PA-18 150 Stick PTT Ball Repair

[mfleming]

In our new to us PA-18 150, the push to talk button is on top of the pilots stick ball. The PTT has been a bit erratic and when I pulled the stick today the PTT wires came right out. They must have had the most tenuous contact with the switch.

Anyway, I see a ball in the Univair parts manual but no reference to the PTT.

Here's some photos of the ball and stick. Others have made great modification. I just want to fix it and move on for now.

Anyone know how to remove the switch so I can re-solder the wires back on? There must be a way.


The stick as removed


The ball and switch


The threaded hollow post


The bottom looks like it might unscrew??


It's hard to see but there are solder tabs in there

 

[BC12D-4-85]

Switch could be threaded into the ball, or simply pressure fitted, maybe with glue. Warm it up with a hot air gun or hair dryer and see if it unthreads leafty loosey, or gets released if pushed in. Look and show pics of wire ends that were removed, that's a clue as to how they were attached.

Edit: When faced with this I typically take a tool - pliers or ? - and if not smooth wrap tape around the jaws to minimize damage. Heat and twist to loosen if threaded, or push from bottom with ?

Gary

 

[mfleming]

Switch could be threaded into the ball, or simply pressure fitted, maybe with glue. Warm it up with a hot air gun or hair dryer and see if it unthreads leafty loosey, or gets released if pushed in. Look and show pics of wire ends that were removed, that's a clue as to how they were attached.

Gary

No photos of the wire. It’s a shielded single conductor. The shielding was soldered onto a very small tab and it looks like the conductor was soldered onto a second tab.
I can rotate the switch and it looks like there might be a small snap ring. How to get in there to release it is a mystery.
The ball does not seem to be openable but ??

 

[BC12D-4-85]

Lots of work to install and remove a snap ring. If it has eyes with holes a pick can open one end then the rest pulls out. Sure it's not threaded if turned left? Shield to tab, center to another. Simple two contact single puch to throw.

https://peerlesselectronics.com/ms2...wuNAI215B1vo4LtMQRGzPY_feup6pTAb2JESzs-AMeXWj

https://peerlesselectronics.com/media//erp_files/files/MS25089-1C.pdf

Gary

 

[mfleming]

Lots of work to install and remove a snap ring. If it has eyes with holes a pick can open one end then the rest pulls out. Sure it's not threaded if turned left? Shield to tab, center to another. Simple two contact single puch to throw.

https://peerlesselectronics.com/ms2...wuNAI215B1vo4LtMQRGzPY_feup6pTAb2JESzs-AMeXWj

https://peerlesselectronics.com/media//erp_files/files/MS25089-1C.pdf

Gary

OK, I got the switch out. It was a press fit. I'll test the switch in the morning, hopefully it's good. Haven't found many sources for a Mason 611-4301 .375 dia press fit switch.

 

[BC12D-4-85]

Diameter and length critical switch might take some searching. I'd be tempted to replace if out as wear unknown. Spruce lists some, but fit? Put a quick disconnect at the stick base for later stick removal.

Gary

 

[BC12D-4-85]

There's lots of threads here and Sparky's that do this, so many ideas. I like the throttle knob for a switch, or just a DC velcro on the stick or lower PTT, as I tend to move my hand lots on that knob, but have had PTT installed as noted. The hole's there so may a well use it. Put an ohm meter on the terminals and push the switch several times to see if it makes and breaks clean every time. If not.....

Gary

 

[Steve Pierce]

Someone drilled the ball and the stud in the stick. I install the PTT in the stick a hand grip down from the ball and push it with my pinky. You have to get very creative to get a new PTT and wires in that ball. I have done it but it is not fun.

 

[mfleming]

Someone drilled the ball and the stud in the stick. I install the PTT in the stick a hand grip down from the ball and push it with my pinky. You have to get very creative to get a new PTT and wires in that ball. I have done it but it is not fun.

I’ve got some ideas for reinstalling the switch. The hard part may be sourcing the switch if it’s bad.

 

[dgapilot]

It is the same switch used in a lot of Beech airplanes and is listed on the Textron web site. Probably find something close on Newark Electric, Mouser or one of the other electronic supply houses.

 

[skysigns]

It is the same switch used in a lot of Beech airplanes and is listed on the Textron web site. Probably find something close on Newark Electric, Mouser or one of the other electronic supply houses.

Would you have a part number

 

[mfleming]

Would you have a part number

My switch is a Mason 611-4301

 

[mfleming]

Just to finish up my part of this thread.
This morning I tested the PTT switch, it was fine. Its erratic nature must have been due to the poor solder connection. Anyway, I soldered a nice pigtail to the switch and made a sturdy splice connection further down the stick. Unless this switch goes belly up, the repair should last a long time.
I'll probably source one of those Mason 611-4301 switches just to have in stock.

 

[dgapilot]

Would you have a part number

NSN 5930-01-254-6613 couldn't find the Textron number but here is the National Stock Number​

 

[KeithO]

If you check eBay you can find lots of Otto push button switches for sale. Lots of different styles to choose from, including press fit switches intended for stick grips. Search for "Otto pushbutton".

 

[farm_boy252]

I ended up just putting ptt on panel to avoid similar headache

 

[PlaneWrangler]

I looked into swapping the balls on the champs sticks (giggity?) if you’re going to go that balls deep into the job, if you have a friend with a lathe maybe just spin up some new ones up in G10, or if you want to get fancy there are some mammoth tusk chunks you can buy, just saying