Inches and Feet: A Camel Conundrum

[Cynic_Al]

The above schematic of the Camel's rudder bar was posted in the DIY rudder bar thread by SeaW0lf. In time we'll return there but the issue here is of the dimensions, specifically the distance marked 'd', which I calculate as 3 and 13/16 inches (about 97mm). Does anyone concur or disagree? This area seems insufficiently wide to accommodate a pilot's foot at full width. The foot 'straps' range from the outer extremity of the bar to the inner edge of the cable bracket, but to use them it seems one would have to have one's feet resting on the upper surface of the bar. I would have to conclude that in normal flight the pilot keeps his feet on top of the bar, only moving them to the vertical surface at d when fine control of the rudder is needed.

Does anyone know different?

Edited November 11, 2018 by Cynic_Al
Corrected imperial result

[Garven]

Your math is wrong.  I got 3.8125 inches.  (4.4375+0.875=5.3125) (20.5/2=10.25) (0.5625*2=1.125) (10.25-5.3125-1.125=3.8125)

 

[SeaW0lf]

When I made a paper mockup, I found it to be very small. If I ever have time to make the pedals, it won't be with the same measurements. I will give it some love.

[Cynic_Al]

41 minutes ago, Garven_Dreis said:

Your math is wrong.  I got 3.8125 inches.  (4.4375+0.875=5.3125) (20.5/2=10.25) (0.5625*2=1.125) (10.25-5.3125-1.125=3.8125)

 

 

I misread my calculation, it should have been 3 and 13/16, which is about 97mm as I stated.

[SeaW0lf]

4 minutes ago, Cynic_Al said:

 

I misread my calculation, it should have been 3 and 13/16, which is about 97mm as I stated.

 

Here's the whole drawing:

[Garven]

7 minutes ago, Cynic_Al said:

 

I misread my calculation, it should have been 3 and 13/16, which is about 97mm as I stated.

Didn't bother to check the metric conversion (which is 25.4 multiplied to inch units to get the metric (mm) equivalent).  So nothing wrong with your calculations then.

[Chief_Mouser]

Agree with your calculations, but both my ordinary UK size 10 outdoor shoes and indoor slippers measure 4" across at the widest part, so pedals that were narrower by 3/16" wouldn't really bother me. Also, men a hundred years ago were, on average, of smaller build than today so perhaps the average shoe size was smaller too? Cheers.

[Cynic_Al]

44 minutes ago, 216th_Cat said:

Agree with your calculations, but both my ordinary UK size 10 outdoor shoes and indoor slippers measure 4" across at the widest part, so pedals that were narrower by 3/16" wouldn't really bother me. Also, men a hundred years ago were, on average, of smaller build than today so perhaps the average shoe size was smaller too? Cheers.

 

 I wear rather heavy-duty size 9s, and at these dimensions I could only get the first 50mm onto the face of that bar. Presumably it's such a sensitive control that there's no issue.

[Cynic_Al]

3 hours ago, SeaW0lf said:

When I made a paper mockup, I found it to be very small. If I ever have time to make the pedals, it won't be with the same measurements. I will give it some love.

 

This design is not the one rendered on the RoF Camel, the latter using an additional two wrap-around cable brackets instead of the attachment points on the sandwiched Dural sheet.

[Archie]

Whenever I've seen uniforms from the time period they always seem much too small for an average person today. This article also states that shoe sizes have gone up quite considerably, like two sizes in just the last 40 years!
https://www.bbc.co.uk/news/health-27662088

[Grunion1MollyMaguire]

OK; I'm going to build one.  Glad i found Seawolf's whole drawing.  I had no idea as to the thickness, so I was going to use 3/4" White Oak. 

I have some Spruce that I can plane down to ~1/2" so that's cool and will make it lighter.  Since Duralum is rather exotic and I have some ~13ga aluminum that will make the 'spine'.  Also, I hadn't considered how narrow the foot rest area is, so I'll probably shift the rudder control wire 'hangers' inboard enough to accommodate a reasonable shoe.

 

(I'm looking for usability - vs. perfect historical accuracy - so I don't mind if its a little Farby)

 

I am considering using a bicycle headtube and associated bearings and bits for the rotational axle, but if somebody has  a better idea, I'm open and eager for suggestion.

Hall Sensor to Pro-micro for position signaling.

 

I just finished a Camel/Tripe/Pup joystick that I posted over at Mudspike.

[SeaW0lf]

9 hours ago, MollyMaguire said:

OK; I'm going to build one.  Glad i found Seawolf's whole drawing.  I had no idea as to the thickness, so I was going to use 3/4" White Oak. 

I have some Spruce that I can plane down to ~1/2" so that's cool and will make it lighter.  Since Duralum is rather exotic and I have some ~13ga aluminum that will make the 'spine'.  Also, I hadn't considered how narrow the foot rest area is, so I'll probably shift the rudder control wire 'hangers' inboard enough to accommodate a reasonable shoe.

 

(I'm looking for usability - vs. perfect historical accuracy - so I don't mind if its a little Farby)

 

I am considering using a bicycle headtube and associated bearings and bits for the rotational axle, but if somebody has  a better idea, I'm open and eager for suggestion.

Hall Sensor to Pro-micro for position signaling.

 

I just finished a Camel/Tripe/Pup joystick that I posted over at Mudspike.

 

The guy also sent me the blue print of the Pup and the Sopwith Triplane. They are similar (attached below - the three of them).

 

[Grunion1MollyMaguire]

THanks, Seawolf.

 

Interesting how 1 shows the routed sections facing in and the other out.   I'm sure that additional work routing the spruce saved them a cool 3/4 of an ounce...

