Airdrome F.1 Camel

[snj5]

Day 2
Worked on wing parts almost exclusively all day - making upper and lower wing rib pieces, coping the ends and de-burring. With the use of Robert's jigs and equipment, this made the trip all worth it. Highly recommended.

In other news, installed mechanical heelbrake actuators under makeshift metal rudder bar (final will be wood). The concept build's on Rick Bennet's Nieuport mechanical brakes. As pictured, I think the final installation is very promising, using heavy duty motorcycle cable handles mounted stationary under the rudder bar. The heavy duty cables actuate the Tracy OBrien 5" drum brakes custom drilled for the Baslee hd 19" wheels.

On an experimental note, after discussing with Robert, we thinned out the wing a little. It's now close to 12%, and thinner after the thickest portion reducing wetted area. The bottom is unchanged. I am trying to ensure the cruise up to 85 mph, but its a lot of wing drag to make up for. Also, perhaps the flying wires will make a difference as others have indicated.
Hope this works.

More Sopwith bits: In a rabid fit, I have ordered a reproduction Sopwith fuel sight gauge, original Air Ministry magneto switches, control stick and watch holder.

Tomorrow more wings
Goodnite all !

[snj5]

Day 3 -
Finished tube shaping, coping and dressing today, and next, my goodness there are a lot of gussets to build! I am soldiering on building the ribs, but a lot left to do. We did mount the wings, set the dihedral and will measure for the flying wires tomorrow sometime.

Will be rebuilding the compass, altimeter and refacing the tach, sending them off Monday. As before, ordered authentic Air Ministry switches, replica Sopwith stick, fuel sight gauge and clock holder.

[snj5]

It would be happy to have just the two mag switches,but the Rotec R-3600 alternator/starter system requires a few more wires. After some Perkel-esque soul searchinh, I've elected to at least start out with only portable avionics, and have simply provided a breaker protected 12 v plug in socket. As a nod to authenticity, the dual ignitions will still be controlled by two OEM 1918 NOS Air Ministry toggles in the lower lh instrument panel, and the starter button replacing the bleed button on the lower rh panel. The entire remainder of the simple-as-possible electrical system will be on a small panel, about 4" x 7", tucked out of the way on the right rear side of the cockpit, but easy to access for use. I've also used some toggle circuit breakers to simplify the components somewhat in support of the fuel and sump pumps. Attached is a draft schematic based on the Rotec suggested wiring.

When using an other than original engine, there are often times concessions needed for good performance versus original look due to torque band characteristics of the engine. Without going into a lot of technicalities, we'll skip to the chase and say that we are trying to get away with a 90" prop that is one foot shorter than the original 102". While we have not settled on pitch, it will probably be about 50" - 53" shooting for a 90 mph cruise. I am also learning there is a lot of "magic" to this prop process. and a large amout of experimentation. Unfortunately, an appropriate 'scimitar' shape was unavailable for my application, but thankfully Camels also used non-scimitar paddle type blades which we will use. Contrary to the more popular multi wood layered look, I've opted for a single hue all maple prop with a dark mahogany stain. An photo example of a similar propellor is attached.

[RobW]

Russ,
I came across this cloth covered wire today... and it occured to me that it may be a nice way to make an electrical system look more vintage... looking at their website they say they use modern PVC insulated wire... which is problematic I would think, but, I would bet you could get the cotton sleeves and put them on aircraft grade wire and be good to go...

Green cotton braided Cloth Wire bobber chopper triumph:eBay Motors (item 320453223589 end time Nov-30-09 15:01:22 PST)

What do you think? Anybody see a flaw to this thought process?

Rob

[snj5]

Originally Posted by RobW

Russ,
I came across this cloth covered wire today... and it occured to me that it may be a nice way to make an electrical system look more vintage... looking at their website they say they use modern PVC insulated wire... which is problematic I would think, but, I would bet you could get the cotton sleeves and put them on aircraft grade wire and be good to go...

