What instruments are you using?

[brinesharks]

I have been considering what instruments I can use for a reasonably accurate replica. I thought replica switches used in period homes would suit the ignition switches, but how about flight instruments? Any ideas?

[Machinbird]

Good question Brineshark. Appropriate instruments are key to a realistic replica cockpit. Each aircraft type has its own suite of appropriate instruments. Many, but not all of these instruments, were common to multiple aircraft types. Some are available on the market, but the majority are scarcer than hen's teeth. I am going to address my comments primarily to German aircraft instruments because that is what I am most familiar.
You may find that you cannot legally fly an aircraft equipped solely with its original WWI instruments because it does not meet minimum equipment list requirements for flight. Airspeed indicators in the Fokker DVII come to mind as an example. They didn't come from the factory with one. Fortunately a number of enterprising WWI pilots recognized the problem and acquired their own anemometer type airspeed indicators so if you can obtain one of these beauties you can be legal as far as US regulations and have an historic method of meeting the regulation. Only these anemometer type indicators are really scarce, and if you find one, it is really expensive. This particular instrument is an ideal candidate for reverse engineering. If we can't find someone willing to take on the job, there are other work arounds that can be tried. Conventional airspeed indicators in some sort of flip down panel come to mind. (Then you could look realistic on the ground, but fly legally.)
I was able to capture an authentic WWI German altimeter. It still works, but its calibration is in kilometers. You would probably need a chart to convert its indications to feet to properly use it in the airspace. I don't think there are enough of them on the market to handle everyone who would like to build an authentic German aircraft. But in this case, the altimeter was not permanently mounted in the aircraft. They were removed between flights. You probably would not want to leave such an item in the aircraft between flights either, so whether or not you need one depends on your objectives.
These altimeters could be replicated but it would be tricky and expensive.
The Maximal type German fuel gages work by a float on a string principle. There are at least two case sizes for the instrument and a number of different faces depending on the application. They are probably good candidates for replication although a number of DR1 builders are using modified P-51 fuel gages.
Pressure gages were recently addressed on another thread and it appears that they can be replicated fairly easily using modern gage movements of appropriate size and configuration with a custom instrument face. For reliability reasons, you might not want to use an original bourdon type pressure gage.
Original German tachometers are somewhat scarce and because of the internal gearing variations, what you find may not be appropriate for your intended engine.
It should be possible to replicate this item and provide a range of gears to adapt to antique and modern engine rpms.
I have not addressed British, French,or Italian equipment at all and I would imagine the situation is similarly complex. It is clear that some replica instruments are desired by the builder community, but is there enough demand to warrant the financial risk to a person who tries to meet this demand? I think we need better information regarding how many would like to build accurate replicas. Some form of market survey is needed.

[brinesharks]

Your reply cerntainly confirmed my suspicions. I have started a poll to get a basic idea of what people are thinking.

Could someone possibly offer instrument bezels and a range of faces? I realise WW1 instruments were very non-standard but a range of sizes to suit most people might be possible. I know others have calibrated their own rebuilt antique instruments and new faces - maybe some enterprising person could offer a CAD file with the faces ready for claibration

The Australian Civil Aviation Orders detail minimum requirements for legal flight in Australia - I'll try to track down a copy. I think it does refer to "sensitive" altimeters which rules out WW1 instruments (although "non-sensitive" are legal in ultralights I believe).

BTW - have you given any thought to the german compasses?

[Machinbird]

Brineshark, there is a lot of external similarity between the Armee Kompass as used in German aircraft and some of the old lifeboat compasses that are on the market. Perhaps you could start with one of those and modify one by changing the dial. So far, the ones I have seen have a different screw arangement on the ring around the window and I don't know if the size is at all compatible. Probably another good item to replicate. When you look at the parts count on one though, you know it won't be all that simple to replicate.

This is all very intresting, i was wondering what people did about instruments. Some british instruments seem not to have changed from late WW1 to early thirtys so maybe thats worth looking into.

[brinesharks]

I have a fantastic article from the April 2000 edition of Kitplanes about a Nieuport 17/23 built from Redfern plans by two Canadian buddies. They used a converted Tiger Moth ASI (heavily reworked and calibrated). It looks very good.

The CAO (Australian regs) Section 20.18 states VFR aircraft must have:

a. an airspeed indicating system
b. an altimeter with a readily adjustable pressure datum setting scale (in millibars)
c. a direct reading compass (or remote compass and standby compass)
d. an accurate time piece showing hours/minutes/seconds (this can be the pilot's watch!).

Therefore, an ASI system (not necessarily an instrument), an altimeter but not a sensitive altimeter (ie. a WW1 style 0-20,000 ft with one pointer is ok), a compass and a clock (or watch). Very basic. I would probably want a radio and transponder so that I can operate at most airfields. For those of you who aren't pilots I can tell you that you should be able to judge speed in these aircraft by the attitude/airstream noise (ask any glider pilot), altitude by eyeballing ground features and just occasionally refer to instruments.

[Fokker210]

I am leaning towards the alteration of modern equipment.
Also check these guys out - they appear to do high quality work !

http://www.precisiondial.com/capabilities.asp

I spoke with them a couple of months ago and they stated they could produce any type of dial face you might need. All they needed was a good image to work from. I believe she said that a set up fee of around $60.00 would be charged if the style was not in their system already and then they could bang them out fairly inexpensively after that depending on diameter, etc.

Maybe something to consider !

[Jim Bruton]

Well, you know what my solution to the fuel gage was- i scanned a DR-1 gage face and PhotoShopped it onto glossy photo paper. I had to modify it because the swing of the needle is opposite on a P-51 fuel gage than to the original. I already have it installed and ready to go. If you have to have a new faceplate made, do know that with a little sit-down time with PhotoShop, you might save yourself some money! If you have any questions, let me know- maybe I can help.

Jim

[brinesharks]

Precision Dial looks very professional. They'd be great for warbird restorers. I'll have to let my friend know (he's rebuilding both P-40 and CAC Mustang plus a whole lot more wonders sitting in his shed!).

Jim, I take your point - my sister is a graphic designer and can do amazing things with Photoshop. She can also get screeen printing done. Your post has given me a little more confidence in doing it "myself".

[Maxim08]

Brineshark,
You have posed an interesting question that is in many ways key to the whole approach to recreating a WW1 aircraft.
Like many, if I could, I would build a completely authentic reproduction from engine to tailskid. There are two major obstacles; 1 availability of 'real' pieces and 2, the usefulness of the finished a/c. For instance, do you include brakes. No problem if you have access to the standard RFC 40 acre field but, if you intend to fly at airshows or to paved strips you need brakes and probably a tail wheel.
I am working on a D7.
I have seen many D7 projects - complete and incomplete - with widely different approaches to authenticity most apparent in the cockpit.
My goal is to replicate as closely as possible the acurate look and feel of a wartime D7.
I have most of the required original instruments. Since they are almost all for the Mercedes engine and it's requirements they are not particularly suited to the Ranger L440 I am using (I am prepared though, if a Mercedes or BMW comes my way).
I am working on recreating authentic looking instruments around more modern gear.
I do not want a 'modern' panel. I do want the instruments to read accurately and conform to local regulations.
BTW, Jim's Maximal fuel gauge is a good example of what can be done. It won't satisfy the purest of the pure, but will work and have the required look so that you won't feel like you are in a pt-19 with an extra wing!.
Regarding ASIs, many captured a/c had supplemental instrumentation provided. I am using just such a documented example as my rationale for a panel based asi.
I vote for 'Convert modern'.
Regards,
Maxim08