DR-1 (Sands): Builders Group - Page 105

Maxim08 · 19 February 2006, 12:40 PM

I thought that I would help to muddy the waters by showing detail from one of the Redfern drawings. Note that these predate the Sands information and plans.
The two tubes in question are purely there to stiffen the wing structure. They do not attach to the axle box.
I will take a wild guess and suggest that Ron Sands was taking a typical engineering appraoach which is to make something, anything, perform more than one function if at all possible. He shifted the axle wing stiffeners inboard towards the axle and allowed them to strengthen the gear. Remember, Sands also shortened the gear with, I believe, two goals; lower cg and stronger structure.
Please note the reference to the N3N wheels. The GWFM use these on their D VII repro. They are early N3N pressed metal wheels with integral brakes, not the later Stearman style, smaller diameter wheels.

Regards,
Maxim08

gipsymoth236k · 19 February 2006, 12:55 PM

Attached is a low-res scan of my Dr.I research drawing that accurately reflects the original design of the Triplane's landing gear. I hope this might help with at least how the original design was built.

Regards, Gary

franzkait · 19 February 2006, 04:13 PM

Fokker 210, about the axel box, ask Jim, he has all info. belive me, the original design is OK. I am using hard aercraft aluminium and for bending a 6m long 20 ton machine what can make the exact radiuses( no cracks).I made tests with a original axle box , and it was hard aluminium.all this guys talking about it, did not see an original box and do not have the original drawing.

Fritz Kempf · 19 February 2006, 04:56 PM

Baldeagle
I have attached a photo of the Ron S. plan he must have added the steel tubes.

Gipsymoth236k
I take it that your plans are for the proto type landing gear like the picture I posted on page 101.

Ed

RFC Pilot · 19 February 2006, 07:29 PM

Here are three views of the gear on the museum triplane, without the fairing over it.

FliegerJG1 · 20 February 2006, 07:55 AM

Quote:

Originally Posted by Fritz Kempf

Franzkait,
It was me who had the problem, the boxes you have look very nice, much better that what Ron has in the plans. The main problem is Ron has us use T3 aluminum which is very hard and cracks easily.

Thanks
Ed

Herr Kempf,

Why not use 6061 T6 aluminum? It will work just as well and bend more easily than the hard 2024 T3.

VBR...
FliegerJG1

Fritz Kempf · 20 February 2006, 10:45 AM

FliegerJG1
I’m sure any other aluminum would work just fine since Ron way over built the landing gear anyway. I had just followed (baaaaaaaaaa…baaaaaaaaaaaa) what was suggested in the plans. It wasn’t until I started to build the box that it hit me, that this is way to complicated to have been the way it was done! But that’s behind me now, my box is done; if I were doing it again; I would buy the box from franzkait and keep some hair.

Thanks
Ed

Maxim08 · 20 February 2006, 11:34 AM

Quote:

Originally Posted by FliegerJG1

Herr Kempf,

Why not use 6061 T6 aluminum? It will work just as well and bend more easily than the hard 2024 T3.

VBR...
FliegerJG1

Flieger,
I seem to recall that a bend in 6061 hardens the bend area up a notch. I think that if you use 6061 T4, the bend areas will work harden to T6. At least that what 'we' used to do with early racecar monocoques.
Regards,
Maxim08

FliegerJG1 · 20 February 2006, 01:14 PM

Quote:

Originally Posted by Maxim08

Flieger,
I seem to recall that a bend in 6061 hardens the bend area up a notch. I think that if you use 6061 T4, the bend areas will work harden to T6. At least that what 'we' used to do with early racecar monocoques.
Regards,
Maxim08

Hi Maxim08,

T4 naturally ages to a higher temper over time. With a generous bend radius (that specified for 2024-T3), T6 will work fine.

VBR...FliegerJG1

gipsymoth236k · 20 February 2006, 04:48 PM

Quote:

Originally Posted by Fritz Kempf

Baldeagle
I have attached a photo of the Ron S. plan he must have added the steel tubes.

Gipsymoth236k
I take it that your plans are for the proto type landing gear like the picture I posted on page 101.

Ed

Ed,

Actually the answer is yes, my drawing reflects not only the F.I Triplane landing gear, but also most production landing gear Dr.I's up until a modification took place in late Dr.I landing gears. This involved the two outer metal box housings being changed to wider-apart bungee retaining tubes, as well as shortening the standard 800mm rib cord, as seen in late Dr.I production types. This shorter cord allowed less damaging contact with the ground and the trailing edge of the sub-wing. You can see the need for this design modification when viewing photos of the 800mm cord landing gear with field-added tube reinforcing attached to this damage-prone trailing edge.

Regards, Gary