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Re: Chieftain Mk V scratch build
Posted: Thu May 17, 2018 7:30 pm
by midlife306
Bloody hell Alwyn, you’ve been busy!!!
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Re: Chieftain Mk V scratch build
Posted: Thu May 17, 2018 7:48 pm
by AlwynTurner
Yup I've already used a kg of filament on this build, and I've just ordered another as I only have about 100m of filament left on this roll.
Alwyn

Re: Chieftain Mk V scratch build
Posted: Fri May 18, 2018 5:20 pm
by AlwynTurner
Made some progress with the upper hull, wired up the headlights an fitted them.

Fitted the bits and pieces to the front of the hull, mounted the tool boxes temporarily, now it's starting to look like a tank

and with the lower hull
I'm trying to manufacture a shroud for between the barrel and the barrel pivot using some soft wire and some 50mm heatshrink
I'm not sure if that will work with the recoil, but I couldn't figure out how to do a 'canvas' shroud that would cover that area, I know the real tank had a canvas cover there.
I'm just printing the drivers hatch, and then it's on with mounting the gun (I've been subconsciously avoiding that job as it's going to be a bit of a fiddle to get into the tight space in the turret and also make the whole mechanism stripable for maintenance). On this job glue is not going to be an option!
Alwyn

Re: Chieftain Mk V scratch build
Posted: Fri May 18, 2018 5:47 pm
by AlwynTurner
Re: Chieftain Mk V scratch build
Posted: Sat May 19, 2018 7:00 am
by B_Man
It's all coming together Alwyn, great work.
For the canvas you could try scraps of fabric. I was never happy with the stock shroud on my T-55 so made a replacement from an old work shirt and painted it. The paint gave it a bit more body and it came out much nicer than the nylon original.
Re: Chieftain Mk V scratch build
Posted: Sat May 19, 2018 11:41 am
by AlwynTurner
Well the reality of mounting the barrel in the turret proved much less of a problem than I had been dreading (probably like most things in life - imagination can sometimes be your enemy!).
prepared the mounting bracket

screwed everything together (very fiddly)

and one tank with a mounted barrel
Simples!
Alwyn

Re: Chieftain Mk V scratch build
Posted: Sat May 19, 2018 1:35 pm
by wibblywobbly
Alwyn, you could save yourself some typing. The 'hull' command creates any shape you want, you just define the corners using cubes, sphere's, or cylinders. Taking your hatch as an example:
module drivershatch ()
{
$fn=100;
union ()
{
hull()//top
{
translate ([22,-12,-7.5])cylinder(3,r=7.25);
translate ([22,12,-7.5])cylinder(3,r=7.25);
translate ([6,-15.5,-7.5])cylinder(3,r=3.75);
translate ([6,15.5,-7.5])cylinder(3,r=3.75);
}
hull()//hinge
{
translate ([6,21.5,-7.5])cylinder(3,r=3.75);
translate ( [4.8,14,-7.5] ) rotate ([0,0,20]) cube ([7.5,7.5,3]);
}
translate ([6,21.5,-7.5])cylinder(16,r=1.1);
}
hull()//inner
{
translate ([21,-11,-7.5])cylinder(6,r=7.25);
translate ([21,11,-7.5])cylinder(6,r=7.25);
translate ([7,-14.5,-7.5])cylinder(6,r=3.75);
translate ([7,14.5,-7.5])cylinder(6,r=3.75);
}
}
drivershatch ();
If you just want a cube with rounded corners then:
$fn=50;
minkowski()
{
cube([10,10,1]);
cylinder(r=2,h=1);
}

Re: Chieftain Mk V scratch build
Posted: Sat May 19, 2018 2:06 pm
by AlwynTurner
Thanks Rob, I'm just exploring the mysteries of hull and minkowski, it should save me loads of design.
Alwyn

Re: Chieftain Mk V scratch build
Posted: Sat May 19, 2018 8:25 pm
by AlwynTurner
Re: Chieftain Mk V scratch build
Posted: Sat May 19, 2018 9:18 pm
by midlife306
Awesome Alwyn, it’s frustrating being away from home boooo...
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