Straightening a 109/BA/G250 adjustment knob.

[Couv]

Hello friends,

If you have a closet full of 109/BA/G250ies, then you probably have a few with bent adjustment knobs. Here is a technique I used today to straiten one. It's not perfect, but noticeably better.

First, please remember you are working with brass-a much softer material than the tools, nuts, and washers used in the process, so don't over stress the item you're trying to repair. All that's needed is a couple of tools, a few washers, and a nut with the proper thread size. If the knob is knurled rather than splined wrap it with electrical tape and carefully use pliers.

Here you can see a slight bend in the adjustment knob shaft.

Add just enough washers to fill the gap between the knob and the threads. A nut that screws onto as many threads as possible is best to divide the stress. Torque the parts together with the appropriate tools.

Voila, an (almost perfectly) straightened knob.

 

[rhwestfall]

That duh moment.... Never thought of the spline wrench.... I feel stupid...

 

[northernone]

Hello friends,

If you have a closet full of 109/BA/G250ies, then you probably have a few with bent adjustment knobs. Here is a technique I used today to straiten one. It's not perfect, but noticeably better.

First, please remember you are working with brass-a much softer material than the tools, nuts, and washers used in the process, so don't over stress the item you're trying to repair. All that's needed is a couple of tools, a few washers, and a nut with the proper thread size. If the knob is knurled rather than splined wrap it with electrical tape and carefully use pliers.
View attachment 449789

Here you can see a slight bend in the adjustment knob shaft.
View attachment 449785

Add just enough washers to fill the gap between the knob and the threads. A nut that screws onto as many threads as possible is best to divide the stress. Torque the parts together with the appropriate tools.
View attachment 449786

Voila, an (almost perfectly) straightened knob.
View attachment 449788

Love this. Missed it the first time around... Got a reg that's been mildly bothering me... This should cure it!

Cameron

 

[buddhasummer]

Love this. Missed it the first time around... Got a reg that's been mildly bothering me... This should cure it!

Cameron

Miss you Cameron.

 

[buddhasummer]

Reviving old thread.

I had a badly bent G250 graphite adjustment knob.

Couldn't find nut of correct size so just used barrel instead. A crescent on square flats of barrel and just screw in adj knob hard against barrel using splined nut tool.

It worked a treat, not sure if there is the potential to damage anything but seems ok to do.

And no, that's not nail varnish it's paint.

Finally, a good use for something resulting from SPS splined nuts.

 

[buddhasummer]

I guess if you snapped adj knob at base it could then make removing knob difficult. Hmmm that does seem like a potential issue and I guess load isn't evenly spread given you're only torquing one side.

Regardless, it worked this time, perhaps I just got lucky. I think @Couv idea is probably better and safer.

 

[buddhasummer]

The more I think about it the less I recommend it.

 

[buddhasummer]

@Couv

 

[buddhasummer]

For what it's worth I think in the majority of cases the knob is bent when techs use screw drivers to manhandle clip back on.

 

[ZamaTim]

For what it's worth I think in the majority of cases the knob is bent when techs use screw drivers to manhandle clip back on.

The knob gets bent because the second stage gets dropped or bumped hard enough to bend it. Seen this happen a lot of times when gearing up at the dock or when a rig is passed to someone on a boat and the second stage is swinging around. Easiest way to protect the knob is to slide a piece of automotive hose over it until it's time to don the gear, and put it back right after the dive. It ended the problem for me anyway.