My first Churchill is a great runner, one of the best I have (Tamiya tank included), I was not expecting that when building it. But the other day, I was running it in the park and I lost a wheel, I never found it. I had to print another one, not a big deal, I had the file... wait, while I was browsing all the files I created for the Churchill to find the wheel, I realize I did a lot of work and that building a second Churchill would be super fast. So I ended up printing the missing wheel... and a whole new set of wheels for a new Churchill.
2 days later I had that :
When I was building the first AVRE, I knew it would be a SBG and I was quite frustrated because 80% of the SBG and I think 100% of the ones that landed on D-Day, had the early tracks (I had the late metal ones made by DKLMRC). I always liked the early tracks better on the Mk IV and previous Churchill version. No question regarding the Mk VII obviously.

So I designed the early tracks, using photogrammetry of an original one to be as accurate as possible.
But I did not want to print them on a FDM printer. I would lose details, I never been able to print correctly track links with that kind of printer and most important : it takes forever.
I wanted them to be resin but I was affraid they would not be strong enough.
I did a print test with some Siraya resin. It was quite promising but very brittle :
Then I came across one of @tankme 's thread : viewtopic.php?t=36203
He mentionned he used Sunlu toughness resin and that the tracks were performing well. I had to try. And I did. It's the best resin I have ever used for tracks ! It's strong but a bit flexible, so the parts won't break.
I now have printed the set of 2 tracks with that resin. They are great, can't wait to try them !
Well I initially wanted to make a MK III at Dieppe to show the tracks (they only had a small portion of the track guards installed) but after staring at pics of the real tanks and pic of my first churchill under construction without the track guards, I came to the conclusion that I prefer the look of the Churchill with the track guards. And with the MK IV turret... And with the spigot mortar...
Oh well you got me, I'm building another Churchill Mk IV AVRE !

But it's going to have some difference :
-First, the tracks of course.
-I modified some of the parts for ease of use or maintenance
-I am 3D modelling some new parts because I was able to take pictures of a real AVRE (the one I used for ref my first Churchill was a regular Mk IV) so I'll be able to use photogrammetry for the AVRE fittings.
-I am re modelling a new side hatch using photogrammetry this time, the frame of the first one was a bit off but I'm sure I wont notice the difference when both Churchill will be side by side !
-I am doing the other style of door hinges, they'll have square corners, the ones I made had round end, small design difference, not sure when it changed during the production of the real thing.