What's on The Workbench (7 Viewers)
- Thread starter Heinz
- Start date
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Crimea_River
Marshal
Looking good Geo. Not heard of that theory before Evan but its creative.. Possibly the machine got one or 2 new prop blades at some point, this resulting in the uneven wear.
fubar57
General
Thanks all
Was thinking something similar Evan. Do the 109 engine cylinders have to be set in a certain position for the engine to be started? I dunno but I also notice that there are an awful lot of photos showing now wear on any prop tipNice Geo
And I have a theory... I have a photo of 4 or so groundcrew starting a Corsair prop, by pulling a rope attached to a small cover fitted to the end of a prop blade. Is it possible that the Germans sometimes did this, especially maybe in the winter, and that a specific blade tip was used (for whatever reason), thus causing the single worn trailing edge..?
Just an idea, as Douglas Adams said, just putting it out there on the plate to see if anyone pours mustard on it.
IMHO Me 109's engine will be started with the crank on the right side (see here:Nice Geo
And I have a theory... I have a photo of 4 or so groundcrew starting a Corsair prop, by pulling a rope attached to a small cover fitted to the end of a prop blade. Is it possible that the Germans sometimes did this, especially maybe in the winter, and that a specific blade tip was used (for whatever reason), thus causing the single worn trailing edge..?
Just an idea, as Douglas Adams said, just putting it out there on the plate to see if anyone pours mustard on it.
View: https://www.facebook.com/watch/?v=1752232721577289) not when rotating the propeller by hand.
fubar57
General
Forgot about that but I do note that one prop is up
cammerjeff
Staff Sergeant
In my experience working on Propeller driven A/C, the blade wear is always greatest at the rear portion of the tips. I have always thought it was that way for the following reasons.
1 - the propeller tip is the fastest moving part of the propeller, thus more likely to be damaged more severely than the rest of the propeller due to impact speed of any sand, dirt gravel ect...
2 - The tip is closest to the ground than the rest of the propeller, thus more likely to be impacted.
3 - While the leading edge of the propeller will show the most impact damage, the back side of the propeller will show the most paint wear due to the lower pressure area of the rear face of the propeller compared to the front. This tends to suck any dirt, sand, debris to the rear face of the blade.
Most of the Propeller aircraft types I have worked on did not have painted blades, but a few did. I remember working on my Fathers C-120, 195, 310, & Fairchild 24. Larger types I have seen it on are PA-31's, Beach King Airs & 1900's, EMB-110's, Shorts-360's, ATR-42 & 72, CV-580's, YS-11's, P-3's, & C-2's. I have also noticed it on some helicopter tail rotors. So I do not think it would have anything to do with any starting techniques. But if anti rotation devices are attached to the blades it can increase the effect. Note this really only applies to the Turboprops with engines with a free power turbines like PT-6's. The engine mass and or compression of other types of engines usually mean the wind is not strong enough to rotate the propeller and the engines internal parts.
But we always used to strap the blades on the Shorts 360's and EMB=110's to prevent propeller rotation when parked.
1 - the propeller tip is the fastest moving part of the propeller, thus more likely to be damaged more severely than the rest of the propeller due to impact speed of any sand, dirt gravel ect...
2 - The tip is closest to the ground than the rest of the propeller, thus more likely to be impacted.
3 - While the leading edge of the propeller will show the most impact damage, the back side of the propeller will show the most paint wear due to the lower pressure area of the rear face of the propeller compared to the front. This tends to suck any dirt, sand, debris to the rear face of the blade.
Most of the Propeller aircraft types I have worked on did not have painted blades, but a few did. I remember working on my Fathers C-120, 195, 310, & Fairchild 24. Larger types I have seen it on are PA-31's, Beach King Airs & 1900's, EMB-110's, Shorts-360's, ATR-42 & 72, CV-580's, YS-11's, P-3's, & C-2's. I have also noticed it on some helicopter tail rotors. So I do not think it would have anything to do with any starting techniques. But if anti rotation devices are attached to the blades it can increase the effect. Note this really only applies to the Turboprops with engines with a free power turbines like PT-6's. The engine mass and or compression of other types of engines usually mean the wind is not strong enough to rotate the propeller and the engines internal parts.
But we always used to strap the blades on the Shorts 360's and EMB=110's to prevent propeller rotation when parked.
cammerjeff
Staff Sergeant
You can just make out the propeller anti rotation straps on this parked Shorts 360
Source Short SD3-60 - Aircraft Recognition Guide
Source Short SD3-60 - Aircraft Recognition Guide
Zippythehog
Staff Sergeant
- 985
- Jan 7, 2017
CJ, the low pressure around the prop disk is in the front-if it were the back, the plane would go backwards. The high pressure is behind-which is why the back of the prop collects the dirt and debris. It's also why the plane goes forward.
I think you're on to something, as the fields that 109 flew off were probably sandy and dusty-not paved.
It's cool that your dad had a 195! That is my vote for the prettiest post war single engine GA all metal plane. I still carry a fantasy of owning a Fairchild 24 (prices are pretty reasonable). Was your dad's Fairchild a Ranger engined or Warner Scarab?
cammerjeff
Staff Sergeant
Zippy, you are correct I reversed the low pressure area in my mind. I agree the low pressure area of the prop is on the front of the blade, I don't know what I was thinking DUH!
fubar57
General
My second attempt at exhaust stains. The first was a mid-engine so doesn't really count. A little higher than I wanted on the left side. I may go back over it with RLM76.....or maybe not, I dunno. What looks like staining on the leading edge for about an inch is just some kinda shadow thang
Now to get on with some weathering and the little things. Really surprised that the pitot tube has hung onto the wing since day one. If you go back and look at the photos of the real aircraft from the left side, you will see it was actually bent straight down. In debations about doing that
Zippythehog
Staff Sergeant
- 985
- Jan 7, 2017
No worries. If it were easy, anybody could do it.Zippy, you are correct I reversed the low pressure area in my mind. I agree the low pressure area of the prop is on the front of the blade, I don't know what I was thinking DUH!
A4K
Brigadier General
Good stuff guys, and nice work Geo.
I hear your dilemma too. If you make it realistic by bending it down, general viewers might think the model pitot just got knocked or something. Just like roughly painted Invasion bands on a D-Day aircraft - were they actually like that, or can the modeller just not paint straight?
Helps to have a copy of a photo of the original to show 'No. It WAS actually like that!'
I agree too re the 109 hand crank. I knew they had those (Fw 190s too), but wondered if they might need an 'extra hand' sometimes, especially in the winter.
I hear your dilemma too. If you make it realistic by bending it down, general viewers might think the model pitot just got knocked or something. Just like roughly painted Invasion bands on a D-Day aircraft - were they actually like that, or can the modeller just not paint straight?
Helps to have a copy of a photo of the original to show 'No. It WAS actually like that!'
I agree too re the 109 hand crank. I knew they had those (Fw 190s too), but wondered if they might need an 'extra hand' sometimes, especially in the winter.
A4K
Brigadier General
Interesting, cheers mate!
fubar57
General
Thanks Evan. About to start the weathering
Crimea_River
Marshal
Its a tough thing to do convincingly on a monochrome scheme like that.
fubar57
General
Couldn't live with the high exhaust stain so I knocked it down a bit. Touch-ups shortly and gloss coat....again
A4K
Brigadier General
Looks just right, Geo 
