start switches...

[ran56]

Thanks for that Efe.

Do you know whether having pushed in the knob, it turns under spring pressure
towards GND - Or is it just the usual force required to operate the switch mechanism ?

Rob

Force required.
You push and the turn left to GND, selonoid will hold it on GND,
till starter cut out and it will be released and return to OFF by
spring power.

Ran.

[Efe Cem Elci]

Ah, I might've misunderstood Rob's question. Ran is right, once depressed there is nothing forcing it towards GND. I thought he was asking about when the knob is depressed and moved towards GND, does it click into place by itself or is the full motion done manually.

[dnoize]

If you want i can take the cover of of one and make some pictures.

Stef

[Gallie]

Guys,

Bidding has ended, you can try to bid again.....

http://cgi.ebay.com/ebaymotors/Boein...5fPartsQ5fGear

Mike

[dnoize]

Hmmm....whats going on with this auction ?

The auction wasnt supposed to have ended yet.

according to ebay:

The seller ended this listing early because the item is no longer available for sale.

and it has been relisted immedeately ?


Strange.....



Stef

[tomenglish2000]

I get the distinct feeling the seller is reading this thread.
Trevor points out that they are nearly worthless and the minimum bid is removed.
Others point out how the switches work and all the extra info is listed on the bid.

hmmm.

Tom.

[RadarBob]

Thanks all - Sorry if my question was not as clear as it could have been - But thanks for decyphering it ran56 !

I understand how these should work now.

I think the fact that the switch to GND is spring-loaded momentary when the solenoid hold-in is not enabled, makes the design easier.

Means that a replica switch mechanism could latch itself on mechanically, with latch release mechanism by solenoid - Don't need to use the solenoid to push/pull the switch back to OFF - So it can be smaller/less powerful.

The push-in first makes it a bit trickier though !

There is still the question as to whether the switch can be taken back to OFF manually once it has been placed into GND - Not too worried about that, but I think that could be handled by a release switch operated by pushing the knob a bit further in once it is in the GND position.

The new auction item says it was re-listed to include international shipping options.

Don't know if Tom is right, but the additional info is useful nevertheless.

Bit rough for top bidder though with another 6 days to go.

Don't know what top bid was, but I suppose it was greater than $400.

From these discussions though, it is clear that the device is not so easy to reproduce, so it is worth a fair bit to someone who wants to add that bit of extra realism to the start up routine.

If you wouldn't mind posting a picture or two Stef, that would be great - Assuming it is possible to take the cover off without too much hassle !


Cheers,

Rob

[tomenglish2000]

I would also be interested to hear how you can place the switch back to OFF from GND. I know that it is possible.

Tom.

[Michael Carter]

If it's similar to the solenoid-held switches that Sperry used in the SP-50, just turn it back to OFF.

The mode control switch on the AP works this way and it must be pushed in to turn when power is applied. It cannot be manipulated without power applied as the solenoid mechanical latches are in the way of the switch rotation mechanism.

It can be manipulated by hand to the MAN position with power applied. I don't see why it wouldn't be the same with the start switch.

Suppose the switch didn't release and you didn't get starter cut-out? I would think rotating the switch by hand might be one of the first memory items on the checklist. Anyone have a checklist that has this?

[ran56]

From B767 QRH

Aborted engine start

Condition: During a ground start, an aborted engine stat condition occurs.

Fuel Control switch - cutoff
If the engine start selector is in GND:
Motor the engine for 30 seconds.
Engine start selector - Auto