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HK 1/32 B-17 Landing Gear Correction?


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#1 Dennis7423

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Posted 07 December 2017 - 04:21 PM

All-

Can anyone direct me to an article, or point it out here, how much I need to cut off the kit oleos to get a more accurate height on the HK 1/32 B-17? I can't seem to remember, or find it!

TIA

- Dennis S.
Thornton, CO USA
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#2 Jennings Heilig

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Posted 07 December 2017 - 05:15 PM

Depends on how loaded or unloaded the aircraft is. There is no one correct height.
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#3 Juggernut

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Posted 07 December 2017 - 11:25 PM

HI Dennis,

 

According to the B-17G Inspection section of the E&R Manual, AN01-20EG-2, page 445, dated 25 AUG 1944, the proper oleo (my word) strut inflation for a flight ready B-17 is 9.50 inches from the centerline of the axle to the upper edge of the lower collar.  In 1/32 scale that equates to 0.297" (~0.300").  See the below image I robbed from the net and modified to illustrate the instructions.  Notice how little of the chrome oleo is showing.  This is approximately what it should look like when laden with bombs, ammo, fuel and oil.

 

 

fKiFquk.png

 

I hope this is where the extra length comes from in the unmodified plastic strut. 

 

If you have access to a center drill (or can drill the center of the strut by eye) I would cut the strut at the lower edge of the lower collar and drill a hole in the upper strut a few thousandths of an inch (0.001 or 0.002) larger in diameter than the oleo portion of the lower strut.  I would drill it sufficiently deep so that you can slide the lower strut into the upper strut and bottom it out so to speak.  I would then slide it out until I got the correct measurement and either run thin super glue around the joint or mark it, pull it apart and add plastic to the lower strut until the lower strut bottoms out in the upper strut at your mark.  That's just my take... I'm sure there's a bunch of other methods but you want to make doubly (triply?) sure you've got a good, solid, strong joint.

 

HTH


Edited by Juggernut, 07 December 2017 - 11:31 PM.

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#4 Peterpools

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Posted 08 December 2017 - 12:02 AM

Dead on the  money for sure - terrific detail info

Keep 'em comin

Peter


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#5 Darren Howie

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Posted 08 December 2017 - 02:15 AM

Aeroplane struts ie real aeroplanes not plastic ones have struts that vary in length every day.
Its all great to have a manual “recommended” length but in the “real world” the variables that can effect them are...
Outside air temp, strut inflation level, the strut design itself, Aircraft zero fuel weight(yes EVERY aeroplane in the world weigh different amounts, fuel on board, payload, crew numbers..ie 10 Crew equals by itself well over 1000Kg ie 2250Ibs.
Aircraft frequently lean with struts at different pressure levels.
Real aeroplanes as opposed to manuals rarely the twain will meet.

Edited by Darren Howie, 08 December 2017 - 02:15 AM.

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#6 brahman104

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Posted 08 December 2017 - 02:54 AM

It was one of the B-17 builds by Tom Probert. I seem to recall he removed about 4mm from each leg, the kit as it is seems to give the impression of the fort on its tip-toes. The corrected version looks a lot more "natural" for a typical B-17......

 

Craig


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#7 Dennis7423

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Posted 08 December 2017 - 04:58 AM

Thanks everyone! Looking for a more accurate stance for a loaded bird, away from the tippy-toe stance the kit currently has. The kit oleos as molded are more or less completely extended, and really gives the kit a nose up, very high stance. I think even the tail wheel strut is too long.

- Dennis S.
Thornton, CO USA

#8 ericg

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Posted 08 December 2017 - 10:08 PM

This smacks of so much ignorance regarding serviceable aircraft, I cannot even begin to form a reply and it's probably best that I don't. Suffice to say that the entire post is pure BS.


Actually I thought the post makes quite good sense.

