M3 Grant (Lee?) scratchbuilt... or that's the plan anyway...

[Rob1970]

It's been a while since I've done some intensive design work for my 3D-printer since my accident in Januari seriously hampered the amount of screen time I could do. I've been doing better since a few months now, and I am actually enjoying it. So today was a day of tweak, print and tweak again while I get this 3-piece the way I want it.


A couple of generations of test prints. The green one is my last version, and it fits amazingly well. There's probably plenty of people that are better at designing for 3D printing, or use more sofisticated software. I use Tinkercad. And as people also use that one to design for Minecraft, you can imagine the sophistication of that software... Alas my computer won't run anything heavier without exploding.


I sanded down the hull until it was flush with axle cover(?) and removed a little from the hull above it to a 45degree angle...


The piece attaches on the bottom with the original HL hole and screw. Still have to model the tab on the top, but I plan to do that as a separate piece together with the strip of bolts. That strip and the tabs will glue to the top of the 3-piece.


And with a clearance of about 0.5mm from the shaved down gearbox I am fairly sure I got it as tight as I could get it.


Now "Miss Print" is on a 4 and a half hour job to print a complete 3-piece gearbox cover. She's my oldest printer, a delta. She's fast but kinda needs an overhaul because sometimes the quality suffers a little. So she mainly does utility prints and fast prototyping. "Big Bad Bombshell" (an Artillery Sidewinder X1) will eventually produce the final piece, probably in PETG or ASA.

To Be Continued...

TTFN,
Rob

[Rob1970]

Nice... fits like a glove...

[Rob1970]

I got some good(?) news today. It meshes with my drawings anyway. I mean, you can't get more precise than a mechanic climbing on an actual M3 Lee with a tape measure?

Hi Rob,
Sorry it has taken us so long to get back to you. The diameter is 64". This includes the armour which is 3" thick so the inner diameter is 58". I hope this helps!
Kind Regards,
Laura Marchmont
Armourgeddon

64 inches makes 162.56 cm which in scale 1/16 makes a nice "round" 10.16 cm. Aaand that is what I get from my various blueprints and MATH!

To Be Continued...

TTFN,
Rob

[Rob1970]

Well, whadayaknow...


I'm still waiting for some parts for my Firefly, and the past few weeks I haven't felt like nor had the energy to do anything modelling related. My recovery from my accident in Januari has kinda ground to a halt, leaving me without energy. But today was sorta different.

I've been pondering how to attack scratchbuilding the Grant, and kinda was overthinking it. So today I decided to channel my inner kindergartener, and with a pot of glue, some print-outs of the paper model of the Lee (suitably scaled up) and a pile of posterboard I went to work. I drew the line at using my ducky scissors (Quack, quack) and opted for a nice fresh scalpel instead. Living on the edge, momma!


...and the result sofar ain't half bad...


... I mean, it kinda looks like a Lee...


...and it even kinda fits. No, actually it fits rather well.

I enlarged the paper kit with the assumption I would be using 2mm ABS sheet for the side walls. The thinnest posterboard I could find was 3mm, so the whole thing is 2mm too narrow on the inside to just drop over the HL Sherman hull.
But otherwise the dimensions check out. For a first attempt at a mock-up before I cut my ABS sheets to bits I am very happy.

This is just the rough and ready "easy" bits, without the weirdly angled pieces for the top sides of the engine deck. The bit I was most worried about at the front was the two-piece front and the angled single piece that connects those to the side. And those worked just as I cut them, without having to shave the to fit.

So yeah, this is gonna work...

To Be Continued...

TTFN,
Rob

[rolling-thunder]

And the irony of making a Toy 1/18 Fuchs more accurate i to am using cardboard to make the rear of the body. Getting those angles right is a pain. You have my admiration for a skilled job on your Grant. Using the card is a cheaper way of making a mistake.

[Rob1970]

And the irony of making a Toy 1/18 Fuchs more accurate i to am using cardboard to make the rear of the body. Getting those angles right is a pain. You have my admiration for a skilled job on your Grant. Using the card is a cheaper way of making a mistake.

I don't know what kind of cardboard you are using, but if it's the pressed kind (Solid, like cornflakes boxes) you can actually turn it solid enough to use as the actual part by soaking it in CA glue once you have the part finished and shaped. I've made struts on scale model biplanes that way. Once soaked in CA and dried you can sand and shape it like plastic.

[rolling-thunder]

I'm actually using poster board. I'm making a template because i alreadt have plastic card of the same thickness. However, thanks for the hint. I'll try that when i've used my templates.

[lmcq11]

Hi,
I do not understand when you say you have enlarged the paper kit. The paper kit should be your outside measurement. How you cut the 2mm ABS to fit inside depends on how you make the joints between every parts. As the Lee has few 90 degree joints, most joints will require a specific angle to fit inside.

[Rob1970]

Hi,
I do not understand when you say you have enlarged the paper kit. The paper kit should be your outside measurement. How you cut the 2mm ABS to fit inside depends on how you make the joints between every parts. As the Lee has few 90 degree joints, most joints will require a specific angle to fit inside.

The paper model is 1/25 scale, so I had to scale it up to be 1/16. That's all there is to it. I scaled up the paper model parts equally so the hull width was 165mm. I am taking the Tamiya Lee as my base and converting the width of that kit's hull (75.5mm) from 1/35 to 1/16 gives me a hull width (hull, not spanning rivets or hatches) of 165.1563mm...
The Tamiya kit's hull height (at the highest point on the side 29.48mm) converted to an acceptable 64.5mm. Close enough for Government work, as they say....

So yeah, that will do nicely on a HL Sherman hull...

[lmcq11]

Thanks, sounds like a very good plan to minimize the risks with those angles.