Scratch Built Thunderfire Cannon - Part 1

I've always wanted to try out the stupendous firepower of the Thunderfire Cannon on the battlefield. Sadly the only time I proxied one it died in the first turn of shooting and never got to return fire :( Sure it's fragile, but that is mitigated somewhat by the 60" range and 3+ cover save that it is hopefully getting.

I was donated an already painted Techmarine a few years ago. I was playing him as Master of the Forge for my Terminator/Dreadnought list. So I have that covered, and it seemed that scratch building a Thunderfire Cannon to go with him shouldn't be too hard... The theme of my Crimson Fists army is "cheap", so the idea fits that perfectly :) I have never done a scratch build before, so don't expect anything wondrous. I should be able to scale the lofty peak of "servicable" however.

Here are the bits I am going to use. The tracks and engine plate come from an old Ork vehicle, a Razorback roof plate and gun casings (i think?) and a bunch of bits kindly donated to the project by Battle Bunker Aki (including the punisher cannon - thanks mate!)

The base has been built - this was the easiest part, as it was these pieces that made me realise this project was possible in the first place. The two stabiliser arms had to be reglued later on as I hadn't left enough room for the techmarine's base! Gluing these on was quite tricky - I ended up sitting them on a ball of blu-tack each which pushed them up to the base plate whilst drying.

The main gun took the most time to figure out what I wanted. In the end I went with something simple that looks good to me. I've filled in the gaps with 1mm card for now. It might need a little bit of green stuff later on...

A side view of the finished gun. Not exactly the same as the Games Workshop product, but it'll do me. Just needs a bit of green stuff in some of the joins.

A view from the front. Note the aquilla which is also on the official model - I grabbed this from the drop pod sprue. Note that the gun can pivot left and right. I will probably add a magnet to the centre so that it can't be accidentally knocked off.

Still to come: magnetizing a techmarine, and a Crimson Fists paint job...