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Junkers J1(J4) the first Flying Tank AKA the Flying Furniture Van - 1/48 Scratchbuild


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Dry fitted with buttons (wheels), decking, rudder  and prop in place (that's a cocktail stick btw) Looking  Pleased with how it's coming together. Next job some more struts, clean up the wings and some interior detailing.

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How on earth could you scratch build this so quickly?! That is looking super - the corugations on the wings are not at all over heavy, the prop looks very good and the whole is coming together extremely well.

 

Just wish I could build one as quickly!!

 

P

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Current state of play. Lots of fiddling over the weekend. Mostly cleaning up the wings with my new favourite thing Citadel Liquid Green stuff.  filing small gaps etc.

 

Thanks for all the nice feedback. As with all things modelling it's down to wether you're enjoying it or not. Not sure why but I'm really liking this build (wichi si probably why the rest of the queue is languishing :)

 

As for the speed I suppose when I'm into a build I can move pretty fast. I  do reckon that with scratchbuilding a good plan is half the battle, e.g. it took me over a week to figure out the best method for the corrugation, but only around a day to actually do it.  Also the JI is mostly fabricated or carved which is a whole lot quicker than molded of shaped parts (my PFalz DR1 is taking ages to get the wings right, more anon) I must admit I'm very pleased with the build and will definitely be dusting off my DI and adding a J10 (found a set of plans over the weekend 1983 airfix magazine;  Ray Rimmell so I know they're good)

 

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As you can see this whole business is stressing out my cat (no he's not dead, just very old and asleep)

Edited by Marklo
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  • 2 weeks later...

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JI now standing up on it's own. Paintwork is still rough but probably dearly there, just need to neaten up the demarcation lines.

 

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Of course this was my larger task over the weekend (apart from cutting a two seat bench down to 1 1/2 to get rid of some rotten timber) I made a paint rack and reorganised my workspace really pleased with that I may have finally brought order to chaos (well sort of) 

 

 

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57 minutes ago, Marklo said:

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The JI gets an engine and a petrol tank er pilots seat, can't imagine sitting on 600 liters of fuel was all that reassuring...

 

The reason why pilots (and sometimes observers in 2 seaters) sat on the fuel tank was because of the centre of gravity. Designers were trying to keep the longitudinal balance of the aircraft as even as possible - when the fuel was used weight would be lost, altering significantly the balance of the aeroplane. By having a crew member in the same place as the fuel the changes in cg would be reduced and stopped the latter from moving too far.

 

I agree that I would not have enjoyed the idea of having all that inflammable material under my seat, but then I would not have been happy to have it in front of me either as in many single seat aircraft.

 

P

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I suppose it was moderately better than the upper wing or just behind the engine, and to be fair early aviators were taking their lives in their hands. But if you read accounts like no parachute’ being burned in a fuel fire was most fliers worst nightmare. 

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On 9/20/2019 at 12:57 AM, pheonix said:

 By having a crew member in the same place as the fuel the changes in cg would be reduced and stopped the latter from moving too far

Almost, P, but having a crew member in the same place doesn't reduce the effect on cg change. That depends on where the fuel is, not where the crew are relative to it. There are two points on an aircraft design that are important: centre of lift (the average point at which the wings lift acts), and centre of gravity (the average point at which the the weight acts). Obviously the closer the two are the better the aircraft will fly. Centre of lift is fixed and is dependent upon the wing design and placement. Centre of gravity, as we all know, varies. If we put the variable weight, ie fuel, which could vary anywhere from near empty to full, close to the centre of lift, we reduce the effect it has on the centre of gravity. The pilot's seat on many of these early aircraft is almost central above the lower wing and therefore very close to the centre of lift. If it's between the centre (fore to aft) of the lower and the centre of the upper wing it will be even closer. Therefore fuel load has a minimal effect on cg.

You'll also notice on many later aircraft that they are designed to be flown solo from the rear seat, since adding a person over the wing, near the centre of lift, has a minimal effect on balance.

 

Ian

 

Edited by limeypilot
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Good explanation  of the physics, still wouldn’t fancy sitting in all that fuel, mind you would be surrounded by armour plate, but it probably was only enough to stop small arms fire.

 

i also note that the pilot is almost completely under the upper wing so his view must have been terrible.

 

but an interesting fact (courtesy of my Airfix magazines) the JI has the distinction of being the only WWI aircraft specifically designed for its role of army cooperation. 

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  • 4 months later...
  • 6 months later...

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Back on to this one. I’m going to try to finish it off. Added a few bits and pieces, rudder, prop, ip and pilots seat. Not a huge amount of work left, but I’m dreading the decals. Waiting for a set in the post but I instead I’ve decided to raid the stash. More to follow.

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  • 2 weeks later...

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ip and stuck in place as well as the decking between the two cockpits. The observer needs a seat and a parabellum but I can finally permanently fix the upper wing. That leaves decals and a few extra undercarriage struts and a tail skid and it’s finished.

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