Anyone know how to open this gauge?

[kurt-olsson]

Really really old.
Before using the saw, anyone know how to open it?

[kurt-olsson]

Pull out as in straight out i guess?

[jackpilot]

Obviously from the front should be some screws or retainers and then slide it out.

[navymustang]

There might be a glass retention wire that is in a groove just above the glass and a wire that spans the majority of the circumference of the gauge in that groove. By prying out that retaining wire from the groove, the glass will fall out and you can then remove gauge components.

[kurt-olsson]

I managed to remove the glass but i have no idea of how to get the rest of the stuff out. Will try to remove the needles and unscrew the two screws besides them and see what happends.

[Trevor Hale]

That;s actually what I had posted, but then I deleted my post because I was afraid to get crucified for suggesting that.  If it was my gauge, I would pry off the needles carefully and undo the 2 screws.  the faceplate will then come out and you should be able to pull the rest of the unit out the front.

Trev

[727737Nut]

I could tell you exactly how to open it but then I would have to kill you.  LOL

[kurt-olsson]

I could tell you exactly how to open it but then I would have to kill you.  LOL

Haha. Putting in a dynamite and wait for the Pooofff doesent count!

[kurt-olsson]

By the way, have you converted the preassure gauges yet Rob?
They are mechanical engineered to work with real air preassure, hard to interface even with airinc haha

[727737Nut]

i had that exact gauge many many moons ago.  If I remember correctly the capillary tube from the back is keeping you from pulling the gauge guts out the front.  You wont use it so just pull.  Gut air chamber and tubes out, install 2 Switec27 steppers and connect to each needle shaft, drive straight from an arduino. 

[kurt-olsson]

Thanks Rob.

Will make a try later tonight!

[kurt-olsson]

Open, in pieces and i wont be able to put it back.

These dual needle gauged are a pain. I dont think i can use this stuff and retrofit an x27 stepper.

Are there any steppers that supports dual needles?

[727737Nut]

Do you have Mike Powell's book on interfacing and building flight sims?  You use some brass tubing and plastic gears to attach the steppers to the needles.  He describes the process in detail and it really isn't that hard.  Sometimes you have to think outside the box on this stuff.   That's why many say, using real parts isn't for the faint of heart.

[paulnd]

Are there any steppers that supports dual needles?

Switec x40

[727737Nut]

Are there any steppers that supports dual needles?

Switec x40

Doesn't have a 'home' position, won't work.  Those are for clocks aka continuous rotation.

[kurt-olsson]

You certanly have to think outside the box. The shafts and gears are allready there, but the space is too tight to fit them direct on the gears. What might work is to attach some rod that turns the pins that the airpreassure use to do.

Problem is the ratio of the gear is extremely sensitive...

This is a part of the hobby i dont really like, when it is too tight of space.

Right now i probably will just use the backlight and see if i have the patience to interface it later.

The other gauges will be easier since they only have one needle and can be mounted direct on the stepper motor.

[kurt-olsson]

Whoa! Looking at my picture, there might be a chance to mount the stepper on the second gear (the one the arms control)

The swingarms are just there to control range.

I will order some motors and see if they might fit...

[paulnd]

Doesn't have a 'home' position, won't work.

There's two versions, one with an internal stop and one without. I've used them for my dual needle OH gauges


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[RayS]

That's exactly how I did mine (Which now resides in a 737 sim in NY).

I left the mechanics intact, because I used the guts to mount 2 stepper motors attached to the shafts. It worked pretty well.

[kurt-olsson]

Paul, i will have to look it up, can make life easy when converting my other dual needle gauges.

Ray, may i ask how you attached the stepper pin, just pushed or glue or some other way?

[RayS]

I fashioned some quirky mounts using MDF for the motors themselves and hot-glued them to the internal structure. (although a 3D printer might be better suited. :-) )

Attaching the shafts was a little tricky but I ended up using heat-shrink tubing with a dab of rubber cement on the shafts to prevent slipping. This allowed for slight misalignment between the stepper shaft and the needle shaft.

[kurt-olsson]

Hehe thats really thinking "outside the box" Ray
Will see if i manage to produce something like that myself.

[_alioth_]

Doesn't have a 'home' position, won't work.

There's two versions, one with an internal stop and one without. I've used them for my dual needle OH gauges


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I was to say the same. There are two versions.  One is X40.879.NS (non stop) and another with stops.

The "clock version" is X10.506, which has gears between the two shafts and a hole to install a homing sensor.

[kurt-olsson]

Anyone know the price of the dual shafts?
I havent found a supplier that list the prices for these...

[paulnd]

Anyone know the price of the dual shafts?
I havent found a supplier that list the prices for these...

I paid about €15 for original Switec steppers with the internal stop, I should have a few spare if you're interested.

They have about 270 degrees of movement so I had to limit the range in the arduino sketch for one or two gauges that have a larger scale but it's unlikely that I'll ever reach the extreme values anyway.

There's a very useful arduino library for Switec steppers

https://github.com/clearwater/SwitecX25

Paul

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