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Main => General Discussion Board. => Topic started by: matta757 on May 08, 2016, 08:05:49 AM

Title: Real MCP set screw wrench size
Post by: matta757 on May 08, 2016, 08:05:49 AM
Hi everyone,

Been lucky enough to have finally gotten a real 767 MCP (see picture below). I want to remove the knobs and light plate to give them a good cleaning. However, I have run into a snag in that I cannot for the life of me find the proper size hex key/allen wrench to remove the stupid knobs.

I have a set with sizes SAE .028 (too small), .035 (too small), and .050 (too big). I also have Metric with 0.7mm (too small), 0.9mm (too small) and 1.3mm (too big).

So I decided to buy ANOTHER set of wrenches that had SAE 3/64" (.047) and metric 1.27mm and both of those were also too big. I am to the hair-pulling-out-stage of this task to get these knobs off.

Anyone have any experience with real MCP's and/or knobs who might be able to provide some answers? I don't know if they are standard sizes across Boeing airplanes or not, but I don't know what else to do.

Thanks,
Matt

(https://farm2.staticflickr.com/1450/26718404555_fd51846e99_k.jpg) (https://flic.kr/p/GH1NPv) (https://flic.kr/p/GH1NPv)
Title: Re: Real MCP set screw wrench size
Post by: iwik on May 08, 2016, 11:21:02 AM
Hi Matt,
I to would be interested as i also am struggling with a real gauge
set screw and have gone thru your journey as well.
Regards
Les
Title: Re: Real MCP set screw wrench size
Post by: matta757 on May 08, 2016, 11:23:31 AM
Les,

What type of gauge are you struggling with? I might be able to help.

Matt
Title: Re: Real MCP set screw wrench size
Post by: mikeybear on May 08, 2016, 01:09:19 PM
Hi Matt

I'm not sure this gives you any clues, but here is a link to a website where I've bought tiny grub screws from in the past.
It lists the allen key sizes for all sorts of metric and imperial grub screws , as the sizes which you've tried already .


http://www.modelfixings.co.uk/steel_grub_screws.htm (http://www.modelfixings.co.uk/steel_grub_screws.htm)
I'm just a customer , of theirs, I have no affliation.

Are you sure they are hex screws , and not torx screws ? I've been caught out by this before .  :(

Regards

Dave
Title: Re: Real MCP set screw wrench size
Post by: iwik on May 08, 2016, 01:41:57 PM
Matt,
I really dont know the size as like you the i tried various hex keys
and found it seemed to fall between .9 and 1.3mm. My guess was
round about 1 to 1.1 which doesnt seem to exist in metric. I guess
it would be some American sizing.
The gauge is a Cessna Directional gyro.
I to thought like mickybear and bought off ebay a set of small torx
screwdrivers but no luck here.
When i had a close look(the screw is very small) i thought it was
like a + but others think not.
I am about to get out my USB microscope and get some magnification, then at least i can see what the head type is.
Thanks for commenting.
Maybe if Rob(727737nut) is reading this can shed some light as he
has had a lot of experience at real gauges.
Regards
Les
Title: Re: Real MCP set screw wrench size
Post by: matta757 on May 08, 2016, 03:03:10 PM
Hi Dave,

I don't think they're Torx screws, they don't look like they are. And when I use the closest hex, it does feel like they are hex...

Matt
Title: Re: Real MCP set screw wrench size
Post by: matta757 on May 08, 2016, 06:09:05 PM
I found a 1.0mm hex key (or what claims to be) on eBay. Coming from the UK. Hopefully this will be "the one"...
Title: Re: Real MCP set screw wrench size
Post by: rjtranth on May 08, 2016, 07:02:31 PM
Guys, do a search for Bristol wrenches for avionics. I bought a set on eBay.