Sand Fokker Dr1 Landing Gear

Chill31 · 18 October 2017, 05:20 AM

I am going to broach heresy here...It appears to me that Rons landing gear are almost the same as the orignal. I've heard they are too short or too far aft, but the geometry in the photos does not support the idea that they are significantly different different from the original...thoughts?

worldcrusier · 18 October 2017, 06:28 AM

Page 359 of the Sands DR1 thread starts a long discussion and worth the read.
Reed Johnson

Maxim08 · 18 October 2017, 09:07 AM

Well, if you put a 110 lerhone and correct propeller on your aircraft, you'll have about 2" of ground clearance when the tail comes up.

Regards
John

Chill31 · 18 October 2017, 11:51 AM

Quote:

Originally Posted by Maxim08

Well, if you put a 110 lerhone and correct propeller on your aircraft, you'll have about 2" of ground clearance when the tail comes up.

Regards
John

The reason for my musing.

Thank you for the thread! The only thing I've seen is speculation as well. If Ron did move them, I'd be shocked to find they are more than 2 inches out of place. The geometry matches very well to the original.

womenfly2 · 19 October 2017, 04:29 AM

DR-1 (Sands): Builders Group: Page-359

Chill31 · 20 October 2017, 06:25 PM

Thank you for the link! It sure would be nice to know the for sure dimensions. So much speculation out there. I guess at the end of the day, I will just have to measure my particular plane and see what prop I need to put on the Le Rhone.

RocketMan · 2 November 2017, 07:10 PM

While recently working on the optimum location of a Rotec for my triplane I found some relevant information that seems to clearly answer the Sands DR-1 landing gear location question. In his Weight & Balance drawing, Sands included two tables. The first table, (for a production aircraft evaluated at the Nov. 1917 Adlershof tests) states that the locations of the wheel centerlines are at +12.25 inches WRT the datum. The second table (for a Sands DR-1 replica) states that the locations of the wheel centerlines on his aircraft are also at +12.25 inches WRT the datum. Therefore, it appears that Sands did not relocate the gear.

gipsymoth236k · 20 November 2017, 08:07 PM

FYI, according to my research, the original design of the Fokker Dr.I Triplane main landing gear in level flight attitude provided 215mm (8.46") clearance between the 2620mm diameter AXIAL propeller tip and ground contact in full landing compression of the main landing gear shocks, and 270mm (10.63") clearance in level flight attitude.

The Ron Sands and Walter Redfern replica Fokker Dr.I Triplane designs moved the main landing gear's original axle location about 6" up and 6" aft for better ground handling characteristics when using a tailwheel landing gear design intended for hard surface runways.

If you intend to operate from grass, I'd keep the original design location of the Dr.I landing gear axle. My advice anyway...and as previously discussed.

Regards, Gary

ghall · 23 November 2017, 07:35 AM

Hi guys,
Thought I would share a conversation I had with Ron Sands when I purchased my plans from him back around 1990. I asked him what was changed from the original and one of the items he mentioned was the landing gear position and length to improve ground handling and lessen the designs tendency to ground loop.

US95Damiani · 23 November 2017, 12:28 PM

Quote:

Originally Posted by Chill31

I am going to broach heresy here...It appears to me that Rons landing gear are almost the same as the orignal. I've heard they are too short or too far aft, but the geometry in the photos does not support the idea that they are significantly different different from the original...thoughts?

IIRC Jim lengthened the gear and made the skid the correct length.
Check out Rhinebecks correct triplane it is a strict sands airplane.