What size IS that Allen wrench?

DKirkpatrick

DKirkpatrick

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DKirkpatrick
Trying to replace the lens on. King ky-196 A. To do this I need an Allen wrench small enough to remove the set screws on the volume knob.
They’re ABOUT .030... but I need to know the right size becausE out of the two dozen tiny Allen wrenches I own... I’m going O-fee.
Sagacious coaching would be much appreciated.
dan
 
The manual (from Google) says its a 3/32".

Did you check your manual?
 
Good idea... find a manual online! Thanks.
The screw is slightly smaller than my wrench sized .035...
Thanks for your response
 
3/32 is nowhere near 0.035.

3/32 is about 0.1 ish - by my guestimation
 
Your wrench might be 3.5mm which is 0.138 inches

3/32 is 0.094 inches
2.5mm is 0.098 in - might fit?
 
Capt. Geoffrey Thorpe said:
That's the size to pull it from the tray. The OP is apparently looking to for unknown reasons.
Click to expand...

oh sorry. Maybe its in that manual I posted.
I like this small phone...but its easy to miss important details!

I found a website that makes replacement faceplates. Their instructions for lens removal say nothing about needing to remove the volume knob for the KY-196a. Their photo makes it looks like the faceplate slides in and out without messing with the volume knob.

Tell us what O-fee means? Cant find on google!
 
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DKirkpatrick said:
I need an Allen wrench small enough to remove the set screws on the volume knob.
Click to expand...
Maybe give a radio shop a call. Some older Bendix radios had spline key screws vs hex key screws especially on the very small ones like the knobs.
 
It’s definitely about .030... I’ve got one that’s .035 and it’s just a tad too big...
Yes, the volume knobs gotta be removed on the KY196A and KY197A... not the 196 and 197... I guess BK was trying to give me a slightly larger knob to hang on too.
Thanks for the help
 
And it’s gonna be SAE and not metric isn’t it?
 
There is a knob thread here but the photos have gone.

https://www.pilotsofamerica.com/community/threads/my-knob-fell-off.88260/

Some avionics knobs apparently use Bristol Wrenches.

You could try a loup or a photo. Modern phones and cameras can often do amazing close ups. Trick is to get some light in the hole and to get it to focus on what you want.

I just took these with a 5 year old, high end at the time, phone, it seems to focus down to about 2 1/2 or 3 inches. Just used a small flashlight for illumination. The screw is 1/2 inch down the hole. Computer seems to need a wash, it is out of use so I doubt it will get one :)

Oh, I use the timer since the phone is hard to hold still as I press the button. Set to say 2s.

20200809_004257.jpg

20200809_004337.jpg
 
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Standard inch Allen wrench sizes are .028, .035, .050, then fractions starting with 1/16 (.0625). Standard metric sizes are 0.7mm (.0276"), 0.9 mm (.0354"), 1.3 mm (.0512mm), 1.5mm (.0591"). So the smallest sizes are almost exactly the same, then they start to diverge.

But in all my years of wrenching, I'd never heard of a Bristol wrench. I learned something new today.
 
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0-fer.... sorry for the cryptic message. Spell check was helping me type. I’m thinking somebody might’ve replaced these screws w Toric or metric... it’s bigger than an 028 smaller than an 035... guess I need to do some trial and error w metric sizes.
Will attach a photo but my cell phone won’t get close enough for me to tell.
Thanks for all the help! I’m amazed at the helpful response.
 

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That's a 6 spline Bristol and not a Torx.... An SS-508 set from Bristol Wrench should have the proper one.
 
Why were Bristol, Torx et al invented?
To prevent diy-ing.
(sound like it might be working!)
 
Let'sgoflying! said:
Why were Bristol, Torx et al invented?
To prevent diy-ing.
(sound like it might be working!)
Click to expand...

I've never stripped a torx head, can't say the same about allen/hex. Plus the torx tools are no more expensive/difficult to find than hex head.
 
I was friends with the purchaser of my mil’s home.... til he tried to remove the security screen door off the front entrance with its proprietary security screws lol.
 
jrcox19 said:
I've never stripped a torx head,
Click to expand...
Unless that is if the fastener is made out of titanium alloy which is rather brittle. Fortunately when that happens there is usually a hex key size that will fit into the broken Torx drive and remove the screw.
 
DKirkpatrick said:
Trying to replace the lens on. King ky-196 A. To do this I need an Allen wrench small enough to remove the set screws on the volume knob.
They’re ABOUT .030... but I need to know the right size becausE out of the two dozen tiny Allen wrenches I own... I’m going O-fee.
Sagacious coaching would be much appreciated.
dan
Click to expand...

I know Collins likes Bristol set screws.
 
Lots of the SCR/ARC series had them, as well as lots of the post WW2 fixed wing and helo control panels.
 
Let'sgoflying! said:
Why were Bristol, Torx et al invented?
To prevent diy-ing.
(sound like it might be working!)
Click to expand...
I don't know. But just about every fastener in the IBM Selectric Typewriter was a bristol (6 flute). There were only a handful on slotted screws and I can't think of a phillips screw on that machine.

I still have my pouch of bristols. Most look like barber poles though.
 
And if I recall, some older Bendix radios came with a small key wrench kit that had several spline keys and hex keys.
 
thanks for the responses... especially Craig who FINALLY identified the problem.
Yep, I'm DIYing! Replacing a manufacturer's defective plastic lens!
appreciate the coaching
—dan
 
Dan: I deal with Torx fasteners all day and hate them with a passion. I'd rather go back to Torq-set's any day of the week....
 
It'd all be funny if it wasn't holding up the installation of the #2 comm on an airplane... and my avionics shop is thirty miles away... jug off my airplane... grr...
 
The answer to today's stump the avionics guy... Torx T3!!!! And I never would've gotten in there without the help of this forum. Thanks for all the input.
And further info? Bell 206 was right. They came out like they were new. Danged things were way tiny...
thanks for pitching in here.
 
Much earlier:
Craig said:
That's a 6 spline Bristol and not a Torx.... An SS-508 set from Bristol Wrench should have the proper one.
Click to expand...

kshaw said:
I thought that these were 5/64". Definitely not metric.
Click to expand...

The photo provided earlier shows pretty clearly a single Bristol spline outline at about 7 o'clock. The rest is too fuzzy for me to discern.

From interwebs:-
T3 .046 1.10mm .14 to .18 Nm
0.046 P to P (I guess peak to peak)

https://bristolwrench.com/
Wrench Major - 0.048
I guess 'major' diameter.

0.046 is clearly very close to but smaller that 0.048.

So I think that it is likely really a Bristol spline but that a T3 did the job. Good enough for me :)

Here is a copy of the image that I fiddled with using Windows Photo Gallery to try and bring the outline of the socket out, but you can see it more or less as clearly in the original.
upload_2020-8-22_5-17-54.png

Bristol-spline-maybe.jpeg
4ed760d7-8887-41d0-b234-fa656dc0fe2a-jpeg.88676
 
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