Sherman M4A1 with cast in appliqué armor using photogrammetry
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Sherman M4A1 with cast in appliqué armor using photogrammetry
Hey guys !
It's me again with all the usual stuff, real tank, photogrammetry, 3D modelling and 3D printing ! But this time I'm going to do something different.
I usually use photogrammetry to create a msh of an existing vehicule then I use it to 3D model it myself. But this time I'm using the mesh itself so I don't alter the original shape at all, it's like I used a magic wand to scale down a real tank.
I wanted to recreate a M4A1 because I like the organic shape of the cast hull. But I had to find the good canditate for photogrammetry in order to create the best mesh I could.
And 3 months ago I found the ideal candidate for that ! It's a tank that has been decorated by an artist, photogrammetry works much better with a surface that has a lot of details :
There's no info about this tank, so here's what I can say from my own observation :
- It's a M4A1 with small hatch and cast in appliqué armor (the ultimate small hatch cast hull).
- It's started its life as a DD Sherman, then stripped off all its DD attribute to become a regular Sherman as they used to do. It's still has proof of it's old DD days : weld scares on the transmission covers, DD fittings welds on the hull, special "skirt" supports and fenders, original taller headlights guards (headlights were higher than usual to be above the skirt), but it doesnt have the DD screws and idler system, it has been replaced by the usual track tensioner and idler.
I took about 400 pics of it, picked up the 293 best ones and then manage to get a good solve of it using Agisoft photoscan. Processing lasted for about one day.
Here you can see the result :
It's me again with all the usual stuff, real tank, photogrammetry, 3D modelling and 3D printing ! But this time I'm going to do something different.
I usually use photogrammetry to create a msh of an existing vehicule then I use it to 3D model it myself. But this time I'm using the mesh itself so I don't alter the original shape at all, it's like I used a magic wand to scale down a real tank.
I wanted to recreate a M4A1 because I like the organic shape of the cast hull. But I had to find the good canditate for photogrammetry in order to create the best mesh I could.
And 3 months ago I found the ideal candidate for that ! It's a tank that has been decorated by an artist, photogrammetry works much better with a surface that has a lot of details :
There's no info about this tank, so here's what I can say from my own observation :
- It's a M4A1 with small hatch and cast in appliqué armor (the ultimate small hatch cast hull).
- It's started its life as a DD Sherman, then stripped off all its DD attribute to become a regular Sherman as they used to do. It's still has proof of it's old DD days : weld scares on the transmission covers, DD fittings welds on the hull, special "skirt" supports and fenders, original taller headlights guards (headlights were higher than usual to be above the skirt), but it doesnt have the DD screws and idler system, it has been replaced by the usual track tensioner and idler.
I took about 400 pics of it, picked up the 293 best ones and then manage to get a good solve of it using Agisoft photoscan. Processing lasted for about one day.
Here you can see the result :
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Re: Sherman M4A1 with cast in appliqué armor using photogrammetry
I could not use the mesh as it was, I had to modify it in order to get it printable. I had to remove the turret, the lifting rings, the headlights guard etc...
I eventually came up with that :
I eventually came up with that :
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Re: Sherman M4A1 with cast in appliqué armor using photogrammetry
I ddi some research about the M4A1 small hatch with cast in appliqué armor. There's not a lot of pictures of them because only a few hundreds (out of 49000 shermans) have been produced.
Several of them became Canadian Grizzly, and most of the other have been used by British and Polish.
I haven't find a pic of one used by the US yet, nor by France.
The appliqué armor are not always easy to spot in period pics.
The one in display in the the Australian armour and artillery museum :
Grizzly, you can find plenty of pics of them, period pics or And the Grizzly at the Caen museum (took several pics of it because you can be above it and I was able to take a lot of picture of the top of turret in order to recreate it for this project) :
Several of them became Canadian Grizzly, and most of the other have been used by British and Polish.
I haven't find a pic of one used by the US yet, nor by France.
The appliqué armor are not always easy to spot in period pics.
The one in display in the the Australian armour and artillery museum :
Grizzly, you can find plenty of pics of them, period pics or And the Grizzly at the Caen museum (took several pics of it because you can be above it and I was able to take a lot of picture of the top of turret in order to recreate it for this project) :
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Re: Sherman M4A1 with cast in appliqué armor using photogrammetry
Using this very Sherman (the Grizzly of the Can museum), I've been able to recreate an accurate 3D model of the low bustle turret.
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Re: Sherman M4A1 with cast in appliqué armor using photogrammetry
After more than a hundred hours of work on the 3D model, I was able to 3D print it. I had to do it in 2 parts because the hull was larger than what my printer could print. This was the first time I was using Siraya tech resin (I used the Build one), and, wow, it's absolutely awesome ! It is well worth the price !
