this using the recommended colours from the CMK instructions: Humbrol black 33, Humbrol brown 133, Humbrol grey/green 76 and Humbrol grey 87. I have since overpainted the grey with matt 147 grey as this will be on the Schnellboot model.

Historical Images

Picture of Various Oerikon Cannons - John Drain's Model PT-Boat Site

A few Oerlikons circa 1942.

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