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#9 Barry

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Posted 08 December 2017 - 10:36 PM

This smacks of so much ignorance regarding serviceable aircraft, I cannot even begin to form a reply and it's probably best that I don't.  Suffice to say that the entire post is pure BS.

45+ years in aviation maintenance says strut servicing takes all the variables Darren mentioned into account.

Most service manuals have a chart or graph the charts the curve of strut servicing as it IS a variable!

 

Barry



#10 Darren Howie

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Posted 09 December 2017 - 12:26 AM

This smacks of so much ignorance regarding serviceable aircraft, I cannot even begin to form a reply and it's probably best that I don't.  Suffice to say that the entire post is pure BS.


Please Juggernut i have spent 32 years flying real aeroplanes and another 10 being around them ie cleaning, helping maintain etc.
If you dont like “real” information about real aircraft and would prefer to bury your head in paper in complete disregard to reality that is fine.
But maybe drag you head out of a book for a moment go out and look at “real” aeroplanes ie not the plastic variety or the paper version ie manuals and you may just find a whole big world that different to what is wriiten in books.
Your post smacks of an IPMS judge who has never set foot on an airport, touched an aircraft as ANY aviation person who has set foot on a real aircraft knows that what i stated happens every day with oleo fitted aircraft.

#11 Darren Howie

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Posted 09 December 2017 - 12:30 AM

A short article on Oleo design and lengths and why they vary and also on the vagaries of strut inflation...for someone with 30 years of maintenance im sorry i cant believe a word of what your writing as it flies in the face of daily aircraft knowledge.
Having flown aircraft that are not in a warzone that and seen variation in strut lengths up to almost a foot between aircraft(not sides) and variation of 6” common i can only imagine what aircraft in a war zone 70 plus years ago would see.

https://www.avweb.co...r/192153-1.html

Two Gear leg phots off two identical aircraft...
First linky..
https://goo.gl/images/aw3euQ

Second linky
https://goo.gl/images/gajmE9

Edited by Darren Howie, 09 December 2017 - 12:51 AM.


#12 LSP_Kevin

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Posted 09 December 2017 - 12:44 AM

OK, I'm going to close this down very quickly, before it gets out of hand. If you can't answer Dennis's original question directly, then perhaps walk on by.

 

Kev



#13 Darren Howie

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Posted 09 December 2017 - 12:51 AM

A couple of images of B-17 strut lengths showing the variation you coukd expect.
First one is about 8 times the lngth ie exposed strut of the second which inassume is fully loaded.
First looks empty as its a mail B-17 i believe.
https://goo.gl/images/t3RXq7

Second possibly fully loaded B-17 ie compressed struts.
https://images.googl...&source=sh/x/im

Regarding crew weights aircraft manufacturers particularly in wartime are very biased to under accounting on crew weight. 125Lbs is a figure arrived at to allow max payload to be carried. If you have felt the weight of kit carried by a B-17 crew member ie parachute, full leather cold gear ie electric heated leather gear, helmet and flak vest that alone woukd weigh 25-30Kg. Throw in your average 5’7 or 5’8 crewmember at 65 to 75Kg and there is your 100Kg average irrespective of what Boeing says they weigh on a data plate.

Edited by Darren Howie, 09 December 2017 - 01:09 AM.


#14 aircommando130

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Posted 09 December 2017 - 01:08 AM

I've been wondering how much to cut the struts on my F model as well. I think I'm going to cut mine and then drill both ends and put a length of stainless steel wire in to hold it together. All the airplanes I ever crewed...C-5A/B...C-130E and MC-130P/MC-130H all had nitrogen in the struts so temp didn't make any difference. 



#15 Dennis7423

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Posted 09 December 2017 - 01:32 AM

Thank you to those staying on topic here, I appreciate the information. I too will be cutting my struts and inserting some stainless to bulk it back up. The finished kit, strangely, isn't too terribly heavy, and the kit struts are rather robust. Thanks Boeing :-)

- Dennis S.
Thornton, CO USA
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