Adapting a real Aircraft Clock with pics.

[727737Nut]

OK, I took some pics of how I mounted the stepper controller and pulse generator on the back of the clock where the original electronics were located. 
Step 1 is easy, remove outer case and remove all electronics inside except the 2 stepper motors, on/off micro switch, and of course the backlighting. 
Step 2, Mount the stepper controllers and pulse generator in back of clock where original electronics were mounted.
Step 3, Solder the 4 wires from the stepper motors to the input pins on the stepper controller.
Step 4, Solder or Plug the 24-28Vdc and Gnd wires to Stepper controller.
Step 5, Hook-up 5Vdc and Gnd to backlighting
Step 6, Solder or Plug the 5Vdc and Gnd Out from stepper controller to Pulse generator board
Step 7, Solder or Plug Output wire from Pulse Generator to Stepper Controller.
Step 8, Put it all back in the case and mount in Sim and enjoy. 
Note, I wired the GND from the 28V pwr supply thru the micro switch in the clk as the pwr must be off when adjusting the clock.  So basically it acts just like the clock does in the real plane.

Refer to excellent doc for stepper motor controller for more on the pin-outs for it.  I made my pulse generator on a little perf board. NOTE; I recommend adding an adjustable pot on the pulse board to compensate for different power supply voltages.  you adjust this to keep the clock running at the proper frequency.  I just started a stop watch next to it and every 10mins checked the accuracy and adjusted pot as needed.  Any questions feel free to ask. Here the links to the sites i used.  You will need 2 of the controllers per clock if you want to run the hands and tape.
http://www.pololu.com/catalog/product/1202

This is the Pulse Generator, Scoll down, you want to build the ASTABLE circuit.  VERY simple!
http://www.kpsec.freeuk.com/555timer.htm

[Nat Crea]

Rob thank you so much.

You know, I have a million more questions now...
but I will try and digest first before I drive you crazy!

Nat

[727737Nut]

Ask away Nat!    Sorry the pics are poor , my phone camera stinks.

Rob

[Nat Crea]

Hi Rob,

First basic questions...you said "two controllers per clock."
Do you mean one Stepper controller and one pulse generator per clock?

I cant see the pot in the pics?

What controls the micro switch? Does it close circuit when power supplied,
or is it controlled by a knob on clock face? 

Ill stop for now

Thanks,

Nat

[727737Nut]

Nat,

1) There are 2 stepper motors in each clock, one for the 'hands' and one for the 'Tape and Elapsed Time Counter'  You will need 2 to drive both or just 1 if you only want one part to work

2) I didn't install a pot but am going to.  Learned after install .  

3) Micro sw is in clock and is controled by Lower Right button on the clock.

4) Ready for more!

Rob

[Nat Crea]

Ok getting clearer...

So two stepper controllers and one pulse generator per clock. ( or two pulse gens ?)

My right lower knob is "CHRO" ...right one?

Thanks Rob!

[727737Nut]

Yes that is the correct knob.  As for the pulse generator, in theory, one could drive both and you could try it. But, i would plan on 2 per clk to have adjustability.   My clock I bought had been worked on previously and one of my steppers was missing so I don't have moving hands in mine. Justed the tape and elasped timer work.   Im looking for another more complete clock.
Rob

[Nat Crea]

Rob, this is the guy I bought mine from:

http://cgi.ebay.com/ebaymotors/Commercial-Jet-Aircraft-Clock-/380348279771?pt=Motors_Aviation_Parts_Gear&hash=item588e862bdb

Nat

[jackpilot]

On a side note , I highly recommend this vendor.
Large inventory
A lot of items start at $10
Fair and fast.
Type in "controls" and see all these gauges!!
JP

[737man]

jackpilot what is the link

[jackpilot]

http://stores.ebay.com/Aircraft-Stock

Jack

[wpslider]

http://stores.ebay.com/Aircraft-Stock

Jack

Be careful with this seller now! I'm having problems to get my parts bought last November and December. Something happened to them. If you look at the feedback, they have received some negative feedback recently.

They were a very good seller in the past, but right now.... not trust-able.

Best regards

[jackpilot]

I'll check with Jim  because I had no problem at all.
Jack

[wpslider]

I'll check with Jim  because I had no problem at all.
Jack

Looks like things are resuming with them. After almost 1 month without any contact from them, looks like my parts are finally on the way. Well, at least I have the tracking number.

Regards

[jackpilot]

Some of these stores are often a one man operation despite a large inventory, and taking some time off, like during Xmas season, may be well deserved.
We tend to take for granted that everyone is "on line" 24/24, and we expect immediate action. 
Hence sometimes unwarrated anxiety!

EBay rating is a good indication.
Oddly, I am more cautious when I see a rating of 100% on 10 items sold, than a rating of 98% spread over 10 000 items.

[wpslider]

Some of these stores are often a one man operation despite a large inventory, and taking some time off, like during Xmas season, may be well deserved.
We tend to take for granted that everyone is "on line" 24/24, and we expect immediate action. 
Hence sometimes unwarrated anxiety!

EBay rating is a good indication.
Oddly, I am more cautious when I see a rating of 100% on 10 items sold, than a rating of 98% spread over 10 000 items.

The problem was almost 2 months without contact.

[727737Nut]

Some of these stores are often a one man operation despite a large inventory, and taking some time off, like during Xmas season, may be well deserved.
We tend to take for granted that everyone is "on line" 24/24, and we expect immediate action. 
Hence sometimes unwarrated anxiety!

EBay rating is a good indication.
Oddly, I am more cautious when I see a rating of 100% on 10 items sold, than a rating of 98% spread over 10 000 items.

Your points are vaid, but it is NOT good business practice and it is obviously a business he is running.  I see it all the time where shops on ebay or online post, going on vacation or no orders taken till bla bla bla... That is courtesy and professionalism.

my 1 cent