 

Got my wood planed down to ~.55.  Rest will have t o wait til I get back...

[Chill31]

1 hour ago, MollyMaguire said:

Interesting how 1 shows the routed sections facing in and the other out.   I'm sure that additional work routing the spruce saved them a cool 3/4 of an ounce...

Haha, yeah. They do it all over the plane though. It adds up over the course of construction. Saving 5 pounds could be the difference between living and dying.  

[Cynic_Al]

21 hours ago, MollyMaguire said:

I have some Spruce that I can plane down to ~1/2" so that's cool and will make it lighter.

 

In a plane weight would be a consideration, but for a PC peripheral not so much.

 

Also, I hadn't considered how narrow the foot rest area is, so I'll probably shift the rudder control wire 'hangers' inboard enough to accommodate a reasonable shoe.

 

This issue was discussed and going by the way the foot straps are mounted, I would conclude that the bar is designed to be used either with feet resting on top and in the straps, or just with toes pressing the edge of the bar. Looking at the rendering of the SE5 bar, it seems to work in the same way.

 

I am considering using a bicycle headtube and associated bearings and bits for the rotational axle, but if somebody has  a better idea, I'm open and eager for suggestion.

 

I did consider that as well as the steering head from a child scooter, but went with the bicycle bottom bracket as suggested by Plank because the sprocket offers an easy mounting method. I would recommend using what's known as the one-piece design, that is to say the type on which the pedal cranks, sprocket and driveshaft are a single piece, as opposed to the type with bolted-on pedal cranks. One-piece BBs are used commonly on kiddie bikes, of which unwanted examples are easy to obtain gratis, however not all sizes are ideal. Ideally look for the one with 47mm diameter and 70mm width. A prepared example may look like this:

 

 

The bearing cylinder is passed through a hole cut in the base board, with the socket acting as a mounting flange on the underside.

 

The bar of my working prototype seen here uses a profile somewhat in the style of SPAD, and is fastened by a concealed U bolt. I also cut a solid Sopwith-style bar (as yet unused) -

 

 

 

- to test a simpler fastening system using a recessed Jubilee clip, which also works well. 

 

In the prototype image, below the bar you can see a piece of stripboard with the Hall sensor mounted at the right side end. You should see one of the two circular magnets used to drive the sensor. The polarity and relative positioning of the magnets determines the response and angle of rotation. Once satisfactory operation is achieved, the calibration can be preserved by hot-gluing the magnets into place.

 

Hall Sensor to Pro-micro for position signaling

 

That's fine if you insist on a stand-alone unit, however I saved the cost by connecting the output of the Hall sensor directly to a channel of an existing joystick, via a phono plug/socket. It's not entirely straightforward because (at least on two popular joysticks) the rudder/twist channel has a hideous deadzone at the centre point, rendering it effectively useless for a precision control. The (simplified) solution is to swap the wiring of the twist and slider potentiometers and feed the Hall sensor's output to the slider channel, treating that channel as the rudder in games. This gives a rudderbar with smooth, deadzone-free operation and a slider with a deadzone in the middle of its travel, which isn't an issue.

 

Eventually I intend to make a construction video (already overdue) which will provide further details.

 

 

 

 

 

 

 

 

 

[ZachariasX]

16 hours ago, Chill31 said:

Saving 5 pounds could be the difference between living and dying.  

That's probably why they added ~30 kg paint on the crate to make it look more dashing.

[BMA_Hellbender]

5 hours ago, ZachariasX said:

That's probably why they added ~30 kg paint on the crate to make it look more dashing.

 

Load bearing paint.

[ZachariasX]

43 minutes ago, J5_Hellbender said:

 

Load bearing paint.

I wasn't talking about lacquer. But (linseed oil) paint on top of that. And then again, paint on top of that to make those nice pesonalized liveries.

 

Edit: Anyway, I was being sarcastic there. Nevertheless, they still did put such extra weight on their crates.

Edited June 9, 2019 by ZachariasX

[Chill31]

On 6/9/2019 at 4:15 AM, ZachariasX said:

That's probably why they added ~30 kg paint on the crate to make it look more dashing.

typically, WWI planes we're minimally painted when they left the factory (on both sides of the trenches). The Pup and Camel were not even painted on the bottom surfaces...weight savings was definitely their highest concern. 

I get what you are saying though ?

[Cynic_Al]

On 6/8/2019 at 12:59 PM, SeaW0lf said:

 

 

 

 

I wish I'd seen this drawing earlier, since the drawing for the Camel doesn't show the cable 'clip' detail.  I guessed the thickness correctly but since there was no bush specified for the pivot hole (unlike the Dural anchoring points for the tail skid cables), I assumed them to be made from steel, which made forming them rather tricky. Presumably the bushing is provided by separate hardware.

 

Some of details on this schematic are not consistent with its origin:

• The American spelling 'center'.
• Metric bolt sizes.
• The specifying of Dural.

I have to assume it has been revised at some point, presumably for the benefit of replica builders.

 

[Grunion1MollyMaguire]

THanks for the help and inspiration, Gents.  Here's what I got so far.  Still need to bash together the electronics so its not just a quaint decoration.

 

 

[SeaW0lf]

Looking good. When you start installing the arduino and connecting the hall sensor and stuff, if you could explain it to the layman it would be great, because until today I couldn't understand how to assemble the electronics (even to choose the arduino set). That's why I didn't even start cutting the wood ? I'm putting together a 12V DC controller for my six fans / 360 radiator which is outside the case, but that's easy compared to a pedal, hall sensor, controller and whatnot. I found a lot of stuff on the internet, but just advanced tutorials skipping critical information [ to me at least].