Set screw needed, Terra TMA 230 Audio Panel

[0TreeLemur]

Hi all,

I have an issue with the Terra TMA 230 audio panel in my Mooney - the set screw is missing on the XMTR select knob.  Any time I want to switch transmitters, I must pull off the knob, turn the shaft on the selector, then put the knob back on.  I do this because I like the way the knob looks and don't want to lose it, but this creates uncertainty regarding "what transmitter is active?"  and is annoying.  If someone has one of these audio panels, could you kindly provide a set screw measurement?  Alternatively, if anyone has an extra, I'd be willing to talk $$.

Photo provided to show you what mine looks like.   I guess I could find a complete replacement knob- that would be plan B.  Advice welcome on source/dims for that too.

Thanks!

Fred

[N201MKTurbo]

Did you try the ACE hardware store?

[0TreeLemur]

2 hours ago, N201MKTurbo said:

Did you try the ACE hardware store?

Good idea, but not where I live.   The local Ace store is not well stocked...    If you want a 3/4" steel galvanized tee, they have that.  It will be in a wet bin near the floor because the roof leaks.  Say "set screw" and you'll get howls and vowels.  I'm going to have to order something.

[EricJ]

If there's a Home Depot or a Lowe's or a Tractor Supply or anything like that, you should be able to shop for set screws.   Take the knob with you and just find what fits.

 

[LANCECASPER]

11 hours ago, Fred_2O said:

Hi all,

I have an issue with the Terra TMA 230 audio panel in my Mooney - the set screw is missing on the XMTR select knob.  Any time I want to switch transmitters, I must pull off the knob, turn the shaft on the selector, then put the knob back on.  I do this because I like the way the knob looks and don't want to lose it, but this creates uncertainty regarding "what transmitter is active?"  and is annoying.  If someone has one of these audio panels, could you kindly provide a set screw measurement?  Alternatively, if anyone has an extra, I'd be willing to talk $$.

Photo provided to show you what mine looks like.   I guess I could find a complete replacement knob- that would be plan B.  Advice welcome on source/dims for that too.

Thanks!

Fred

click the e-mail in this link (freeflight now handles support for Terra) and ask what size set screw it uses.

http://www.freeflightsystems.com/support/customer/16-support/130-customer-support

 

If that doesn't work, here's a long shot, buy the CD of Terra manuals on Ebay and see if the manual shows the specs on the set screw. https://www.ebay.com/itm/TERRA-INSTRUMENT-MANUALS-DATA-PACKAGE/202348630512?hash=item2f1ceb11f0:g:9bAAAOSwnFZXVipW

[N201MKTurbo]

Im betting on a 4-40 x 1/8 cup point.

 

[CaptRJM]

I agree that it is probably 4-40. It should be available in any decent hardware store or hobby shop. If you are still uncertain on the size someone you know must have a tap set so you can determine the correct size. If the threads are stripped on the knob you could use the next size tap to make it 5-40 or even 6-32.

Buying a manual just to get the size of a set screw seems like overkill to me. 

[0TreeLemur]

On 6/30/2018 at 6:47 PM, LANCECASPER said:

click the e-mail in this link (freeflight now handles support for Terra) and ask what size set screw it uses.

http://www.freeflightsystems.com/support/customer/16-support/130-customer-support

 

If that doesn't work, here's a long shot, buy the CD of Terra manuals on Ebay and see if the manual shows the specs on the set screw. https://www.ebay.com/itm/TERRA-INSTRUMENT-MANUALS-DATA-PACKAGE/202348630512?hash=item2f1ceb11f0:g:9bAAAOSwnFZXVipW

I have the installation manual, it doesn't mention the set screw.

[CaptRJM]

I doubt it would even be found in the manual. I’d be quite sure they show it as part of the knob.

[N201MKTurbo]

Just go to McMaster and order some 4s and 5s and 6s and use which ever fits!

[0TreeLemur]

I tested a No. 4 and that seems to fit the hole in the knob.   It is a short little bugga, the wall of the knob is only 0.1" thick.   I'll try some parts stores around town tomorrow and see if anyone has a set screw collection.   If not, I'll order from McM-C.

@N201MKTurbo  and @CaptRJM thanks for your input.  It didn't occur to me that this would be a standard screw size being an "airplane" part. 

[Piloto]

You may want to try Digi-Key https://www.digikey.com/catalog/en/search?searchText=Knobs

Hundreds of different type of knobs

José

 

[0TreeLemur]

9 hours ago, Piloto said:

You may want to try Digi-Key https://www.digikey.com/catalog/en/search?searchText=Knobs

Hundreds of different type of knobs

José

 

Thx.  Tried them already.  When I applied the selection filter for shaft diameter, there was only one and it was too large.