Asi

[Kerbo]

This thread will show my construction of an airspeed indicator using the techniques in Mike Powell's book.
So far I have the faceplate and motor deck constructed from 0.064" aluminum.
The motor was salvaged from an old HP Scanjet flatbed scanner, it is a nice little 1.8° stepper.

I hope the pictures work, I am using Facebook to save my poor home DSL connection.


Laying out the holes for the motor deck


Faceplate and motor deck


Motor deck from rear

My wife was totally unimpressed, but maybe somebody here will appreciate what I am trying to do.

[Mike.Powell]

My wife was totally unimpressed,

Yup! Been there.

[ak49er]

Wow, looks great Wriley, tell us a bit about the servo motor and how you plan on interfacing it.

[Kerbo]

Wow, looks great Wriley, tell us a bit about the servo motor and how you plan on interfacing it.

Thanks for the kind words.

I haven't decided yet on how I am going to interface my instruments. The OpenCockpits stuff looks great but I may roll my own since I am familiar with Atmel AVR microcontrollers and enjoy that hobby as well. The downside would be having to write my own software. SIOC looks very nice and all the hard work is already done. For now I am enjoying dusting off my fabrication skills.

I have started prototyping a USB-interfaced GA nav/com unit so have a head start on rolling my own, but that is for another thread someday.

[Kerbo]

Final test assembly before painting. The only mechanical piece left is the connector that joins the stepper motor shaft to the pointer shaft.

A big thank you to Jackpilot for sending me the faceplate graphic.

[No Longer Active]

That is a graet looking ASI, can i just ask if the acrylic as used in the cutout is for back lighting, is there a reason you have acrylic (clear plastic)?

Alex


Ps.How the heck do you make gauges that requires 2 pointers? does that completely change the design of the DIY gauge?

[Mike.Powell]

Ps.How the heck do you make gauges that requires 2 pointers? does that completely change the design of the DIY gauge?

You can use brass hobby tubing to make concentric shafts. Jan Verley has posted pictures of his DC-3 gauges here: http://home.versateladsl.be/verlejan/instr1E.html

Also, take an extended look at Scott Hendry's superlative gauges: http://home.exetel.com.au/flightsim/Engine_Gauges.htm

[Kerbo]

That is a graet looking ASI, can i just ask if the acrylic as used in the cutout is for back lighting, is there a reason you have acrylic (clear plastic)?

Thanks! Right now all I can see is the crooked faceplate deck and the misaligned holes in the light diffuser deck and the... but I'll get over it and do better on the next instrument.

And yes, the thick acrylic is there for back lighting. You can't see it in these photos but there are four holes drilled into the back of it for LEDs.

Ps.How the heck do you make gauges that requires 2 pointers? does that completely change the design of the DIY gauge?

The basic construction is the same but you add a concentric shaft and gearing. It's all documented in Mike Powell's excellent book.

[Kerbo]

[Tony Hill]

Nice work. I love to see people who can build their own stuff.


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