FYI!

[joelsmith]

Tamiya has announced a Hummel SPG to be released this summer. Yay! No more dealing with a bazillion parts and vague instructions!

[joelsmith]

Over on track-link, there is a photo just posted today. The kit comes with link & lemgth tracks, the gun barrel and sight are synchronized, and, a metal barrel is available as a option.

[Tobi]

Apr 15, 2019 8:35:11 GMT -5 joelsmith said:

Over on track-link, there is a photo just posted today. The kit comes with link & lemgth tracks, the gun barrel and sight are synchronized, and, a metal barrel is available as a option.

I take it this description is related to the reference pointer on the elevation scale?
If I'm correct the sighting aperture should be always in the same position.
Because most of the time artillery shooting is about indirect fire according to the aiming circle.

[joelsmith]

Tobi, I'm not sure. I'm OK on direct fire weapons, but, not so much on indirect fire weapons. Thanks for the info, I'm always ready to learn something new.

[Tobi]

Joel, I'm far from an expert either, let's assume the big T will get it right.

I like the figures that come with the kit, but I'm afraid the price will be somewhere near their Nashorn, which is a tad too expensive for my taste, especially if the metal barrel comes also as an extra.

If you find the time I can only recommend doing some research about artillery. It's complex but also very interesting. Today with GPS and computers much of the process is totally automated, but the possible mission profiles have also increased to such a degree, modern artillery systems can strike with deadly surgical precision in just a few moments after reaching the firing position right on the heads of a handful of moving fighters. The PzH 2000 for example can fire three rapid shots in under one minute, and by changing elevation and propellant amount the rounds will drop all at the same time in the same spot due to different trajectories.

The typical WWII old school procedure, requiring much more preparation, was the mentioned aiming circle (a theodolite form). The fire director is measuring the position of each artillery piece in the gun line, and to make sure all guns are pointed in parallel each detachment is passed a near fix point (actually that's where the gunners are aiming at), an azimuth angle and an individual gun correction value. On an incoming fire mission the fire director can then calculate deflection, elevation and the needed propellant to the target, taking into account wind, temperature, air pressure and humidity, and then the battery will crank up and establish readiness for a synchronized shot.

[joelsmith]

On You Tube there is a "full build" video at the Andy's Hobby Headquarters department for your enjoyment.

[Tojo72]

Just about any release is a good release,keep them coming.
Never understand the we don't need more Panthers,Tigers,or Shermans remarks.
I'm sure this will be a fine kit.

[joelsmith]

My Hummel just came in from Japan. It looks just as good as the photos!

[sturmbird]

Apr 15, 2019 10:35:23 GMT -5 Tobi said:

Apr 15, 2019 8:35:11 GMT -5 joelsmith said:

Over on track-link, there is a photo just posted today. The kit comes with link & lemgth tracks, the gun barrel and sight are synchronized, and, a metal barrel is available as a option.

I take it this description is related to the reference pointer on the elevation scale?
If I'm correct the sighting aperture should be always in the same position.
Because most of the time artillery shooting is about indirect fire according to the aiming circle.

Tobi,
Your pretty much correct on shooting indirect fire. Systems are all similar, but still vary. Era's have some input as well. Yet in the end are still similar. Barrel elevation is dialed in (in mils), and then the barrel is raised or lowered till the buble is centered in the sight glass. BUT! Remember I said era? In WWII, Korea, and all the way back into the 19th century for sure, a protractor that works off a buble level. This is placed on top of the breech block. The the barrel is moved till centered.
Direct fire is another story. Most is guess work, unless you have a secondary sighting system to take over. Even then it will only work with one type of round and velocity.
Gary

[Tobi]

Jul 15, 2019 23:00:38 GMT -5 sturmbird said:

Apr 15, 2019 10:35:23 GMT -5 Tobi said:

I take it this description is related to the reference pointer on the elevation scale?
If I'm correct the sighting aperture should be always in the same position.
Because most of the time artillery shooting is about indirect fire according to the aiming circle.

Tobi,
Your pretty much correct on shooting indirect fire. Systems are all similar, but still vary. Era's have some input as well. Yet in the end are still similar. Barrel elevation is dialed in (in mils), and then the barrel is raised or lowered till the buble is centered in the sight glass. BUT! Remember I said era? In WWII, Korea, and all the way back into the 19th century for sure, a protractor that works off a buble level. This is placed on top of the breech block. The the barrel is moved till centered.
Direct fire is another story. Most is guess work, unless you have a secondary sighting system to take over. Even then it will only work with one type of round and velocity.
Gary

Hi Gary,

thanks for your input and good to hear from you friend.

Cheers
Tobi

[sturmbird]

a round out of a rifle is similar to a round shot out of a 155mm howitzer. Both travel in an arc that has several factors adjusting the curve while in flight. The Earth's gravitational pull is a constant. The actual shape of the bullet matters greatly once you've cleared the 500 meter mark. We call that a ballistic coefficient. I suggest a comparison between the basic 105 or 155 projectile and the old 175mm gun round. The 175 round has a much greater B.C. than the other two, and is actually very similar to a 7mm rifle bullet in the 150 grain weight.
So we make a computer to do the job, BUT! That computer is doing what a guy did with a slide rule 80 years ago! It's faster now days, but fifty years ago they were about the same speed. So both of them are doing a second semester algebra equation. I recently saw a series of photos of a group of WWII German Wespe SPG's, and read some of the comments with a slight smile. Most were saying the ammo was placed on the wrong side of the gun (WRONG!), but none of the arm chair generals saw the aiming stakes placed out front. Actually a little too close to the muzzle blast for me. Normally you like to place them behind you so they don't get moved around by the blast. The scope (actually called a Pentell Scope) will rotate 360 degrees, so you set it on the number your after and move the barrel left or right till the two aiming stakes come together as one line. There's a little more to this, but I'm trying to keep it simple. Elevation is similar, in the you raise or lower the barrel till the bubble is centered.
After you shoot the first round things move (act of nature, but really recoil). If the gun moves back much more than 12", your in trouble! You may not be able to get the elevation right, and unless everything came strait back you may have to call the piece out of action. (They don't like those words). In the end, it's a safety issue down range. And you really don't want that. I called a piece out twice, and they liked to went nuts!
gary