I bought a "static" Heng Long sherman for this project (not really static as it has everything inside it, even the old 27Mhz receiver). For now I'm using the chassis but I think I'm going to rebuild most of it, I may end up just using the geaborx and the tub, after heavy modifications of course.
The hull is roughly sanded and primed, but it will get more care and a "cast" finish to it. The transmission cover is a Tamiya one, it needs more work to fit the Heng Long chassis but I'm confident it'll work in the end.
I've always been disappointed with all the M4A1 cast hull offered by all the b rand in any scale (Tamiya, Tasca etc). Some are really close but never spot on, that's what I was aiming with this project, something I could look at and "feel" it has the right shape. I'm pretty happy the result so far and I don''t think I could get any better as it direcly came out of an original tank...
I bought a "static" Heng Long sherman for this project (not really static as it has everything inside it, even the old 27Mhz receiver). For now I'm using the chassis but I think I'm going to rebuild most of it, I may end up just using the geaborx and the tub, after heavy modifications of course.
The hull is roughly sanded and primed, but it will get more care and a "cast" finish to it. The transmission cover is a Tamiya one, it needs more work to fit the Heng Long chassis but I'm confident it'll work in the end.
I've always been disappointed with all the M4A1 cast hull offered by all the b rand in any scale (Tamiya, Tasca etc). Some are really close but never spot on, that's what I was aiming with this project, something I could look at and "feel" it has the right shape. I'm pretty happy the result so far and I don''t think I could get any better as it direcly came out of an original tank...
Last edited by MonsieurTox on Thu Jan 25, 2024 5:37 pm, edited 1 time in total.
- Ecam
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Re: Sherman M4A1 with cast in appliqué armor using photogrammetry
That Witchcraft/Magic is impressive! The hull came out great, incredible details! How soon until you are mass producing these? I'll have a lower ready.
"Don't believe everything you see on the internet" - George S. Patton
Eric
Eric
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Re: Sherman M4A1 with cast in appliqué armor using photogrammetry
Thank you Eric ! Haha I don't think I'll ever mass produce them ! The I Love Kit M4A1 is coming so people will get that cast hull ! And to be honest the M4A1 small hatches with appliqué armor is quite a niche ! But next year (or later this year), next project will be to do the same but this time with a M4A1 with large hatches, I'll do a trip to take hundred of pics of one in order to recreate an accurate 3D model !
Here are some more pics :
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Re: Sherman M4A1 with cast in appliqué armor using photogrammetry
I've started to modify the Heng Long chassis. The rectangular sponson bases have been trimmed in order to fit the new cast hull.
Same with the rear bulkhead, a new one will be created. Rear door and exhaust are cut off and filled. I'm going to recreat the correct M4A1 doors.
The Heng Long is going to get more modifications to get it more rigid like I did on the chassis of my I Love Kit M4A3E8 (I haven't posted it yet !). I'm not sure if I'm going to replace the track tensioner and idler by metal Mato ones, I used that on my M4A3E8 and those parts are really... bad. Bad finish, metal is way too soft (one of the screw doesnt work after removing and puting it back only once lol, even plastic is better ), it does not even look good or accurate. It is really not worth the few $ I spent for them.
Same with the rear bulkhead, a new one will be created. Rear door and exhaust are cut off and filled. I'm going to recreat the correct M4A1 doors.
The Heng Long is going to get more modifications to get it more rigid like I did on the chassis of my I Love Kit M4A3E8 (I haven't posted it yet !). I'm not sure if I'm going to replace the track tensioner and idler by metal Mato ones, I used that on my M4A3E8 and those parts are really... bad. Bad finish, metal is way too soft (one of the screw doesnt work after removing and puting it back only once lol, even plastic is better ), it does not even look good or accurate. It is really not worth the few $ I spent for them.
- Herr Dr. Professor
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Re: Sherman M4A1 with cast in appliqué armor using photogrammetry
MonsieurTox, you knowledge of electronics, of computerized drafting, of 3D printing all amaze me.
I just look at the photos and am stunned. If I ever get to Paris, I want to see your AFVs.
I just look at the photos and am stunned. If I ever get to Paris, I want to see your AFVs.
- Ecam
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Re: Sherman M4A1 with cast in appliqué armor using photogrammetry
Never thought to simply cut out the M4A3 rear doors and replace with card! I've always worked for hours to chisel/scrape/grind/cry them off. Next time...
That hull looks fantastic, will be watching for updates.
That hull looks fantastic, will be watching for updates.
"Don't believe everything you see on the internet" - George S. Patton
Eric
Eric