I agree. If your happy just swapping out the gun tube and leaving off the rear bustle rack, it is probably close enough to convince most people.

I spent my early days as a lieutenant building M1A1s out of Tamiya M1 and Esci M1 tanks. Folks were happy with a new barrel (I made copies of the Esci M1A1's 120mm barrel). It was good enough for them way back then.

I remember those days... I used brass tubing and Verlinden epoxy putty to make a 120mm guns for the Tamiya "conversion".

Absolutely Gary, nothing wrong with that either, after all its your model.
Regards
Pete

And somehow the fact that other lines that certainly are parallel meet in one point is not important? Magically barrel distortion only caused problems to these inner lines on panels and not to any others?...

Anyway, I made the same perspective check on a few other photos I have of M1 that show all panels clearly and every time result is the same (below is a few more examples). Everyone can make their models the way they, but unless someone proves me wrong with actual measurements, I will still believe that my findings are true.



I believe that at least some of factory produced M1IPs also had 3-panel style. I have a couple of photos of tanks that clearly show enlarged turrets with new mantlet type (more similar to M1A1 mantlet) and longer side rails (that meet with the bustle rack at their rear like on M1A1, unlike on XM1 and M1 where they ended earlier and were bent and welded to the turret side) and still with 3 blow-off panels.





Pawel

It still doesn't prove it! Lens distortion make it meaningless. That's the problem with calculating measurements, especially anything to do with angles, from photographic images. It simply can't be done with any exactitude!

Anyway, I said you were probably correct about the panels, just that the way you prove it doesn't count. What? You don't like the Laws of Physics now? :-)

Vinnie

Well, it does prove it to me. I know that it is not a scientific proof, but what I wanted to show is that if these photos can be used to draw any conclusions then they rather prove that panels were not rectangles.
Lens distortions causes that the theoretical single point in which parallel (red) lines should meet is not really a single point, as can be seen on my drawings. But significant shift of the yellow lines from red lines in my opinion can only be caused by these lines not being parallel and lens distortion alone could not have caused it.

Below is different attempt to show that these panels were not really rectangular. This method is even less scientific, as lens distortion and position of the photographer relative to panels centerline make it difficult to get clear results. But in my opinion despite distortions these drawings strongly suggest that front and rear edges of panels were not of equal length. Even if all my drawings are not exactly solid proof, then they all consequently suggest that center panel was wider at front and narrower at the back (and side panels were opposite: wider at the back).




By the way, some time ago I tried to "guesstimate" dimensions of panels using multiple photographs and if I remember correctly my conclusion was that difference in width of side panels at front and back was only about one inch or so, so it probably was not obvious even if you looked at these panels on real tank and was not specifically trying to verify their shape.

Pawel

I am going back to the Paint and History Forum. Peter's kit will be en route to him on Tuesday. He's going to do a spectacular job on it and make us proud that we contributed to his success.
Signed
I know nothing
DJ

Hi

Pavel, I am sorry but you are trying to use a 2D solution to a 3D problem. I worked with technical drawers for seven years and it would take a couple of days for them to come up with basic 3 view drawings of the photo you providing using a then very complex program.

Vince is absolutely correct when he points out that you are not taking lens distortion into account. If you have fisheye lens, try to image the fun you would have.

Not trying to slam you and I applaud your attempts to help

I also agree with the statement about where if all you want to do is switch the gun and call it day being okay as is the counter statement stating that going to town is also okay. We often forget this hobby has people from across the modeling spectrum.

Do keep us apprised of your work to backdate your M1.

Tom

Well, I'm an engineer with university degree in metrology myself, so I have at least a very basic idea about things I describe here. I wrote clearly in my last post that I'm aware that my methods are not scientific and I would certainly not be able to tell exact dimensions of panels from photos (I mentioned in my last post that I "guesstimated" dimensions - it was a lot of work and results were certainly not very accurate, but they gave me some idea of the shape). But my experience and knowledge tells me that whatever these panels were, they were not rectangles.

But of course everyone can draw their own conclusions - if despite everything I described you still believe that the panels were rectangles, it's fine with me.

By the way, isn't there any XM1, M1 or M1IP with 3 panels available for someone in the US to take simple measurements of at least a single panel to cut this discussion with some 100% verified information?

Pawel

I have to agree with Pawel,

His scientific method is very similar to the method they proved the moon landings were faked.

In the end, you know the old saying........ Arguing on the internet is like running in the Special Olympics...

Cheers!

Amen to that!
What may be throwing me off is the distance between the panels (pink lines) appears to be parallel, which it may well be even if the panels are angled slightly. I thought the position of the bolts would be a clue, but they don't seem to be centered (red lines, pale blue lines from edges), as their distance from the edges aren't uniform. Actually, I think it's an interesting discussion, even for us rivet-counters! Considering how long the Tamiya kit/M1 has been around, wouldn't it be nice to know for sure?


Cheers,
Jim

I'd bet that the original prototype had the angular ones and that a production one went to rectangles since they would be easier to manufacture.

There are several Abrams of various marks on display here. It's just not the nicest weekend to be climbing on display tanks to settle a matter for the rivet counters.

Could be. However I guess there was some good technical reason to make these panels angular - maybe a layout of ammo racks below them? I don't know if this was changed between XM1s and regular prodution tanks. Certainly these panels were not angled (assuming that they indeed were angled) only to make things more complicated for us modelers.



Good to know. Finding answer to the question of panel shapes is not important for me now, but in the near future I may need this information for a new project (and I don't just mean my own model), so it would be great if you could take such measurements when weather improves and you have nothing really important to do

Pawel