Sherman's Bendy Barrel


An issue that arises all too often when printing models in resin is warping of components. Gun barrels are especially problematic in this way. I don't know if the issue is with the resin itself, or my printing settings, but resin prints don't seem to have the dimensional stability that FDM has. I assume it's probably the resin layers shrinking microscopically while curing.

I printed this M4A3E8 a few days ago, and I've just started painting it. I don't know if the warping of the gun barrel has actually got worse, or whether it's just preying on my mind, but in any case I've decided that it just can't be borne any longer.

I have some 2mm brass rod, and a little cheap mini-lathe that I got from AliExpress — it's basically just a Jacobs chuck attached to a little electric motor on an aluminium frame — so I've decided to have a go at replacing the gun barrel with a nice straight brass one. The 2mm rod is out of scale for the 76mm gun, but it's the same size as the barrel as designed, so at least I can be sure that the muzzle brake isn't going to suddenly look too hugeous.

The new turned barrel (a bit out of focus) is sitting in front of the model. Cutting off the muzzle brake and barrel should be straightforward enough with a razor saw; I'll just have to be a bit careful with the drilling for the brass tenons to slot into.

Something the lathe doesn't have is any kind of tool holder, so it all has to be done with hand-held tools. Not ideal, and it makes getting crisp, straight, square angles a bit tricky. Hey-ho, needs must as they say.

Later on...

Well, at least it's straight now

I see from the photos that there are a bunch of tiny supports in the running gear that I overlooked, so I guess there will be more disruption of the paintwork than I'd hoped. I'll start again from the beginning I guess.

A few days later...

This is about where I give up trying to paint it any more. I was trying for a tank that looked well used, but without all the chipping that tends to be splattered all over tank models these days (and of which I am as guilty as any).I've ended up with a bit of a mess, but it will do okay at tabletop distances I think.

The decals come from Skytrex, and they seem pretty good to me. They respond well to decal softener without becoming so fragile that they fall to bits, and the multi-colour ones I bought (German crosses) are printed in good registration, unlike any of the Battlefront decals I've had.


  1. Replies
    1. Thanks. For future models I'll print the turret and muzzle-brake separately, with sockets to take the metal barrel, and I'll probably try to give the barrel a slight taper too, like the real gun.