Green cotton braided Cloth Wire bobber chopper triumph:eBay Motors (item 320453223589 end time Nov-30-09 15:01:22 PST)

What do you think? Anybody see a flaw to this thought process?

Rob

The eBay link was pulled by the time I got there, but very high quality cloth covered modern wiring is widely available through antique car suppliers found in Hemming's Motor News and elsewhere.

I am not sure of any prohibition against it in experimental aircraft, and it does carry a lot of patina.

Something to look at for sure.

[snj5]

Have tentatively settled on approximating Camel D9402 of 208 Sqn, the same shown in Robert Taylor's print "Balloon Buster".

For other Rotec engine Sopwith builders, I have found someone who will try to take the VDO tachometer and re-face and re-case it into a 4" face instrument with the 5" bezel as the original tachometer. I'll post the results if he is successful.

For those not following the seatbelt thread, a summary is that through almost up until the end of the war, Sopwiths had wide canvass lap belts that may not have been that good - certainly by modern standards. By the very end of the war, some Camels may have started carry a Sutton Harness or similar, incorporating shoulder straps. There is evidence that these were used by SE5 aircraft. Sutton harnesses are used in a wide variety of antique British aircraft, i.e. Tiger Moths, and are still available through Anglia Sailplanes, who supply them for The Vintage Aviator in NZ. One of Anglia Sailplanes' Tiger Moth harnesses is shown below.

Time to break for the American Holiday of Thanksgiving, and I wish the best for all my Aerodrome friends and their families on both sides of the Atlantic.

[bristol scout]

All the best to you Russ, enjoy the holiday

Dave.

[RobW]

Originally Posted by snj5

I am not sure of any prohibition against it in experimental aircraft, and it does carry a lot of patina.

Something to look at for sure.

actually, I was referring to the pvc covered wire... If I recall correctly, when you burn PVC it gives off poisonous gas...

of course, now that I think of it... the open cockpit would probably provide more than enough fresh air that pvc gasses would not be an issue...

hmmmm....

rob

[snj5]

Thought I would post some of my data points for Rotec props on ww1 replicas:
Will follow format of plane/engine/prop/results

1. Airdrome Pup #1 /R-2800/ 85"D x 42"P/ Plane has yet to fly, but is predicted to be a 75mph cruise

2. Airdrome N28 #2 /R-2800/ 86"D x 49"P / Flys very well, cruise about 83 mph

3. Airdrome N28 #1 /R-3600/ 96"D x 54"P, 90"D x 50"P/ This was first R-3600 installation, with teething difficulties. Static and flying rpms were 2600/2750 (out of 3600 possible). Owner stated airplane was way overpowered, and ran into a 'brick wall' at 70 mph, could not hold enough down stick. This was with a 16% Clark Y

There were also some airframe differences between the first N28 with the 3600 and the second with the R-2800, namely the second had a slightly thinner airfoil at about 14% and a reduced angle of attack.

4. Full scale N24/R-3600/94"D x 67"P/ no data

5. Czech 1&1/2 Strutter (85%)/R-2800/ Looks huge, at least 90"/ no data, but aircraft is flying!

6. Circa N17 (100%) /R-2800/ hsi 404 with 53" pitch/ not flying

This list does not have the data from the AIM planes or Blue Swallow 504, as the still are not flying

Rotec recommends for the R-2800 a 76" x 55"D prop, and for the R-3600 an 84"D x 67" prop, but states that the R-3600 should support up to a 90" propellor.

Thw Airdrome Camel will also incorporate a thinner wing (12%), reduced angle of incidence and 1.5 degrees downthrust. We are initially going with a 90" prop with a 50 - 53" bite, de-rating the R-3600 to around 3000 rpm into the 3:2 reduction instead of 3600rpm.

[drrivah]

Great data summary.

Are the Rotec dia and pitch recommendations for the R-3600 (84"D x 67"P)and the R-2800 (76"D x 55"P) based solely on empirical results or is there a calculation involved?

Do they list static RPM for best torque or dyno data on these prop/engine/airframe combinations?

What is the basis for allowing up to 90" D prop for the R3600?

Thanks.

-pete